Inverter device and method for detecting heat dissipation characteristics of inverter device

Patent metadata

Field	Value
Publication number	US-11016045-B2
Application number	US-201816110724-A
Country	US
Kind code	B2
Filing date	Aug 23, 2018
Priority date	Dec 18, 2017
Publication date	May 25, 2021
Grant date	May 25, 2021

Abstract

According to one embodiment, an inverter device configured to be capable of switching an on or off state of each of a plurality of switching elements, on the basis of a control command signal, and operable as a single-phase inverter, includes: a pulse width modulator configured to set a voltage value at a time when one of the switching elements is set to the on state to a first voltage, and set a voltage value at a time when the other three of the switching elements are set to the on state to a second voltage larger than the first voltage, in operation as the single-phase inverter; and a detection unit configured to detect the control command signal in operation as the single-phase inverter.

First claim

What is claimed is:

1. An inverter device comprising:
a first switching element electrically connected between a first node and a second node;
a second switching element electrically connected between a third node and the second node;
a third switching element electrically connected between the first node and a fourth node;
a fourth switching element electrically connected between the third node and the fourth node;
a current feedback controller configured to output a control command signal to control an on or off timing of the first to the fourth switching elements on the basis of a current signal indicating a current flowing through the second node or the fourth node;
a pulse width modulator configured to be capable of switching an on or off state of each of the first to the fourth switching elements on the basis of the control command signal; and
a detection unit configured to detect heat dissipation characteristics of each of the first to the fourth switching elements on the basis of the control command signal,
wherein, when the detection unit detects the heat dissipation characteristics of each of the first to the fourth switching elements, the pulse width modulator applies a first voltage to one of the first to the fourth switching elements at a time when the one of the first to the fourth switching elements is set to the on state, and applies a second voltage larger than the first voltage to other three of the first to the fourth switching elements at a time when the other three of the first to the fourth switching elements are set to the on state.

2. The device of claim 1 , wherein the pulse width modulator is configured to switch the on or off state of each of the first to the fourth switching elements by generating first to fourth pulse width modulation signals.

3. The device of claim 1 , wherein the detection unit is configured to detect the heat dissipation characteristics of the switching element to which the first voltage is input on the basis of the control command signal.

4. The device of claim 1 , wherein the detection unit is configured to:
extract an upper envelope and a lower envelope of the control command signal, and
detect the heat dissipation characteristics of the switching element to which the first voltage is input on the basis of a difference between a value of the upper envelope and a value of the lower envelope after a predetermined time period has passed.

5. The device of claim 4 , wherein the detection unit is configured to detect the heat dissipation characteristics of the switching element to which the first voltage is input on the basis of whether the difference exceeds a predetermined threshold.

6. The device of claim 1 , further comprising:
a fifth switching element electrically connected between the first node and a fifth node; and
a sixth switching element electrically connected between the third node and the fifth, node;
wherein the pulse width modulator is configured to switch the fifth switching element and the sixth switching element to an off state when the heat dissipation characteristics of each of the first to the fourth switching elements is detected.

7. The device of claim 6 , wherein
an on-resistance of each of the first to the sixth switching elements decreases with an increase in temperature when each of the first to the sixth switching elements is switched to the on state with the first voltage, and
increases with an increase in temperature when each of the first to the sixth switching elements is switched to the on state with the second voltage.

8. The device of claim 7 , wherein
each of the first to the sixth switching elements includes a plurality of field effect transistors connected in parallel.

9. The device of claim 8 , wherein
each of the field effect transistors includes silicon carbide (SiC).

10. An inverter device configured to be capable of switching an on or off state of each of a plurality of switching elements on the basis of a control command signal, and be operable as a single-phase inverter, comprising:
a pulse width modulator configured to apply a first voltage to one of the switching elements at a time when the one of the switching elements is set to the on state, and apply a second voltage larger than the first voltage to other three of the switching elements at a time when the other three of the switching elements are set to the on state when the inverter device operates as the single-phase inverter; and
a detection unit configured to detect the control command signal when the inverter device operates as the single-phase inverter.

11. The device of claim 10 , wherein the detection unit is configured to:
extract an upper envelope and a lower envelope of the control command signal, and
detect heat dissipation characteristics of the one of the switching elements to which the first voltage is input on the basis of a difference between a value of the upper envelope and a value of the lower envelope after a predetermined time period has passed.

12. The device of claim 11 , wherein
the detection unit is configured to detect the heat dissipation characteristics of the switching element to which the first voltage is input on the basis of whether the difference exceeds a predetermined threshold.

13. The device of claim 10 , wherein
an on-resistance of each of the switching elements decreases with an increase in temperature when each of the switching elements is switched to the on state with the first voltage, and
increases with an increase in temperature when each of the switching elements is switched to the on state with the second voltage.

14. The device of claim 13 , wherein
each of the switching elements includes a plurality of field effect transistors connected in parallel.

15. The device of claim 14 , wherein
each of the field effect transistors includes silicon carbide (SiC).

16. A method for detecting heat dissipation characteristics executed with an inverter device configured to be capable of switching an on or off state of each of a plurality of switching elements with a plurality of pulse width modulation signals generated on the basis of a control command signal generated on the basis of a current flowing through a motor coil, the inverter device configured to be operable as a single-phase inverter, comprising:
when the inverter device operates as the single-phase inverter,
setting one of the pulse width modulation signals to a first voltage when one of the switching elements is set to the on state, and setting other pulse width modulation signals to a second voltage larger than the first voltage when other switching elements are set to the on state; and
detecting the heat dissipation characteristics of the switching element to which the first voltage is applied on the basis the control command signal.

17. The method of claim 16 , wherein
an on-resistance of each of the switching elements decreases with an increase in temperature when each of the switching elements is switched to the on state with the first voltage, and
increases with an increase in temperature when each of the switching elements is switched to the on state with the second voltage.

18. The method of claim 16 , wherein
the detecting includes:
extracting an upper envelope and a lower envelope of the control command signal; and
detecting the heat dissipation characteristics of the switching element to which the first voltage is input on the basis of a difference between a value of the upper envelope and a value of the lower envelope after a predetermined time period h

Assignees

• Toshiba Kk

Inventors

• Takakura Shinji
• Yasunaka Shigen

Classifications

• H05K7/209 Primary

  Heat transfer by conduction from internal heat source to heat radiating structure (H05K7/20909 takes precedence) · CPC title

• H02P29/68

  based on the temperature of a drive component or a semiconductor component · CPC title

• G01N25/18 Primary

  by investigating thermal conductivity (by calorimetry G01N25/20; by measuring change of resistance of an electrically-heated body G01N27/18) · CPC title

• H05K7/20945

  Thermal management, e.g. inverter temperature control · CPC title

• H02M1/088

  for the simultaneous control of series or parallel connected semiconductor devices · CPC title