Switched System Modeling for Three-Phase AC–DC Converters in the Rotating Frame and Its Control Strategy With Guaranteed Large-Signal Stability

Regarding the stability control of three-phase ac–dc converters, many control schemes with a dual-loop structure are proposed based on the converter averaged model. However, two common issues exist. First, the inner-loop dynamics are usually neglected in the design stage of the outer loop. Therefore, rigorous demonstration of the large-signal stability for the whole control system is an unsettled question. Second, the design complexity of tuning a family of control parameters is relatively high. In this article, a switched system model (SSM) in the rotating frame is proposed for the three-phase ac–dc converter. The established SSM indicates that the converter can continuously exhibit dissipativity by orchestrating the switching actions among the circuit modes. On this basis, a control strategy immune to circuit parameter variations is investigated. The Lyapunov large-signal stability of the whole control system is ensured. In addition, only one parameter needs to be designed in the proposed strategy. Finally, a prototype is built. Simulations and experiments validate the presented theoretical analysis and the good control performance of the proposed strategy.