Apparatus and method for driving a switching element, and a vehicle air-conditioning apparatus

Patent metadata

Field	Value
Publication number	US-10369867-B2
Application number	US-201414911816-A
Country	US
Kind code	B2
Filing date	Sep 3, 2014
Priority date	Oct 25, 2013
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

Abstract

A drive apparatus providing a heat source and driving a switching element, along with a corresponding method of using the drive apparatus. The switching element includes a transistor having a high-heat resistant semiconductor including silicon carbide. The drive apparatus is provided with a voltage adjusting unit that varies a drive voltage to be applied to a conduction control terminal of the switching element in order to put the switching element in an ON state, and the voltage adjusting unit applies, as the drive voltage, a voltage in an active region of the transistor to the conduction control terminal.

First claim

The invention claimed is:

1. A drive apparatus for driving a switching element, the switching element including a transistor having a high-heat resistant semiconductor including silicon carbide, the apparatus comprising:
a voltage adjusting unit configured to vary a driving voltage, the driving voltage being applied to a conduction control terminal of the switching element in order to put the switching element in an ON state;
a mode switching unit configured to switch between a normal mode and a heat generating mode; and
a temperature sensing unit configured to detect an ambient temperature of the switching element;
wherein, in the heat generating mode, when a temperature detected by the temperature sensing unit exceeds a predetermined threshold, the heat generating mode is switched to the normal mode by the mode switching unit, and
wherein the voltage adjusting unit applies, as the driving voltage, a voltage in an active region of the transistor to the conduction control terminal in the heat generating mode, and applies, as the driving voltage, a voltage in a saturation region of the transistor to the conduction control terminal in the normal mode.

2. The drive apparatus according to claim 1 , further comprising:
a current sensing unit configured to detect a current flowing in the switching element;
wherein, in the heat generating mode, the voltage adjusting unit obtains a voltage value corresponding to the current value detected by the current sensing unit from information associating a value of the current flowing in the switching element with the voltage value and applies a voltage corresponding to the obtained voltage value to the conduction control terminal.

3. A vehicle air conditioning apparatus comprising:
a heat pump cycle for heating operation, the heat pump cycle being formed by connecting an electric compressor that compresses a refrigerant, a vehicle cabin interior condenser, a throttling valve, and a vehicle cabin outside heat exchanger in that order via a refrigerant pipe;
an inverter for driving a motor of the electric compressor, the inverter including a switching element, the switching element being constituted by a transistor that includes a high-heat resistant semiconductor including silicon carbide; and
a drive apparatus of the inverter including the drive apparatus according to claim 1 ;
wherein the inverter is installed in the electric compressor so that the refrigerant compressed by the electric compressor is heatable by heat generated by the switching element; and
the mode switching unit sets the heat generating mode during the heating operation of the heat pump cycle.

4. The vehicle air conditioning apparatus according to claim 3 , wherein the mode switching unit sets the heat generating mode when an outside air temperature has dropped to a temperature that necessitates defrosting of the vehicle cabin outside heat exchanger during the heating operation of the heat pump cycle.

5. A drive method for driving a switching element, the switching element including a transistor having a high-heat resistant semiconductor including silicon carbide, the method comprising the step of;
detecting an ambient temperature of the switching element;
switching from a heat generating mode to a normal mode when the detected ambient temperature exceeds a predetermined threshold in the heat generating mode;
applying, as a driving voltage, a voltage in an active region of the transistor to a conduction control terminal of the switching element in the heat generating, mode; and
applying, as the driving voltage, a voltage in a saturation region of the transistor to the conduction control terminal in the normal mode.

Assignees

• Mitsubishi Heavy Ind Thermal Systems Ltd

Inventors

• Nagasaka Keiji
• Nakamura Hideo
• Nakano Koji
• Morishita Masatoshi
• Yakushiji Shunsuke

Classifications

• H02M1/08

  Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters · CPC title

• B60H1/00921

  where the flow direction of the refrigerant does not change and there is an extra subcondenser, e.g. in an air duct · CPC title

• B60H2001/2262

  related to the period of on/off time of the heater · CPC title

• B60H1/143

  the heat being derived from cooling an electric component, e.g. electric motors, electric circuits, fuel cells or batteries · CPC title

• B60H1/00907

  where the flow direction of the refrigerant changes and an evaporator becomes condenser · CPC title