| The apparatus equipment which is the largest amount usage and preliminary costequipment its reliable operation directly impacts the security and stability of the powersystem. Solid insulating material has an excellent electrical, chemical physical andmechanical property which is commonly used on apparatus equipment. According tostatistics, the insulation fault is the most important reason for capacitive electricalequipment, so the study of capacitive equipment insulating state monitoring has greatsignificance.The capacitive apparatus equipment insulation status online dynamic monitoring hassuch core issues: accuracy of insulation condition assessment, different insulation indexweight coefficient affection problem; accuracy of online monitoring insulationcharacteristic under complex environment, insulation characteristic variation of insulationmaterial ageing process and hardware design of online monitoring system of capacitiveapparatus. This paper lannchs the reacherch from above described problems.(1) According to the insulated condition evaluation problem of solid-insulated ringmain unit, a new method which can assess insulated condition of solid-insulated ring mainunit when there was no standard fault model is proposed. Through improving traditionalgrey target theory, improved weighted grey target approaching degree calculation methodis derived. The different affection of insulation index problem is solved by analytichierarchy process-entropy method weight coefficient calculation method. The insulatingstate classification strategy is given by solid-insulated ring main unit characteristics.Experiments show that this method can objectively and reasonably assess solid-insulatedring main unit insulating state, providing a reference for insulated condition evaluation ofsolid-insulated ring main unit.(2) Considering problems of poor anti-interference ability, synchronous samplingcriterion strictly and low calculation resolution in the present dielectric loss onlinemonitoring on solid-insulated ring main unit, a new method which applies instantaneouspower transforms theory to solve the above mentioned problems is proposed in this paper.Resistive current and capacitive current can be instantaneously extracted by signaldecomposition to realize dielectric loss monitoring, combining with the filter design andmonitoring system hardware design to make sure the high monitoring accuracy. Finally,the method is verified by experiments with high monitoring accuracy, effectivelyovercoming the spectral leakage and fence effect caused by asynchronous and non-integral period sampling, providing a reference for solid-insulated ring main unit dielectric lossonline monitoring.(3) Considering the imperfection data of epoxy material aging mechanism seriouslyhampering the capacitive apparatus insulated condition assessment, thousands of hours ofaging experiment is done on switchgear, systematic study various electrical characteristicsvariation law on the gradual aging process of epoxy resin insulation materials. Therefore,study on the aging characteristics of switchgear insulation and its lifetime estimationmethod is the key technology to understand aging mechanism better, search for new faultdiagnostic method and the way to extend the useful lifetime of switchgear.(4) Considering the difficulties of many index simultaneous sampling, large memorycapacity, serious electromagnetic interference, this paper uses solid-insulated ring mainunits as an example, put forward DSP+CPLD+USB real-time monitoring strategy,consider the immunity to electromagnetic interference at PCB design process. Lastly, thispaper realizes online monitoring system of capacitive apparatus equipment, providing areference for insulated condition evaluation of solid-insulated ring main unit. |
