背景谐波电压环境下的负载谐波电流检测方法

针对现有谐波电流检测方法未考虑公共连接点处谐波电流的耦合现象而导致谐波治理效果不理想的问题，提出了一种有效解决该问题的负载谐波电流检测方法。在分析现有检测方法不足的基础上，借鉴德国DIN40110-2标准分解电流的思想，以谐波电压为基准，依据等效前后负载消耗有功功率不变的原则，定义了谐波等效电导、集总谐波电压和集总谐波有功功率。利用希尔伯特变换对谐波电压进行移相。进而定义了集总谐波无功功率和谐波等效电纳，分解出由背景谐波电压产生的谐波电流。据此，可检测出负载谐波电流，实现背景谐波电压环境下对负载谐波电流的补偿。仿真分析及实测数据验证结果表明：采用所提方法对检测到的谐波电流进行补偿，可有效提高公共连接点的谐波治理效果。

A load harmonic current detection method in a background harmonic voltage environment

There is a problem in that the existing harmonic current detection method does not consider the coupling phenomenon of the harmonic current at the common connection point. This leads to the unsatisfactory harmonic control effect. Thus this paper proposes a load harmonic current detection method to effectively solve the problem. Having analyzed the shortcomings of existing detection methods, this paper draws on the idea of decomposing current in the German DIN40110-2 standard, takes the harmonic voltage as the benchmark, and according to the principle that the active power consumption of the load before and after the equivalent is unchanged, the harmonic equivalent conductance, the lumped harmonic voltage and the lumped harmonic active power are defined. The Hilbert transform is used to shift the phase of the harmonic voltage. Then the lumped harmonic reactive power and harmonic equivalent susceptance are defined, and the harmonic current generated by the background harmonic voltage is decomposed. Accordingly, the load harmonic current can be detected, and compensation of the load harmonic current in the background harmonic voltage environment can be realized. Simulation analysis and measured data verification results show that the proposed method can effectively improve the harmonic control effect of the public connection point by compensating the detected harmonic current. This work is supported by the National Natural Science Foundation of China (No. 51777166).