Single-Phase Standalone Inverter Using Closed-Loop PI Control for Electromagnetic Suspension

Abstract

This paper discusses the operation of a single-phase standalone inverter in renewable energy applications, specifically for active magnetic bearings (AMB), electromagnetic suspension (EMS), and high-speed transportation utilizing magnetic levitation. Previous methods have encountered difficulties with Total Harmonic Distortion (THD) limits, sudden fluctuations, and system complexity. The proposed approach employs a closed-loop PI controller with unipolar pulse width modulation (PWM) and an LC output filter to simplify the system, reduce THD in the output voltage and current, ensure stability, and decrease mechanical vibrations. The proposed system's effectiveness in reducing THD and simplifying the overall design was tested using PSIM software simulations. The objective is to provide a superior alternative to existing switching power amplifier topologies with feedback controllers for different types of inductive loads.