适应于逆变型风电接入系统的改进故障序分量选相方法

针对传统故障序分量选相元件在逆变型风电接入系统中可靠性较低的问题，提出了一种改进的故障序分量选相方法。首先，分析在最新风电场低电压穿越策略下，风电侧的故障序阻抗特性及传统故障序分量选相元件的适应性。然后，利用负正序、负零序阻抗相位差等效正负序、零负序电流分支系数相位差，以补偿传统序分量选相判据的相角误差。最后，采用补偿后的故障序电流相位差作为选相判据，实现了故障相的判别。同时通过调整零负序选相分区，使其具有较好的耐过渡电阻能力。仿真实验表明，在不同故障类型、故障位置和过渡电阻下改进选相方法均能可靠地选出故障相。

An improved fault sequence component phase selection method adapted toan inverter-interfaced wind farm access system

To address the low reliability of traditional fault sequence component phase selection in an inverter-interfaced wind power access system, an improved fault sequence component phase selection method is proposed. First, the fault sequence impedance characteristics of the wind power side and the adaptability of the traditional fault sequence component phase selection element are analyzed in the latest low voltage-through strategy of a wind farm. Then negative positive sequence and negative zero impedance phase difference are used to the equivalent positive and negative sequence current branch coefficient phase difference so that the phase angle error of the traditional sequence compensating phase selection criterion can be compensated. Finally, the compensated fault sequence current phase difference is used as the phase selection criterion, and the fault phase identification is realized. The method has better resistance to transition resistance by adjusting the zero negative sequence phase selection partition. The simulation results show that the improved method can reliably select the fault phase with various fault types, different fault locations and transition resistance.