Dynamic equivalent of inverter-based distributed generations for large voltage disturbances

Abstract

As the differences among inverter-based distributed generators (DGs) in the active distribution network (ADN), the aggregated dynamic model under large disturbances cannot effectively represent transient characteristics of the ADN. To overcome this issue, in this paper, a generic dynamic equivalent model of DGs is proposed. First, a simulation platform for multiple DGs is built based on electromagnetic transient simulation tool. The simulation results show that the aggregated transient characteristics under large disturbances are mainly determined by the fault ride-through control strategy of each inverter. Based on this, a control strategy is proposed to characterize the differences between inverters, and the equivalent model is derived. To achieve engineering applications, the equivalent structure is simplified, and multiple disturbance curves are used to identify the parameters. The validity and generalization ability of the proposed model is verified by simulation analysis under different disturbance strengths.