| 摘要 |
This invention relates to a control method and a circuit for MOS-gated power semiconductor switching devices such as IGBTs or MOSFETs, which allows control and optimisition of the current and voltage commutation of a power semiconductor switching device and freewheel diode pair in the basic half-bridge circuit found in a wide range of equipment. The method comprises the stages of: applying, upon receipt of a switch-on command signal, a voltage function to the control terminal or the gate of the power semiconductor switching device that allows a regulated current rise in the device whilst maintaining the voltage across the device falling at a predetermined rate; and at the instant when the voltage across the diode begins to change from the on-state towards the off-state level, applying a voltage function to the control terminal or the gate of the power semiconductor switching device to enable the voltage falling across the power semiconductor switching device to track the voltage falling across the diode in order to ensure a fast and controlled completion of the switching operation without diode reverse voltage overshoot. The gate drive automatically modifies the voltage function according to the working condition thereby accounting for the actual operating conditions.
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