基于拓展电压矢量集合的永磁同步电机无差拍控制

Dead-Beat Control of Permanent Magnet Synchronous Motor Based on Extended Voltage Vectors Set

针对永磁同步电机直接转矩控制转矩脉动较大的问题,提出了磁链与转矩无差拍控制。对永磁同步电机磁链与转矩变化量计算模型进行了简化,并验证了简化模型的可行性。基于简化模型,求解出满足磁链与转矩无差拍控制的理想电压矢量,提出通过求解出的理想电压矢量角度和幅值来简化选择7个基本电压矢量的方法(DB-MPC-7)。为了提升系统性能,从角度和幅值对备选电压矢量进行拓展,将备选电压矢量角度扩展至36个,通过查表方式可生成幅值为线性调制范围内任意值的电压矢量(DB-MPC-36r)。仿真验证了永磁同步电机磁链和转矩无差拍控制可行性。相较于DB-MPC-7,DB-MPC-36r可显著减小转矩脉动和电流谐波含量,动态响应基本相当,但增大平均开关频率。

In order to solve high torque ripple caused by direct torque control(DTC),the dead-beat(DB)control of stator flux and torque of permanent magnet synchronous motor(PMSM)is proposed.Simplified models to calculate the change of stator flux and torque based on stator flux coordinate system are given,thus the ideal voltage vector for the DB control can be calculated.A simplified method to select applying voltage vector among 7 basic voltage vectors is proposed(DB-MPC-7).In order to improve control performances,candidate voltage vectors are expanded(DB-MPC-36r).The angles of candidate voltage vectors are 36 and the values of applying voltage vector can be arbitrary.Simulation results testify the effectiveness of the DB control.And compared with the DB-MPC-7,the DB-MPC-36r can decrease torque ripples and the total harmonic distortion(THD)of stator currents and keep almost the same dynamic response,but increase the mean switching frequency.