Semiconductor device and power conversion apparatus

A semiconductor device comprising:

• a first circuit including semiconductor switching elements connected in parallel, each semiconductor switching element having a first electrode, a second electrode, and a third electrode and being configured to be controlled, according to a voltage between the first electrode and the third electrode, to attain conduction or non-conduction between the second electrode and the third electrode;
• and
• a controlling circuitry connected to the first electrode of each semiconductor switching element and configured to control the voltage between the first electrode and the third electrode, wherein
• the semiconductor device is configured to satisfy a first condition that an impedance Zg on a first path between the first electrodes of the respective semiconductor switching elements is higher, by at least a set value, than an impedance Zs on a third path making connection between the third electrodes of the respective semiconductor switching elements,
• the first condition is satisfied on the basis of an impedance at a resonance frequency of a series resonance circuit including:
• an inductance component on a second path making connection between the second electrodes of the respective semiconductor switching elements;
• an inductance component and a resistance component on the first path;
• and a capacitance component of each semiconductor switching element,
• the set value is indicated as Zg/Zs which is a multiplication value, for the impedance Zg on the first path, relative to the impedance Zs on the third path, and
• the multiplication value Zg/Zs is set to 10.

A power conversion apparatus comprising:

• a power converter having phases and configured to perform power conversion between DC and AC;
• and
• a semiconductor device provided to each of the phases, wherein
• the semiconductor device comprising:
• a first circuit including semiconductor switching elements connected in parallel, each semiconductor switching element having a first electrode, a second electrode, and a third electrode and being configured to be controlled, according to a voltage between the first electrode and the third electrode, to attain conduction or non-conduction between the second electrode and the third electrode;
• and
• a controlling circuitry connected to the first electrode of each semiconductor switching element and configured to control the voltage between the first electrode and the third electrode, wherein
• the semiconductor device is configured to satisfy a first condition that an impedance Zg on a first path between the first electrodes of the respective semiconductor switching elements is higher, by at least a set value, than an impedance Zs on a third path making connection between the third electrodes of the respective semiconductor switching elements,
• wherein the controlling circuitry controls the power converter to perform power conversion between DC and AC,
• the first condition is satisfied on the basis of an impedance at a resonance frequency of a series resonance circuit including:
• an inductance component on a second path making connection between the second electrodes of the respective semiconductor switching elements;
• an inductance component and a resistance component on the first path;
• and a capacitance component of each semiconductor switching element,
• an inductive inductance element having a frequency characteristic that an impedance thereof increases at a resonance frequency of the series resonance circuit, is provided on the first path, and
• the first condition is satisfied on the basis of the impedance at the resonance frequency of the series resonance circuit including the inductive inductance element.