低压直流微网短路故障特性分析及检测

Analysis and Detection of Short Circuit Fault Characteristics in Low Voltage DC Microgrid

针对直流微网系统要求可靠性高、线路阻抗小、短路故障检测速度快,构建基于太阳能、储能单元和负载的环形直流微网结构,通过分析短路故障的特性,提出基于短路电流变化率的故障检测方法。在MATLAB/Simulink中搭建母线电压为400 V的直流微网模型进行仿真,仿真结果表明所提方法可以在2 ms内实现对母线和单元短路故障的检测,确保整个系统可靠工作。

To meet the requirements of high reliability of DC microgrid system,small line impedance and fast short-circuit fault detection,a ring DC microgrid structure based on solar energy,energy storage unit,and load is constructed.The fault detection method based on the short-circuit current change rate is proposed by analyzing the characteristics of short-circuit faults.A DC microgrid model with a bus voltage of 400 V is built and simulated in MATLAB/Simulink.The simulation results show that the proposed method can achieve the detection of bus and cell short-circuit faults in less than 2 ms,ensuring the reliable operation of the whole system.