Research On Active On-Line Insulation Device For Electric Vehicle

With oil crisis and people's enhanced consciousness for environment protection, more and more attentions are paid to EV. In all kinds of cars, EV has become one of the most important development directions, due to the realization of the true "zero emission". Compared with the traditional car, battery provides power to EV, where the insulation performance has been put forward higher request. In order to ensure the safety of the passenger and the car, developing the real-time, accurate and reliable monitoring device for EV insulation states have great necessary.Firstly, this paper introduces some insulation monitoring methods and points out their shortages, then gives us an algorithm of insulation detection based on EV. The characteristic of this algorithm is that the DC signal is injected through the positive and negative insulation resistance. This method can improve the calculation accuracy of insulation resistance. The transformer separates the sampling unit and high voltage side. Lastly, we deduce the calculation formula of insulation resistance. Considering the applying environment and compression problem, we give the optimization design of PCB.For the software part, a system software compiler environment is described. By introducing the flow chart of the main program and subroutine descriptions, each module function of the program is shown.At the end of the article, it shows us some pictures about experimental platform and commissioning procedures. The experimental data illustrate that the insulation monitoring device for insulation resistance measurement is accurate and reliable.