Development Of Dielectric Loss Measuring Instrument Based On DSP With Variable Frequency Method

In this thesis, traditional and some modern dielectric loss measurement methods were analysed and explained firstly, then dielectric loss variable frequency method was presented on the basis of considering the interference of strong electric field with the power frequency in local measurement. Meanwhile, the hardware and the software of dielectric loss measuring instrument with variable frequency method were introduced.In this subject, the controlling center of the hardware system was TMS320F2810. The hardware of this system mainly included variable frequency power, signal sampling, interface circuit of LCD( Liquid Crystal Display), printer, keyboard, communication, and the direct-current power supply etc. As to software, C language programs were designed to achieve the functions of control, measuring, display, key, print and communication etc.In local dielectric loss measurement, the measurement accuracy was influenced by the interference of strong electric field with the power frequency. In order to improve measurement accuracy, we changed the same-frequency interference to different-frequency interference, and combined with Fourier transform frequency spectrum analysis to get parameter of dielectric loss. Based on this theory, a dielectric loss measuring instrument with variable frequency method was designed.Anti-interference measures were considered in hardware and software of this design, which made the whole measuring system have good anti-jamming perforance and high measurement precision.