永磁同步电机模糊自适应低开关频率模型预测 电流控制

在永磁同步电机有限集模型预测控制中没有脉宽调制环节，最优电压矢量直接作用于逆变器，开关频率高。为降低 开关频率，拟通过永磁同步电机模型预测电流控制系统的代价函数中，引入权重系数自适应调整的开关频率控制项。首先， 建立模型预测电流控制模型，分析运行工况及控制周期对开关频率的影响；其次，在代价函数中引入开关频率控制项，分析开 关频率控制项权重系数对开关频率和电机控制性能的影响规律；然后，基于模糊控制理论设计权重系数自适应调整的模型预 测电流控制系统，通过检测定子电流和参考电流的控制误差值作为模糊控制的输入量，开关项权重系数作为模糊输出量，实 现开关项权重系数的自适应调整。仿真结果表明，模糊自适应开关项权重系数控制方式相比于固定权重系数控制，在转速为 500 r/min时电流谐波增大0.36%时而开关频率降低1.5 kHz 左右，在2000 r/min时开关频率降低0.8 kHz 左右。

Fuzzy adaptive low switching frequency model predictive current control for permanent magnet synchronous motor

In the finite set model predictive control of permanent magnet synchronous motors,there is no pulse width modulation link,and the optimal voltage vector directly acts on the inverter,the switching frequency is high.To reduce switching frequency,in the predictive current control system of permanent magnet synchronous motor model,a switching frequency control term with adaptive weight coefficient adjustment is introduced in the cost function.Firstly, establish a predictive current control model and analyze the impact of operating conditions and control cycles on switch frequency.Secondly,the switch frequency control term is introduced into the cost function,and the influence of the weight coefficients of the switch frequency control term on the switch frequency and motor control performance is analyzed.Then,based on fuzzy control theory,a model predictive current control system with adaptive adjustment of weight coefficients is designed.By detecting the control error values of stator current and reference current as the input of fuzzy control,and the switch term weight coefficient as the fuzzy output,the adaptive adjustment of the switch term weight coefficient is achieved.The simulation results show that compared to fixed weight coefficient control,the fuzzy adaptive switch term weight coefficient control method reduces the switching frequency by about 1.5 kHz when the current harmonic increases by 0.36%at a speed of 500 r/min,and by about 0.8 kHz at a speed of 2000 r/min.