Compound control for energy management of the hybrid ultracapacitor-battery electric drive systems

This paper proposes a compound control framework for energy management of hybrid ultracapacitor-battery electric drive system. It includes a topology and compound controllers. The topology guarantees that the ultracapacitor current and the battery current can be controlled individually. In addition, the control of the hybrid power source is linked with the control of the electric drive system directly. Compound controllers include an active disturbance rejection controller, two current controllers and two operational modes switch controllers. Active disturbance rejection controller is applied in the control of the ultracapacitor in a load-following mode. Current controllers are applied to control the battery current and the charge current of the ultracapacitor. Event trigger based operational modes switch controllers coordinate the active disturbance rejection controller and the current controllers. The advantages of the proposed compound control are that ultracapacitor supplies peak and ripple current while battery supplies smooth and steady current; the control of the hybrid power source is linked with the control of the electric drive system; the high power discharge ability of ultracapacitor is used to reject disturbance. The experimental results validate the performance of the proposed control framework in this work.