Acquisition circuit and method for improving acquisition accuracy of temperature sensor

Abstract

The invention relates to an acquisition circuit and method for improving the acquisition accuracy of a temperature sensor, comprising a thermistor Rntc, an impedance Rx of a temperature-sensing acquisition line, and a pull-up resistor R1 sequentially connected in series between a ground terminal GND and a power supply voltage terminal VDD; The VAD terminal is used to collect the AD voltage value Vad of the CPU terminal, and the terminal is connected between the impedance Rx of the temperature sensing acquisition line and the pull-up resistor R1; the resistor R2 is connected in parallel to both ends of the thermistor Rntc; the switch S1 is used for Control the on-off of the branch where the resistor R2 is located; first obtain the impedance value of the temperature-sensing acquisition line impedance RX, and then calculate the precise resistance value of the thermistor Rntc according to the temperature-sensing acquisition line impedance RX.

Description

A collection circuit and method for improving the collection accuracy of a temperature sensor technical field The invention belongs to the field of new energy vehicle battery management system, especially the electric power that improves the acquisition accuracy of temperature sensor. Ways and Methods. Background technique Battery management system (Battery Management System, BMS) is one of the core components of electric vehicles. First, it has always been the focus of electric vehicle research and development; in the BMS system, the temperature sensor is generally used to collect the temperature of the charging socket or thermal management. The temperature of the coolant inlet and outlet, but the temperature-sensitive connector and the wiring harness are used for a long time, such as vibration, aging, condensation, etc. Factors such as dew are likely to appear: cause the looseness of the temperature sensor connection line: when the connection line is loose, it is e...

AI Technical Summary

Problems solved by technology

[0002] As one of the core components of electric vehicles, the battery management system (BMS) has always been the focus of electric vehicle research and development; in the BMS system, the temperature sensor is generally used to collect the temperature of the charging socket or the temperature of the coolant inlet and outlet for thermal management, but During the long-term use of the connector and wiring harness connected to the temperature sensor, factors such as vibration, aging, condensation, etc. will likely appear: cause the temperature sensor connection line to loosen and fail: when the connection line is loose and faulty, it is equivalent to the temperature sensor acquisition line The impedance above becomes larger, and the extra impedance will be superimposed on the calculation result of the NTC's temperature resistance value, resulting in a large error in the temperature value after the table lookup. According to the law of the RT table of temperature sense, the larger the resistance value is The smaller the temperature value of the meter, the smaller the calculated temperature value will be when the actual temperature is already high, which will make the BMS system fail to diagnose the temperature of the charging socket or the water inlet and outlet. In fact, the temperature of the charging socket It is already very high, and the charging operation needs to be disconnected but not disconnected, resulting in extreme dangers such as fire, or the actual battery is still very hot and needs to continue cooling without continuing to cause the battery to overheat and cause extreme dangers such as thermal runaway

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