Stability Analysis and Current-loop Reshaping for Voltage-Source Converters with Power Control

The power control structure is essential when the inverter works in application scenarios such as energy storage. However, the configuration of power control profoundly influences the behavior of the inverter. Therefore, this paper derives an impedance model of inverter with power control. Based on the impedance model, the influence of power control on the stability margin of the system is explored. Furthermore, this paper introduces the current-loop impedance reshaping (CIR) strategy, aimed at enhancing the system's stability margin under weak grid conditions. Finally, experimental results substantiate the efficacy and validity of the CIR strategy.