Parameter design for voltage-source power conversion system with SVPWM control strategy

A new method to determine the ac-side inductor and dc-link capacitor for voltage-source power conversion system (PCS) under different modulation modes is proposed in this paper. The parameter values of these components are very important to the PCS: the inductor on ac-side suppresses the current harmonics and contributes to the functionality of voltage source converter (VSC); the dc-link capacitor sustains dc voltage and decreases the voltage fluctuation, especially for renewable energy sources. However, traditional ways of parameter design are not accurate and sometimes even far above the ideal value. To calculate more accurately, the method in this paper analyzes fluctuation of current and voltage under every switching status, and in this way the deduced lower limit of parameter values are more closed to the real minimum. Also the analysis reveals the cause and regulation of fluctuation of ac side current and dc-link voltage. Simulation results show that the method is feasible for both SPWM and SVPWM, and the method can also be used as theoretical basis for parameter design of PCS.