永磁同步电机模型预测转矩控制简化控制策略

Simplified control strategies of model predictive torque control for permanent magnet synchronous motor

中文关键词  永磁同步电机  模型预测转矩控制  约束条件  计算负担

英文关键词  permanent magnet synchronous motor  model predictive torque control  constraint  computational burden

中文摘要

      传统永磁同步电机(PMSM)模型预测转矩控制(MPTC)遍历逆变器生成的全部7个电压矢量, 计算负担较大.当转矩误差较小时, 零电压矢量利用率较高, 则可当转矩误差位于阈值范围, 电机系统直接输出零电压矢量, 否则,依然遍历7个电压矢量, 并给出阈值确定方法. 基于上述策略, 本文增加了6个定子磁链扇区位置约束, 将转矩误差大于阈值时的备选电压矢量降至4个, 并增加磁链扇区数目至12个和磁链误差约束, 进一步减小备选电压矢量. 仿真结果表明, 提出的3种简化策略控制下, 永磁同步电机系统运行正常, 控制性能与传统模型预测转矩控制基本相当,平均开关频率分别降低至77.48%, 77.09%和76.12%, 平均遍历电压矢量个数分别降低至58.29%, 32.86%和29.14%.实时性实验结果表明运行时间分别减小至57.70%, 32.96%和29.48%.

英文摘要

      The conventional permanent magnet synchronous motor (PMSM) model predictive torque control (MPTC) traverses all 7 voltage vectors generated by the inverter and results in large calculation burden. When torque error is small, zero voltage vector is used primarily. When torque error is less than the threshold, zero voltage vector is outputted directly, otherwise the MPTC still uses 7 voltage vectors. And the method to determine the threshold is given. Based on the simplified strategy above, the constraint of 6 stator flux sectors is adopted to decrease candidate voltage vectors to 4 when torque ripple is more than the threshold. The number of stator flux sector is increased to 12 and the constraint of stator flux error is also used, which can decrease candidate voltage vectors further. Simulation results show the PMSM works properly under the control of proposed 3 simplified strategies and the control performances are almost the same as conventional MPTC. And the average switching frequency is decreased to 77.48%, 77.09% and 76.12%, the average number of traversal voltage vectors is decreased to 58.29%, 32.86% and 29.14%. Real-time experiment results show the total computation time is reduced to 57.70%, 32.96% and 29.48%.