This paper presents an equivalent circuit of high frequency voltage-controlled switch model of IGBT, and a surge voltage absorption circuit as well. This model can not only significantly reduce the surge voltage, decrease EMI noise, but also obviously inhibit common mode voltage towards the DC power mains.
In this paper, the software development of vehicle switch detection systems is explained in detail. The system software is programmed by Visual C++ 6.0 (hereinafter referred to as VC) which is page-friendly and easy for operation. Under the control of the software, the data collection card can collect real-time data through multiple high speed channels. At the same time, the software has date processing function which differentiate the abnormal data and use reasonable and reliable data to replace abnormal data. Finally, the accurate data can be displayed by Teechart control. The accuracy and reliability of the test result are approved by experiments, which meet the requirements of vehicle switch detection.
Using PLC and Kingview software, a friction durability test system is designed. The overall program, hardware configuration, software structure and monitoring interface are described in detail. PLC ensures the stability of data acquisition, and the KingView software makes the HMI easy to manipulate. The practical application shows that the proposed system is cheap, economical and highly reliable.