基于模糊控制的永磁同步电机动态有限状态集模型预测转矩控制

Model predictive torque control for permanent magnet synchronous motor based on dynamic finite-control-set using fuzzy control

永磁同步电机传统有限状态集模型预测转矩控制一般采用逆变器生成的全部电压矢量,并且电机在任何运行状态下,备选电压矢量集合均固定,从而使得转矩脉动大和计算量较大。基于电压矢量幅值和角度对磁链和转矩变化的作用规律,采用模糊控制器动态确定备选电压矢量集合。模糊控制器输入为定子磁链和转矩误差,输出为3个备选电压矢量的幅值和角度。仿真结果表明与传统固定有限状态集相比,其可有效减小磁链和转矩脉动,减小了模型预测转矩控制的运算量,但平均开关频率有所增大。为了减小平均开关频率,将零电压矢量也作为备选电压矢量之一。仿真结果表明:使用零电压矢量可有效减小平均开关频率,但动态下转矩响应较慢。为了提高转矩动态响应,提出当系统处于动态时,备选电压矢量只使用模糊控制器输出的3个电压矢量,仅当系统处于稳态时,才加入零电压矢量。仿真结果表明:该策略使得系统控制性能基本保持不变,提高了转矩动态响应速度,并消除了动态下磁链和转矩脉动。

Conventional finite-control-set(FCS)model predictive torque control(MPTC)of permanent magnet synchronous motor(PMSM),which leads to a large amount of calculation and large torque ripple,based on effects of the value and angle of applying voltage vector on stator flux and torque,the fuzzy controller is used to dynamically output candidate voltage vectors.The inputs of fuzzy controller are errors of stator flux and torque and outputs are the angle and value of 3 candidate voltage vectors.Simulation results show compared with conventional FCS-MPTC,the proposed strategy can decrease stator flux and torque’s ripples and calculation burden of MPTC,but it will increase average switching frequency.In order to decrease average switching frequency,zero voltage vector was also used as one of candidate voltage vectors.Simulation results show it can decrease average switching frequency,but it will decrease dynamic torque response.Thus the strategy that zero voltage vector is only used at steady state was given.Simulation results show it can keep the same control performances,improve torque response and suppress stator flux and torque’s ripple at dynamic state.