不平衡电网下脉宽调制整流器模型预测直接功率控制

摘要

目前关于脉宽调制(PWM)整流器模型预测控制(MPC)的研究主要集中在平衡电网条件下进行,在电网不平衡时采用 MPC 进行控制的研究比较鲜见。为此,文中提出一种适用于电网不平衡下 PWM 整流器控制的模型预测直接功率控制(MPDPC),其控制目标是消除输入有功功率的二倍频脉动并保证网侧电流正弦。相比传统的 MPC,该方案仅在原有功率参考值的基础上增加一个补偿值即可实现。该功率补偿值的获取无需坐标旋转变换和电网电压电流的正负序分解,具有原理简单、容易扩展和鲁棒性好等优点。仿真和实验结果验证了所提出的 MPDPC 在电网不平衡时的有效性和可行性。%The study of model predictive control (MPC) on a pulse-width modulation (PWM) rectifier is mainly implemented under the condition of ideal balanced grid voltage at present,while few investigations are reported on control under unbalanced grid voltage.Thus,this paper proposes a new model predictive direct power control (MPDPC) for PWM rectifier suitable for operation under unbalanced grid voltage,which is aimed to eliminate the double grid frequency oscillation in active power and ensure sinusoidal grid current.Compared with conventional MPC,only one compensation block is required to be added to the original power reference.The calculation of the power compensation has no need of rotary transformation and positive and negative sequence decomposition of grid voltage/currents.It has the advantages of simple principle,easy extension and strong robustness,etc.Simulation and experimental results have verified the effectiveness and feasibility of the proposed method under unbalanced grid voltage.