Patent ID: 7607827

Claim:
A temperature detection device comprising: a cooling medium temperature calculation device that is configured to calculate a temperature of a cooling medium in a cooling system in which a temperature detection subject driven at a prescribed driving ratio is cooled; a heat calculation device that is configured to calculate an amount of heat at the temperature detection subject based on drive information for the temperature detection subject; a temperature calculation device that is configured to calculate a temperature of the temperature detection subject based on the amount of heat calculated by the heat calculation device, a thermal resistance between the temperature detection subject and the cooling medium, and the temperature of the cooling medium calculated by the cooling medium temperature calculation device; a correction device that is configured to correct the amount of heat calculated by the heat calculation device using a temperature of the temperature detection subject calculated in a previous calculation period by the temperature calculation device; wherein the temperature calculation device is configured to calculate a temperature of the temperature detection subject based on the amount of heat corrected by the correction device, the thermal resistance, and the temperature of the cooling medium; a current detection device that is configured to detect a value of current flowing through the temperature detection subject; and a voltage detection device that is configured to detect a value of voltage applied to the temperature detection subject; wherein the current value detected by the current detection device, the voltage value detected by the voltage detection device, and drive ratio information for the temperature detection subject are configured to be contained in the drive information for the temperature detection subject.