分析了逆变器的开关频率、滞环宽度、电机转速三者的关系,提出了开关频率优化的方法;为进一步提高系统的稳定性和响应速度,将模糊控制技术用于永磁同步电动机控制中,提出了一种新的模糊控制方案,并引入零矢量控制,对模糊控制规则进行简化。仿真实验结果表明,通过开关频率优化和模糊控制,不仅能充分利用功率器件的开关频率,而且模糊直接转矩控制的磁链轨迹更接近于圆形;转速在较短的时间内上升到稳定值;转矩快速、平稳地变化。
The relation among motor speed, torque hystersis band width and switching frequency was analyzed, and switching frequency optimization method was proposed. In order to improve the system stability and raise the response speed,fuzzy logic based direct torque control for a permanent magnet synchronous motor (PMSM) was put forward. In this scheme, zero voltage space vector control was introduced to simplify fuzzy control rules. Simulation results show that the flux locus of the fuzzy direct torque control is approximatively a circle by switching frequency optimization and fuzzy control, and the rotational speed can reach table value quickly and the torque for the proposed scheme can change smoothly.