Gate drive apparatus, switching apparatus, and gate drive method

A gate drive apparatus comprising:

• a gate drive unit configured to drive a gate of a switching device;
• a parameter measuring unit configured to measure a parameter corresponding to current flowing through the switching device;
• a control unit configured to set a change speed of a gate voltage of the switching device during a period from a turn-off start of the switching device to a timing when a reference time has elapsed since then to any of a plurality of speeds, based on the parameter;
• and
• a correction unit configured to correct the reference time to be used during a next turn-off time period of the switching device, based on a change speed of the gate voltage during a period from a previous turn-off start of the switching device to the timing when the reference time has elapsed since then.

A gate drive method comprising:

• parameter measuring of measuring a parameter corresponding to current flowing through a switching device when driving a gate of the switching device;
• discrepancy detecting of detecting discrepancy between current flowing through the switching device during an on-state of the switching device and a reference value, based on the parameter;
• and
• controlling of, if the discrepancy is not detected, switching a change speed of a gate voltage of the switching device at a timing when a reference time has elapsed since a turn-off start of the switching device during a next turn-off time period of the switching device, and if the discrepancy is detected, keeping the change speed of the gate voltage during the next turn-off time period of the switching device.