有源电力滤波器两种电流检测方式研究

Comparison between source current and load current detection type for active power filters

按照电流检测方式划分,有源电力滤波器可以分为网侧电流检测和负载侧电流检测两种方式。本文旨在从补偿效果以及系统稳定性两个方面对这两种电流检测方式进行比较。理论分析表明:在理想状况下,两种电流检测方式互为等效。但当考虑到电流传感器的非理想特性、检测误差和控制误差等因素时,网侧电流检测方式相较于负载侧电流检测方式补偿精度高,但是属于直接控制的网侧电流检测方式对负载扰动敏感,存在系统稳定性问题。仿真和实验结果证明上述结论的正确性。

With large amounts of power electronic equipments connected to the grid, huge harmonics are injected to the power system, deteriorating the power quality and threating power grid security. In this case, the study of Ac-tive Power Filter （APF） is essential and necessary for harmonic elimination and power quality improvement. Active power filters can be classified into two types. One is toad current detection type and another one is source current detection type. In this paper, works focused on the comparison between these two different current detection types from filtering performance and system stability aspects are presented. Analysis results show that in ideal conditions, by taking current control loop into consideration, one of these two current detection types can be transferred into the other. However, in non-ideal conditions, source current detection is superior to the load current detection for im-proved compensation precision. However, source current detection type is sensitive to the load disturbance and has system stability problem. Conclusions are verified by simulation and experiment results.