35千伏及以上电压监测中存在的问题及对策

Problems and Countermeasures in Voltage Monitoring at 35 kV and above

摘要: 电压管理是供电企业的一项重要基础，通常以电压合格率指标进行表征。国家相关标准中统计电压合格范围时，对于20 kV及以下电压等级采用了固定限值，对于35 kV及以上电压等级采用了浮动限值两种评价标准。在实际电压监测工作中，对固定限值的电压监测方法，采用了准实时计算法。对浮动限值的电压监测也沿用了这种方法，但由于电压门限的设置受人为因素的影响较大，导致电压合格率统计失真，不能真实反映电网电压的合格状况。为此，通过对35 kV及以上电网电压的波动分析，提出了日零点结算法，并通过案例论证了该方法能更好地统计与分析35 kV及以上电压等级的电压合格率，满足电压管理的客观要求。

Abstract: The voltage management is an important foundation of power supply; it usually uses the voltage qualification rate to characterize. There are two kinds of evaluation standards in the relevant national standard. The fixed limits are applied for voltage levels below 20 kV, but a floating limit is adopted for voltage levels above 35 kV. In the actual voltage monitoring, the method of quasirealtime calculation is adopted for the voltage monitoring points with fixed limits. And this method is also used for the voltage monitoring points with floating limits. Due to the uncertainty of voltage limits and the influence of human factors, the statistics of voltage qualification rate can not reflect the state of the grid voltage properly. Therefore, the method of day zero settlement is put forward by analyzing the fluctuation of voltage levels above 35 kV. The case proves that this method can better calculate and analyze the voltage qualification rate of voltage levels above 35 kV, and meet the objective requirements of voltage management.