电压波动与闪变对距离保护影响的研究

The Study of Effect of Voltage Fluctuation and Flicker on Distance Protection

电压波动与闪变引起电压幅值和电网频率发生变化。高压输电线路的距离保护中方向阻抗继电器无论幅值式还是相位式,都与电压幅值直接相关;极化电压受频率影响较大,严重时导致继电器拒动。依据电压波动与闪变影响电压幅值、频率的机理,以及影响距离保护正确动作的各因素,探究电压波动与闪变的影响;基于Matlab/Simulink搭建电压波动与闪变基础上的距离保护模型,就故障、电压波动与闪变、既有电压波动与闪变又有故障3种情况进行仿真,验证了电压波动与闪变对距离保护影响分析的合理性。

Voltage fluctuation and flicker can change voltage amplitude and frequency of the power grid. The directional impedance relay for distance protection of the high voltage transmission line, regardless if it is the amplitude or phase type, is directly related to the amplitude of the voltage. The determination of the polarization voltage is heavily affected by the frequency. When the voltage,especially the frequency of the voltage,fluctuate seriously,the relay will refuse to move. According to the character of voltage fluctuation and flicker and the factor that influences the correct action of distance protection, the influence of voltage fluctuation and flicker is explored.The distance protection model based on voltage fluctuation and flicker is built by Matlab/Simulink. The simulation is carried out for system with the following three situations： fault, voltage fluctuation and flicker and a combined situation of the two situations above. The conclusion obtained from analyzing the influence of the voltage fluctuation and flicker on the distance protection is verified through this simulation.