Temperature sampling circuit, circuit board, motor controller and electric vehicle

Abstract

The invention discloses a temperature sampling circuit, a circuit board, a motor controller and an electric vehicle. The temperature sampling circuit comprises an IGBT module, a self-oscillating circuit, a digital isolator and a main control chip; a thermosensitive device is arranged in the IGBT module, the IGBT module is connected with the self-oscillating circuit through the thermosensitive device, the output end of the self-oscillating circuit is connected with the input end of the digital isolator, and the output end of the digital isolator is connected with the input end of the main control chip. According to the temperature sampling circuit, the circuit board, the motor controller and the electric vehicle, the resistance value of the thermosensitive device is converted into digital signals for transmission, since the digital signals are adopted, the precision influence of a power supply on sampling signals can be lowered, and the anti-jamming capability is better; meanwhile, theprecision influence of linear isolation devices on temperature drift, zero drift, nonlinearity, gain errors and the like can be reduced.

Description

technical field [0001] The invention relates to the technical field of vehicles, in particular to a temperature sampling circuit, a circuit board, a motor controller and an electric vehicle. Background technique [0002] At present, there are two main ways to monitor the temperature of the IGBT, and they have the following defects respectively: (1) Non-isolated resistor voltage divider: Although the circuit is simple, there is no isolation between the thermal sensor part inside the module and the low-voltage control circuit. It can guarantee the requirements of basic insulation; (2) The isolation sampling method using linear isolator: use linear isolation chip, the accuracy of linear isolation chip is greatly affected by temperature drift, zero drift, nonlinearity and gain error, etc., and higher cost. Contents of the invention [0003] In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a temperature sampling circuit,...

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Problems solved by technology

[0002] At present, there are two main ways to monitor the temperature of the IGBT, and they have the following defects respectively: (1) Non-isolated resistor voltage divider: Although the circuit is simple, there is no isolation between the thermal sensor part inside the module and the low-voltage control circuit. It can guarantee the requirements of basic insulation; (2) The isolation sampling method using linear isolator: use linear isolation chip, the accuracy of linear isolation chip is greatly affected by temperature drift, zero drift, nonlinearity and gain error, etc., and higher cost

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