SYSTEM FOR CONTROLLING AC EXCITING SYNCHRONOUS MACHINE

摘要

A control system for an AC exciting synchronous machine for use in an electricity generator/motor system. The AC exciting synchronous machine can be driven not only in a variable-speed operation based on 2-axis current control but also in a constant exciting frequency operation based on only direct-axis current component control. A phase signal is switched to drive stably the AC exciting synchronous machine in a self-excited operation or in a rotary phase modifying operation. Further, when it is desired to start pumping-up water, a synchronizing power is provided to keep constant the rotational speed of the machine at the time of establishing a desired water pressure. Because of such switching arrangement of the phase signal, the AC exciting synchronous machine can be operated as an ordinary synchronous machine exhibiting ordinary synchronous characteristics, that is, self-excited operation characteristics, rotary phase modifying operation characteristics and pumping-up start characteristics. Even when the synchronous machine is cut off from an AC power system and the voltage of the synchronous machine is abruptly changed, the stable self-excited operation of the machine can be realized.