Decoupled Current Vector Control of Dual Three Phase PMSM Drives with Two Independent Micro Control Units Utilizing Current Observer

抄録

This paper presents a coupling estimation based decoupled current vector control scheme for current control of a Dual Three Phase (DTP) Surface Permanent Magnet Synchronous Motor (SPMSM) drive with two micro control units (MCUs), to solve its inherent magnetic coupling issue. Aiming for an enhanced fault tolerance, the SPMSM drive utilized is a redundant and modular system composed of two subsystems in terms of three-phase inverters, sensing, and controllers, with respect to each winding set in the DTP SPMSM. The current of each winding set along with the rotor position is separately detected and applied for control by individually assigned MCU. This comprehensive modularity prevents interference between subsystems in local fault conditions, thus improving the fault tolerance capability. However, the magnetic coupling existing between the winding sets would deteriorate the performance and even cause instability in the whole system without proper decoupling control. Previous studies adopted communication between MCUs for real time current sampling sharing demanded by decoupling control. Nevertheless, communication bandwidth becomes a limiting factor of system design. Some general communication approaches would not satisfy the current sharing requirement of decoupling control for implementation. To eliminate this undesirable limit, a novel decoupled current vector control that utilizes a current observer to estimate the relevant magnetic coupling between winding sets is proposed in this paper. As validated from the experiment results, the proposed decoupled control scheme is able to decouple the system for dynamic improvement so that modularity of the drive can be achieved without communication, leading to an eventual improvement in fault tolerance capability.