Design of three-level APF experiment monitor platform based on ethernet interface software

Given numerous nonlinear loads in modern power systems, quantities of current harmonics will seriously pollute the power environment. The three-level active power filter (APF) is an effective method to compensate for harmonics. This paper designs the current loop of three-level APF and investigates the phase-locked loop based on the second-order generalized integrator (SOGI) to improve the harmonic compensation performance. In order to observe the load currents, grid voltages, and currents of the APF system, a three-level APF experiment monitor platform based on ethernet interface software is designed. The ethernet communication board is designed based on the W5300 chip, and the ethernet interface software of the APF system is compiled by Visual Studio. The experimental results show that current harmonics can be effectively compensated by the three-level APF, and the designed ethernet interface software can observe voltage, current, and internal-variable waveforms, which is convenient for experimental debugging and monitoring.