一种新的永磁同步电机直接转矩控制方法

提出了一种新的无速度传感器永磁同步电机直接转矩控制方法。针对内埋式永磁同步电机直接转矩控制存在较大脉动转矩和逆变器的开关频率不恒定的缺点,设计了一种自适应模糊控制器确定占空比的方法。与其它基于自适应模糊控制器的直接转矩方法不同,这种自适应模糊控制器通过控制正反电压矢量作用时间,在每一采样周期计算出最优占空比。该控制器输出部分的比例因子可以根据转矩的变化趋势经自适应机构的模糊规则库在线调整,不仅可以使永磁同步电机直接转矩控制系统保持恒定的开关频率,而且可以有效地减小磁链和转矩脉动,特别是低速时的转矩脉动。为了获得高性能的无速度传感器永磁同步电机控制系统,设计了一种无速度传感器方案。理论分析和仿真实验结果证明了自适应模糊永磁同步电机直接转矩控制策略的有效性。

Direct Torque Control of Novel Interior Permanent Magnet Synchronous Motor

A novel sensorless direct torque control (DTC) scheme for an interior permanent magnet synchronous motor (IPMSM) was proposed, which features almost fixed switching frequency and low torque and flux ripple. In interior permanent magnet synchronous motor direct torque control, to decrease the torque ripple, a new approach to direct torque control of interior permanent magnet synchronous motor was designed. As compared to other existing adaptive fuzzy logic direct torque control (DTC) scheme, the fuzzy logic controller introduces a two state modulation between the conventionally selected active state and the reverse switching state. This modulation is controlled by a fuzzy logic adaptive controller, which calculates the optimum duty cycle for each sampling period. The controller output scaling factor is adjusted on line by fuzzy rules according to the current torque variety trend of the controlled process. The torque ripple is significantly reduced compared with those of the basic interior permanent magnet synchronous motor direct torque control reported in the literature, particularly at low speeds. A speed estimation scheme was integrated with proposed DTC scheme in order to achieve a fully sensorless high-performance IPMSM drive. The theoretical analysis and simulation results illustrate the operation and performance of proposed adaptive fuzzy-logic-based controller.