含单相配电支路的配电网单相接地故障行波测距技术

当前中国部分中压配电网采用单相配电的方式以提高电网运行经济性。但是含单相配电支路的配电网在发生单相接地故障后,行波传输过程相对复杂,影响了行波故障测距的准确性。文中深入研究了含单相配电支路的配电网发生单相接地故障后的行波传输机理,具体包括相模变换、不同模量的传输速度,以及单相配电支路分界处的传输特性。在此基础上,提出了根据线模、零模分量传输时间差判定故障位于单相配电支路或三相配电支路,以及准确的故障测距方法。EMTP/ATP仿真验证了所提出方法的可靠性和准确性。

Technology of Traveling Wave Fault Location on Single Phase-to-ground Fault in Distribution Network with Single-phase Power Supply Lines

Nowadays partial medium voltage distribution networks adopt single-phase power supply lines in order to improve the economics of grid operation. However, the propagation process of traveling wave is complicated if the single-phase-to-ground fault occurs, which affects the accuracy of the fault location. This paper proposes a novel method which considers the propagation mechanism of traveling wave produced by single-phase-to-ground fault, including phase-mode transformation, the transfer velocity of different mode, and the propagation characteristic at boundary. Whether the fault position is at the single-phase power supply line or at the three-phase power supply line can be identified and the fault distance can be calculated based on the time difference of the arrival surge between the aerial mode and zero mode components. EMTP/ATP simulation verifies the reliability and accuracy of the method.