中性点接地方式对电能计量的影响分析

Effecting Neutral Point Earthing on Analysis of Electric Energy Calcultion

在电能计量工作中,不同的中性点接地方式会直接影响电能表的计量结果。因此正确选择与电力系统运行方式相匹配的计量方式可以减少计量误差,从而实现线损归真。针对电力系统中的有效接地系统和不接地系统,本文分别采用了三相三线和三相四线两种计量方式,通过理论计算和技术分析对其计量的准确性和合理性进行了验证。最后结合220kV系统线损率异常的实际案例,论证分析了中性点接地方式对电能计量的影响,为实现正确选择电能计量方式和有效管理同期线损提供了理论依据。

In working of electric energy calculation,the different kinds of neutral-grounded methods can impact measure results of electric energy metering.If the measurement matched with operation of the power system is selected,the line loss computation can be consistent with the actual situation.For effectively grounded system and non-grounded system in the power system,the paper has adopted respectively two measure modes of three-phase three-wire and three-phase four-wire.And accuracy and rationality of measurement can be proved by theoretical calculation and technical analysis.Based on a practical case with normal line loss ratio of220kV,the paper has analyzed influence of neutral grounding mode.This study provides the theoretic basis for selecting electric energy measurements and effective management line loss by synchronization.