基于模型预测的三电平PWM变流器直接功率控制

为了满足脉宽调制型变流器功率响应速度快以及绝缘栅双极型晶体管开关频率恒定等要求，提出了基于模型预测的直接功率控制策略用于三电平PWM变流器。该控制策略采用电压外环、功率内环的双闭环控制，外环省略了锁相环环节，简化了控制系统结构；内环无需PI调节器，参数设计简单，响应速度快。利用MATLAB/SIMULINK仿真平台搭建了三电平中性点箝位型PWM变流器模型，对比分析了提出的控制策略与传统PI控制的效果。仿真结果表明，新的控制策略有效降低了交流侧电流总谐波失真率，提高了交流侧功率因数，具有良好的动态和稳态性能。

Model Prediction Based Direct Power Control Strategy for Three-level PWM Converter

To meet the requirements of fast power response speed for pulse width modulation (PWM) type converter and constant switching frequency for insulated gate bipolar transistor (IGBT), a direct power control strategy based on model prediction was proposed for three-level PWM converter. The double closed-loop control was adopted in this strategy, namely voltage outer-loop and power inner-loop. The phase-locked loop in the outer-loop is omitted, which simplifies the structure of the control system. A PI regulator is not need in the inner-loop, which makes parameters' design simple and the response speed fast. A model of three-level neutral point clamp type PWM converter was built in MATLAB/SIMULINK. The effects between the presented control strategy and traditional PI control were analyzed. The simulation results show that the new control strategy effectively reduces the total harmonic distortion rate of the AC-side current, improves the AC-side power factor, and has good dynamic and steady-state characteristics.