Reduced-Order Feedback Linearization for Independent Torque Control of a Dual Parallel-PMSM System

Abstract

Connecting two PMSMs in parallel to a 2-level 3-leg inverter gives a way to build up a high power-density driving system using existing electronic devices. But this type of system has a nature of nonlinearity that creates an obstacle in high performance control and the original system cannot be feedbacklinearized directly. This paper presents a reduced-order feedback-linearization method. In the first place, an extra order-reducing step that separates the system as a main system and an auxiliary system is applied. Then a feedback-linearization method is applied to the reduced-order system. With these effort, the original system can be converted into a linear time-invariant system bringing the controller design problem into the linear domain. In the last step, a linear robust state-feedback controller is used to achieve the speed control as well as compensate the unmeasurable external load torque. An extensive experiment is given to verify the feasibility and good performance in a highly unbalanced load torque situation of the designed controller.

Lyapunov-Function-Based Feedback Linearization Control Strategy of Modular Multilevel Converter–Bidirectional DC–DC Converter for Vessel Integrated Power Systems

“…(17) can be rewritten as: (19) which shows that the product of the current error and its derivative is positive, illustrating that the internal dynamic is unstable. Hence, MMC is a multi-input-multi-output nonminimum phase nonlinear system.…”

“…Feedback linearization control strategy has been utilized in the field of power electronics by researchers. Compared with traditional local linearized control methods, the flexible nonlinear system can be turned into a global linearized system with feedback linearization control, which makes the dynamics of the system more controllable [11][12][13][14][15][16][17][18][19][20]. Feedback linearization control shows higher control accuracy, better dynamic performance and better decoupling characteristics than traditional PI control methods.…”