Electronics Letters | 2019
Dynamic voltage-sharing among series-connected IGBTs during turning-on process
Abstract
An active clamping circuit for voltage sharing among series-connected insulated gate bipolar translators (IGBTs) during turning-on process is proposed at first, which detects the C-E\n voltage of the leading IGBT and generates gate pumping current to slow down the turning-on speed, and thus reduces the voltage difference between the IGBTs. Then, a turn-on edge regulation algorithm for the driving signal is proposed, which further reduces the voltage spike and turn-on power loss, and optimises the regulation speed. A time detection circuit is introduced to detect the pulse signal indicating the working time of the active clamping circuit for driving signal regulation. The turn-on edge regulation for each IGBT is determined by the feature that the rising edge of the detected pulse signal coincides with the corresponding IGBT turn-on edge delay. The experimental results prove the feasibility and effectiveness of the proposed method.