An Adaptive Dead Time Control based on the Switch-Node-Voltage Derivative

Abstract:
With an increasing demand for higher switching frequencies in power electronic applications, the switching losses of semiconductor devices become more crucial. This can be avoided by operating the device in soft switching, which usually imposes restrictions on the dead time. This study proposes an active dead time controller that ensures soft switching by adjusting the dead time as a function of in situ measurements. For this purpose, the switch-node-voltage derivative is measured with a high-pass filter to determine the switching-transient length for the controller to set the ideal dead time for soft switching. The proposed controller can quickly adapt to changing operating conditions without the need for extensive offline training procedures.