Generalized Predictive DC-Link Voltage Control for Grid-Connected Converter

The main function of the grid-connected converter in many applications is to control the DC-link voltage with high performance, i.e. strong disturbance rejection capability and good dynamic response. Take the grid connected PWM rectifier of a motor drive system as an example, good disturbance rejection capability is essential for the DC-link voltage control to address the varying loads on the motor side, and the dynamic process of the DC-link voltage control is preferred to be fast and overshoot-free, so as to adaptively adjust the DC-link voltage according to the motor speed and reduce the switching losses. However, the performance of the conventional PI-based DC-link voltage control is not always satisfying and can be further improved. In this paper, the generalized predictive control (GPC) method is applied to the DC-link voltage control of a grid-connected converter for the first time, which can provide both good disturbance rejection capability and satisfying dynamic performance. Moreover, stability analysis of the proposed GPC-based DC-link voltage control strategy is theoretically studied, and a parameter tuning guideline is provided. The effectiveness and advantages of the proposed method are validated with experimental results.