An Adaptive Virtual Impedance Control Strategy Based on Power Synchronization Control

The traditional virtual impedance control mode is relatively complex, and the traditional virtual impedance setting strategy can easily cause the fault current of the inverter to be excessively limited in the case of a mild fault, affecting power transmission capability. This paper first proposes an open-loop voltage control strategy for grid-forming inverters based on power synchronous control. Furthermore, based on the proposed control strategy, this paper presents an adaptive virtual impedance setting strategy coupled with fault voltage, achieving that the fault current under different fault depths is limited to a specified value without the risk of excessive limitation. Finally, experimental results validate the correctness and effectiveness of the theory.