Design of a multichannel dynamic temperature measurement system for developing thermal management system of new energy vehicles

A multichannel temperature measurement system based on LabVIEW and modular instruments with general purpose input/output interface is described. External simple electronic components, such as analog switches arrays, sampling resistors and voltage reference are used to expand the analog input channel of the instrument. The interface circuit for 3-wire resistance temperature device powered by the voltage reference was designed and constructed. The feasibility of filtering algorithm based on moving average filter and the data conversion method by direct computation of the polynomial are verified in LabVIEW. A comparison test with the commercial temperature measurement instrument is conducted to test the same point of a li-ion battery. Meanwhile, the temperature in different points on the surface of a battery was clearly captured by the proposed system, when the battery was discharging. The results of the test clearly shows that the two channels for comparison has basically the same curve progression with a deviation of less than 0.2°C. The temperature measurement accuracy is better than ±0.3°C, and the sampling rate reaches 1000 Hz. The temperature measurement system can be used in the development of new energy vehicle thermal management system especially when the number of points to be measured exceeds the number of sampling channels of the instruments. © 2020, Tech Science Press. All rights reserved.