applied
sciences
Article
Three-Phase 75 kW Brushless Direct Current Motor for Electric
Vehicles: Different Power Stage Design, Calculation of Losses,
Cooling Techniques, and Comparison
Ali Bahadir 1 , Omer Aydogdu 2
1
2
3
*
and Elif Bahadir 3, *
Department of Electronics and Communication Engineering, Faculty of Electrical and Electronics Engineering,
Istanbul Technical University, Istanbul 34467, Türkiye
Department of Electrical and Electronics Engineering, Faculty of Engineering and Natural Sciences,
Konya Technical University, Konya 42130, Türkiye; oaydogdu@ktun.edu.tr
Department of Mathematics Education, Faculty of Education, Yıldız Technical University,
Istanbul 34220, Türkiye
Correspondence: elfbahadir@gmail.com; Tel.: +90-505-251-1434
Abstract: This study focuses on determining the technical specifications and parameters of an allelectric passenger vehicle, modeling it according to these parameters, selecting the appropriate
electric motor as a result of the modeling, and then designing and making a new 75 kW three-phase
DC-AC converter (inverter) as per to automotive standards for the brushless DC motor used for
vehicle propulsion. Three different power stage designs are conducted and compared. The system
losses were calculated, and three variants of cooling systems were used for cooling the power stage
to reduce losses. Performances of such cooling systems were compared. Air cooling, fan-assisted air
cooling, and liquid cooling structures are designed for power stage cooling, and the performances of
these three systems were compared.
Keywords: brushless DC motor; electric vehicles (EV); power stage; cooling system; losses
Citation: Bahadir, A.; Aydogdu, O.;
Bahadir, E. Three-Phase 75 kW
Brushless Direct Current Motor for
1. Introduction
Electric Vehicles: Different Power
Climate changes threatens the world’s future. Gas emissions such as CO2 and SO2 into
the atmosphere should be controlled. The necessary measures are tried to be coordinated
with international agreements and negotiations such as the Kyoto Protocol and Copenhagen
Criteria. The most effective measure that can be taken today is to reduce the need for power
plants that use fossil fuels on a big scale. In other words, by increasing efficiency in energy
consumption, comfort and technology can be maintained with less energy. The increase
in oil prices globally and the environmental pollution caused by fossil fuels have forced
automotive manufacturers to work on and produce hybrid and electric vehicles [1–3].
The brushless direct current (BLDC) motor is widely used in electric vehicles. BLDC
motor has attracted the attention of the automotive industry and scientific community for
the next generation of electric vehicles due to its high power and torque density, high efficiency, and reliability [1]. The operational reliability and longevity of the BLDC motor are
limited by high internal heat generation and inefficient heat dissipation. The proper measurement of heat generation in the electric motor and embedded motor cooling techniques
are significant. The BLDC motor often suffers from high internal heat generation due to
electromagnetic power losses, which in turn causes the premature demagnetization of the
permanent magnets and ultimately reduces power density, longevity, and reliability [2,3].
Therefore, improved thermal management becomes a mandatory prerequisite for further
improvement of the power and torque density of the motor.
Reducing the losses of electric motors and drives, where energy efficiency is vital, is
one of the most critical issues. The calculation of these losses and the necessary designs to
Stage Design, Calculation of Losses,
Cooling Techniques, and Comparison.
Appl. Sci. 2024, 14, 1365. https://
doi.org/10.3390/app14041365
Academic Editors: Peter Gaspar
and Junnian Wang
Received: 17 November 2023
Revised: 15 January 2024
Accepted: 19 January 2024
Published: 7 February 2024
Copyright: © 2024 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/).
Appl. Sci. 2024, 14, 1365. https://doi.org/10.3390/app14041365
https://www.mdpi.com/journal/applsci
Appl. Sci. 2024, 14, x FOR PEER REVIEW
Appl. Sci. 2024, 14, 1365
2 of 22
2 of 20is
Reducing the losses of electric motors and drives, where energy efficiency is vital,
one of the most critical issues. The calculation of these losses and the necessary designs to
reduce losses are emphasized in this study. Three different cooling systems were designed
reduce
losses
are and
emphasized
in thiswere
study.
Three different
to lower
losses,
performances
compared
[4–6]. cooling systems were designed
to lower
losses,
and
performances
were
compared
[4–6].
After calculating a power requirement of 75 kW for the vehicle’s drive system, a
After calculating
a power
of 75
kW for
vehicle’sAfter
drive
system,the
a
brushless
direct current
motor requirement
(BLDC) of this
power
wasthe
preferred.
selecting
brushless
direct
current
motor
(BLDC)
of
this
power
was
preferred.
After
selecting
the
motor type, the bus voltage and current were determined. The nominal DC-Bus voltage
motor
type, the
bus V.
voltage
and current
weretodetermined.
DC-Bus
voltageto
was chosen
as 375
The ‘nominal’
current
be drawn atThe
thisnominal
voltage was
calculated
was
chosen
as
375
V.
The
‘nominal’
current
to
be
drawn
at
this
voltage
was
calculated
be 200 A. Within the scope of the electric vehicle project, another study in which PID and
to be 200 A. Within the scope of the electric vehicle project, another study in which PID
fuzzy control were performed with dSpace for rapid prototyping of this motor was puband fuzzy control were performed with dSpace for rapid prototyping of this motor was
lished as an article [7]. This study, a different part of the electric vehicle project, focused
published as an article [7]. This study, a different part of the electric vehicle project, focused
on different power stage designs and their developments with various cooling systems,
on different power stage designs and their developments with various cooling systems,
loss calculations, and comparison of all these structures.
loss calculations, and comparison of all these structures.
IGBT was selected as the optimum switching element according to the selection criIGBT was selected as the optimum switching element according to the selection criteria
teria in this study. Different power stage designs were made using IGBTs in various
in this study. Different power stage designs were made using IGBTs in various sheaths.
sheaths. Protection, filter, and isolation circuits were designed and practically developed
Protection, filter, and isolation circuits were designed and practically developed to protect
to protect the switching elements and the system. With the implemented design approach,
the switching elements and the system. With the implemented design approach, a fullya fully-controlled original 75 kW three-phase DC-AC converter was considered for a
controlled original 75 kW three-phase DC-AC converter was considered for a BLDC motor
motor in
compliance
with
automotive
standards
at a high
efficiency
inBLDC
compliance
with
automotive
standards
operating
at a operating
high efficiency
of 97.5%
at idleof
97.5%
at
idle
and
94.5%
at
load.
and 94.5% at load.
Mostofofthe
theworks
worksregarding
regardingthe
thethermal
thermalmanagement
managementininelectric
electricvehicles
vehiclesare
arefocused
focused
Most
on
either
improving
the
battery
cooling
[8–10]
or
the
e-motor
cooling
[11,12],
without
takon either improving the battery cooling [8–10] or the e-motor cooling [11,12], without taking
ing account
into account
the cooling
system
energy
consumption.
Conventional
control
strategies
into
the cooling
system
energy
consumption.
Conventional
control
strategies
are
are
based
on
a
feedback
control
on
the
radiator
inlet
temperature,
with
a
thermostat
valve.
based on a feedback control on the radiator inlet temperature, with a thermostat valve.
Aninteresting
interestingcontrol
controlapproach
approachtotoreduce
reducethe
themotor
motorcooling
coolingsystem
systemenergy
energyconsumption
consumption
An
is
proposed
in
[13],
but
the
considered
vehicle
is
a
hybrid
electric.
There
are
different
studis proposed in [13], but the considered vehicle is a hybrid electric. There are different
ies
in
the
literature,
such
as
those
testing
the
control
strategy
that
reduces
the
energy
constudies in the literature, such as those testing the control strategy that reduces the energy
sumption of of
thethe
cooling
system,
that
is,is,
thethe
pump
and
fan,
with
consumption
cooling
system,
that
pump
and
fan,
withnumerical
numericalsimulation
simulationin
driving
cycles
[14].
However,
there
is no
in the
comparing
three
indifferent
different
driving
cycles
[14].
However,
there
is study
no study
in literature
the literature
comparing
different
power
stages
and and
cooling
system
designs,
andand
lossloss
calculations.
This
study
fothree
different
power
stages
cooling
system
designs,
calculations.
This
study
cuses
on
this
issue.
focuses on this issue.
2.2.Vehicle
Vehicleand
andDrive
DriveSystem
SystemModel
Model
The
ofof
thethe
electric
vehicle
is configured
in MATLAB/Simulink
based
on
Theoverall
overallmodel
model
electric
vehicle
is configured
in MATLAB/Simulink
based
parameters
such
as
aerodynamic
drag
force,
rolling
friction
resistance
force,
acceleration
on parameters such as aerodynamic drag force, rolling friction resistance force, acceleraforce,
and pitch
force. Figure
1 shows1 the
forcethe
components
acting onacting
the vehicle.
tion force,
andresistance
pitch resistance
force. Figure
shows
force components
on the
Table
1
shows
the
parameters
of
the
vehicle.
vehicle. Table 1 shows the parameters of the vehicle.
Figure1.1.Force
Forcecomponents
componentsacting
actingon
onthe
thevehicle.
vehicle.
Figure
Table1.1.Vehicle
Vehicleparameters.
parameters.
Table
Parameter
Parameter
m
m
w
w
JJtt
Name
Name
1600
1600
44
1.140
1.140
Bt
0.010
Value
kg
kg·m2
Value
kg
kg·m2
Nm·s/rad
Description
Description
Vehicle mass
Vehicle mass
Number of
wheels
Number
of wheels
Moment of
inertia
a wheel
Moment
of of
inertia
of a wheel
A tire’s viscous friction
Appl. Sci. 2024, 14, 1365
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Table 1. Cont.
BParameter
t
CCrrrr
RRo
o
CCx
x
A
A
Rt
Rt
α
α
g
g
u
u
Va
Va
mg
mg
Fad
F
Fhcad
Fhc
0.010
Name
0.010
0.010
1.293
1.293
0.120
0.120
1
1
0.265
0.265
0.000
0.000
9.810
9.810
1
1
-
Nm·s/radValue
kg/m3 kg/m3
m2
m2
m
m
rad
rad
m/s2
m/s2
-
A tire’s viscous
friction
Description
Tire rollingTire
resistance
rolling resistance
Air densityAir density
Aerodynamic
coefficient
Aerodynamic coefficient
Vehicle cross-section
Vehicle cross-section
Tire effective radius
Tire effective radius
Slope
Slope
Gravitational acceleration
Gravitational acceleration
Gear rotation ratio
Gear rotation ratio
Velocity
Velocity
The force of gravity
The force of gravity
Wind resistance
Wind resistance
The reverse force due to the slope
The reverse force due to the slope
The overall vehicle Simulink model configured is shown in Figure 2. The gain value
Thebeoverall
vehicle
model
configured
inthe
Figure
The gain
value
should
chosen
so thatSimulink
the motor
average
voltage is
is shown
equal to
bus 2.
voltage
when
the
should
be
chosen
so
that
the
motor
average
voltage
is
equal
to
the
bus
voltage
when
the
control signal is at its maximum value. Figure 3 shows the internal structure of the overall
control
vehicle signal
model.is at its maximum value. Figure 3 shows the internal structure of the overall
vehicle model.
Figure2.
2. Vehicle
Vehiclegeneral
generalmodel.
model.
Figure
The mathematical expression of the brushless direct current motor used for the motor
drive is shown in Equation (1).

  R
−
i (t)
d1   L
i2 ( t ) =
0
dt
i3 ( t )
0
0
− RL
0

  1
−L
0
i1 ( t )
0   i2 ( t )  +  0
− RL i3 (t)
0
0
− L1
0
   

0
e1 ( t ) 
 V1
0  · V2  − e2 (t)


V3
e3 ( t )
− L1
(1)
The detailed block diagram for the BLDC motor is shown in Figure 4. A current
limiting block of 1.5 times the nominal motor current is placed at the output of the motor
impedance block to be more realistic. The maximum current that the DC source can deliver
or the current limit of the driver circuit can be modeled with this limiting block.
In Figure 5, all forces acting on the vehicle and the load moment acting on the engine
shaft are modeled. Here, tire rolling resistance is represented by a constant block as it is
a ‘constant’ force. Fcn is a function block that produces output when the vehicle speed is
above zero. Here, all parameters, such as the aerodynamic friction, vehicle mass, slope of
Appl. Sci. 2024, 14, 1365
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Appl. Sci. 2024, 14, x FOR PEER REVIEW
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the road, tire rolling resistance, wheel diameter, and desired reference speed information,
are included in the calculations of the load model.
Figure 3. Internal structure block of the general vehicle model.
The mathematical expression of the brushless direct current motor used for the motor
drive is shown in Equation (1).
 R
−
 i1 (t )  L
d 
i2 (t ) =  0
dt 

i3 (t ) 
 0
0
R
L
−
0

 1
0 
− L
(
)
i
t


1


0  i2 (t ) +  0


R  i3 (t ) 
− 
 0
L
0
−
1
L
0

0 
 V1   e1 (t ) 
0   V2  − e2 (t ) 
 

1  V3  e3 (t ) 
− 
L
(1)
The detailed block diagram for the BLDC motor is shown in Figure 4. A current limiting block of 1.5 times the nominal motor current is placed at the output of the motor
impedance block to be more realistic. The maximum current that the DC source can deliver or
the
current
limit block
of
theof
driver
circuit
can bemodel.
modeled with this limiting block.
Figure
Internal
structure
block
of
thegeneral
general
vehicle
model.
Figure
3.3.Internal
structure
the
vehicle
The mathematical expression of the brushless direct current motor used for the motor
drive is shown in Equation (1).
 R
−
 i1 (t )  L
d 
i2 (t ) =  0
dt 

i3 (t ) 
 0
0
−
R
L
0

 1
0 
− L
(
)
i
t


1


0  i2 (t ) +  0


R  i3 (t ) 
− 
 0
L
0
−
1
L
0

0 
 V1   e1 (t ) 
0   V2  − e2 (t ) 
 

1  V3  e3 (t ) 
− 
L
(1)
The detailed block diagram for the BLDC motor is shown in Figure 4. A current limiting block of 1.5 times the nominal motor current is placed at the output of the motor
impedance block to be more realistic. The maximum current that the DC source can deliver or the current limit of the driver circuit can be modeled with this limiting block.
Appl. Sci. 2024, 14, x FOR PEER REVIEW
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Figure 4.
4. BLDC motor Simulink model.
Figure
model.
In Figure 5, all forces acting on the vehicle and the load moment acting on the engine
shaft are modeled. Here, tire rolling resistance is represented by a constant block as it is a
‘constant’ force. Fcn is a function block that produces output when the vehicle speed is
above zero. Here, all parameters, such as the aerodynamic friction, vehicle mass, slope of
the road, tire rolling resistance, wheel diameter, and desired reference speed information,
are included in the calculations of the load model.
Figure 4. BLDC motor Simulink model.
In Figure 5, all forces acting on the vehicle and the load moment acting on the engine
shaft are modeled. Here, tire rolling resistance is represented by a constant block as it is a
‘constant’
force. Fcn is a function block that produces output when the vehicle speed is
Figure
Figure 5.
5. Load
Loadmodel.
model.
above zero. Here, all parameters, such as the aerodynamic friction, vehicle mass, slope of
the road,
rolling
resistance,
wheel the
diameter,
and desired
reference
speed
information,
As atire
result
of vehicle
modeling,
requirement
for a 75
kW drive
power
was calcuare
included
in the
calculations
the load
model.
lated.
The BLDC
motor
that canof
provide
this
power was identified and its parameters were
determined. The current voltage values of the appropriate switching elements that can be
used in the power stage to drive this electric motor were determined, and for this purpose,
Appl. Sci. 2024, 14, 1365
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As a result of vehicle modeling, the requirement for a 75 kW drive power was calculated. The BLDC motor that can provide this power was identified and its parameters
were determined. The current voltage values of the appropriate switching elements that
can be used in the power stage to drive this electric motor were determined, and for this
purpose, the nominal supply voltage of the switching element with a nominal current of
200 A was preferred as 375 V. The parameters of the motor and power system are given in
Table 2 below.
Table 2. Parameters of the BLDC motor and power system.
Parameter
Value
Unit
Definition
V_Buss
375.0
Volt
Busbar voltage
Lq
0.6
mH
2-phase inductances
Rq
0.1634
Ohm
2-phase resistance
Kp
1.55
Nm/A
Moment constant
Ki
1.55
Volt·s/rad
Back EMF constant
Jm
0.341
kg·m2
Motor moment of inertia
In
200
A
Nominal current
Pn
75
kW
Motor power
3. Power-Stage Design
As seen in Table 3, the DC-bus voltage values vary between 250 and 400 V in the designed
power system. The voltage, current, and system’s ambient temperature values are among the
critical selection criteria of IGBTs. These values are given in Tables 4 and 5, respectively.
Table 3. Busbar voltage values.
Minimum DC-Bus Voltage
Nominal DC-Bus Voltage
Maximum DC-Bus Voltage
250 V
375 V
400 V
Table 4. Nominal and maximum values of electric motor.
Pnom-motor
Pmax
Vnommotor
Vmax
Inom-motor
Imax
75 kW
100 kW
375 V
400 V
200 A
300 A
Table 5. Operating temperature values.
Operating Temperature—Lower Limit
Operating Temperature—Upper Limit
−30 ◦ C
80 ◦ C
Considering the motor voltage and current values in Table 4, IGBT modules with
Vces = 1200 V, TJ = 175 ◦ C were selected to prevent damage to the IGBTs in the design due
to voltage and current exceedances of 2 or 3 times the nominal value that may occur on
the IGBT. Three different sheathed modules were used in the designs. The preferred IGBT
modules are shown in Figure 6. Here, switching loss values, high switching frequency, and
cost are the reasons for the preference.
In Table 6, the IGBT modules of the Semikron company that are suitable for the
determined values are given collectively. These modules were selected by considering
Semikron’s recommendations for choosing the module values according to the DC-Bus
voltage and nominal current.
In addition, designs were made along with SKM300GB126D and SKiM459GD12E4V2,
composed of six combined modules, to compare performance using different cases.
Appl. Sci. 2024, 14, 1365
Considering the motor voltage and current values in Table 4, IGBT modules with Vces
= 1200 V, TJ = 175 °C were selected to prevent damage to the IGBTs in the design due to
voltage and current exceedances of 2 or 3 times the nominal value that may occur on the
IGBT. Three different sheathed modules were used in the designs. The preferred IGBT
6 of 20
modules are shown in Figure 6. Here, switching loss values, high switching frequency,
and cost are the reasons for the preference.
Figure 6.
6. IGBT
modules selected
selected for
for BLDC
BLDC motor
motor driver.
driver.
Figure
IGBT modules
6, switching
the IGBTmodules.
modules of the Semikron company that are suitable for the deTableIn
6. Table
Selected
termined values are given collectively. These modules were selected by considering
Module
Code
Voltage
Current
Semikron’s
recommendations
for choosing
the(V)
module values according
to(A)
the DC-Bus
SEMIX604GB12E4S
1200
600
voltage
and nominal current.
SEMIX904GD126HDs
Table 6. Selected switching modules.
SKM200GB12E4
1200
600
1200
200
Module Code
Current
(A)
SKM300GB126D
1200Voltage (V)
300
SEMIX604GB12E4S
600
SKiM459GD12E4V2
1200 1200
450
SEMIX904GD126HDs
1200
600
SKiM306GD12E4
1200
300
SKM200GB12E4
1200
200
SKM300GB126D
1200
300
IGBT modules also have temperature resistance up to 175 ◦ C and operating tem1200
peratures SKiM459GD12E4V2
up to 150 ◦ C. The switching losses vary
between 19 and 25 mJ 450
depending on
SKiM306GD12E4
1200
300
temperature. This value is low compared to the module values of many companies,
which
provides the system with a reduced energy loss and a high efficiency [15]. An IGBT driver
In addition,
were
made were
along
withandSKM300GB126D
and
was designed.
DC-busdesigns
and snubber
capacities
calculated
specified.
SKiM459GD12E4V2, composed of six combined modules, to compare performance using
4.
Calculation
different
cases.of Losses
IGBT
modules
have temperature
resistance
up are
to 175
°C andby
operating
temperThe total
lossesalso
of power
semiconductor
systems
obtained
calculating
and
atures up
150 °C. The
losses
vary
betweenSwitching
19 and 25losses
mJ depending
on temadding
thetoswitching
andswitching
conduction
losses
separately.
are the losses
that
perature.
Thisatvalue
is low compared
to theand
module
values
of many
companies, which
turn
into heat
the moments
of conduction
cut-off
of IGBT
modules.
provides
the system
a reduced
energy
loss and
a high
efficiency
[15]. An
driver
According
to thewith
datasheet
details
obtained
from
the IGBT
company,
theIGBT
conduction
was designed.
DC-bus
andatsnubber
were calculated
and
specified.
switching
loss of
the IGBT
a 150 ◦ Ccapacities
junction temperature,
600 V
nominal
voltage, and 600
A nominal current is 35 mJ. Under the same criteria, the cut-off switching loss is 110.4 mJ.
4. Calculation
of Losses
In
this study, since
the nominal current value of the system is 200 A and the voltage
valueThe
is 375
V, losses
the approximate
switching power
loss ofare
theobtained
system can
calculatedand
by
total
of power semiconductor
systems
by be
calculating
proportioning
as
follows.
adding the switching and conduction losses separately. Switching losses are the losses
For IGBT;
that turn
into heat at the moments of conduction and cut-off of IGBT modules.
According
to the
datasheet
details obtained
from
the(joule))
IGBT company,
the conduction
Pd(IGBT)
= (System
Switching
Frequency
(Hz)) · Eon
+ Eoff
= PowerLoss-1
(Watt) (2)
switching loss of the IGBT at a 150 °C junction temperature, 600 V nominal voltage, and
In Equation (2), the system switching frequency is 8 kHz, the Eon conduction switching
loss is 35 mJ, and the cut-off switching loss is 110.4 mJ;
Pd( IGBT ) = 8000·(35 + 110.4)·(10−3 ) = 1163.2 W
(3)
IGBT switching power dissipation is calculated in Equation (3).
For the diode;
Pd(Diode) = (System Switching Frequency (Hz)) · (Eon (joule)) = PowerLoss-2 (Watt)
(4)
In Equation (4), the system switching frequency is 8 kHz, Eon conduction switching
loss is 44 mJ;
Pd( Diode) = 8000·(44)·(10−3 ) = 352 W
(5)
Appl. Sci. 2024, 14, 1365
7 of 20
The diode switching power dissipation is calculated in Equation (5). The total switching power dissipation is calculated in Equation (6).
Pd(TOTAL) = Pd( IGBT ) + Pd( Diode) = 1163.2 + 352 = 1515.2 W
(6)
The value calculated in Equation (7) was performed at nominal voltage and current
values of 600 V, 600 A. Since the nominal current value of the system is 200 A and the
nominal voltage value is 375 V, the approximate switching power loss is expressed as
shown in Equation (7) and obtained as shown in Equation (8).
Pd(TOTALnom) = Pd(TOTAL) ·( Inom ·Vnom )/( Imax ·Vmax )
(7)
Pd(TOTALnom) = 1515.2·(200·375)/(600·600)
Pd(TOTALnom) = 315.66 W
(8)
The switching power dissipation for a single IGBT diode pair is 315.66 W. Considering
that there are 6 IGBT diode groups in the system, the total switching power dissipation is
expressed as shown in Equation (9) and obtained as shown in Equation (10).
Pd(6·TOTALnom) = Pd(TOTALnom) ·6
(9)
Pd(6·TOTALnom) = 315.66·6
Pd(6·TOTALnom) = 1894 W
(10)
This calculated value shows the maximum power loss. This amount of loss does not
occur continuously while the system is operating.
Transmission losses are directly proportional to the square of the nominal current
value passing through the IGBT modules and the IGBT module internal resistance values.
According to the data obtained from the IGBT data file, conduction loss calculations were
performed by selecting the values of the switch internal resistance values of the IGBT
module to be used at the maximum temperature. Equation (11) was used for IGBT in these
calculations. It is calculated as shown in Equation (12).
Pi IGBT = VCEO · Inom + rCE ·( Inom )2
(11)
Pi IGBT = 0.8·200 + 2.7·10−3 ·2002
Pi IGBT = 268 W
(12)
Equation (13) was used for the diode in these calculations. It is calculated as shown in
Equation (14).
PiDiode = VFO · Inom + r F ·( Inom )2
(13)
PiDiode = 1.1·200 + 2.1·10−3 ·2002
PiDiode = 304 W
(14)
The values calculated above are for one IGBT and diode connected in reverse parallel.
The sum of the IGBT and diode conduction losses is computed, as seen in Equation (15).
Pi(TOTAL) = Pi( IGBT ) + Pi( Diyot) = 268 + 304 = 572 W
(15)
As there are 6 of these pairs in the system, the total transmission loss is found in
Equation (16).
Pi(6·TOTAL) = Pi(TOTAL) ·6 = 572·6 = 3432 W
(16)
𝑃𝑖(𝑇𝑂𝑇𝐴𝐿) = 𝑃𝑖(𝐼𝐺𝐵𝑇) + 𝑃𝑖(𝐷𝑖𝑦𝑜𝑡) = 268 + 304 = 572 W
(15)
As there are 6 of these pairs in the system, the total transmission loss is found in
Equation (16).
Appl. Sci. 2024, 14, 1365
𝑃𝑖(6·𝑇𝑂𝑇𝐴𝐿) = 𝑃𝑖(𝑇𝑂𝑇𝐴𝐿) · 6 = 572 · 6 = 3432 W
8 of 20
(16)
When we apply these values calculated for 600 A to the system, the total transmission
loss is expressed
shown
Equation
(17) and
lossthe
is total
calculated
as
When we as
apply
theseinvalues
calculated
for the
600 transmission
A to the system,
transmission
shown
lossin
is Equation
expressed(18).
as shown in Equation (17) and the transmission loss is calculated as shown
in Equation (18).
𝑃𝑖(6·𝑇𝑂𝑇𝐴𝐿 𝑛𝑜𝑚) = 𝑃𝑖(𝑇𝑂𝑇𝐴𝐿) · (𝐼𝑛𝑜𝑚 · 𝑉𝑛𝑜𝑚 )/(𝐼𝑚𝑎𝑥 · 𝑉𝑚𝑎𝑥 )
(17)
Pi(6·TOTALnom) = Pi(TOTAL) ·( Inom ·Vnom )/( Imax ·Vmax )
(17)
𝑃𝑖(6·𝑇𝑂𝑇𝐴𝐿𝑛𝑜𝑚) = 3432 · ( 200 · 200 )/(600 · 600)
Pi(6·TOTALnom) = 3432·(200·200)/(600·600)
𝑃𝑖(6·𝑇𝑂𝑇𝐴𝐿𝑛𝑜𝑚) = 381.33 W
(18)
Pi(6·TOTALnom) = 381.33 W
(18)
This calculated value is again based on the maximum values of the system. The
This calculated value is again based on the maximum values of the system. The power
power stage total loss of the power electronics and control circuit are formulated in Equastage total loss of the power electronics and control circuit are formulated in Equation (19),
tion (19), hence Equation (20). The result of the calculation can be seen in Equation (21).
hence Equation (20). The result of the calculation can be seen in Equation (21).
(19)
𝑃𝑇𝑂𝑇𝐴𝐿 = Switching Loss + Transmission Loss
PTOTAL = Switching Loss + Transmission Loss
(19)
𝑃𝑇𝑂𝑇𝐴𝐿 = 𝑃𝑑(6·𝑇𝑂𝑇𝐴𝐿𝑛𝑜𝑚) + 𝑃𝑖(𝑇𝑂𝑇𝐴𝐿𝑛𝑜𝑚)
PTOTAL = Pd(6·TOTALnom) + Pi(TOTALnom)
(20)
(20)
𝑃𝑇𝑂𝑇𝐴𝐿
= 1894
+ 381.33
PTOTAL
= 1894
+ 381.33
∼ 2.3 KW
PTOTAL
= 2275.33
𝑃𝑇𝑂𝑇𝐴𝐿
= 2275.33
WW
≅=
2.3 kW
(21)(21)
calculated
value
shows
a loss
of roughly
2.3 kW.
Based
on this
value,
TheThe
calculated
value
shows
a loss
of roughly
2.3 kW.
Based
on this
lossloss
value,
the the
efficiency
of the
circuit
be approximately
calculated,
as shown
in Equation
efficiency
of the
circuit
cancan
be approximately
calculated,
as shown
in Equation
(22).(22).
The
efficiency
value
can
be
calculated
as
follows:
The efficiency value can be calculated as follows:
(75 − 2.3) kW ∼
Efficiency =
= ɲ=
Efficiency
= 75 kW ≅ 0.97
= 0.97
75 kW
(75−2.3) kW
(22)(22)
5. Cooling
Calculations
Cooling
System
Design
5. Cooling
Calculations
andand
Cooling
System
Design
In power
stage
design,
some
criteria
considered
to select
heatsink.
Figure
Appl. Sci. 2024, 14, x FOR PEER REVIEWIn power
9 of
stage
design,
some
criteria
are are
considered
to select
the the
heatsink.
Figure
7 227
shows
the
thermal
resistances
of
the
system
with
the
heatsink.
Such
thermal
resistances
shows the thermal resistances of the system with the heatsink. Such thermal resistances
parameters
described
in Table
andand
the the
parameters
are are
described
in Table
7. 7.
Figure 7. Thermal resistance of the system with cooler.
Figure 7. Thermal resistance of the system with cooler.
Table 7. Parameters and their meanings.
The total thermal resistance is calculated with Equation (23) using the catalog values
of ΘJC (RParameter
JC) and ΘCS (RCS) in the heatsink catalog to
determine the heat emitted by the
IGBT
Name
Unit
◦
modules used.
ΘJC
Thermal resistance between the junction and IGBT case
C/W
ΘCS
ΘSA
Case to heatsinkTthermal
j − TA resistance
Θ +Θ +Θ =
JC
SA
Thermal resistance between P
the heatsink and medium
Tj
Table 7. Parameters and their meanings.
TA
Parameter
P
ΘJC
ΘCS
ΘSA
Tj
TA
P
CS
◦ C/W
(23)
◦ C/W
Junction temperature
◦C
Ambient Temperature
◦C
Name
Lost power
Thermal resistance between the junction and IGBT case
Case to heatsink thermal resistance
Thermal resistance between the heatsink and medium
Junction temperature
Ambient Temperature
Lost power
◦C
Unit
°C/W
°C/W
°C/W
°C
°C
°C
Appl. Sci. 2024, 14, 1365
9 of 20
The total thermal resistance is calculated with Equation (23) using the catalog values
of ΘJC (RJC ) and ΘCS (RCS ) in the heatsink catalog to determine the heat emitted by the
IGBT modules used.
Tj − TA
(23)
ΘJC + ΘCS + ΘSA =
P
The total junction thermal resistance can be expressed by Equation (24), as computed
in Equations (25) and (26).
QjaTotal = Diode(K/W) + IGBT(K/W) + Module (K/W)
(24)
QjaTotal = (0.086 · 6) + (0.049 · 6) + (0.03 · 3)
(25)
QjaTotal = 0.9 K/W
(26)
Equation (27) can be used to calculate the lost power. The parameter values are
substituted in Equation (28), and the result can be seen in Equation (29).
Pdissipation = (Tj − Ta )/QjaTotal
(27)
Pdissipation = [(150 − 80) ◦ C]/0.9 = (423 − 353) K/0.9
(28)
Pdissipation = 77.8 W
(29)
Effect of mounting distances of IGBTs on heat dissipation; when the IGBT modules
are positioned as shown in Figure 8, the thermal resistance between the IGBT case and
the heatsink decreases, thus ensuring that the amount of heat dissipated to the heatsink is
Appl. Sci. 2024, 14, x FOR PEER REVIEW
10 of 22
equal and the temperature value is lower than the value when they are positioned side by
side [16].
Figure8.8.Placement
Placementof
ofIGBT
IGBTmodules
modulesin
inthe
theheatsink.
heatsink.
Figure
ItItis
recommended for
forliquid-cooled
liquid-cooledsystems
systemstotoimplement
implement
a similar
spacing
is also
also recommended
a similar
spacing
bebetween
IGBTsasasininair-cooled
air-cooledsystems.
systems. The
The liquid
liquid cooling
cooling system
system should
tween IGBTs
should be
be designed
designed by
by
maintaining the distance between the IGBTs [16]. When the SKM300GB126D module case
maintaining the distance between the IGBTs [16]. When the SKM300GB126D module case
was used in this thesis, such points were considered in thermal design.
was used in this thesis, such points were considered in thermal design.
The analysis was performed in the Fluent program using the following parameters:
The analysis was performed in the Fluent program using the following parameters:
ambient and heatsink parameter (Ta ): 40 ◦ C, number of elements installed per heat-sink:
ambient and heatsink parameter (Ta): 40 °C, number of elements installed per heat-sink:
6, number of parallel devices on the same heat-sink: 1, additional power supply: 0 W on
6, number of parallel devices on the same heat-sink: 1, additional power supply: 0 W on
this heat-sink, cooling methods forced air cooling, correction factor: 1, flow rate: 80 m3 /h or
this heat-sink, cooling methods forced air cooling, correction factor: 1, flow rate: 80 m3/h
L/min, and Rth (s − a): 0.11 K/W. If the number of switches on the heatsink and the number
or L/min, and Rth (s − a): 0.11 K/W. If the number of switches on the heatsink and the
of components connected in parallel are more than one, the total power is calculated by
number of components connected in parallel are more than one, the total power is calcuEquation (30).
lated by Equation (30).
PTOTAL = ns ·n p ( Pd(6·TOTALnom) + P
)
(30)
i ( TOTALnom)
𝑃𝑇𝑂𝑇𝐴𝐿 = 𝑛𝑠 · 𝑛𝑝 (𝑃𝑑(6·𝑇𝑂𝑇𝐴𝐿𝑛𝑜𝑚) + 𝑃𝑖(𝑇𝑂𝑇𝐴𝐿𝑛𝑜𝑚) )
(30)
ns = number of switches on the heatsink;
ns = number of switches on the heatsink;
np = number of components connected in parallel in the switch.
In the thermal analysis example shown in Figure 9, it was determined that the IGBTs
had a temperature of 90 °C with a distance of 20 mm between them. As illustrated in Figure 10, the temperature rises to 96 °C when there is no space between the IGBTs [16].
this heat-sink, cooling methods forced air cooling, correction factor: 1, flow rate: 80 m3/h
or L/min, and Rth (s − a): 0.11 K/W. If the number of switches on the heatsink and the
number of components connected in parallel are more than one, the total power is calculated by Equation (30).
Appl. Sci. 2024, 14, 1365
𝑃𝑇𝑂𝑇𝐴𝐿 = 𝑛𝑠 · 𝑛𝑝 (𝑃𝑑(6·𝑇𝑂𝑇𝐴𝐿𝑛𝑜𝑚) + 𝑃𝑖(𝑇𝑂𝑇𝐴𝐿𝑛𝑜𝑚) )
10 of 20
(30)
ns = number of switches on the heatsink;
nnpp == number
number of
of components connected in parallel in the switch.
In
In the
the thermal
thermal analysis
analysis example
example shown
shown in
in Figure
Figure 9,
9, itit was
was determined that
that the IGBTs
IGBTs
◦ C with a distance of 20 mm between them. As illustrated in
had
temperature of
of 90
90°C
had a temperature
with a distance of 20 mm between them. As illustrated in Fig◦ C when there is no space between the IGBTs [16].
Figure
temperature
rises
to 96
ure 10,10,
thethe
temperature
rises
to 96
°C when
there is no space between the IGBTs [16].
Appl. Sci. 2024, 14, x FOR PEER REVIEW
11 of 22
Figure
Figure 9.
9. Sample
SampleIGBT
IGBT(20
(20mm)
mm)thermal
thermaldistribution.
distribution.
Figure 10. Sample IGBT (0 mm) thermal analysis.
Figure 10. Sample IGBT (0 mm) thermal analysis.
Since the combined layout will cause higher temperatures in case of high current flow
Sincethe
theIGBTs,
combined
layout will
cause 9higher
temperatures
in case of design.
high current
flow
through
the design
in Figure
is adopted
as the optimum
A greater
through
IGBTs,IGBTs
the design
in for
Figure
9 is adopted
as the optimum
design. A
greater
distance the
between
is better
maintaining
low temperatures.
However,
when
the
distance
between
IGBTs
is better
for maintaining
low temperatures.
However,
the
distance is
more than
30 mm,
the value
of the stray inductance
of the system
wouldwhen
increase,
distance
is damage
more than
mm, the
the strayvoltages.
inductance
of the system
wouldis inwhich will
the30
system
andvalue
cause of
unwanted
Therefore,
the distance
set
crease,
which
will
damage
the
system
and
cause
unwanted
voltages.
Therefore,
at such a level. Thus, the temperature rise at higher current values will be less, the
anddisthe
tance
is set at suchwill
a level.
Thus,
the temperature
rise at higher current values will be less,
stray inductance
remain
at optimum
levels [16].
and the stray inductance will remain at optimum levels [16].
5.1. Liquid Cooling Module
5.1. Liquid
Module
After Cooling
taking the
aspect lengths of the IGBT modules to be used and setting the optimumAfter
distance
to
be
left
between
them,
theIGBT
dimensions
cooler
module
taking the aspect
lengths
of the
modulesoftothe
bewater
used and
setting
the were
opticalculated.
Thetodrawing
in Figure
11 shows
the moduleofdimensions
in millimeters.
The
mum
distance
be left between
them,
the dimensions
the water cooler
module were
calculated. The drawing in Figure 11 shows the module dimensions in millimeters. The
module has a structure consisting of copper tubes embedded in an aluminum substrate
through which water or coolant passes. In the design, drawings were made depending on
the substrate thickness value, copper tube wall thickness, and the distance to be buried
from the surface to the inside. The liquid cooler module is designed to remove the heat
Appl. Sci. 2024, 14, 1365
11 of 20
module has a structure consisting of copper tubes embedded in an aluminum substrate
through which water or coolant passes. In the design, drawings were made depending on
the substrate thickness value, copper tube wall thickness, and the distance to be buried from
Appl. Sci. 2024, 14, x FOR PEER REVIEW
12 of 22
the surface to the inside. The liquid cooler module is designed to remove the heat generated
by the switching and conduction losses caused by the IGBT modules in the power stage
of the power electronics and control circuit and to operate the power electronics circuit
Appl. Sci. 2024, 14, x FOR PEER REVIEW
12 of 22
at the optimum temperature. The switching and conduction losses are calculated
using
the information obtained from the data sheets of the IGBTs used and the current, voltage,
switching frequency, and physical dimensions of the system.
Figure 11. Liquid cooler module top and profile view.
Figure 11. Liquid cooler module top and profile view.
Anair-cooled
air-cooledsystem
systemand
andSemikron’s
Semikron’sWP16
WP16liquid
liquidcooling
coolingsystem
systemwere
wereused
usedin
inthe
the
An
Figurefirst
11. Liquid
cooler
moduleInIn
top
anddesigns,
profile
view.
first
prototype
studies.
later
designs,
these
structures
were
revised
and
liquid
coolprototype
studies.
later
these
structures
were
revised
and
thethe
liquid
cooling
system
was designed
as shown
in Figures
12 and1213.
This
coolingcooling
systemsystem
was made
ing system
was designed
as shown
in Figures
and
13.liquid
This liquid
was
An
air-cooled
system
Semikron’s
WP16 liquid cooling system were used in the
with
machining
CNCand
processes.
made
with machining
CNC
processes.
first prototype studies. In later designs, these structures were revised and the liquid cooling system was designed as shown in Figures 12 and 13. This liquid cooling system was
made with machining CNC processes.
Figure12.
12.Liquid
Liquidcooling
coolingmodule
moduletop
topview.
view.
Figure
Figure 12. Liquid cooling module top view.
Appl.
Appl.Sci.
Sci.2024,
2024,14,
14,1365
x FOR PEER REVIEW
13
of20
22
12 of
Figure13.
13.Liquid
Liquidcooling
coolingmodule
modulewith
withIGBTs
IGBTsininplace.
place.
Figure
As
Asseen
seenfrom
fromthe
thecalculation
calculationin
inEquation
Equation(21),
(21),the
themodule
modulecompensates
compensatesfor
foraaloss
lossof
of
◦ C when the inlet water temperature
2300
W
and
keeps
the
outlet
water
temperature
at
20.5
2300 W and keeps the outlet water temperature at 20.5 °C when the inlet water temperaisture
16 ◦is
C.16
It removes
a temperature
value ofvalue
4.5 ◦ C
thefrom
system.
In this case,
thecase,
surface
°C. It removes
a temperature
of from
4.5 °C
the system.
In this
the
temperature
of
the
cooler,
that
is,
the
surface
temperature
to
which
the
IGBTs
are
connected,
surface temperature of the cooler, that is, the surface temperature to which the IGBTs are
◦ C.
remains
constant
at 34.5
connected,
remains
constant
at 34.5 °C.
5.2. Cooling Profiles
5.2. Cooling Profiles
The heatsink material must show optimum thermal conductivity and heat dissipation
The heatsink material must show optimum thermal conductivity and heat dissipa(high coefficient of thermal conductivity λ) at reasonable material and processing costs.
tion (high coefficient of thermal conductivity λ) at reasonable material and processing
Aluminum is therefore usually preferred (λ = 247 W/K·m for pure Al). But copper can also
costs. Aluminum is therefore usually preferred (λ = 247 W/K·m for pure Al). But copper
be used to meet specifically high requirements (λ = 398 W/K·m). The dependence of the
can also be used to meet specifically high requirements (λ = 398 W/K·m). The dependence
heat dissipation on the manufacturing process and the alloy used is striking; in practice,
of the heat dissipation on the manufacturing process and the alloy used is striking; in
the λ-values of coolers range from 150 W/K·m (Al-die cast alloy) to 220 W/K·m (AlMgSi
practice, the λ-values of coolers range from 150 W/K·m (Al-die cast alloy) to 220 W/K·m
extruded material). The heat dissipation in the material has a significant influence on the
(AlMgSiefficiency
extrudedofmaterial).
The[17].
heat dissipation in the material has a significant influthermal
the heatsink
enceTherefore,
on the thermal
efficiency
of
the
[17]. number of fins, fin height, and fin
optimized sizing for heatsink
root thickness,
Therefore,
optimized
sizing
for
root
thickness,
number
of fins,
height,
fin
thickness is critical: The fins of an air cooler are used to
dissipate
mostfin
of the
heatand
to the
thickness
is
critical:
The
fins
of
an
air
cooler
are
used
to
dissipate
most
of
the
heat
to
the
environment by convection. The root of a cooler is the finless part of the mounting surface
environment
by convection.
root of a cooler
is the
finless part
of the mounting
surface
for
power modules
where heatThe
is dissipated
[17]. To
determine
the optimum
conditions
for
for
power
modules
where
heat
is
dissipated
[17].
To
determine
the
optimum
conditions
forced air-cooled chiller profiles, heat conduction and convection can also be integrated
for forced
chiller profiles,
heat conduction
and convection
through
the air-cooled
fin height pattern
and calculated
by the following
formula: can also be integrated through the fin height pattern and calculated by the following formula:
1
Rth(s− a) = r
h1
i
𝑅𝑡ℎ(𝑠−𝑎)
=
n· ∝ ·U ·λ· A· 1+e1−2k1− 1+1e2k 1
𝑛 · √∝ · 𝑈 · 𝜆 · 𝐴 · [
−
]
1 + 𝑒 −2𝑘 1 + 𝑒 2𝑘
q
α·U𝛼 · 𝑈
where
wherek 𝑘==h·ℎ ·λ√· A
𝜆·𝐴
(α:heat-transfer
heat-transfercoefficient,
coefficient,U:
U:fin
fincircumference,
circumference,λ:λ:coefficient
coefficientof
ofthermal
thermalconductivity
conductivityof
of
(α:
the
theheatsink
heatsinkmaterial,
material,A:
A:cross-section
cross-sectionofoffins,
fins,h:h:fin
finheight).
height).
Fans generate
generate the
the air
air flow
fanfan
types
areare
used
deFans
flow required
required for
forair
aircooling.
cooling.Different
Different
types
used
pending
on
the
kind
of
cooler
and
application
(Figure
14):
depending on the kind of cooler and application (Figure 14):
Axial flow fans run with the axis of rotation of the axial rotor parallel to the air flow.
The air is moved along the axial rotor, which moves similar to an air screw. The advantages of axial flow fans are their relatively small size relative to the high air flow rate
processed. Their disadvantage is the increase in pressure compared to radial flow fans.
fans provide a high air flow rate even at low speeds and can therefore be configured to
14 of 22
generate relatively low noise. The rotor length and outlet slot are matched to the heatsink
width [17]. The energy consumption of the cooling system is associated with two components: the pump and the fan. In conventional cooling systems, the pump and the fan are
13 the
of 20
Radial flow
fans
(Figure 14) In
[17],
in studies,
contrastthe
to axial
flowloads
fans,ofare
where a of
higher
controlled
with
a thermostat.
new
thermal
allused
components
pressure
is critical
forsimulated,
the same amount
of air.
Air is sucked
in parallel[14].
or axial to the
vehicle
arerise
calculated
and,
and control
strategies
are developed
drive axis of the radial flow fan and blown out in a radial direction, deflected 90° by the
rotation of the radial rotor. In order to minimize pressure losses due to the high outlet
velocity of the air exiting the radial flow fan, care must be taken to maintain air channeling, for instance, by using a diffuser. Cross-flow or tangential fans have an inlet and blowing slot along their entire length. Air is sucked from the inlet slot into the interior of the
rotor, where it is swirled, deflected, and blown out extremely homogeneously. Cross-flow
fans provide a high air flow rate even at low speeds and can therefore be configured to
generate relatively low noise. The rotor length and outlet slot are matched to the heatsink
width [17]. The energy consumption of the cooling system is associated with two components: the pump and the fan. In conventional cooling systems, the pump and the fan are
Figure
14.
Axial-flow
fan;
fan;
fan.
Figure
14.(a)
(a)with
Axial-flow
fan;(b)
(b)Radial-flow
Radial-flow
fan;(c)
(c)Cross-flow
Cross-flow
controlled
a thermostat.
In new studies,
the
thermalfan.
loads of all components of the
vehicle
are
calculated
and,
simulated,
and
control
strategies
developed
[14].
AxialDesign
flow fans run with the axis of rotation of the axial are
rotor
parallel to
the air flow.
6. DC-Bus
The air is moved along the axial rotor, which moves similar to an air screw. The advantages
The DC-Bus can be designed in different ways. In general, a “sandwich busbar” deof axial flow fans are their relatively small size relative to the high air flow rate processed.
sign is used in applications, because the sandwich busbar design reduces the stray inductTheir disadvantage is the increase in pressure compared to radial flow fans. Radial flow
ance value, which means reducing the additional voltage that will be reflected on the DCfans (Figure 14) [17], in contrast to axial flow fans, are used where a higher pressure rise
Bus voltage and thus on the IGBTs, as mentioned before. The design’s three-dimensional
is critical for the same amount of air. Air is sucked in parallel or axial to the drive axis
model is illustrated in Figure 15 [16].
of the radial flow fan and blown out in a radial direction, deflected 90◦ by the rotation
As shown in Figure 15, the + and − plates of the busbar are parallel to each other and
of the radial rotor. In order to minimize pressure losses due to the high outlet velocity
separated by an insulator. DC-bus capacitors will be used as mounted on these busbar
of the air exiting the radial flow fan, care must be taken to maintain air channeling, for
coppers. The cooler and its placement on the IGBTs are shown in Figure 16. As shown in
instance, by using a diffuser. Cross-flow or tangential fans have an inlet and blowing slot
Figure 16, DC-Bus capacitors are placed on the DC busbar located on the appropriate IGBT
along their entire length. Air is sucked from the inlet slot into the interior of the rotor,
Figure
14. (a) Axial-flow
fan; (b)
Radial-flow
fan;
(c) Cross-flow
fan. group. The desired capacthat
provides
input parallel
to the
forming
a parallel
where
it is swirled,
deflected,
andcooler
blownby
out
extremely
homogeneously.
Cross-flow fans
itance
value
is created
thiseven
wayat
[16].
provide
a high
air flowinrate
low speeds and can therefore be configured to generate
6. DC-Bus Design
relatively low noise. The rotor length and outlet slot are matched to the heatsink width [17].
The DC-Bus
can be designed
in different
ways.
In general,
a “sandwich
busbar” the
deThe energy
consumption
of the cooling
system
is associated
with
two components:
sign
is
used
in
applications,
because
the
sandwich
busbar
design
reduces
the
stray
inductpump and the fan. In conventional cooling systems, the pump and the fan are controlled
ance avalue,
which means
the thermal
additional
voltage
will be reflected
on the DCwith
thermostat.
In newreducing
studies, the
loads
of allthat
components
of the vehicle
are
Bus voltage
andsimulated,
thus on the
IGBTs,
as strategies
mentionedare
before.
The design’s
calculated
and,
and
control
developed
[14]. three-dimensional
model is illustrated in Figure 15 [16].
As shown
in Figure 15, the + and − plates of the busbar are parallel to each other and
6. DC-Bus
Design
separated
by
an
insulator.
DC-bus
capacitors
willInbegeneral,
used asa “sandwich
mounted on
these design
busbar
The DC-Bus can
be designed
in different
ways.
busbar”
coppers.
The
cooler
and
its
placement
on
the
IGBTs
are
shown
in
Figure
16.
As
shown
in
is used in applications, because the sandwich busbar design reduces the stray inductance
Figure
15.
Sandwich
busbar
design.
Figurewhich
16, DC-Bus
capacitors
on the
DC busbar
located
on the appropriate
IGBT
value,
means
reducingare
theplaced
additional
voltage
that will
be reflected
on the DC-Bus
that provides
input
parallel
toas
the
cooler by before.
forming
a parallel
The desired model
capacvoltage
and thus
on the
IGBTs,
mentioned
The
design’sgroup.
three-dimensional
The current resistance is increased by connecting the capacitors in parallel instead of
itance
value is
in [16].
this way [16].
is
illustrated
in created
Figure 15
current flowing through the DC bus, interfering with a single capacitor. The surface area
and thickness of the DC-bus are designed according to the current to pass. It is manufactured for a current passage of 300 A. If the capacitor’s voltage-current values are not at
values appropriate to all be connected in parallel, the sandwich busbar can be designed
both in series and parallel.
Appl. Sci. 2024, 14, x FOR PEER REVIEW
Appl. Sci. 2024, 14, 1365
Figure15.
15. Sandwich
Sandwich busbar
busbar design.
design.
Figure
As
in resistance
Figure 15, is
the
+ and − by
plates
of the busbar
are parallel
to each other
and
Theshown
current
increased
connecting
the capacitors
in parallel
instead
of
separated
by
an
insulator.
DC-bus
capacitors
will
be
used
as
mounted
on
these
busbar
current flowing through the DC bus, interfering with a single capacitor. The surface area
coppers.
The cooler
its placement
on according
the IGBTs to
arethe
shown
in to
Figure
shown
and thickness
of the and
DC-bus
are designed
current
pass.16.
It isAs
manufacin Figure 16, DC-Bus capacitors are placed on the DC busbar located on the appropriate
tured for a current passage of 300 A. If the capacitor’s voltage-current values are not at
IGBT that provides input parallel to the cooler by forming a parallel group. The desired
values appropriate to all be connected in parallel, the sandwich busbar can be designed
capacitance value is created in this way [16].
both in series and parallel.
Appl.
Appl.Sci.
Sci.2024,
2024,14,
14,1365
x FOR PEER REVIEW
15
of20
22
14 of
Appl. Sci. 2024, 14, x FOR PEER REVIEW
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Figure16.
16.DC-Bus
DC-BusIGBT
IGBTheatsink
heatsinkand
andcapacitance.
capacitance.
Figure
The current
resistanceofisOther
increased
byStage
connecting
the capacitors in parallel instead
7. Design
and Assembly
Power
Circuits
of current flowing through the DC bus, interfering with a single capacitor. The surface
Whether the cooling system is air, fan assisted air, or a liquid cooled system, IGBT
area and thickness of the DC-bus are designed according to the current to pass. It is
modules are mounted on these coolers after manufacturing. A busbar or sandwich busbar
manufactured for a current passage of 300 A. If the capacitor’s voltage-current values
is mounted on these IGBT modules. After this, DA-Bus capacitors and the snubber are
are not at values appropriate to all be connected in parallel, the sandwich busbar can be
assembled.
Depending
on the sheath
structure of the IGBT, the IGBT driver (Skyper 32) is
Figure
16.both
DC-Bus
IGBT heatsink
and capacitance.
designed
in series
and parallel.
connected to the system either directly or through an intermediate mounting tube. In
Figure
16,and
dueAssembly
to the sheath
of the Power
IGBT
an intermediate auxiliary circuit (board)
Design
and
Assembly
ofOther
Other
Powermodule,
StageCircuits
Circuits
7.7.
Design
of
Stage
manufactured for easy connections is used.
Whether the
the cooling
cooling system
system is
is air,
air, fan
fanassisted
assisted air,
air,or
oraaliquid
liquidcooled
cooledsystem,
system,IGBT
IGBT
Whether
The placement of the auxiliary board circuit on the IGBT modules together with the
modulesare
aremounted
mountedon
onthese
thesecoolers
coolersafter
aftermanufacturing.
manufacturing.A
Abusbar
busbaror
or sandwich
sandwichbusbar
busbar
modules
Skyper 32 Pro is shown in Figure 17 [16].
isismounted
mounted on
onthese
theseIGBT
IGBTmodules.
modules. After
After this,
this, DA-Bus
DA-Bus capacitors
capacitors and
and the
the snubber
snubber are
are
assembled.
the sheath
sheathstructure
structureof
ofthe
theIGBT,
IGBT,the
theIGBT
IGBTdriver
driver(Skyper
(Skyper32)
32)
assembled. Depending on the
is
isconnected
connectedtotothe
thesystem
systemeither
eitherdirectly
directly or
or through an intermediate
mounting
tube.
In
intermediate mounting tube. In
Figure
Figure16,
16,due
dueto
tothe
thesheath
sheathof
ofthe
the IGBT
IGBT module,
module, an
an intermediate
intermediate auxiliary
auxiliary circuit
circuit (board)
(board)
manufactured
manufacturedfor
foreasy
easyconnections
connectionsisisused.
used.
The
Theplacement
placementof
ofthe
theauxiliary
auxiliaryboard
boardcircuit
circuiton
onthe
theIGBT
IGBTmodules
modulestogether
togetherwith
withthe
the
Skyper
Skyper32
32Pro
Proisisshown
shownin
inFigure
Figure17
17[16].
[16].
Figure 17. IGBT module design on a fluid cooling system.
In this study, the original design of both air and liquid-cooled three-phase power
plants with a nominal power of 75 kW and a maximum power of 100 kW is presented.
The DC-AC converter (inverter) was designed, manufactured, and operated.
In the air-cooled system, the DA-Bus capacitors are installed by connecting eight 4500
µF 450 V capacitors in parallel. Figure 18 shows the original 75 kW fan-assisted natural-
Figure17.
17.IGBT
IGBTmodule
moduledesign
designon
onaafluid
fluidcooling
coolingsystem.
system.
Figure
In this study, the original design of both air and liquid-cooled three-phase power
plants with a nominal power of 75 kW and a maximum power of 100 kW is presented.
The DC-AC converter (inverter) was designed, manufactured, and operated.
In the air-cooled system, the DA-Bus capacitors are installed by connecting eight 4500
µF 450 V capacitors in parallel. Figure 18 shows the original 75 kW fan-assisted natural-
Appl. Sci. 2024, 14, 1365
15 of 20
Appl. Sci. 2024, 14, x FOR PEER REVIEW
16 of 22
In this study, the original design of both air and liquid-cooled three-phase power
plants with a nominal power of 75 kW and a maximum power of 100 kW is presented. The
DC-AC converter (inverter) was designed, manufactured, and operated.
Appl. Sci. 2024, 14, x FOR PEER REVIEW
16 of 22
air cooled
inverterthe
circuit.
Withcapacitors
the emergence
of film capacitors
with the
deIn the three-phase
air-cooled system,
DA-Bus
are installed
by connecting
eight
velopment
instead
of electrolytic
film capacitors
used in
4500
µF 450of
V technology
capacitors in
parallel.
Figure 18 capacitors,
shows the original
75 kW were
fan-assisted
the secondcooled
design,three-phase
the liquid-cooled
natural-air
invertersystem.
circuit. With the emergence of film capacitors with
air
cooled
three-phase
inverter
circuit.
With
emergence
film
capacitors
with
the
deIn
the
liquid
cooled
inverter
circuit
in the
Figure
19,
twoof
film
capacitors
are
used.
The
the development of technology instead of
electrolytic
capacitors,
film
capacitors
were
used
velopment
of
technology
instead
of
electrolytic
capacitors,
film
capacitors
were
used
in
structure
of the
the liquid-cooled
system is much
smaller.
inphysical
the second
design,
system.
the second design, the liquid-cooled system.
In the liquid cooled inverter circuit in Figure 19, two film capacitors are used. The
physical structure of the system is much smaller.
Figure18.
18.Original
Original75
75kW
kWfan
fanassisted
assistednatural-air
natural-aircooled
cooledthree-phase
three-phaseinverter
invertercircuit.
circuit.
Figure
In the liquid cooled inverter circuit in Figure 19, two film capacitors are used. The
physical
of kW
the fan
system
is much
smaller.
Figure 18.structure
Original 75
assisted
natural-air
cooled three-phase inverter circuit.
Figure 19. Original 75 kW liquid cooled three phase inverter circuit.
As shown in the above figures, the space occupied by both designs is large. A new
Figure
19. Original
Original
75
kWliquid
liquid
cooled
three
phaseinverter
inverter
circuit. to reduce the physical footsandwich
busbar75
design
withcooled
a film
capacitor
was required
Figure
19.
kW
three
phase
circuit.
print. After such a design is completed; It turned out that it was appropriate to design the
As
the
figures,
space occupied
by
designs
isislarge.
As shown
shownain
in“module
the above
above
figures, the
the
by both
both
designs
large. A
A new
new
system
using
containing
sixspace
IGBTsoccupied
in a single
case”.
The SKiM459GD12E4
sandwich
busbar
design
with
a
film
capacitor
was
required
to
reduce
the
physical
footprint.
sandwich
busbar design
with afor
film
capacitor systems,
was required
to reduce
the
physical
footmodel, produced
by Semikron
three-phase
with six
IGBTs in
a single
housing
After
such
a such
design
is completed;
It turned
out thatout
it was appropriate to design the system
print.
After
a design
is completed;
It turned
and with
a suitable
thermal
structure, was
selected. that it was appropriate to design the
system
a “module
containing
IGBTs
in a single
case”.
The SKiM459GD12E4
Theusing
design
of two 220
µF 1200 Vsix
film
concentrators
and
the ‘sandwich-bara’
design
model,
produced
by
Semikron
for
three-phase
systems,
with
six
IGBTs
in a 20.
single
housing
that will allow us to connect them to the IGBT module is shown in Figure
In addition,
and with a suitable thermal structure, was selected.
The design of two 220 µF 1200 V film concentrators and the ‘sandwich-bara’ design
that will allow us to connect them to the IGBT module is shown in Figure 20. In addition,
Appl. Sci. 2024, 14, 1365
16 of 20
using a “module containing six IGBTs in a single case”. The SKiM459GD12E4 model,
produced by Semikron for three-phase systems, with six IGBTs in a single housing and
Appl. Sci. 2024, 14, x FOR PEER REVIEW
17 of 22
Appl. Sci. 2024, 14, x FOR PEER REVIEW
17 of 22
with a suitable thermal structure, was selected.
The design of two 220 µF 1200 V film concentrators and the ‘sandwich-bara’ design
that will allow us to connect them to the IGBT module is shown in Figure 20. In addition,
the
placement
SKiM459GD12E4
IGBT
module
on
the liquid
liquid cooling
cooling
unit,
the
the
ofof
thethe
SKiM459GD12E4
IGBT
module
on the
liquid
cooling
unit, the
adapter
theplacement
placement
of
the
SKiM459GD12E4
IGBT
module
on
the
unit,
the
adapter
circuit
(Adaptor
Board
93
GD)
required
for
the
connection
of
the
IGBT
module
circuit
(Adaptor
93 GD)
required
forrequired
the connection
the IGBT module
and the
IGBT
adapter
circuit Board
(Adaptor
Board
93 GD)
for the of
connection
of the IGBT
module
® 42SKYPER
®connection
and
the
IGBT
driver
circuit,
the
placement
of
the
IGBT
driver
circuit
42
LJ
R,
the
driver
circuit,
the
placement
of
the
IGBT
driver
circuit
SKYPER
LJ
R,
the
®
and the IGBT driver circuit, the placement of the IGBT driver circuit SKYPER 42 LJ R, the
of
current
sensors,
and
the
input
and
output
connectors
are
shown
in
three
dimensions
connection
of
current
sensors,
and
the
input
and
output
connectors
are
shown
in
three
connection of current sensors, and the input and output connectors are shown in three
in
the designin
Figure
It can 20.
be It
seen
thethat
new
design
is a very
compact
and
dimensions
the
design
in
20.
It
can that
be seen
seen
that
the
newdesign
design
verycompact
compact
dimensions
inin
the
design20.
in Figure
Figure
can
be
the
new
isisaavery
space-saving
one.
and
space-saving
one.
and space-saving one.
Figure
20.
Original
three-phase
75kW
kWliquid
cooledinverter
invertercircuit
circuitwith
withsix
sixIGBT
IGBTmodules.
modules.
Figure20.
20.Original
Originalthree-phase
three-phase75
liquidcooled
cooled
inverter
circuit
with
six
IGBT
Figure
modules.
In
module
were
made
and
the
InFigure
Figure21,
21,three-dimensional
three-dimensional drawings
drawings
of
the
cooler
In
Figure
21,
three-dimensional
drawings of
of the
the cooler
cooler module
modulewere
weremade
madeand
andthe
the
mounting
locations
of
the
IGBT
module
were
determined
so
as
not
to
coincide
with
the
mounting locations
locations of
of the IGBT module were
mounting
were determined
determined so
so as
asnot
notto
tocoincide
coincidewith
withthe
the
liquid
six-IGBT
module
in
Figure
22
was
liquidchannels
channelsof
ofthis
thiscooler.
SKiM459GD12E4
liquid
channels
of
this
cooler. The
The SKiM459GD12E4
SKiM459GD12E4 six-IGBT
six-IGBT module
modulein
inFigure
Figure22
22was
was
selected
etc.
selectedbased
basedon
ontechnical
technicalrequirements
requirementssuch
such
as
system
current
voltage
values,
selected
based
on
technical
suchas
assystem
systemcurrent
currentvoltage
voltagevalues,
values,etc.
etc.
Figure 21.Three-dimensional
Three-dimensional designvisuals
visuals of the
the cooling module
module from the
the front, top
and side.
Figure
Figure21.
21. Three-dimensionaldesign
design visualsof
of thecooling
cooling modulefrom
from thefront,
front,top
topand
andside.
side.
First
Firstofofall,
all,this
thisIGBT
IGBTmodule
modulewas
wasmounted
mounted on
on this
this heatsink
heatsink block.
block. The “Adaptor
“Adaptor
First of all, this IGBT module was mounted on this heatsink block. The “Adaptor
Board
module, was
wasselected
selectedfrom
from
Board93
93GD”,
GD”,which
whichisisan
anadapter
adapter circuit
circuit suitable
suitable for the IGBT module,
Board 93 GD”,
which iscircuit
an adapter
circuiton
suitable
for the
IGBTasmodule,
was selected
from
Semikron.
The
adapter
is
mounted
the
IGBT
module
in
the
design
structure
in
Semikron. The adapter circuit is mounted on the IGBT module as in the design structure
Semikron.
The
adapter
circuit
is
mounted
on
the
IGBT
module
as
in
the
design
structure
Figure
22
[18].
in Figure 22 [18].
in Figure
22 [18].
As shown
in Figure 23, a different sandwich busbar was designed and connected for
the assembly of the SKiM459GD12E4 IGBT module and film capacitors. The sandwich bar
Appl. Sci. 2024, 14, x FOR PEER REVIEW
18 of 22
Appl. Sci. 2024, 14, 1365
17 of 20
was manufactured. In Figure 23, the original three-phase 75 kW fully controlled liquidcooled DC-AC converter circuit was designed and manufactured. Three 600 A current
Appl. Sci. 2024, 14, x FOR PEER REVIEW
18 of 22
sensors from the LEM company were connected to the converter outputs to measure the
current. In this study, the power stage was designed in three different structures.
Figure 22. SKiM459GD12E4 IGBT module, adapter circuit, and IGBT driver assembly.
As shown in Figure 23, a different sandwich busbar was designed and connected for
the assembly of the SKiM459GD12E4 IGBT module and film capacitors. The sandwich bar
was manufactured. In Figure 23, the original three-phase 75 kW fully controlled liquidcooled DC-AC converter circuit was designed and manufactured. Three 600 A current
sensors from the LEM company were connected to the converter outputs to measure the
current.
In22.
this
study, the power
stage
wasadapter
designed
in three
different
structures.
Figure
22.
SKiM459GD12E4
IGBT
module,
adapter
circuit,
andIGBT
IGBTdriver
driver
assembly.
Figure
SKiM459GD12E4
IGBT
module,
circuit,
and
assembly.
As shown in Figure 23, a different sandwich busbar was designed and connected for
the assembly of the SKiM459GD12E4 IGBT module and film capacitors. The sandwich bar
was manufactured. In Figure 23, the original three-phase 75 kW fully controlled liquidcooled DC-AC converter circuit was designed and manufactured. Three 600 A current
sensors from the LEM company were connected to the converter outputs to measure the
current. In this study, the power stage was designed in three different structures.
(a)
(b)
Figure
23. (a)
three-phase
75 kW75liquid
cooledcooled
inverter
circuit with
sixwith
IGBTsix
modules.
(b)
Figure
23.Original
(a) Original
three-phase
kW liquid
inverter
circuit
IGBT modules.
Figure
in (a) viewed
from different
angle. angle.
(b) Figure
in (a) viewed
from different
dSpace
DS1401
Digital
Signal
Processing
for rapid
control
protoTheThe
dSpace
DS1401
Digital
Signal
Processing
unitunit
waswas
usedused
for rapid
control
prototyping
of
the
BLDC
motor.
The
DS1401
DSP,
which
is
compatible
with
MATLAB/Simulink
typing of the BLDC motor. The DS1401 DSP, which is compatible with MATLAB/Simulink
blocks,
embeds
Simulink
blocks
hex
code
into
the
processorand
andgenerates
generatesthe
theconcontrol
blocks,
embeds
thethe
Simulink
blocks
as as
hex
code
into
the
processor
control
(a)system
(b)
trolsignals.
signals.A
Areal-time
real-timecontrol
control
systemwas
wascreated
createdby
bytransferring
transferringthe
thePID
PID
controlsystem
systemand
the
fuzzy
control
system
to
the
dSpace
board
via
MATLAB/Simulink
blocks
for
testing
and Figure
the fuzzy
control
system
to the 75
dSpace
board
via MATLAB/Simulink
blocks
for test23. (a)
Original
three-phase
kW liquid
cooled
inverter circuit with six
IGBT modules.
(b)
the
HIL
system
and
the
power
stage.
By
changing
the
control
parameters
in
the
HIL
ing the
HIL
andfrom
thedifferent
power stage.
Figure
in system
(a) viewed
angle. By changing the control parameters in the HIL
system,
optimum
control
parameters
were
determinedand
andthe
thesystem
systemwas
wasoperated
operated in
system,
thethe
optimum
control
parameters
were
determined
real-time.
The
tested
power
stage
and
control
software
were
transferred
to
a
dSP-based
in real-time.
tested
powerDigital
stage and
control
software
were
to a dSP-based
TheThe
dSpace
DS1401
Signal
Processing
unit
wastransferred
used for rapid
control
protoembedded
structure.
embedded
structure.
typing of the BLDC motor. The DS1401 DSP, which is compatible with MATLAB/Simulink
The BLDC motor, PID, and fuzzy control were designed using MATLAB R2018b Fuzzy
The BLDC
motor,
PID, andblocks
fuzzy as
control
were
designed
using and
MATLAB
R2018b
blocks,
embeds
the Simulink
hex code
into
the processor
generates
the conLogic Toolbox. This HIL system provides a very good solution for rapid prototyping. The
Fuzzy
Toolbox.
This HIL
system
provides
a very by
good
solution for
prototyptrolLogic
signals.
A real-time
control
system
was created
transferring
therapid
PID control
system
block diagram of this system is shown in Figure 24 [7].
ing. and
The the
block
diagram
of system
this system
is dSpace
shown in
Figure
[7].
fuzzy
control
to the
board
via24
MATLAB/Simulink
blocks for testThe developed control algorithms were tested with this rapid prototyping. This experiing the HIL system and the power stage. By changing the control parameters in the HIL
mental platform is shown in Figure 25. Cooling platforms in the electric vehicle HIL system
system, the optimum control parameters were determined and the system was operated
were also tested as a practical application. For this purpose, the DC motor, DC generator,
in real-time. The tested power stage and control software were transferred to a dSP-based
DS1401 dSpace Micro—AutoBox in the HIL structure, CAN-BUS Communication, PC
embedded structure.
connections, DC power supply, DC motor driver, and liquid cooling system were used.
The BLDC motor, PID, and fuzzy control were designed using MATLAB R2018b
Fuzzy Logic Toolbox. This HIL system provides a very good solution for rapid prototyping. The block diagram of this system is shown in Figure 24 [7].
Appl.
FOR PEER REVIEW
Appl.Sci.
Sci.2024,
2024,14,
14,x1365
19 of 22
18 of 20
Figure 24. The BLDC motor’s rapid control prototyping block diagram with dSpace Micro—Auto
Box.
The developed control algorithms were tested with this rapid prototyping. This experimental platform is shown in Figure 25. Cooling platforms in the electric vehicle HIL
system were also tested as a practical application. For this purpose, the DC motor, DC
generator, DS1401 dSpace Micro—AutoBox in the HIL structure, CAN-BUS CommunicaFigure
24.
BLDC
motor’s
rapid
control
prototyping
diagram
with dSpace
Micro—Auto
Figure
24.The
The
BLDC
motor’s
rapid
control
prototyping
block
diagram
with
dSpace
Micro—
tion, PC
connections,
DC power
supply,
DC
motorblock
driver,
and
liquid
cooling
system
were
Box.
Auto
Box.
used.
The developed control algorithms were tested with this rapid prototyping. This experimental platform is shown in Figure 25. Cooling platforms in the electric vehicle HIL
system were also tested as a practical application. For this purpose, the DC motor, DC
generator, DS1401 dSpace Micro—AutoBox in the HIL structure, CAN-BUS Communication, PC connections, DC power supply, DC motor driver, and liquid cooling system were
used.
Figure25.
25.System
Systemengine-generator
engine-generatortest
testplatform
platformwith
withDS1401
DS1401dSpace
dSpaceMicro—Auto
Micro—AutoBox.
Box.
Figure
AAsimulation
simulationmodel
modelfor
forthe
thevehicle
vehiclewas
wasobtained
obtainedin
inthis
thisstudy
studyby
bydetermining
determiningthe
the
basic
parameters
of
a
passenger
electric
vehicle.
A
brushless
DC
motor
was
selected
basic parameters of a passenger electric vehicle. A brushless DC motor was selected acaccording
the
simulation
result,
a unique
75 kW
DC-AC
converter
of three
different
cording toto
the
simulation
result,
a unique
75 kW
DC-AC
converter
of three
different
types
types
in
compliance
with
automotive
standards
was
designed
to
drive
this
motor,
and
in compliance with automotive standards was designed to drive this motor, and practical
practical
test
results
demonstrated
the
success.
The
BLDC
motor
phase
currents
and
test results demonstrated the success. The BLDC motor phase currents and voltages were
Figure
25.
System
engine-generator
test
platform
with
DS1401
dSpace
Micro—Auto
Box.
voltages were monitored with an oscilloscope. This is shown in Figure 26. The simulation
and the application results have shown compatibility, and the system performance has
simulation tested.
model for the vehicle was obtained in this study by determining the
beenAsuccessfully
basic The
parameters
of a passenger
electric
vehicle. Asoftware,
brushlessand
DCthe
motor
selected
acperformance
of the control
algorithms,
threewas
types
of power
cording
to the simulation
result, The
a unique
75 motor
kW DC-AC
three
different
stages designed
were tested.
BLDC
phaseconverter
currentsof(If1
Maroon;
If2 types
Gray;
in
with
automotive
designed
driveVthis
motor,Vand
practical
If3compliance
Orange) and,
BLDC
motor standards
interphasewas
voltages
(V23toBlue;
were
12 Green;
13 Red)
test
results demonstrated
the success.
The BLDC
motor
monitored
with an oscilloscope
as shown
in Figure
26. phase currents and voltages were
Appl. Sci. 2024, 14, x FOR PEER REVIEW
20 of 22
monitored with an oscilloscope. This is shown in Figure 26. The simulation and the
appli19 of
20
cation results have shown compatibility, and the system performance has been successfully tested.
Appl. Sci. 2024, 14, 1365
Figure 26. BLDC motor phase currents (If1 Maroon; If2 Grey; If3 Orange), and BLDC motor interphase
Figure 26. BLDC
motor phase currents (If1 Maroon; If2 Grey; If3 Orange), and BLDC motor interphase
voltages (V23 Blue; V12 Green; V13 Red).
voltages (V23 Blue; V12 Green; V13 Red).
performance of the control algorithms, software, and the three types of power
8. ExperimentalThe
Results
stages designed were tested. The BLDC motor phase currents (If1 Maroon; If2 Gray; If3 Or-
Three ange)
different
systems,
namely
air-cooled,
fan-assisted
andmonitored
liquidand,cooling
BLDC motor
interphase
voltages
(V23 Blue;
V12 Green;air-cooled,
V13 Red) were
cooled, were
used
in
the
three
different
power
stages
that
were
considered
to
drive
the
with an oscilloscope as shown in Figure 26.
brushless direct current motor. In Table 8, when the surface temperatures of IGBTs used
as switching
elements in the
power stage are measured, the performances of the cooling
8. Experimental
Results
systems are shown,
from
best
worst;
It is seen
that the
systemfan-assisted
with the best
performance
Three different to
cooling
systems,
namely
air-cooled,
air-cooled,
and liqis liquid cooled,
followed
by
fan
assisted
air
cooling,
and
then
air
cooled.
In Table
9,
uid-cooled, were used in the three different power stages that were considered
to drive
experimental
results
of cooling
rate in percentage
the application
brushless direct
current
motor. Insystem
Table 8,efficiency
when the decline
surface temperatures
of IGBTs
used
as switching
in the
powerofstage
are measured, the performances of the
comparisons
according
to theelements
mounting
method
IGBTs.
cooling systems are shown, from best to worst; It is seen that the system with the best
Table 8. Experimental
application
results of
coolingby
system
temperature
comparisons
to In
performance
is liquid cooled,
followed
fan assisted
air cooling,
and thenaccording
air cooled.
the mounting
method
of IGBTs. application results of cooling system efficiency decline rate in perTable
9, experimental
centage comparisons according to the mounting method of IGBTs.
Surface Temperatures According to
Mounting Type
Surface when IGBTs are combined
Fan-Assisted
Liquid-Cooled
No Cooling
Air-Cooled
Table 8. Experimental application results of coolingAir-Cooled
system temperature comparisons according to
the mounting
96 ◦ C method of IGBTs.
78 ◦ C
75 ◦ C
38 ◦ C
IGBT 6 Module (◦ C)
◦C
94Surface
75 ◦ C
71 ◦ C
34 ◦ C
IGBT 20 mm apart (◦ C)
90 ◦ C
72 ◦ C
69 ◦ C
Temperatures
Fan-Assisted 30 ◦ C
No Cooling
Air-Cooled
Liquid-Cooled
According to
Air-Cooled
Mounting
Type
Table 9. Experimental
application
results of cooling system efficiency decline rate in percentage
when
IGBTs
comparisons Surface
according
to the
mounting96
method
of IGBTs.
°C
78 °C
75 °C
38 °C
are combined
IGBT 6 Module (°C) Efficiency
94 °C Decline Rate
75in
°CPercentage 71 °C
34 °C
Surface Temperatures According to
IGBT
20
mm
apart
Fan-Assisted
Mounting Type
90 °C
72 °C
69 °C Liquid-Cooled
30 °C
No Cooling
Air-Cooled
Air-Cooled
(°C)
Surface when IGBTs are combined
36
28
25
8
IGBT 6 Module
34
25
21
4
IGBT 20 mm apart
30
22
19
2
9. Conclusions
In the three different power stages studied to drive the brushless direct current motor, it
was measured that the performances of the cooling systems were ranked, from better to poor,
as liquid cooling, fan-assisted air-cooled and, air-cooled systems. As per the configuration
of the semiconductors, it is seen that the liquid-cooled system with at least 20 mm between
them, using a single module, gives the best performance. The performance of fan-assisted aircooled and fanless air-cooled systems decreases further. In power-semiconductor systems, if
no cooling system is employed, the nominal operating temperatures are exceeded, especially
during load operations. Therefore, using a cooling system is essential. According to the
results of this study, the installation of power semiconductors and the choice of cooling
system should be optimized according to the requirements of future studies.
Appl. Sci. 2024, 14, 1365
20 of 20
Author Contributions: A.B.: conceptualization, experimentation, data interpretation, and writing;
O.A.: experimentation and data interpretation; E.B.: conceptualization, data interpretation, and
writing. All authors have read and agreed to the published version of the manuscript.
Funding: This research received no external funding.
Institutional Review Board Statement: Not applicable.
Informed Consent Statement: Not applicable.
Data Availability Statement: The raw data supporting the conclusions of this article will be made
available by the authors on request.
Conflicts of Interest: The authors declare no conflicts of interest.
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