Power device drive and control

Self-quenching devices such as MOSFETs and IGBTs are divided into linear, saturation, and cutoff regions depending on the gate voltage. Analog semiconductor devices used in amplification circuits are mainly used in the saturation region. Unlike analog semiconductor devices, power semiconductor devices used in power conversion circuits use the conduction state in the linear region and the blocking state in the blocking region for power conversion operation. The transition between the linear and cutoff regions of a power semiconductor device is called switching. In switching operation, gate drive is required to change the gate voltage, and in this process, the device passes through the saturation region. The loss generated in the power semiconductor device in the saturation region is called switching loss. If the time required to pass through the saturation region is simply shortened to reduce switching losses, the electromagnetic noise generated by the switching operation will increase. Fine gate drive control can reduce both switching loss and electromagnetic noise. However, these conditions vary depending on the power semiconductor device used and the operating conditions of the circuit. Therefore, gate drive conditions that suppress switching losses and electromagnetic noise are determined in real time using machine learning to control gate drive.

Research work