Temperature detection circuit and method

Abstract

The invention provides a temperature detection circuit and method. A plurality of temperature sensors are placed in a measured object, wherein one temperature sensor is used as a main temperature sensor, and the other temperature sensors are used as standby temperature sensors. Each temperature sensor is connected to a control chip through a corresponding signal processing circuit; the structuresof the signal processing circuits are the same; after power on, whether signals of the main temperature sensor are normal or not is detected; when the main temperature sensor breaks down, one of the standby temperature sensors is selected as the main temperature sensor, and temperature signals are transmitted to the control chip through the corresponding signal processing circuit to ensure that the control chip can continuously monitor the temperature of a measured object, thereby improving reliability of temperature detection of the measured object and the system. A temperature detection circuit carries out filtering, following, optical coupler isolation, differential amplification processing and the like on the temperature signal of the measured object, so that anti-interference capability and accuracy of the temperature detection system of the measured object in a strong electromagnetic interference environment are improved.

Description

technical field [0001] The invention relates to the field of temperature detection, in particular to a temperature detection circuit and method. Background technique [0002] The drive motor is one of the most critical and core parts of the electric vehicle. During the operation of the drive motor, due to the different driving conditions of the electric vehicle, especially when the electric vehicle accelerates and climbs, the current flowing through the motor stator is very large. The temperature varies greatly, and there is also strong electromagnetic interference. Excessive temperature of the driving motor may cause damage to the motor, especially for permanent magnet synchronous motors. Excessive temperature will cause its demagnetization and even cause serious accidents. Therefore, in the motor control system, the motor driver needs to detect and monitor the temperature of the motor to ensure the safety of the motor and the control system. [0003] In the prior art, th...

AI Technical Summary

Problems solved by technology

However, in a strong electromagnetic environment, there will be great interference to the motor temperature, resulting in inaccurate temperature detection, which cannot be accurately monitored, and electromagnetic interference will also enter the driver through the connecting line, which will seriously interfere with the normal operation of other parts of the driver; and a temperature The sensor detects the temperature of the driving motor. When the sensor is damaged or the connection line between the motor and the driver is broken, which causes the motor temperature to fail, the driver loses monitoring of the temperature of the driving motor, and the reliability is poor.

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