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
H02P25/00—Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details
H02P25/02—Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details characterised by the kind of motor
H02P25/022—Synchronous motors
H02P25/024—Synchronous motors controlled by supply frequency