Development of Fast DC Bus Cascaded Voltage Controller for Supercapacitor Energy Storage System

This paper analyses controller design for DC bus voltage stabilization during the braking process of electric motor. Since supercapacitors can supply high current, they are well suited for regenerative braking energy recovery. To prevent overvoltage voltage controller should be fast. Large DC-DC converter inductor inductance can limit fast response therefore switching frequency should be high to decrease output filter size. In this case it is considered that GaN transistor-based converter will be used and therefore the switching frequency can be increased. Based on simulation model the cascaded current and voltage controller has been developed and simulations results are shown. The results show that developed controller is fast and can limit overvoltage.