Induction generator (induction motor as generator IMAG)
Pros
- cheaper than synchronous generator
- readily available
- can easily be coupled to the grid
Cons
- needs a capacitor bank. Once you reach power ranges of 30kW or more, the costs of the capacitor bank can diminish the advantage of the cheap price
- needs a good load controller (IGC induction generator controller) in order to keep voltage stable.
- Frequency can not be controlled and is determined by the winding and rotor design of the motor. Frequency will always be a bit higher than nominal frequency, when used in generator mode.
Synchronous Generator
Pros
- Frequency and Voltage are controlled separately -> more precise regulation. Voltage: controlled by AVR. Frequency: controlled by ELC
- no capacitor bank needed
Cons
- more expensive, because mostly built to order
- additional synchronizing equipment needed, if connected to grid