Indirect Excitation Systems (brushless) UNITROL® series
The Excitation Converter - Automatic Voltage Regulator (AVR) - send DC current to the exciter (attachted to the main generator). The exciter will rectify the current through rotating diodes on the main machine shaft.
- Indirect excitation current range: 1 - 400 A
- Exciter respnse limited by the exciter machine
- Field discharge with natural time constant
- Size of exciter machine increases with the speed
- No slip rings (less maintenance and dust)