Power switching apparatus
AssigneeMitsubishi Electric Corporation
InventorsShota Morisaki, Yoshiko Tamada, Yoshitaka Naka, Yukihiko Wada, Hiroyuki Takagi
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Abstract
A power switching apparatus includes a plurality of semiconductor switching devices connected in parallel with each other and a plurality of balance resistor units. The plurality of balance resistor units each have one end connected to a control electrode of an associated semiconductor switching device and the other end to which a common control signal is input. Each balance resistor unit is configured to have a resistance value switched between different values depending on whether the plurality of semiconductor switching devices are turned on or turned off in accordance with the control signal.
Claims9
A power switching apparatus comprising:
- a plurality of semiconductor switching devices connected in parallel with each other, the semiconductor switching devices each including a first main electrode, a second main electrode and a control electrode;
- a control circuit including:
- at least one output node to output a control signal for turning on and turning off each of the semiconductor switching devices;
- a first resistor element to adjust a turn-on switching speed of each of the semiconductor switching devices;
- and
- a second resistor element to adjust a turn-off switching speed of each of the semiconductor switching devices;
- a plurality of balance resistor units each associated with a respective one of the plurality of semiconductor switching devices and connected between the control electrode of the associated semiconductor switching device and the at least one output node,
- the balance resistor units each being configured to suppress parasitic oscillation between the semiconductor switching devices, the parasitic oscillation occurring during at least one of turn-on and turn-off of the semiconductor switching devices,
- the balance resistor units each being configured to have a resistance value switched between different values depending on whether the semiconductor switching devices are turned on or turned off in accordance with the control signal;
- a plurality of first protection circuits each:
- associated with a respective one of the plurality of semiconductor switching devices;
- and
- reducing a voltage between the control electrode and the first main electrode of the associated semiconductor switching device when detecting overcurrent flowing between the first main electrode and the second main electrode of the associated semiconductor switching device;
- and
- a second protection circuit configured to:
- detect current flowing through an interconnection provided for supplying the control signal;
- determine, based on the detected current, whether at least one of the plurality of first protection circuits is in operating state;
- and
- when an associated protection circuit of the plurality of first protection circuits is in operating state, change the control signal for causing each of the semiconductor switching devices to be turned off.
Dependencies are inferred from the claim text.