双三相永磁同步电机改进型模型预测电流控制

Improved Model Predictive Current Control for Dual Three-phase Permanent Magnet Synchronous Motor

针对双三相永磁同步电机模型预测共模电压抑制方法存在寻优计算量大、开关频率较高、稳态性能不佳的问题,提出一种改进型模型预测电流控制.首先,改进六相两电平逆变器,降低零矢量共模电压幅值;其次,选择小共模电压矢量构造虚拟电压矢量,简化价值函数的同时减小共模电压和电流谐波含量;再次,通过计算参考电压矢量直接选择最优电压矢量以减少寻优次数,并引入占空比控制提升电机控制精度,改善电机稳态性能.最后,仿真对比传统模型预测电流控制、RCMV(Reduced Common Mode Voltage)-1、RCMV-2和所提控制方法.结果表明,所提控制方法在减小共模电压的同时,降低了转矩脉动和谐波电流,且较RCMV-2方法开关频率明显降低;此外,寻优代码执行时间相较于RCMV-1和RCMV-2分别降低了约91%和65%,减小了计算量.

An improved model prediction current control is proposed to address the disadvantages of the model predictive common-mode voltage suppression method for double-three-phase permanent magnet synchronous motors,including the size of the optimization calculation,high switching frequency,and poor steady-state performance.Firstly,the six-phase two-level inverter is improved for reducing the common-mode voltage of zero-vectors.Secondly,the virtual voltage vector is constructed by choosing small common-mode voltage vectors,which simplifies the value function and reduces the common-mode voltage and current harmonics.Then,the optimal voltage vector is directly selected by calculating the reference voltage vector to reduce the number of optimization-seeking times,and the duty cycle control is introduced to enhance the motor control accuracy and steady-state performance.Finally,the traditional model predictive current control,RCMV(reduced common mode voltage)-1,RCMV-2,and the proposed control method are simulated and compared.The results show that the proposed control method reduces the torque pulsations and harmonic currents while decreases the common-mode voltage,and the switching frequency is significantly lower than that of the RCMV-2 method.In addition,the execution time of the optimization-seeking code is reduced by about 91%and 65%compared with RCMV-1 and RCMV-2,respectively,which reduces the computational amount.