间谐波存在时的电能计量方法研究

为了减少间谐波存在时带来的电能计量误差,提出了一种含间谐波的电能计量方法。首先分析现有谐波电能计量中的不合理性,给出含间谐波的功率计算式,然后提出了一种基于Pisarenko的改进算法。传统Pisarenko算法能够准确提取频率和幅值分量,却不能提取相位信息,该算法克服了传统算法不能提取相位信息的缺点。仿真结果也表明,该算法能够准确提取电气信号各频率分量参数,特别是相位信息,能滤除虚假频率分量,具有很强的抗干扰能力。功率计算采用考虑潮流方向的Budeanu功率定义。最后运用所提的计量方法对用户和电力企业的影响进行了分析,分析结果表明新的计量方法适用于间谐波存在时的电能计量。

Study of electric energy metering method while inter-harmonic exists

In order to reduce the error of energy metering, an electric energy metering method is proposed while inter-harmonic exists. First, some deficiency of current electric energy metering method is analysed, then power formula is presented, and an improved algorithm based on Pisarenko is proposed. Frequency and amplitude components can be extracted by traditional Pisarenko algorithm accurately, but phase information can not be extracted. This paper presents an improved algorithm based on Pisarenko. The simulation results show that Pisarenko algorithm can identify parameters for each frequency component of the electrical signal accurately, especially phase information, filter out false frequency component and have a strong anti-jamming capability. Budeanu power definition that considered the direction of flow is used in power calculation. Finally, the influence to customers and power enterprises is analyzed by use of the measurement method based on this paper. The result shows that the new measurement method is suitable for energy metering while inter-harmonic exists.