Part of the book: Advances in Reinforcement Learning
This chapter presents a synergy-based cascade control scheme for a hybrid battery-ultracapacitor (UC) energy storage system. The purpose is to improve the dynamic response of the battery-based energy storage system using an ultracapacitor module as an auxiliary energy storage unit. A bidirectional DC-DC converter is designed to interface between the ultracapacitor module and the main DC-bus. The control scheme is based on a fast inner current control loop using sliding mode control and an outer loop for DC-bus voltage regulation using synergy-based control. The improvement in performance is demonstrated through simulation and experiments. The results show that the DC-bus voltage is well regulated under external load disturbances with fast dynamic transients. The ultracapacitor module is able to absorb the sudden load variations and limit the battery power requirements by maintaining an optimal power balance between the two embedded storage units. The performance of the proposed synergy-based controller is compared with the standard PI controller, and its ability to achieve optimal transient performance is verified.
Part of the book: Advancements in Energy Storage Technologies
This chapter presents an optimum design of synergetic control for a permanent magnet synchronous motor (PMSM) drive system. New macro-variables are proposed to improve the performance of the standard controller. The controller’s performance is compared with that of the field-oriented control scheme. The chapter also investigates the regenerative braking mode of operation in PMSM. Regenerative braking is achieved by operating the motor in torque control mode. The different algorithms are validated through experiments using a 1-hp PMSM drive system. We also provide an extensive study of the controller parameters tuning for optimal performance. The experimental results show that the proposed macro-variables improve the performance of the synergetic controller significantly. The synergetic controller is able to overcome nonlinearities in the system, such as static friction, faster than the field-oriented controller. The system also experiences fewer harmonics under the synergetic controller. The synergetic controller shows also better performance under wide signal variations. As for regenerative braking, the torque control mode of operation is shown to be suitable for harvesting energy and both techniques showed similar performance levels. The proposed synergetic control strategy will be very useful in electric vehicle (EV) applications, as it allows to improve the dynamic response and efficiency of the drive system required by the EV dynamics.
Part of the book: Induction Motors