基于多级滞环控制器的永磁同步电机直接转矩控制

Direct Torque Control for Permanent Magnet Synchronous Motor With Multilevel Hysteresis Controller

该文提出一种多级滞环控制器与基于离散占空比的扩展开关表相结合的新型直接转矩控制策略。该策略可以在保证系统具有快速响应能力的前提下有效地降低磁链和转矩波动。所提出的多级滞环控制器将转矩、磁链误差大小划分成若干等级,从而能够更详尽的描述系统需要增、减转矩或磁链的程度。文中对占空比进行离散化处理,在此基础上生成不同幅值、不同相角的矢量作为备选矢量,丰富和扩展了传统DTC开关表。此外,本文采用倒三角矩阵存储备选矢量集合,并采用"二次寻优"的方法准确、快速地从扩展开关表中选出目标矢量。最后对本文算法的可行性与有效性进行了实验验证。

A novel direct torque control strategy was proposed which use multilevel hysteresis controller and extended switching table based on discrete duty ratio. This strategy assures that the system has fast response capability and the ripples of flux linkage and torque can be decreased significantly. Firstly, with the proposed multilevel hysteresis controller, the magnitude of flux linkage and torque error can be described as different levels. These levels can be utilized to indicate different degrees to which the flux linkage and torque of the system have to increase or decrease. In addition, discrete duty ratio was applied to create more vectors with different amplitude and phase angle as alternatives for the extended switching table. Furthermore, inverted triangular matrices were used to store alternative vector sets and the target vectors were selected fi＇om the extended switching table accurately and quickly by way of the secondary optimization technique. Lastly, experimental tests were carried out to validate the effectiveness of the proposed strategy.