Analysis of Transient Overvoltage Impacted by PV Grid-Connected Control with Series Compensation

Aiming at the structure of the photovoltaic(PV) inverter grid-connected by the line of the series reactive power compensation, the focus of the converter control is on the association between the parameters and the transient overvoltage. Considering the phase-locked loop (PLL) dynamic effect of the conversion relationship between control vector and the actual system variables, the dynamic model of the grid-connected system is established with the double dq rotating coordinate system, which involves the characteristics of the PV, the output filter, and the series reactive power compensation line, to analyze the impact of the PLL dynamics and the inner-loop control of the PV grid-connected converter on the voltage of the grid-connected point. Based on the trajectory sensitivity analytical model, the quantization indicator about the impact of control parameters on the transient overvoltage is proposed, which is used to evaluate the impact of different control parameters on the amplitude and the trend of the overvoltage, and screen the key parameter dominating the level of the transient overvoltage. The optimization suggestion is provided by this indicator to suppress transient overvoltage.