特高压半波长输电线路潜供电弧低压模拟实验研究

潜供电弧是半波长输电技术面临的关键问题之一,因此针对特高压半波长输电线路潜供电弧进行了低压物理模拟实验研究。通过分析半波长线路潜供电流与恢复电压特性,进行回路等效变换,获得满足等价性的低压模拟实验回路拓扑,通过实验获得了不同潜供电流值、恢复电压梯度等组合方案下潜供电弧的燃弧时间,并与常规输电线路的情况进行对比。比较了短路电弧与潜供电弧的电流、电压特征,并通过高速摄像仪获得潜供电弧的运动轨迹,分析了风速等因素对短路电弧与潜供电弧运动的影响机制。研究表明:当潜供电流值<150A,恢复电压梯度<3.9kV/m时,潜供电弧将快速自灭;当潜供电流值>240A,恢复电压梯度>7.0kV/m时,潜供电弧将会长时间燃弧;风力是影响潜供电弧运动与燃弧的关键因素。研究结果可为解决半波长输电技术的潜供电弧问题提供参考依据,同时对常规线路潜供电弧以及长间隙电弧研究具有借鉴价值。

Experimental Research on Secondary Arcs of UHV Half-wavelength AC Transmission Lines

Secondary arcs and its reliable suppression is one of the key technical challenges of half-wavelength transmission lines(HWTL).We tested and physically simulated the HWTL secondary arcs to study its extinction characteristics,and proposed an equivalent test topology via Thevenin transform based on the established equivalent circuitry.Moreover,we experimentally investigated different secondary arc currents as well as voltage gradients to obtain the physical dynamics of the arcs,compared the frequency spectra of the short arcs and the secondary arcs through the Fourier transform,and captured the developing images of the arcs with a high-speed imaging system.Also,we investigated the impacts of wind on the arcing behaviors.The obtained results show that,the secondary arc will extinguish immediately when the secondary arc current is below 150 A and the recovery voltage gradient is less than 3.9 kV per meter.However,the arcing time will be more than one second when the secondary arc current and the recovery voltage gradient are more than 240 A and 7.0 kV per meter respectively.It is also shown that wind is the critical factor influencing the secondary arc motion and the arcing time.