Patent ID: 8842453

Claim:
A control method of a converter system, wherein the converter system is coupled between a multi-phase generator and an electric grid, and the multi-phase generator has N three-phase windings, wherein N is a natural number greater than or equal to 2, and the three-phase windings are mutually separated, and correspondingly the converter system has N converters, wherein the converters are correspondingly coupled to the three-phase windings, and the N th converter is a primary converter, the i th converter is a secondary converter, where 1≦i<N, the control method comprising: a) sampling a current at an output end of each of the three-phase windings to obtain a real-time current of each of the converters; b) enabling the primary converter to obtain the real-time current of each of the secondary converters, to obtain a mean current by averaging the real-time current of each of the secondary converters and the real-time current of the primary converter, and to transfer the mean current to each of the secondary converters; c) enabling each of the secondary converters to obtain a differential-mode current corresponding thereto according to its mean current and real-time current; d) enabling each of the secondary converters to perform a circulation current control on its mean current and differential-mode current based on a d-q coordinate system for respectively generating a mean-current conditioning signal and a differential-mode current conditioning signal, thereby controlling each of the secondary converters; and e) enabling the primary converter to obtain a sum of the differential-mode current conditioning signals of the secondary converters and then negate the sum to obtain the differential-mode current conditioning signal of the primary converter; and controlling the primary converter according to the differential-mode current conditioning signal of the primary converter and the mean-current conditioning signal.