Power conversion apparatus and method of estimating power cycle life

• US 7,904,254 B2
• Filed: 02/29/2008
• Issued: 03/08/2011
• Est. Priority Date: 04/20/2007
• Status: Active Grant

• Current Assignee: Hitachi Industrial Equipment Systems Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi Industrial Equipment Systems Company Limited (Hitachi, Ltd.)
• Inventors: Hirota, Masayuki, Ibori, Satoshi, Hiraga, Masahiro, Kamezawa, Tomoya, Mao, Jiangming
• Primary Examiner(s): Cosimano; Edward R
• Application Number:
  US12/039,979
• Publication Number:
  US 20080262750A1
• Time in Patent Office: 1,103 Days
• Field of Search: 324/71.1, 324/71.5, 340/500, 340/540, 340/584, 340/588, 340/635, 340/645, 340/646, 340/653, 340/654, 340/679, 374/100, 374/101, 374/102, 374/141, 374/152, 702/1, 702/33, 702/34, 702/127, 702/130, 702/132, 702/182, 702/187, 702/189
• US Class Current: 702/34
• CPC Class Codes: H02M 5/451 with automatic control of output voltage or frequency

Abstract

For applications in a facility where a power conversion apparatus is frequently started and stopped, a power conversion apparatus and a power cycle longevity estimation method are provided which improve an ease of use of the facility. The power conversion apparatus comprises power conversion circuits to supply ac power of variable voltage and variable frequency, a detection circuit to detect a temperature of the power semiconductor in the power conversion circuits, and a computation device to calculate a power cycle longevity of the power semiconductor based on a maximum temperature rise detected by the detection circuit.

Claims

1. A power conversion apparatus comprising:

a power conversion circuit to supply an ac power of variable voltage and variable frequency;

a detection circuit to detect a temperature of a power semiconductor in the power conversion circuit; and

a computation device to diagnose a power cycle longevity of the power semiconductor from a detected value of the detection circuit.

2. A power conversion apparatus according to claim 1, wherein the computation device calculates a power cycle longevity of the power semiconductor based on a maximum temperature rise in a start/stop operation pattern of the power conversion apparatus.

3. A power conversion apparatus according to claim 1, wherein the detection circuit is provided inside the power semiconductor and a temperature detection signal from a temperature sensing element installed inside a power semiconductor module is used to calculate the power cycle longevity of the power semiconductor.

4. A power conversion apparatus according to claim 1, further including a cooling fin having the power semiconductor mounted thereon,

wherein a temperature detection signal from a temperature sensing element mounted on the cooling fin is used to calculate the power cycle longevity of the power semiconductor.

5. A power conversion apparatus according to claim 1, wherein the detection circuit is provided inside the power semiconductor and a temperature detection signal from a temperature sensing element installed inside a power semiconductor module is used to calculate the power cycle longevity of the power semiconductor;

wherein the temperature sensing element in the temperature detection circuit is formed of a thermistor that exhibits a resistance proportional to the temperature.

6. A power conversion apparatus according to claim 1, further including a cooling fin having the power semiconductor mounted thereon,

wherein a temperature detection signal from a temperature sensing element mounted on the cooling fin is used to calculate the power cycle longevity of the power semiconductor;

wherein the temperature sensing element in the temperature detection circuit is formed of a thermistor that exhibits a resistance proportional to the temperature.

7. A power conversion apparatus according to claim 1, further including a display unit that displays a power cycle longevity in years based on the temperature detected by the detection circuit.

8. A power conversion apparatus according to claim 1, wherein the computing device calculates the power cycle longevity of the power semiconductor based on a maximum temperature rise in a start/stop operation pattern of the power conversion apparatus;

wherein a display unit is provided which displays the power cycle longevity in years based on the temperature detected by the detection circuit.

9. A power conversion apparatus according to claim 1, wherein the detection circuit is provided inside the power semiconductor and a temperature detection signal from a temperature sensing element installed inside a power semiconductor module is used to calculate the power cycle longevity of the power semiconductor;

wherein a display unit is provided which displays the power cycle longevity in years based on the temperature detected by the detection circuit.

10. A power conversion apparatus according to claim 1, further including a cooling fin having the power semiconductor mounted thereon,

wherein a temperature detection signal from a temperature sensing element mounted on the cooling fin is used to calculate the power cycle longevity of the power semiconductor;

wherein a display unit is provided which displays the power cycle longevity in years based on the temperature detected by the detection circuit.

11. A power conversion apparatus according to claim 1, wherein the detection circuit is provided inside the power semiconductor and a temperature detection signal from a temperature sensing element installed inside a power semiconductor module is used to calculate the power cycle longevity of the power semiconductor;

wherein the temperature sensing element in the temperature detection circuit is formed of a thermistor that exhibits a resistance proportional to the temperature;

wherein a display unit is provided which displays the power cycle longevity in years based on the temperature detected by the detection circuit.

12. A power conversion apparatus according to claim 1, further including a cooling fin having the power semiconductor mounted thereon,

wherein a temperature detection signal from a temperature sensing element mounted on the cooling fin is used to calculate the power cycle longevity of the power semiconductor;

wherein the temperature sensing element in the temperature detection circuit is formed of a thermistor that exhibits a resistance proportional to the temperature;

wherein a display unit is provided which displays the power cycle longevity in years based on the temperature detected by the detection circuit.

13. A power conversion apparatus according to claim 1, further including a display unit that displays a power cycle longevity in years based on the temperature detected by the detection circuit and a temperature difference used in calculating the power cycle longevity in years.

14. A power conversion apparatus according to claim 1, further including an operation panel to set the power cycle longevity in years based on the temperature detected by the detection circuit and an operation condition of the power conversion apparatus;

wherein a display unit is provided in the operation panel.

15. A power conversion apparatus according to claim 1, further including

a display unit that displays a power cycle longevity in years based on the temperature detected by the detection circuit and a temperature difference used in calculating the power cycle longevity in years and

an operation panel to set an operation condition of the power conversion apparatus;

wherein a display unit is provided in the operation panel.

16. A power conversion apparatus according to claim 1, further including an operation panel to set the power cycle longevity in years based on the temperature detected by the detection circuit and an operation condition of the power conversion apparatus;

wherein a display unit is provided in the operation panel;

wherein the operation panel can select a test mode as an operation condition of the power conversion apparatus.

17. A power conversion apparatus according to claim 1, further including

a display unit that displays a power cycle longevity in years based on the temperature detected by the detection circuit and a temperature difference used in calculating the power cycle longevity in years and

an operation panel to set an operation condition of the power conversion apparatus;

wherein a display unit is provided in the operation panel;

wherein the operation panel can select a test mode as an operation condition of the power conversion apparatus.

18. A power conversion apparatus according to claim 1, further including an operation panel to set the power cycle longevity in years based on the temperature detected by the detection circuit and an operation condition of the power conversion apparatus;

wherein a display unit is provided in the operation panel;

wherein the operation panel can select a test mode as an operation condition of the power conversion apparatus;

wherein, when the test mode is selected, the operation panel can be used to set, as the operation condition of the power conversion apparatus, the number of times that a start/stop action is repeated per unit time, operational hours in a day and operational days in a year.

19. A power conversion apparatus according to claim 1, further including

a display unit that displays a power cycle longevity in years based on the temperature detected by the detection circuit and a temperature difference used in calculating the power cycle longevity in years and

an operation panel to set an operation condition of the power conversion apparatus;

wherein a display unit is provided in the operation panel;

wherein the operation panel can select a test mode as an operation condition of the power conversion apparatus;

wherein, when the test mode is selected, the operation panel can be used to set, as the operation condition of the power conversion apparatus, the number of times that a start/stop action is repeated per unit time, operational hours in a day and operational days in a year.

20. A power cycle longevity estimation method to diagnose a power cycle longevity of a power semiconductor installed in a power conversion circuit that supplies an ac power of variable voltage and variable frequency, the power cycle longevity estimation method comprising the steps of:

detecting a temperature of the power semiconductor; and

calculating the power cycle longevity of the power semiconductor based on a maximum temperature rise determined from the detected temperatures of the power semiconductor.