Cooling system for on-board secondary battery

Abstract

A cooling system for an on-vehicle secondary battery, when the battery temperature (TB) of the main battery 10 reaches a first temperature (T0) or higher after the start of the hybrid vehicle, the cooling fan is driven at a first command value for a predetermined period of time (40) The first fixed control of the fixed control, and the abnormality detection process of detecting whether the cooling fan (40) is abnormal based on the actual rotation speed of the cooling fan (40) during the fixed control, and in addition, when the battery temperature (TB) of the main battery (10) reaches When the first temperature (T0) is above and the first fixed control is prohibited due to a predetermined condition, if the noise level in the vehicle interior reaches a predetermined value (Lo) or above, the cooling fan is driven at a second command value (D3) ( 40) of the second fixed control, and abnormality detection processing is performed based on the actual rotation speed of the cooling fan (40) during the second fixed control. Thereby, it is possible to sufficiently secure a chance to detect whether or not there is an abnormality in the cooling fan while suppressing discomfort to the occupants and overheating of the secondary battery.

Description

[0001] This application claims priority based on Japanese Patent Application No. 2015-080686 filed on April 10, 2015, and the contents thereof are incorporated herein by reference. technical field [0002] The present invention relates to a cooling system for cooling a secondary battery for driving a hybrid vehicle. Background technique [0003] A hybrid vehicle is equipped with a secondary battery (battery) that stores electrical energy for driving the vehicle. The temperature of the secondary battery rises as charge and discharge are performed due to its own internal resistance. Therefore, in the prior art, some solutions have been proposed, that is, a cooling fan is provided around the secondary battery, and the secondary battery is forcedly air-cooled by the cooling fan. [0004] For example, Japanese Patent Application Laid-Open No. 2010-158964 discloses a cooling device for electrical components of a vehicle, which includes a cooling fan near a secondary battery. In ...

AI Technical Summary

Problems solved by technology

However, when the cooling fan is driven at a fixed duty ratio, it is of course difficult to perform appropriate cooling according to the temperature of the secondary battery. For example, if the rotation speed is insufficient to sufficiently cool the secondary battery, there is a possibility that the secondary battery may overheat.

[0008] In addition, in order to cope with high-temperature secondary batteries, constant control of the cooling fan in a high-output state (such as the maximum duty ratio) has been studied, but this will cause excessive cooling (overcooling) of the secondary battery.

In addition, there was a problem that the noise of the cooling fan became louder, causing discomfort to passengers.

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