International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com (ISSN 2250-2459, Volume 2, Issue 11, November 2012)
Operating Three Phase Induction Motor Connected to Single
Phase Supply
Shivanagouda.B.Patil1, M. S. Aspalli2
1,2
Department of Electrical and Electronics Engineering, P.D.A.C.E, Gulbarga, Karnataka, India
Abstract – This paper presents a simple converter
topology for driving a three-phase induction motor with a
single-phase ac supply. Using only two active switches and a
Triac, the converter can start the motor with high starting
torque and low input current, and run the motor at rated
speed. The converter supplies balanced output voltages at
rated frequency, the proposed control approaches are
supported by test results. In the proposed scheme,
dsPIC30F2010 controller is used to produce PWM signals.
A 3-phase, 415V, 1440RPM, 1.5HP Induction motor is used
as load for testing the developed hardware. Textronics
TDS2024B storage oscilloscope is used to store the gate
pulses and waveforms. The experimental result showed that
PWM pulses produced remained approximately constant
with increase in load and the developed hardware has
satisfactory converted the single phase power to three phase
power.
Therefore, it is desirable to replace the single-phase
induction motor drives by the three-phase induction
motor drives in some low-power industrial applications
[4] and [5]. However, in some rural areas where only a
single-phase utility is available, we should convert a
single-phase to a three-phase supply. This paper proposes
an alternative solution for phase conversion with very
low overall cost, moderate motor performance during
start up and high steady-state performance at line
frequency. This system fits the requirements in rural
areas where only a single-phase supply is available. This
paper describes the conversion of 1-phase power supply
to 3-phase and driving 3-phase AC induction motor using
16 bit High Performance Digital Signal Controller. The
dsPIC30F2010 devices contain extensive Digital Signal
Processor (DSP) functionality with high performance 16bit microcontroller (MCU) architecture.
The use of this 16-bit Digital Signal Controllers yields
enhanced operations, fewer system components, lower
system cost and increased efficiency. The system is
designed for driving medium power (1.5hp), 3-phase AC
induction motors. Our work consists of a half-bridge
rectifier, a split-capacitor dc bus, two active
devices(IGBTs) realizing the inverter section for
regulating the motor current and a TRIAC for controlling
the motor current.
The developed hardware is tested on a 3-phase, 415V,
50Hz Induction motor. According to the requirement, a
software program is written and is fed to the digital
signal controller (dsPIC30F2010) for the necessary
action. The inverter output current is regulated by a sine
wave reference, generated by software, and the TRIAC is
triggered at constant delay angle. The various
graphs/waveforms are analyzed and studied on Digital
Storage Oscilloscope.
Keywords – Single phase to Three phase, TRIAC, IGBTs,
Induction Motor, Split Capacitor
I.
INTRODUCTION
Motor drives constitute a predominant load for the
agricultural sector. As most rural communities in the
India are supplied with single-phase ac power, these
drives have to be realized with single-phase motors, or
with three phase motors (Induction Motors) driven by
phase converters. Autotransformer capacitor phase
converters and rotary phase converters have been used
for several decades [1].Both have the advantages of
simple
structure
and
reasonably
low
cost.
Autotransformer capacitor phase converters, however,
cannot easily obtain balanced output voltage with
reasonable cost, and rotary converters are heavy and have
significant no-load losses, also both topologies have high
inrush current during motor startup [2]. The three-phase
induction motors have some advantages in the machine
efficiency, power factor, and torque ripples compared to
their single-phase counterparts [3]. Though the precise
control of single phase induction motor is less complex in
comparison to the three phase induction motor, but when
the torque requirement is considered then three phase
induction motor is the best choice. The applications for
these motors cover almost every stage of manufacturing
and processing. It is not surprising to find that among all
type of electric motors, Induction motor is so popular,
when one considers its simplicity, reliability, and low
cost.
II. B LOCK D IAGRAM AND ITS EXPLANATION
A. System overview
The block diagram of the proposed single phase to
three phase power conversion and driving three phase
induction motor is shown in figure 1.
It has half bridge rectifier and split capacitor, half
bridge inverter, Triac circuit, control circuit. In the
proposed work, the half bridge rectifier consists has 46A-100L. In leg having two diode sets (upper and lower).
523
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com (ISSN 2250-2459, Volume 2, Issue 11, November 2012)
Each set has two diodes connected in parallel to
increase/double current rating. The output of the rectifier
is filtered by using two 1000µF, 450V capacitors which
acts as split capacitor.
The half bridge inverter has 2-FGA25N120ANTDIGBT’s switches. The triac used is TO-220AB (BTB16800) with the snubber circuit to meet the requirement.
The output of half bridge rectifier with split capacitor,
half bridge inverter and triac is applied to the three phase
induction motor. A digital signal controller
(dsPIC30F2010) is used to implement the core of the
control function, which simplifies the hardware setup.
F ig2. Half bridge rectifier and half bridge inverter
Single phase 230V, 50Hz AC supply is applied to the
half bridge rectifier and Triac via starter assembly. Triac
switches are protected against surge voltages using
snubber circuit. This half bridge rectifier converts single
phase AC input into DC which is filtered by two split
capacitors. The pure DC supply is applied to the half
bridge inverter which is made up of two IGBT switches.
The 3-phase induction motor is connected to half bridge
rectifier with split capacitors, half bridge inverter and
Triac as shown in figure 1. The half bridge with split
capacitors and half bridge inverter is shown in figure 2.
The energy that a switching power converter delivers to a
motor is controlled by Pulse Width Modulated (PWM)
signals applied to the gates of the switches. PWM signals
are pulse trains with fixed frequency and magnitude and
variable pulse width.
C. Control circuit
The control circuit of the proposed scheme consists of
a Digital signal Controller dsPIC30F2010.A Digital
Signal Controller (DSC) is a single-chip, embedded
controller that seamlessly integrates the control attributes
of a Microcontroller (MCU) with the computation and
throughput capabilities of a Digital Signal Processor
(DSP) in a single core. The dsPIC DSC has the “heart” of
a 16-bit MCU with robust peripherals and fast interrupt
handling capability and the “brain” of a DSP that
manages high computation activities, creating the
optimum single-chip solution for embedded system
designs. The dsPIC30F devices contain extensive Digital
Signal Processor (DSP)
functionality within highperformance 16-bit microcontroller (MCU) architecture.
It also consists of two opto-coupler for isolating the
control and power circuits. In this work an optocoupler
PC817 is used to isolate the gate drive circuit and the
IGBT-based power circuit. Two IGBTs of the power
circuit are controlled by the PWM signals generated by
the control circuit. MOC-3021 optoisolator is used for
triggering the Triac.
Fig1. Block diagram of the proposed system
B. Power circuit design
The power circuit designed contains half bridge
rectifier with split capacitors assembly, half bridge
inverter assembly and Triac assembly. At the start of the
motor it experiences a very high current and the motor
may not run at the rated speed. An electromagnetic relay
is used in the proposed scheme. Starting current of the
induction motor is six times that of the rated current for a
duration of 4 Seconds. To limit this heavy current flow,
two wire wound resistances of 50Ω, 10W each are
connected in parallel to the input supply. A single pole
change over relay is used to insert these wire wound
resistors for a period of 4secs and then the relay bypasses
these resistors for the rest of the operation.
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International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com (ISSN 2250-2459, Volume 2, Issue 11, November 2012)
3.2 Experimental Result for the Input Voltage 140V,
50Hz
III. EXPERIMENTAL SETUP AND ITS RESULTS
The conversion from single phase to three phase is
done successfully and the developed hardware is tested
with load. The proposed control system is implemented
by a DSC (dsPIC30F2010) based PWM inverter. C
language is used to develop the program. The device is
programmed using MPLAB Integrated Development
Environment (IDE) tool. It is a free, integrated toolset for
the development of embedded applications employing
Microchip's PIC and dsPIC controllers. For execution of
C-code, MPLAB compiler is used. In this work, I have
used 415V, 50Hz, 3-Ph, 1.5 HP Induction motor.
The hardware set is developed and tested in power
electronics laboratory and the photograph of complete
setup is shown in fig 3. The test is carried out on
induction motor for different loads and voltages. For
different loads and voltages, current drawn by the motor
and voltages across all lines are noted and are tabulated.
In the complete experiment the oscilloscope used is
Tektronix TDS2024B Digital Storage Oscilloscope
(DSO) to store gate pulses and voltage waveforms. The
speed of the induction motor is 1410 RPM, At particular
RPM, load is varied from 1KG to 4KG and
corresponding voltages and currents are noted.
Table 3.2, 3.4, 3.6 shows the output for variable
voltages and variable loads, corresponding waveforms
are taken from the DSO and are shown in figs 3.4 to 3.14.
The gate pulses are observed for different loads and
voltages are shown in the figs 3.1, 3.2, 3.3.
Table 2
Experimental Result for the Input Voltage 140V, 50Hz
Sl.
No.
Load
Stator
Current
Amperes
0.5kg
140
VA
181
VB
178
VC
188
0.62
2
1 kg
140
179
181
186
0.63
3
1.5 kg
140
173
183
188
0.64
4
2.0 kg
140
181
178
186
0.64
5
2.5 kg
140
181
178
186
0.7
6
3.0 kg
140
183
183
186
0.75
7
3.5 kg
140
181
183
186
0.8
8
4.0 kg
140
187
181
189
0.85
3.3 Experimental Result for the Input Voltage 180V,
50Hz
Table3
Experimental Result for the Input Voltage 180V, 50Hz
Sl.
No.
Table 1
Experimental Result for the Input Voltage 110V, 50Hz
Output Voltage
Volts
Output Voltage
Volts
1
Load
1
0.5kg
Inpu
t
Volt
age
Volts
180
2
1 kg
180
22
7
23
1
23
3
0.65
3
1.5
kg
180
22
7
22
9
23
1
0.7
2.0
kg
2.5
kg
3.0
kg
180
23
0
22
8
23
1
23
1
23
1
22
8
22
9
23
4
22
9
0.7
7
3.5
kg
180
23
3
22
7
23
0
0.9
8
4.0
kg
180
23
1
23
1
23
3
0.95
3.1 Experimental Result for the Input Voltage 110V,
50Hz
Sl.
No.
Input
Voltage
Volts
Load
Input
Voltage
Volts
Stator
Current
Amperes
1
0.5kg
110
VA
133
VB
130
VC
136
0.6
2
1 kg
110
131
131
134
0.63
4
3
1.5 kg
110
131
129
133
0.63
5
4
2.0 kg
110
133
136
134
0.63
6
5
2.5 kg
110
136
134
138
0.66
6
3.0 kg
110
138
134
137
0.75
7
3.5 kg
110
136
136
139
0.9
8
4.0 kg
110
138
133
138
0.92
525
180
180
Output
Voltage Volts
Stator Current
Amperes
VA
VB
VC
22
8
22
9
23
1
0.62
0.75
0.83
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com (ISSN 2250-2459, Volume 2, Issue 11, November 2012)
The gate pulses are observed for different loads and
voltages are shown in the following figs.
Fig 3.5 split capacitor waveform at 1kg
Fig 3.1 Gate pulse at 1kg
Fig 3.6 Traic waveform at 1kg
Fig 3.2 Gate pulse at 2kg
Fig 3.7 Traic waveform at
2kg
Fig 3.3 Gate pulse at 3kg
Fig 3.8 waveform across three lines
Fig 3.4 waveform across three lines
526
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com (ISSN 2250-2459, Volume 2, Issue 11, November 2012)
Fig 3.13 split capacitor waveform at 4kg
Fig 3.9 split capacitor waveform a 2kg
Fig 3.10 waveform across inveter at 2kg
Fig 3.14 waveform across three lines at 4kg
Fig 3.11 Traic waveform at 3kg
Fig4. photograph of complete Experimental setup
IV. CONCLUSION
Three phase asynchronous induction motors are
widely used in industrial applications due to their
features of low cost, high reliability and less
maintenance. Due to the need for three-phase electricity
in today's remote areas for agriculture work where three
phase power is not available easily, in those areas these
single phase to three phase converters are use full.
Fig 3.12 waveform across inverter 3kg
527
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com (ISSN 2250-2459, Volume 2, Issue 11, November 2012)
Operating a three phase induction motor using single
phase supply has been presented. The developed single
phase to three phase conversion hardware setup is tested
on a three phase 1.5hp, 415V, 50Hz induction motor with
loading in power electronics laboratory. From the
experimental setup and results chapter it is clear that the
developed hardware satisfactory converts from single
phase power to three phase power.
The developed system is useful in remote areas where
three phase supply is not available easily.
Applications of single phase to three phase converter
are:
 In Irrigation Pumps for Agriculture purpose.
 Rural Area Water Supply.
B. Inverter parameters :
Vin : lnput voltage 230V
C1, C2 : DC bus capacitors 1000µ , 250V each
Q1,Q2: IGBTs FGA25N120ANTD 1200V, 25A
REFERENCES
[1 ] C. Hertz, “Current techniques in phase conversion systems,”
IEEE Rural Electric Power Con$ Rec., pp. 3549, 1978.J.
[2 ] J. Nesbitt et al., “A novel single phase to three phase converter,”
IEEE APEC Con$ Rec., pp. 95-99, 1991.
[3 ] P. N. Enjeti et al., “Economic single phase to three phase
converter topologies for fixed frequency output,” IEEE APEC
Con$ Rec., pp. 88-94, 1991.
[4 ] C. Chen et ab, “A single phase to three phase power converter for
motor drive applications,” IEEE IAS Con$ Rec., pp. 639-646,
1992.
[5 ] P. N. Enjeti and A. Rahman, “A new single-phase to three-phase
converter with active input current shaping for low cost ac motor
drives,”IEEE Trans. Ind. Applicar., vol. 29, no. 4, pp. 80C813
July/Aug. 1993.
[6 ] Chingchi Chen, “A Hybrid Inverter/cylcoconverter-Based
Variable-Speed Three-phase Induction Motor Drive for Singlephase
Inputs”
IEEE
Tran.
on
Industry
application,Vol.31.no.3,may/june 1995
APPENDIX
The following defines the nomenclature and system
parameters used in this paper :
A. Molar parameters and nomenclature :
50Hz, 415V, 1.5hp, 3-phase, 4-pole induction machine.
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