Optimization Design and Research of Control Strategy Based on Dual Closed-Loop Three-Phase Voltage PWM Rectifier

The control of three-phase voltage source PWM rectifiers is generally carried out in a two-phase synchronous rotating coordinate system, which can convert the three-phase quantities into DC components, making it easy to control and adjust. Through the analysis of the mathematical model, it was found that there is a coupling term of inductance L in the current inner loop of the control system, and the value of inductance L will change, affecting control performance. Under low frequency and strong disturbance conditions such as ocean currents, traditional control strategies face significant challenges. Therefore, an optimized design scheme based on a dual closed-loop three-phase voltage source PWM rectifier control strategy is proposed. The voltage outer loop uses the square of the DC output voltage as an indirect control variable to achieve fast tracking of the output voltage; The current inner loop obtains a decoupling control method for reducing order and removing the influence of inductance L by constructing a linear decoupling model. Further simulation analysis has demonstrated the feasibility and effectiveness of this control strategy optimization design scheme.