Modulated predictive current control for a two‐level grid‐connected converter with over‐modulation capability

Abstract

Modulated model predictive control (M2PC) approaches have been widely investigated owing to their improved steady-state performance and constant switching frequency operation. However, most of these methods either increase control complexity or cannot obtain optimal solutions under certain operating conditions such as lower modulation index and near the boundary of linear and over-modulation regions. To overcome these limitations, this study proposes a new modulated predictive current control technique based on a novel virtual vector synthesis. The optimal duty cycle is obtained by solving the optimisation problem defined by the cost function. To minimise the tracking error of the input current, a simple non-linearity compensation method for the converter is also demonstrated. The experimental results confirm that the proposed technique significantly reduces the steady-state error of the controlled objective and the ripples in the input current without sacrificing the transient performance compared to other existing M2PC methods.