一种新的异步电动机调速系统的混合控制方法

A new mixed control strategy for induction motor drives

矢量控制(FOC)和直接转矩控制(DTC)是目前高性能异步电动机调速系统中的两种主要控制方法。研究和工程实践表明,这两种方法各有优缺点,国内外很多学者也提出了很多方案,试图改进和完善这两种控制方法。本文从全新的思路出发,尝试把这两种方法结合到一个控制系统中,取长补短,形成一种新的混合控制方法。该方法使用户可以根据实际运行的不同需要,在线灵活地切换到合适的控制方法(FOC或DTC),以提高控制性能。为了实现两种控制方法之间的平滑切换,本文把传统的PI控制器改造成可重置PI控制器。仿真和实验结果表明,这种可重置PI控制器可以有效减少FOC和DTC切换时造成的系统波动,同时能保持原有控制系统的性能,提高了本文提出的混合控制方法的实用价值。

Field oriented control (FOC) and direct torque control (DTC) are two major control methods for high performance induction motor drives. Research on these two schemes shows that FOC and DTC each has its own advantages and disadvantages. An innovative control strategy, which is an organic combination of the two schemes, is presented in this paper to adopt the other's strong points to offset one's weakness, with the purpose of realizing more flexible and high performance motion control and providing users with more options in various applications. For smooth switching between DTC and FOC, a new 'resetable' PI controller is designed to replace the conventional PI controller. Simulation and experiments show that the new 'resetable' PI controller can remarkably reduce the fluctuation of mixed control system, and the control performance of DTC and FOC can be maintained.