关键词: AC-DC矩阵变换器, 模型预测控制, 卡尔曼滤波器, 不平衡电网, 对称分量

Abstract:

To reduce the fluctuation of active power on the grid side of AC-DC matrix converters under unbalanced input conditions and to address the issue of variable switching frequency in discrete model predictive control, this paper proposes a novel model predictive control method. This method selects effective vectors based on the phase angle of the grid current, thus avoiding the computational burden of evaluating the value function in traditional model predictive control. Additionally, a second-order extended complex Kalman filter is introduced, which achieves the computation accuracy of the second-order term of the Taylor series expansion and enables the application of the novel model predictive control in unbalanced grid systems. Simulation results show that the proposed control strategy can effectively suppress grid-side current harmonics and stabilize the active power output of the system under unbalanced input voltage conditions, demonstrating excellent performance.

Key words: AC-DC matrix converters, model predictive control, Kalman filter, unbalanced power grids, symmetrical components