摘要
针对目前非正弦不平衡条件下电能计量时不同谐波功率会正负抵消的现象,提出一种基于瞬时无功功率来计量相功率的电能计量方法。该方法通过改变广义瞬时无功功率计量中p-q坐标系的旋转方向和速度,得到三相三线制系统中电压、电流的任一谐波的正负序分量,进而求得正负序功率。最后将正负序功率转换成相功率,从而得到非正弦不平衡条件下的系统功率。文中方法不仅可以获得不同次谐波的功率,实现功率的正反向计量,避免不同次谐波功率抵消的现象,而且计算量小,计算精度高。最后通过Matlab仿真验证了文中方法的准确性。
In this paper,a method of electric energy measurement method based on instantaneous reactive power theory is put forward according to the deficiency that power under different frequency will be offset at the same time under the non sinusoidal and unbalanced condition.By changing the rotation direction and velocity of the coordinate system in the generalized three-phase instantaneous reactive power theory,we can obtain the positive and negative sequence voltage and current of any harmonic in the three-phase three-line system.Then,the positive and negative sequence power can be converted to phase power,thus the system power under non-sinusoidal and unbalanced condition is obtained.This method can calculate the power of different harmonics,avoiding the unreasonable phenomena of power under different frequency offset,and the calculation amount of this method is small and the calculation accuracy is high.Finally,the accuracy of this method is validated by Matlab simulation.
作者
李贺龙
郑智斌
刘建志
赵进全
Li Helong;Zheng Zhibin;Liu Jianzhi;Zhao Jinquan(Electric Power Research Institute,Beijing 100192,China;School of Electrical Engineering,Xi’an Jiaotong University,Xi’an 710049,China)
出处
《电测与仪表》
北大核心
2018年第17期43-47,共5页
Electrical Measurement & Instrumentation
关键词
电能计量
非正弦不平衡
三相三线制
瞬时无功功率
electric energy measurement
non-sinusoidal and asymmetry
three-phase three-line system
instantaneous reactive power
