A simple control method of supercapacitor DC-DC converter for grid-connected application

The bi-directional DC-DC converter (DDC) is commonly employed for the battery or supercapacitor (BA/SC) to accomplish the power management flexibility. The current and voltage control for the DDC is crucial for power management. Focusing on the control of the DDC, this paper first proposes a simple order-reduction control method for the first-order system, then applies the proposed control method to the current and voltage control of the SC DDC. The effect of the inner current loop on the outer DC bus voltage loop is also analyzed. With the proposed simple order-reduction control method, the dynamic response of the SC DDC is obviously improved, and the robustness to the SC voltage variation is achieved. The double-line-frequency ripple is also eliminated through the proposed simple and effective method. Finally, the effectiveness of the developed control algorithm is tested by the experiment.