Model predictive power control for grid‐connected ac–dc converters with trajectory optimisation of the modulated voltage vector

As a classical control algorithm for grid‐connected ac–dc converters, the conventional proportional–integral (PI) based direct power control (DPC) has several disadvantages, including the complexity of tuning PI parameters and poor dynamic performance. To tackle those drawbacks, this study presents a simple model predictive power control (MPPC) scheme with pulse‐width modulation stage for single‐phase ac–dc converters. Distinct from previous MPPC schemes, the proposed approach is formulated in terms of the terminal trajectory of modulated voltage vector, which is defined as an elliptic region. From the elliptical trajectory point of view, the proposed approach applies a cost function to predict an optimal radius of elliptic trajectory instead of the outputs of inner‐loop PI controllers in PI‐based DPC. To solve the parameter sensitiveness problem of MPPC schemes, a quantitative relationship between the predicted powers and their references considering inductance mismatch is analysed in detail. Then, an inductance estimation method is developed according to the analysis. A comprehensive experimental comparison with conventional PI‐based DPC, and finite‐control‐set MPPC schemes have been conducted to verify the effectiveness of the proposed scheme.