Development Of Insulation Parameter Testing Of Train

Insulation parameter testing of train is an important means to ensure the train normally power supply and the train traffic safety.Insulation parameter testing of train has some characteristics: Firstly, only one insulation parameter needs to be tested. The insulation resistance between phases and to the ground will be tested. Secondly, it has a large amount of testing data. Not only the main train but also the sub train needs to test insulation resistances. In addition, according to different forms of distribution, for example the three-phase 4-wire distribution form, we need to test the resistances between phases of AB,AC,BC,AN,BN and CN, so the amount of data is very large. Thirdly, it needs to print data measured at the scene to ensure the reliability of the data. Finally, the instrument must be small size, light weight, easy to carry.This thesis introduces the hardware and software project design of insulation parameter testing instrument and their application.High-voltage generator is an important part of the insulation testing instrument. This paper designed a DC-DC boost circuit, whose unique transformer winding structure and PWM work methods make the structure of circuit simple, decrease the volume of instrument and switch the voltage range in the low voltage-switching, thus it can improve security of the system.The accuracy of measurement data is an important specification according to the testing system. Not only power stability will affect the accuracy, but the measurement method will. In this paper, double slip measurement model is introduced, its measuring principle is very simple, and easy to realize. More importantly it can offset the impact of the power stability, reduce the difficulty of power production and improve the data accuracy.In addition, this thesis extends the memory cell based on microcontroller SPI interface. Insulation resistance values, measuring time, measuring train, measuring staff, temperature and humidity at the scene can be stored in the form of stored records. It can meet the requirement of large amount of data measured and facilitate data query.At the same time, the system also provides micro-printer interface, which can printer data measured at the scene. It can improve data reliability.This instrument helps operator judge the insulation state of train, improve the efficiency of fault judgment and guarantee the train traffic safety.