Sliding mode PIR control for a four-IGBT five-level rectifier

Multilevel PWM rectifiers are featured with low-voltage stress of switching devices, low harmonic content and suitable for high-voltage high-power applications. This paper presents a novel single-phase five-level PWM rectifier based on coupled inductor. In order to improve the dynamic response of the system and reduce the current harmonic content of the grid side, a sliding mode proportional integral resonance (PIR) control algorithm was proposed. Firstly, the circuit topology and working principle of the new single-phase five-level PWM rectifier were analysed. A mathematical model of the rectifier in d–q axis synchronous rotating reference frame was derived and analysed its voltage outer loop sliding mode and current inner loop PIR control algorithm. Compared with the traditional PI current control algorithm based on d–q axis, the proposed sliding mode PIR control algorithm has a faster dynamic response speed and a lower current harmonic content on the grid side. Finally, a simulation model based on MATLAB/Simulink and a hardware-in-the-loop real-time simulation experiment platform based on RT-lab were built up, and the proposed sliding mode PIR and the traditional PI current control algorithm based on d–q axis were compared. Simulation and experimental results have verified the correctness and feasibility of the proposed algorithm.