Harmonic Compensation Control Srategy for Multilevel Active Power Filters Based on Silicon Carbide Devices

Harmonic pollution caused by nonlinear loads is seriously affecting the power quality and the safety of electricity consumption. In order to solve the problems of lower harmonic compensation accuracy, response speed and power density in existing active power filters (APF), firstly, a modular multilevel APF topology based on silicon carbide (SiC) metal oxide semiconductor field effect transistor (MOSFET) semiconductor devices was proposed. Secondly, an improved adaptive filtering detection algorithm based on adaptive noise cancellation (ANCT) and least mean square (LMS) was adopted, the weight of the step size was updated to achieve fast and accurate harmonic detection. Based on a double closed-loop structure, a current tracking controller was constructed. The current loop is improved by adopting the principles of proportional integral (PI) control and repetitive control, and a composite current tracking compensation method is designed, which improves the effect of current tracking compensation. Finally, a simulation model was built to validate the proposed strategy, and the experimental results proved the feasibility and effectiveness of the harmonic compensation control strategy.