Semiconductor switch having reverse voltage application circuit and power supply device including the same

A semiconductor switch to be provided in a power conversion device and to be connected in series to a second semiconductor switch between a positive line and a negative line of the power conversion device, the semiconductor switch comprising:

• a main element including a voltage-drive-type switching element and a first antiparallel diode connected in anti-parallel with the switching element;
• and
• a reverse voltage application circuit which is connected in parallel with the main element, and which includes a high-speed free wheeling diode, a capacitor, and an auxiliary element;
• wherein:
• the high-speed free wheeling diode has a reverse recovery time which is shorter than a reverse recovery time of the antiparallel diode, and a reverse recovery charge which is smaller than a reverse recovery charge of the antiparallel diode;
• the capacitor is connected in parallel to a power supply;
• the auxiliary element is turned on at a dead time set before the second semiconductor switch is turned on;
• the high-speed free wheeling diode, the capacitor, and the auxiliary element are connected in series to each other;
• and
• a diode is connected in parallel with the capacitor and the auxiliary element which are connected in series to each other.

A semiconductor switch to be provided in a power conversion device and to be connected in series to a second semiconductor switch between a positive line and a negative line of the power conversion device, the semiconductor switch comprising:

• a main element including a voltage-drive-type switching element and a first antiparallel diode connected in anti-parallel with the switching element;
• and
• a reverse voltage application circuit which is connected in parallel with the main element, and which includes a high-speed free wheeling diode, a capacitor, an auxiliary element, and a second antiparallel diode;
• wherein:
• the high-speed free wheeling diode has a reverse recovery time which is shorter than a reverse recovery time of the first antiparallel diode, and a reverse recovery charge which is smaller than a reverse recovery charge of the first antiparallel diode;
• the capacitor is connected in parallel to a power supply;
• the auxiliary element is turned on at a dead time set before the second semiconductor switch is turned on;
• the second antiparallel diode is connected in anti-parallel with the auxiliary element;
• and
• the high-speed free wheeling diode, the capacitor, and the auxiliary element are connected in series to each other.

A power conversion device comprising:

• first and second semiconductor switches connected in series to each other between a positive line and a negative line, the first semiconductor switch being connected to the positive line, and the second semiconductor switch being connected to the negative line;
• wherein the first semiconductor switch comprises:
• a first main element including a voltage-drive-type switching element and an antiparallel diode connected in anti-parallel with the switching element;
• and
• a first reverse voltage application circuit which is connected in parallel with the first main element, and which includes a high-speed free wheeling diode, a capacitor, and an auxiliary element;
• wherein:
• the high-speed free wheeling diode comprises a plurality of diodes connected in series to each other, and has a reverse recovery time which is shorter than a reverse recovery time of the antiparallel diode, and a reverse recovery charge which is smaller than a reverse recovery charge of the antiparallel diode;
• the capacitor is connected to a power supply;
• the auxiliary element is turned on at a dead time set before the second semiconductor switch is turned on;
• and
• the high-speed free wheeling diode, the capacitor, and the auxiliary element are connected in series to each other;
• and
• wherein the second semiconductor switch comprises:
• a second main element including a voltage-drive-type switching element and an antiparallel diode connected in anti-parallel with the switching element;
• and
• a second reverse voltage application circuit which is connected in parallel with the second main element, and which includes a high-speed free wheeling diode, a capacitor, and an auxiliary element;
• wherein:
• the high-speed free wheeling diode comprises a plurality of diodes connected in series to each other, and has a reverse recovery time which is shorter than a reverse recovery time of the antiparallel diode, and a reverse recovery charge which is smaller than a reverse recovery charge of the antiparallel diode;
• the capacitor is connected to a power supply;
• the auxiliary element is turned on at a dead time set before the first semiconductor switch is turned on;
• and
• the high-speed free wheeling diode, the capacitor, and the auxiliary element are connected in series to each other.