H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
H02P9/00—Arrangements for controlling electric generators for the purpose of obtaining a desired output
H02P9/14—Arrangements for controlling electric generators for the purpose of obtaining a desired output by variation of field
H02P9/16—Arrangements for controlling electric generators for the purpose of obtaining a desired output by variation of field due to variation of ohmic resistance in field circuit, using resistances switched in or out of circuit step by step
H02P9/18—Arrangements for controlling electric generators for the purpose of obtaining a desired output by variation of field due to variation of ohmic resistance in field circuit, using resistances switched in or out of circuit step by step the switching being caused by a servomotor, measuring instrument, or relay