谐波对无功电能表计量特性的影响

目前谐波对无功电能表计量特性影响的研究还不完善.文章从理论上分析了各种常用无功电能表的移相误差,然后对感应式和电子式无功电能表做了频率响应和谐波无功功率试验,并对试验数据采用最小二乘法进行分析.理论和试验分析结果表明,谐波环境下无功电能表的计量误差可分为幅值误差和相位误差两类:谐波环境下感应式和电子式无功电能表均产生很大的相位误差,使最大计量误差可能达到2倍的谐波视在功率;随着谐波次数的升高,感应式和电子式无功电能表计量的谐波无功幅值减小,感应式电能表计量的幅值减小得更快.

INFLUENCE OF HARMONICS ON REGESTRATION OF VARHOUR METER

At present the research of the influence of harmonics on registration of varhour meter is still imperfect. The authors analyzed the phase-shifting errors of common used varhour meters, then the experiments of frequency response and reactive power of harmonics are carried out, and the results of experiments are analyzed by least square method. The results from theoretical and experimental analysis show that in harmonic environment the metering errors of varhour meter can be divided into amplitude error and phase error. Meanwhile there are evident phase errors in both induction varhour meter and solid-state varhour meter, so the maximum metering error may be twice as much the apparent power of harmonics. With the increment of harmonic order, the amplitudes of reactive harmonic power metered by induction varhour meter and solid state varhour meter are decreased and the metered amplitude by induction varhour meter decreases more rapidly.