VSVPWM-STSMO Strategy for Voltage Stabilization Control of PMSG

This paper focuses on the voltage stabilization control strategy of a permanent magnet synchronous generator (PMSG) based on the T-type three-level converter topology. An optimization control strategy VSVPWM-STSMO is proposed, which combines the midpoint potential balance method and sensorless control algorithm. To address the issue of traditional methods limitations in dealing with the midpoint potential, the VSVPWM (Virtual Space Vector Pulse Width Modulation) is adopted and a balance factor is introduced for small vectors and medium vectors to balance the neutral point potential. Additionally, a Super-Twisting Sliding Mode Observer (STSMO) is designed to estimate the electrical angle and angular velocity for the PMSG without a rotary encoder or a rotary resolver. The simulation results show that VSVPWM exhibits better neutral point balance performance under high modulation ratio conditions with the electric angle estimation error of the STSMO controlled within 0.4 rad and the electric angular velocity estimation error controlled within 3 rad/s, which can meet the actual control requirements. The effectiveness of the proposed VSVPWM-STSMO strategy is also demonstrated.