基于暂态高频能量的直驱风场汇集线路保护

Protection of a direct-driven wind farm collection line based on transient high-frequency energy

针对直驱风场汇集线路故障难以识别的问题,提出了一种基于暂态高频能量的直驱风场汇集线路保护方法。首先,基于风机变流器控制系统与电气参数影响,结合元件在高频区段的暂态特性,建立由感性阻抗构成的风场汇集线路暂态高频模型。在此基础上,建立区内外故障下的暂态高频网络,根据不同故障场景与保护安装处暂态高频能量的匹配特性,构建基于暂态高频能量方向差异的保护判据。最后,在RT-LAB仿真平台验证了所提方法在各种故障情况下,均能正确识别区内外故障,故障识别不受同步误差影响,耐过渡电阻能力强。

It is difficult to identify a fault on a direct-driven wind farm collection line. Thus a protection of the line based on transient high-frequency energy is proposed. First, considering the converter control strategy, the electrical parameters and component transient characteristics in the high-frequency section, a wind farm collection line transient high-frequency model composed of inductive impedance is established. Then a transient high-frequency network of internal or external faults is established. According to the matching degree of different fault cases and transient high frequency energy at the protection installation site, a protection criterion is constructed using the difference of transient high-frequency energy direction. Finally, an RT-LAB simulation platform verifies that this method can correctly identify the internal or external faults under various fault conditions. The fault identification is not affected by synchronization error, and has strong resistance to transition resistance.