DC-side small-signal model of a PWM converter with a DC voltage controller

Compared to AC distribution network, DC distribution network has a significant technical and economic advantages in the new energy grid connect, power supply to the load driven by converters and transmission loss. DC distribution network usually connects with AC grid by PWM inverter, thus establishing the DC side model of the PWM converter station is very important. In this paper, the fixed DC voltage control model of the converters is presented and the active balance equation is linearized, then the DC side Small-signal model is built. Furthermore, the DC-side input impedance of the converter can be constructed by a resistor in parallel with an inductor. The circuit model is useful not only for analyzing the DC micro-grid´s stability, dynamic and static characteristics but also for analyzing and designing the parameters of the DC circuit in new energy generation systems. Finally, the PSCAD simulation results show the effectiveness of the proposed equivalent circuit model.