基于隶属云和动态时间规整的电能计量误差估计方法

Error estimation method of electric energy metering based on membership cloud and dynamic time warping

电能计量系统误差估计是针对由电能表、电流互感器(Current Transformer,CT)、电压互感器(Voltage Transformer,VT)和二次回路组成的电能计量装置潜在危害的有效手段。电能表和二次回路的计量误差可以在线监测,但CT和VT的计量误差不能直接测量,且随温度、泄漏电流等因素的变化而变化。文中提出了一种利用隶属云(Membership Cloud,MC)和动态时间规整(Dynamic Time Warping,DTW)连续估计CT和VT变比和相位误差的方法。该方法构造了一个新的混合半梯形MC生成器(MC Generator,MCG),以解决在不同影响因素下误差偏差的随机性和模糊性问题。利用改进的DTW算法(Modified DTW,MDTW),可以根据误差时间序列与量化影响因素之间的相似性,估计CT和VT误差。将电能表和二次回路的测量误差与估计的电流互感器和电压互感器误差相结合,便可得到电能计量系统的综合误差。通过110 kV变电站电能计量装置的现场测试数据,验证了所提方法的有效性。

The error estimation of electric energy metering system is an effective way to find out the potential harm of electric energy metering device which is composed of electricity meter,current transformer(CT),voltage transformer(VT) and secondary circuit.The measurement error of the electricity meter and the secondary circuit can be monitored on-line,but the measurement error of CT and VT cannot be measured directly,and changes with the change of temperature,leakage current and other factors.In this paper,a method of continuous estimation of CT and VT ratio and phase error by using membership cloud(MC) and dynamic time warping(DTW) is proposed.This method constructs a new mixed semi-trapezoid MC generator(MCG) to solve the problem of randomness and fuzziness of different influence factors of error deviation.The modified DTW(MDTW) algorithm can be used to estimate CT and VT errors according to the similarity between the error time series and the quantitative influencing factors.By combining the measurement error of electricity meter and secondary circuit with the estimated error of current transformer and voltage transformer,the comprehensive error of electric energy metering system can be obtained.The effectiveness of the proposed method is verified by the field test data of 110 kV substation power metering device.