Dynamic Response of a Wind Farm Consisting of Doubly-Fed Induction Generators to Network Disturbance - Simulation and Modeling Methodologies, Technologies and Application - page 138

The response of the wind farm to a 3 phase fault of 200ms duration was
investigated. The fault was created at 1s at the middle of 100km, 400kV line. The
results of the response of the DFIG speed, the electrical torque, voltage at the point of
common connection (PCC) and the pitch controller are presented in Fig 15. The speed
of the generator is limited by the pitch angle. The first swing of the DFIG speed
reached a value of 1.26pu from the prefault value of 1.21pu. The fault causes a dip in
voltage at the PCC, the pitch controller acts to stabilize the speed of the generator.

1.24

-0.6

-0.7

1.22

-0.8

1.2

-0.9

1.18 -1

0 1 2 3 4 5

0 1 2 3 4 5

(a) Time (s)

( b ) Time (s)

1 0.658

0.656

0.9

0.654

0.8

0.652

0.7

0.65

0.648

0 1 2 3 4 5

0 1 2 3 4 5

(d) Time (s)

(c) Time (s)

With rotor side controller Without rotor side contoller

Fig. 13. The response of (a) DFIG speed (b) Active power, (c) Electrical torque (d) Terminal
voltage to 20% step change in local load at 1s

0.72

-0.39

0.70 -0.40

0.68

-0.41

-0.42

0.66

-0.43

0.64

-0.44

0.62

0 1 2 3 4 5

0 1 2 3 4 5

( b) Time ( s )

( a ) Time (s )

6

1.0

0.5

4

0.0

2

-0.5

0

-1.0

0 1 2 3 4 5

0 1 2 3 4 5

(d) Time (s)

Fig. 14. The response of (a) Rotor d-axis current (b) Rotor q-axis current (c) Crowbar
protection (d) Pitch controller when a step change of 20% is initiated in the local load at 1s

(c) Time (s)