The Design And Research Of The Digital Device Of Dielectric Loss Measurement Based On DSP

With the rapid development of electric power enterprise, the demand on the reliability of electric power system is further more, and the development of insulation monitoring technique has been paid more attention. The dielectric loss factor tand measurement of high voltage power apparatus is very important to guarantee the safety of power system running, find insulation faults in time and increase the reliability of power supply. Therefore, the study on the tand measurement of high voltage equipment has important practical meaning.On the basis of analysis and comparison of conventional and some moderndielectric loss measurement methods in this paper, aim at the impact of the dielectric loss measurement result because of the interference of the electric field and high harmonic, using the method of frequency conversion,to avoid the main frequency interference; At the same time, adopt digital filtering technology, design digital comb notch filter, then, the harmonic and DC interference is to be eliminated effectively. Use the fundamental waves phase detachment method, Extract the fundamental signals, carry out the dielectric loss tand measurement.In this paper, the effect of comb notch filter is verified through simulation by Matlab, Difference equation of the comb notch filter is to be deduced.Thus,it can be directly applied to program design. On this basis, the paper gives a block diagram of the overall system, and designs a digital device of dielectric loss measurement based on DSP TMS320LF2407; Designs a PLL frequency circuit and selecte a Dual A/D converter, so as to achieving two-way signals in the synchronous sampling; Adopts the method of infrared data communication to realize the signal high-voltage isolation transmission in reverse measurement; Designs the automatic gain control circuit to achieve wide-range measurements...