Method and apparatus for driving power switch tube

An apparatus for driving a power switch tube, comprising:

• a drive unit;
• a transformer;
• a rectifier unit;
• and
• a power switch tube,
• an input unit connected to the drive unit and configured to input a group of drive signals into the drive unit;
• wherein the drive unit comprises a plurality of field-effect transistors and is configured to control the statuses of the plurality of field-effect transistors to power on a field winding of the transformer according to the group of drive signals input by the input unit,
• wherein the transformer is connected to the drive unit and the rectifier unit and has specified magnetizing inductance configured to store energy,
• wherein the transformer either inputs a drive voltage signal into the control end of the power switch tube through the field winding of the transformer according to the stored energy, or inputs a drive voltage signal into the control end of the power switch tube by making the induced voltage of an output winding of the transformer induced from the field winding induction pass through the rectifier unit according to the stored energy,
• wherein the transformer is configured to implement zero-voltage switching in a plurality of scenarios,
• wherein the rectifier unit comprises at least one rectifier, wherein the rectifier comprises a rectifier switch and a control circuit of the rectifier switch and is configured to rectify the induced voltage of an output winding of the transformer induced from the field winding induction so as to obtain a drive voltage signal,
• wherein the power switch tube is connected to the transformer and comprises a parasitic capacitance, and
• wherein the parasitic capacitance and the transformer constitute a resonant circuit configured to control that the drive voltage signal of the power switch tube has a slow edge rate.

A method for driving a power switch tube, comprising:

• powering on a field winding of a transformer according to an input group of drive signals, so the transformer stores energy;
• and
• either inputting a drive voltage signal into the control end of the power switch tube through the field winding of the transformer, or inputting a drive voltage signal into the control end of the power switch tube through the induced voltage of an output winding of the transformer induced from the field winding induction such that the transformer periodically stores and releases energy and makes the field-effect transistor, driven by the drive signal, implement zero-voltage switching according to a change of the transformer energy and a change of the group of drive signals;
• wherein the group of signals comprises a first drive signal, a second drive signal, a third drive signal, and a fourth drive signal,
• wherein the first drive signal is input into the gate of the first field-effect transistor so as to control a status of the first field-effect transistor,
• wherein the second drive signal is input into the gate of the second field-effect transistor so as to control a status of the second field-effect transistor,
• wherein the third drive signal is input into the gate of the third field-effect transistor so as to control a status of the third field-effect transistor,
• wherein the fourth drive signal is input into the gate of the fourth field-effect transistor so as to control a status of the fourth field-effect transistor,
• wherein the first field-effect transistor, the second field-effect transistor, the third field-effect transistor, and the fourth field-effect transistor constitute a full-bridge structure,
• wherein the first drive signal and the second drive signal are complementary signals,
• wherein a dead time, which is between the first drive signal and the second drive signal, is used for the first field-effect transistor and the second field-effect transistor to implement zero-voltage switching,
• wherein the third drive signal and the fourth drive signal are complementary signals,
• wherein the dead time, which is between the third drive signal and the fourth drive signal, is used for the third field-effect transistor and the fourth field-effect transistor to implement zero-voltage switching,
• wherein the phase difference between the first drive signal and the third drive signal is 180 degrees,
• wherein the phase difference between the second drive signal and the fourth drive signal is 180 degrees,
• wherein powering on the field winding of the transformer according to the input group of drive signals comprises powering on the field winding of the transformer according to the connection relationship between the field winding of the transformer and the full-bridge structure when the group of signals changes according to a preset frequency,
• wherein the connection relationship between the field winding of the transformer and the full-bridge structure is that an end of the field winding of the transformer is connected to the middle point of a bridge arm of the full-bridge structure, and
• wherein another end of the field winding of the transformer is connected to the middle point of another bridge arm of the full-bridge structure.