Research on Double-Closed-Loop Control for the Frequency Converters in Parallel Operation

In order to achieve the two drive synchronous operation , it's necessary to add an inner current loop on the basis of the outer voltage regulator which improve the system s dynamic response speed in the premise of ensure the stability of the system. The frequency converter parallel technology controlled by voltage and current double closed loop is researched. Design the controllers parameters of the current inner ring and voltage outer ring and these parameters are demonstrated according to the classical control theory. At last we conduct the simulation whose results show that the parallel converter system which controlled by the voltage and current double closed loop has good static and dynamic performance.