Power factor regulation for rotating frequency changer - allowing reactive current variation during overload peaks for optimum use of commutating machine

摘要

The regulator is intended for use with a motor-generator set, normally an asynchronous machine driving a single phase synchronous machine, for example for supplying a railway tractions system as 16 2/3 Hz. Attached to the motor is a power factor correction machine coupled to the motor rotor. At normal loads the motor is held at a fixed power factor, typically unity. When a sudden overload occurs the fixed power factor condition can lead to the demand for very high voltages from the compensating machine. A voltage limit of the regulator is prevented from being exceeded by reducing the phase compensation of the asynchronous machine. This is achieved by influencing the set value of the regulator working in this direction by measured values. Thus, compensating machines with less iron can be employed.