逆变型电源对故障分量方向元件的影响机理研究

Influence Mechanism of Inverter-Interfaced Renewable Energy Generators on Fault Component Based Directional Relay

新能源电源结构特征与控制方法均迥异于传统同步发电机,其故障特性发生了实质性变化,给传统继电保护带来挑战。为此研究了逆变型电源对故障分量方向元件的影响机理。在分析故障特性基础上,推导了逆变型电源等效正、负序突变量阻抗解析表达式,分析了不同控制策略、故障条件和负荷电流下等效序突变量阻抗角的变化规律,进而揭示了逆变型电源对各类故障分量方向元件的影响机理。RTDS仿真和录波数据验证了机理分析的正确性。

Due to difference in structures and controls, fault features of renewable energy generators are greatly different from that of synchronous generator, bringing challenges to traditional relays. Impact of inverter-interfaced renewable energy generators（IIREGs） on fault component based directional relays is discussed. Based on IIREG fault features, analytic expressions of its equivalent positive-and negative-sequence superimposed impedances were deduced. Angular characteristics of the two sequence superimposed impedances were analyzed considering different control strategies, fault conditions and load currents. Then influence mechanism of IIREGs on the fault component based directional relay was revealed. Results from RTDS simulations and field data validate correctness of the theoretical analysis.