APF series active filter is a three-level, high-power cryptographic power electronic product independently developed by Guangdong Huizhihua Electric Co., Ltd., with completely independent intellectual property rights, which has been used to suppress power harmonics and dynamic reactive power compensation. The product technology has reached the domestic leading level, and the product series includes 30A, 50A, 75A, 100A, 150A, 200A, specifications. With harmonic compensation, reactive power compensation, three-phase imbalance compensation functions, it can be flexibly configured into a single, mixed mode compensation mode, and can be widely used in 0.4KV power supply system power quality improvement.