近年来，各类电力电子型设备的广泛使用，在增大用户侧谐波电流的同时也导致配电网供电侧出现系统谐波电压，影响着配电网高效稳定运行，背景谐波电压环境下配电网的谐波治理已经成为目前电能质量领域研究的热点之一。谐波电流准确检测是谐波污染治理的前提，也是谐波分析的关键环节，因此研究适用于背景谐波电压环境下的谐波电流检测方法具有重要的意义。
背景谐波电压环境下公共电气连接点处的谐波电流由背景谐波电压和非线性负载共同作用而形成，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的问题，从配电网公共电气连接点处的谐波电流特性出发，深入分析背景谐波电压与负载谐波电流的耦合机理以及对现有谐波电流检测方法的影响。提出基于 DIN40110-2标准的背景谐波有功电流检测方法，以背景谐波电压为基准，依据等效前后负载消耗有功功率不变的原则，通过定义谐波等效电导检测出反映背景谐波电压畸变程度的谐波有功电流，实现对公共电气连接点处谐波电流解耦。
为了检测出公共电气连接处反映背景谐波电压畸变的谐波无功电流，利用希尔伯特变换能对电压各频率分量进行准确 90度移相的特点，提出基于希尔伯特变换的背景谐波无功电流检测方法，对背景谐波电压进行移相，通过定义集总谐波无功功率和谐波等效电纳，实现背景谐波无功电流的检测，提取反映背景谐波电压畸变程度的谐波无功电流。
针对现有谐波电流检测方法存在谐波治理效果不理想、不符合谐波治理原则的问题，在以上背景谐波有功电流和背景谐波无功电流的基础上，提出改进的负载谐波电流检测方法，实现从公共电气连接点的测试电流中分离出仅代表用户负载发射的谐波电流的目的。改进的负载谐波电流检测方法分解出的负载谐波电流不受背景谐波电压影响，可降低有源滤波器的补偿电流和补偿容量，提高了并联型有源滤波器对配电网谐波治理效果。
建立配电网的仿真模型，通过对背景谐波电压环境下本文方法和传统 ip-iq方法进行对比，验证了所提检测方法的正确性。以企业谐波电流实测数据为例，进一步验证所提检测方法在背景谐波电压环境下的有效性。

In recent years, the widespread use of various types of power electronic equipment increases the harmonic current on the user side, but also leads to the occurrence of system harmonic voltage on the power supply side of the distribution network, which affects the efficient and stable operation of the distribution network. In the background harmonic voltage environment, harmonic control of lower distribution network has become one of the hotspots in the field of power quality research. Accurate detection of harmonic current is the premise of harmonic pollution control and the key link of harmonic analysis. Therefore, it is of great significance to study the harmonic current detection method suitable for the background harmonic voltage environment.
   In the background harmonic voltage environment, the harmonic current at the common electrical connection point is formed by the coupling of the background harmonic voltage and the harmonic current generated by the nonlinear load. The existing harmonic current detection method does not consider the harmonic current at the common connection point. In order to solve the problem of current coupling phenomenon, the paper starts from the characteristics of harmonic current at the public electrical connection point of the distribution network, and deeply analyzes the coupling mechanism of the background harmonic voltage and the load harmonic current and the influence on the existing harmonic current detection methods. A background harmonic active current detection method based on the DIN40110-2 standard is proposed. Taking the background harmonic voltage as the benchmark, according to the principle that the active power consumption of the load before and after the equivalent is unchanged, reflects background harmonic voltage distortion degree of harmonic active current is detected by defining the harmonic equivalent conductance, realizes decoupling of harmonic current at the common electrical connection point. 
Aiming at the problem that the harmonic reactive current generated by reflecting the background harmonic voltage at the common electrical connection is not detected, this paper uses the Hilbert transform to perform accurate 90-degree phase shift for each frequency component of the voltage. A background harmonic reactive current detection method based on Hilbert transform is proposed, this method realizes the phase shift of the background harmonic voltage, realizes the detection of the background harmonic reactive current by defining the lumped harmonic reactive power and harmonic equivalent susceptance, and extract the harmonic reactive current that reflects the distortion degree of the background harmonic voltage.
Aiming at the problems of unsatisfactory harmonic control effect and non-compliance with harmonic control principles in existing harmonic current detection methods, on the basis of the above background harmonic active current and background harmonic reactive current, an improved load harmonic current is proposed. The detection method realizes the purpose of separating the harmonic current only representing the emission of the user load from the test current of the common electrical connection point. The load harmonic current decomposed by the improved load harmonic current detection method is not affected by the background harmonic voltage, which can reduce the compensation current and compensation capacity of the active filter, and improve the parallel type active filter to the distribution network harmonics governance effect.
The simulation model of the distribution network is established, and the correctness of the proposed detection method is verified by comparing the method in this paper with the traditional method in the background harmonic voltage environment. Taking the measured data of enterprise harmonic current as an example, the validity of the proposed detection method in the background harmonic voltage environment is further verified.