Research On Partial Discharge Detection And Recording Technology Of Insulation Test Based On ARM+FPGA

The insulation reliability of the insulating medium(insulating material or insulation structure,etc.)of electrical equipment directly affects the safe and stable operation of the equipment.The reduction of insulation reliability is often caused by the insulation degradation of the insulating medium,and led to the decline of insulation performance.In fact,the change of the insulating medium from mild deterioration to complete failure is a gradual process of long-term stress accumulation and complex state changes.In order to further study on the related law between the dielectric degradation process and PD(partial discharge),speed up the acquisition of insulation performance information of new insulation materials,shorten the time to obtain the variation parameters of the insulation medium aging process,it is necessary to conduct an insulation accelerated aging test on an insulating medium to obtain the insulation state information.In order to accurately study the partial discharge law of the dielectric medium in the accelerated aging test,and provide effective reference data for the establishment of the insulation medium life prediction and insulation performance evaluation model,it is necessary to collect and record the PD information of the insulation medium during the insulation test.However,the current insulation accelerated aging test needs to last at least tens of hours to hundreds of hours.At the same time,since the duration of the partial discharge signal is short,the actual sampled data amount accounts for a small proportion of the total sampled data amount,using the traditional way to record its process data will occupy a large amount of data storage space and reduce space utilization.Therefore,the collection and recording of PD information requires a low-memory data recording method.In addition,based on the principle of the partial discharge pulse current detection method,a voltage sampling channel is added,which not only increases the acquisition path of the characteristic parameters of the PD signal,but also improves the evaluation method of reflecting the deterioration state of the dielectric medium by PD,and combining the sampling data of the voltage and current channels,it can also be used to reduce the detection error of the partial discharge signal.Based on the above-mentioned partial discharge detection and recording requirements and insulation test requirements,a device for detecting and recording PD signals of insulation test was designed in this thesis,and carried out the following research work:Firstly,the characteristics of the output signals on different sampling channels in the insulation accelerated aging test are analyzed,and the hardware design requirements of thesignals are obtained.At the same time,in order to reduce the storage space of the sampled data and reduce the complexity of data transmission and processing,an intelligent detection and recording method for partial discharge is proposed,and then the application software requirements of the insulation test is analyzed,two recording data transmission and backup methods and QT-based sampling data display applications were designed respectively.Finally,based on the ZYNQ XC7Z010 heterogeneous microprocessor,the embedded Linux system and QT program were transplanted,and the programmable logic design of signal sampling control and processing,as well as the design of parallel signal detection and recording program were completed by using on-chip dual ARM core and FPGA programmable logic unit.After completing the debugging of the software and hardware system functions,the experimental test and verification scheme was designed.The overall function of the data transmission were tested step by step,including the sampling and display,detection and recording of the data signal based on the device.After the preliminary experiment and test,the design function basically meets the actual use requirements,and basically meets the needs of the detection and recording of the partial discharge of the insulation test in this thesis,and achieves the intended purpose.