Method and apparatus for driving a voltage controlled power switch device

A method for driving at least one voltage controlled power switch device comprising the steps of:

• generating a first driving signal in response to a rising edge of a pulsed signal and a second driving signal in response to a falling edge of said pulsed signal,
• generating a trigger signal for a control electrode of said power switch device,
• wherein an on-voltage trigger signal is generated in response to the first driving signal,
• wherein an off-voltage trigger signal is generated in response to the second driving signal;
• and
• storing signal energy of said trigger signal until a threshold voltage of said power switch device is reached and releasing the stored signal energy to the control electrode of said power switch device when and after the threshold voltage has been reached,
• wherein the released energy provides a voltage oversway which accelerates switching of said power switch device,
• wherein maintenance pulses are added to said first driving signal in case that said pulsed signal is stable in an active state and to add maintenance pulses to said second driving signal in case that said pulsed signal is stable in an non-active state, and
• wherein said first driving signal and second driving signal are not active at the same time.

A driving circuit for at least one voltage controlled power switch device comprising:

• a driver signal generating circuit configured to receive a pulsed signal and to generate
• a first driving signal in response to a rising edge of said pulsed signal
• a second driving signal in response to a falling edge of said pulsed signal;
• a trigger signal generating circuit configured to generate a trigger signal for said voltage controlled power switch device, and comprising a first driving transistor configured to be switched on by the first driving signal such that an on-voltage of the trigger signal is supplied to a control electrode of said power switch device, and comprising a second driving transistor configured to be switched on by the second driving signal such that an off-voltage of the trigger signal is supplied to the control electrode of said power switch device;
• and
• at least one energy buffer component coupled between the trigger signal generating circuit and the control electrode of said power switch device,
• said energy buffer component being adapted to store signal energy of the on-voltage trigger signal until a threshold voltage of said power switch device is reached and adapted to release the stored signal energy to said control electrode of said power switch device when said threshold voltage of said power switch device has been reached, wherein the released energy stored in said energy buffer component provides a voltage oversway on the control electrode of said power switch device which accelerates the switching of said power switch device;
• wherein the trigger signal generating circuit is connected to a corresponding DC power supply circuit providing at least one positive power source which defines an amplitude of the on-voltage of the said trigger signal and at least one negative power source which defines an amplitude of the off-voltage of the said trigger signal;
• and
• wherein the DC power supply circuit comprises two half wave rectifiers with smoothing capacitors connected to a secondary coil of a power supply transformer having a primary winding connected to a power supply switching circuit controlled by a temperature dependent driving signal being generated by a temperature control unit depending on a temperature of said power switch device.