# PSCAD Example Permanent Magnet Machine

```PSCAD Example
Permanent Magnet Machine
Manitoba HVDC Research Centre
a division of Manitoba Hydro International Ltd.
211 Commerce Drive
www.hvdc.ca
Permanent magnet machine
This example shows the dynamics of Permanent Magnet (PM) machine during different
transient conditions. The setup of the Permanent Magnet machine is shown as follows.
W
w
Te
BRK
A
V
Te
0.0002
0.0002
Es R=0
Timed
Breaker
Logic
[email protected]
BRK
ABC-&gt;G
Timed
Fault
Logic
During the start up the machine the speed is kept constant at 1 pu till 1sec. Mechanical
dynamics are initialized at 1sec this time. The following block models the rotational
dynamics of the rotor. The inputs are electrical torque (Te) and mechanical torque (Tm).
J=2 pu
=&gt;1/J=0.5pu
Te
D + -
1
sT
D + F
Tm
F
*
0.5
*
0.002
wm
A
1.0
Ctrl = 1
B
Ctrl
w
B (damping coeff)
SW
The machine open circuit voltage is about 78 V (1pu) peak for mag.
First a step change is applied to the mechanical torque (Tm) as follows:
&copy;2013 Manitoba HVDC Research Centre a division of Manitoba Hydro International Ltd.
Page 1 of 17
Init, Sep 1, 2016
A
Ctrl = 1
B
-0.8
Ctrl
Tm
TIME
The mechanical torque changes from -0.32 pu to -0.8pu at 2sec. The electric torque and
the power variations are shown as follows. The speed settles down at 1 pu after
undergoing transients.
-0.20
Te
Tm
Torque (pu)
-0.40
-0.60
-0.80
-1.00
-1.20
1.0200
wm
Speed (pu)
1.0150
1.0100
1.0050
1.0000
0.9950
Power (pu)
0.9900
1.20
1.00
0.80
0.60
0.40
0.20
0.00
-0.20
-0.40
1.50
Active Pow er
2.00
React ive Pow er
2.50
3.00
3.50
4.00
&copy;2013 Manitoba HVDC Research Centre a division of Manitoba Hydro International Ltd.
Page 2 of 17
Init, Sep 1, 2016
Second the breaker opens at 4 sec and closes at 4.1 sec. The rms voltage at the
terminal of the PM machine drops 0.9pu but recovers back to 1pu after some dynamics.
Voltage (pu)
Voltage (V)
Main
Volt age (Machine)
80
60
40
20
0
-20
-40
-60
-80
Voltage (Source)
RMS Volt age
1.060
1.050
1.040
1.030
1.020
1.010
1.000
0.990
0.980
Current
200
150
Current (A)
100
50
0
-50
-100
-150
3.50
3.75
4.00
4.25
4.50
4.75
5.00
5.25
5.50
5.75
6.00
The following figure shows the transients in Te, speed (Wm) and active and reactive
powers. The magnitude of the speed transient depends on the inertia.
&copy;2013 Manitoba HVDC Research Centre a division of Manitoba Hydro International Ltd.
Page 3 of 17
Init, Sep 1, 2016
Torque (pu)
1.0
0.0
-1.0
-2.0
-3.0
-4.0
-5.0
-6.0
-7.0
-8.0
-9.0
1.040
Te
Tm
wm
1.030
Speed (pu)
1.020
1.010
1.000
0.990
0.980
Power (pu)
0.970
2.50
2.00
1.50
1.00
0.50
0.00
-0.50
-1.00
-1.50
3.50
Act ive Pow er
4.00
Reactive Pow er
4.50
5.00
5.50
6.00
Third a fault occurs at 8sec for 0.05 sec duration and voltage drop to 0.3 pu. The
current rises incredibly however the PM machine and the power system resort to pre
fault values once the fault is cleared.
&copy;2013 Manitoba HVDC Research Centre a division of Manitoba Hydro International Ltd.
Page 4 of 17
Init, Sep 1, 2016
Voltage (pu)
Voltage (V)
Main
80
60
40
20
0
-20
-40
-60
-80
1.10
1.00
0.90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
150
Volt age (Machine)
Voltage (Source)
RMS Volt age
Current
Current (A)
100
50
0
-50
-100
-150
8.00
8.10
8.20
8.30
8.40
8.50
&copy;2013 Manitoba HVDC Research Centre a division of Manitoba Hydro International Ltd.
Page 5 of 17
Init, Sep 1, 2016