How does an induction generator work?
Whenever an induction motor is run higher than its synchronous speed by the help of a prime mover it starts generating power instead of absorbing power. All induction machines always operate at a lagging power factor (i.e. the current vector lags the voltage vector and the cosine of the angle of the lag is defined as the power factor). The power factor depends on the slip, which is a function of the loading of the motor. The lag angle will be 90 deg. when the machine runs at zero slip, that is at synchronous speed and this is known as quadrature. At quadrature, it will neither absorb nor generate power. If with the help of a prime mover such as the angle increases beyond 90 degrees and the power factor is negative, which means the machine is generating power. The power factor is adjusted by adding the required KVAR capacitor bank. Since the excitation of the IG is from the grid, it does not require any governing. Grid acts as the governor. Also it does not call for synchronizing as it
