High performance controller for voltage-controlled current source inverter with nonlinear loads

This paper presents an advanced voltage control method for voltage-controlled current source inverter(VC-CSI) with nonlinear loads. The proposed technique adopts the proportional sinusoidal signal integrator (PSSI) controller to achieve a rather good voltage tracking ability under nonlinear load conditions, which can be implemented directly in the stationary alphabeta frame with no need of the rotating coordinate transformation. This method can selectively eliminate the harmonics of the output voltage and does not require accurate circuit parameters, which can improve the control system´s flexibility and robustness. Both the control principle of the proposed technique for the whole system and the influence of the PSSI controller´s parameters on the control performance have been discussed in detail. Finally, all these analyses and the effectiveness of the proposed control method are firstly validated by simulation, and then are verified further in a 5 kVA laboratory prototype.