Fault-Tolerant Hybrid Current Control of Dual Three-Phase PMSM With One Phase Open

A fault-tolerant hybrid current control is proposed for dual 3-phase permanent magnet synchronous machines (PMSMs) with one phase open in this paper. The maximum torque control, minimum copper loss control, and single 3-phase mode control are unified in the proposed method, which is a combination of single 3-phase mode control and maximum torque control with different percentages. When the percentage of single 3-phase mode control (k) varies from 0% to 100%, the hybrid current control transitions from maximum torque control (k=0%), to minimum copper loss control (k=50%), and then to single 3-phase mode (k=100%). Therefore, the hybrid current control can be switched among the aforementioned three control methods easily and smoothly. Meanwhile, it can be a mixed-mode with a tradeoff between the maximum torque control and minimum copper loss control, such as the minimum copper loss control for a given torque within the full torque range, which can be achieved by changing k. The smoothness of transition among the maximum torque control, minimum copper loss control, and single 3-phase mode control is verified by experimental results on a prototype machine.