An Adaptive Driving Signals Delay Control for Voltage Balancing of Multiple Series-Connected SiC MOSFETs

For voltage balancing of series-connected silicon carbide (SiC) metal-oxide-semiconductor field-effect transistor (MOSFET), adjusting the delay time of the device's drive signals is an effective method. However, most of the research is based on the two series-connection SiC MOSFETs, which still cannot meet the requirements of medium/high voltage occasions. So it is necessary to study the voltage balancing of multiple series-connection SiC MOSFETs, which is much more complicated. This paper models the turn-off process of multiple series-connection SiC MOSFETs and proposes a control strategy which can achieve rapid voltage balancing for multiple devices. Besides, as the characteristics of the voltage balancing system are greatly affected by the load current, in order to achieve great performance when load current changes, an adaptive controller is proposed which can adjust the parameters in real time according to the load current. Experimental results are presented to verify the practicability of the control strategy and adaptive controller for multiple series-connected SiC MOSFETs.