Partial Discharge Test System Design And Mechanism Research Of Partial Discharge In Power Cable Accessories

Partial discharge in insulating medium of Power Equipment will causeslow-deterioration, and will eventually result in insulation breakdown and leadingto insulation failure. Partial discharge tests for electrical equipment can help engineerto know the insulation condition and quality of high voltage apparatus, andensure the security and stability of electrical equipment in power system. Thus, theresearch of partial discharge has been the principal issue in the field of high-voltageinsulation.Based on the existing test equipments of a high voltage cable accessoriesmanufacture company,this paper elaborates an automatically detecting partialdischarge test system inspired by the characteristics of partial discharge process ofhigh voltage electrical equipment. The design of this system is based on DSP chip.This system can monitor the whole process of testing, and simultaneously can acquireand process data automatically to meet the requirements of the partial discharge test.Initially, the paper discusses the significance of partial discharge test ofpower equipment and states the relevant principles and developing-situation of onlinemotoring methods. It also compares the merits and limitations of these methods andanalyzes various factors that would influence the development of online detectiontechnology. Meanwhile, the equipment for partial discharge test and thetest circuits are elaborated in this issue. According to the design requirements ofthe project, an automatically detecting partial discharge test system based on DSPtechnique for high voltage cable accessories has been established.Additionally, the paper elaborates the function of DSP control system, technicalparameters and design principles of each hardware module, including the DSP powersupply modules, data storage module, communication module, etc. The system withcorresponding software and hardware can realize the high voltage test equipment’sfunctions(the auto-boost, the auto-buck, automatic data transmission and automaticgeneration of test reports and so on).The test results show that the partial dischargedetection system for high voltage cable accessories designed in this paper hasaccuracy, reliability, stability, strongly anti-interference etc. The system can alsosupervise the whole process of the test and meanwhile collect and process dataautomatically. Moreover, practical high-voltage cable terminal has been utilized to detect and identify partial discharge under the conditions of the single void in powercable accessories.Finally, According to the partial discharge model in single void of solidinsulation, researches have applied the streamer discharge model based on fluidmechanics. Besides, these researches utilize the FCT-FEM method to simulatethe formation of partial discharge pulse current. The outcome clearly shows theconcentration distribution of various charged particles and electric field distributioninside the interval during the partial discharge formation process. And the resultprovides a new theoretical approach for the research of the mechanism of partialdischarge gap and has certain theoretical and practical value.