含逆变型分布式电源的电网故障电流特性与故障分析方法研究

Study on Fault Current Characteristics and Fault Analysis Method of Power Grid With Inverter Interfaced Distributed Generation

为满足并网规程的要求,提出一种逆变型分布式电源的低电压穿越运行控制策略。在此基础上,从逆变器控制器的动态响应特性出发,对逆变型分布式电源的故障电流特性进行研究。建立逆变型分布式电源在对称故障和不对称故障下短路电流的计算模型,并对含逆变型分布式电源的配电网故障分析理论和方法进行探讨和分析。数字仿真结果验证了理论分析结果的正确性。研究结果有助于提高逆变型分布式电源的故障穿越运行能力,并深化其故障特性分析,为分布式电源规模化接入后电网的继电保护原理研究和性能评估提供参考。

In order to meet the grid code of distributed generation, a control strategy for low voltage ride through （LVRT） of inverter interfaced distributed generation （IIDG） is proposed. Based on it, the dynamic responses of inverter controller and fault current characteristics of IIDG are studied under conditions of symmetric fault and asymmetric fault. Besides, the calculation model of the fault current of IIDG is established. Moreover, the fault analysis method for the distribution network with penetration of IIDGs is analyzed. Digital simulation results validate the correctness of the theoretical analysis results. The research results are helpful to improve the LVRT capability of IIDG and study the fault characteristics of the power grid with IIDGs. The research results can also provide reference for principle study and performance evaluation of the relaying protection which is applicable for the power gird with penetration of IIDGs.