Stability analysis of DC microgrid considering the action characteristics of relay protection

Abstract

The stability of microgrid is the key issue of microgrid operation control. This paper focuses on the transient stability after the correct operation of relay protection. In this paper, 400V DC microgrid with photovoltaic and energy storage system is taken as the research object. Research on the fault characteristics of voltage and current after the system is subjected to short-circuit, it is proposed to introduce current differential protection. With bus voltage as the only indicator, whether the transient stability is improved after the protection system operates correctly. The DC microgrid is modeled and simulated based on MATLAB/Simulink to confirm the validity of the proposed statement. The simulation results show that the fault can be correctly located, accurately isolated and timely removed by the protection system after the short-circuit fault occurs, bus voltage is restored to maintain stable operation of the system.