Squirrel Cage Induction Generator (SCIG) Connected In Power Plant
- This generator is simple in construction and coupled to the turbine through gear box. It is a constant speed generator.
- Power control : Aerodynamically by pitch yaw and small active control.
- To compensate reactive power, capacitor bank is connected to cross-lines. This increases active power and also improves power factor.
- In this case the stator of squirrel cage induction generator is to ‘Grid’ by back-to-back power electronics converter bridge.
- Output voltage from generator is stepped-up by 3-ph step-up transformer to suit the connection to grid system.
Advantages and Drawbacks of Squirrel Cage Induction Generator (SCIG) used in Wind Power Plant
Advantages of Squirrel Cage Induction Generator (SCIG) used in Wind Power Plant :
- Better wind energy utilization.
- Reduces reactive power demand on self-excited capacitor bank.
- Very simple in construction, robust size, rugged construction.
- Cheaper in cost.
- Rectifier can generate excitation current for generator.
- Fast transient response.
- Few parts, so reliable operation.
- No frequency conversion, so no problem of current harmonics.
Disadvantages of Squirrel Cage Induction Generator (SCIG) used in Wind Power Plant :
- Noisy operation.
- Power converter is costly.
- It has very low efficiency.
- Additional components such as reactive power compensator is required in the circuit.
- For smooth grid connection, a soft starter is required.
- Gear box maintenance is frequent, so cost increases.