High-precision temperature measurement circuit with compensation function

Abstract

The invention discloses a high-precision temperature measurement circuit with a compensation function and belongs to the technical field of power electronics. The high-precision temperature measurement circuit comprises a thermistor signal processing circuit group for measurement, a thermistor signal processing circuit group for compensation and a temperature compensation circuit group. The thermistor signal processing circuit group for measurement comprises a thermistor for measurement, a constant current circuit, a follower circuit and a subtraction circuit; the thermistor signal processingcircuit group for compensation comprises a thermistor for compensation, a constant current circuit, a follower circuit and a subtraction circuit. Therefore, the influence of thermal resistance from atemperature measurement point to the thermistor body for measurement on processing errors can be weakened and the temperature value of the temperature measuring point can be obtained more accurately;meanwhile, an adjustable voltage division circuit is adopted, and adjustment can be conducted according to the actual application working condition, so that the application range is widened; the constant-current circuit is applied to provide power for the thermistor, and subsequent linear electric signal processing is facilitated.

Description

technical field [0001] The invention relates to the technical field of power electronics, more specifically, to a high-precision temperature measuring circuit with a compensation function. Background technique [0002] The bridge arm of the MMC flexible direct current transmission converter valve is composed of many power units in series. Under rated operating conditions, each power module will generate thousands of watts of power consumption. The state, as well as the forward voltage drop and reverse recovery state of the diode, will affect the loss of the power module. Since the water cooling flow of the power module is fixed, measuring the device temperature rise of the power device can reflect the loss of the power module. [0003] At present, the traditional temperature measurement method is to install a thermistor on the component under test. The thermistor is connected to the temperature measuring board through the lead wire for signal processing. However, due to the...

AI Technical Summary

Problems solved by technology

[0003] At present, the traditional temperature measurement method is to install a thermistor on the measured component, and the thermistor is connected to the temperature measuring board through the lead wire for signal processing. However, due to the existence of the lead wire, the temperature of the thermistor body will be lower than The temperature of the measured temperature point causes temperature measurement error, and the greater the temperature difference between the measured point temperature and the temperature measuring plate, the greater the measurement error

Images