Decoupling current control for voltage source converter in synchronous roating frame

There may be serious current interactions between d and q-axis in synchronous rotating frame for the three-phase voltage source converter. For the first time, the "relative gain" concept is introduced to analyze the coupling and decoupling quantitatively in this paper. Three different decoupling control methods including cross coupling decoupling, series decoupling and state feedback decoupling algorithms are compared in detail based on the "relative gain" concept. The theoretic results are confirmed by simulating Bode diagram and experiment waveform.