抽水蓄能电站电网内中性点接地方法研究

Research on Neutral Point Grounding Method in Pumped Storage Power Plant Grid

为进一步优化抽水蓄能电站高压系统的接线方式、保障其稳定运行,以典型抽水蓄能电站为主要研究对象,调查了该电站的基本线路情况,并进行了相关工艺比选分析。对厂用高压系统单相接地电容电流的大小进行了计算,对不接地、消弧线圈接地和低电阻接地方式进行了充分讨论,提出了适合抽水蓄能电站的接地方式,明确了接地电流的取值方法和中性点引出方式。通过试验研究以及理论分析发现,该抽水蓄能电站适宜采用低电阻接地方法,使用高压变压器采用Δ-Y接线,厂高变低压(10 kV)侧中性点经低电阻接地。这种接地方案不良影响较小、应用创新效果较好,可为后续相关研究提供参考,对抽水蓄能电站的电网系统设计发挥重要作用。

To further optimize the wiring mode of the high-voltage system of pumped storage power plant and to guarantee the stable operation,a typical pumped storage power plant is taken as the main research object,the basic wiring situation of the power plant is investigated,and the relevant process comparison analysis is carried out.The magnitude of the single-phase grounding capacitance current of the plant high-voltage system is calculated,and the ungrounded,arc extinguishing coil grounding and lowresistance grounding methods are fully discussed to propose a grounding method suitable for pumped storage power plants,and the grounding current taking method and neutral point leading method are clarified.Through experimental research and theoretical analysis,it is found that this pumped storage power plant is suitable for low-resistance grounding method,usingΔ-Y wiring for high-voltage transformer and low-resistance grounding for the neutral point of the low-voltage(10 kV)side of the plant highvoltage transformer.This grounding scheme has less adverse effects and better application innovation,can provide reference for subsequent related studies and play an important role in the design of grid systems for pumped storage power plants.