Temperature abnormality detection method for power conversion apparatus, and temperature abnormality detection device for power conversion apparatus

Patent metadata

Field	Value
Publication number	US-10739207-B2
Application number	US-201616302761-A
Country	US
Kind code	B2
Filing date	May 27, 2016
Priority date	May 27, 2016
Publication date	Aug 11, 2020
Grant date	Aug 11, 2020

Abstract

A temperature abnormality detection method for a power conversion apparatus basically includes a detecting a first power converter temperature, a second power converter temperature and a cooling water temperature and then determining a presence of an abnormality in a preceding stage power converter based on a first temperature difference between the first power converter temperature and the cooling water temperature. The abnormality detection method further includes determining a presence of an abnormality in a subsequent stage power converter based on a second temperature difference between the second power converter temperature and an added temperature that is obtained by adding to the loss component of the preceding stage power converter converted to a temperature to the cooling water temperature.

First claim

The invention claimed is:

1. A temperature abnormality detection method for a power conversion apparatus provided with a plurality of power converters that convert and transmit electric power, and a cooling flow path that passes through the plurality of power converters and cools each of the power converters, the method comprising:
detecting temperatures of the plurality of power converters and detecting a temperature of a cooling fluid of the cooling flow path on an upstream side of the plurality of power converters;
determining a presence of an abnormality in a preceding stage power converter disposed upstream in the cooling flow path from among the plurality of power converters based on a difference between a temperature of the preceding stage power converter and the temperature of the cooling fluid; and
determining a presence of an abnormality in a subsequent stage power converter disposed downstream from the preceding stage power converter in the cooling flow path based on a difference between the temperature of the subsequent stage power converter and a temperature obtained by converting a loss component of the preceding stage power converter into a temperature which is added to the temperature of the cooling fluid.

2. The temperature abnormality detection method according to claim 1 , wherein
the temperature obtained by converting the loss component is set to a value based on a temperature that is converted from a maximum loss assumed in the preceding stage power converter.

3. The temperature abnormality detection method according to claim 1 , wherein
the temperature obtained by converting the loss component is set to a value that is calculated based on loss calculation information that includes at least one of a semiconductor characteristic, a carrier frequency or a current in the preceding stage power converter.

4. The temperature abnormality detection method according to claim 1 , wherein
the temperature obtained by converting the loss component is set to a value that is estimated based on the difference between the temperature of the preceding stage power converter and the temperature of the cooling fluid.

5. A temperature abnormality detection device for a power conversion apparatus, the temperature abnormality detection device comprising:
a plurality of power converters that convert and transmit electric power;
a cooling flow path that passes through the plurality of power converters and cools each of the power converters;
a plurality of power converter temperature sensors that detect temperatures of the plurality of power converters;
a cooling fluid temperature sensor that detects a temperature of a cooling fluid of the cooling flow path that is upstream from the plurality of power converters;
a preceding stage temperature difference calculation unit that calculates a difference between a cooling fluid temperature and a temperature of a preceding stage power converter disposed upstream in the cooling flow path;
a preceding stage power converter abnormality detection unit that carries out abnormality determination based on the difference calculated by the preceding stage temperature difference calculation unit;
a temperature addition unit that converts a loss component of the preceding stage power converter into a temperature and adds the temperature corresponding to the loss component to the cooling fluid temperature;
a subsequent stage temperature difference calculation unit that calculates a difference between the temperature calculated by the temperature addition unit and a temperature of a subsequent stage power converter disposed downstream from the preceding stage power converter in the cooling flow path; and
a subsequent stage power converter abnormality detection unit that carries out abnormality determination based on the difference calculated by the subsequent stage temperature difference calculation unit.

Assignees

• Nissan Motor

Inventors

• Maruyama Sho

Classifications

• H10W40/47

  by flowing liquids, e.g. forced water cooling · CPC title

• G01K3/08 Primary

  giving differences of values (using thermoelectric elements G01K7/02); giving differentiated values · CPC title

• H02M1/327

  against abnormal temperatures · CPC title

• H02M1/32

  Means for protecting converters other than automatic disconnection · CPC title

• H02M7/5395

  by pulse-width modulation · CPC title