| 摘要 |
PROBLEM TO BE SOLVED: To make an actual output voltage match a command voltage of an inverter while the oscillation phenomenon of a voltage waveform, in an antiparallel recovery time of a diode connected in parallel with a device such as an IGBT or the like constituting an inverter or the like, is avoided. SOLUTION: A gate drive circuit of an IGBT comprises a filter circuit 18, a one-shot circuit 20, a logic operation circuit 22, etc. If the pulse period width of a gate command signal is shorter than 1/2 of a minimum off-period T, an off-operation is prohibited by the circuit 18 and, if the pulse period width is T/2-T, an off-period is forcibly changed to be T by the circuit 20, and, if the pulse period width is not shorter than T, the operation is continued as it is. |
