Prediction of high-voltage equipment’s insulation system status by applying law on increasing probability

[F. Zec]

130 str.

Elektrotehnika - elektroenergetika / electrical engineering - electroenergetics

Predmet istraživanja doktorske disertacije su modelovanje i procesi starenja izolacionih sistema visokonaponskih objekata (obrtne mašine, kablovi). Modelovanje se odnosi na utvrđivanje važenja zakona porasta verovatnoće nekog ishoda za model i n puta uvećani realni objekat (uvećana površina, broj elemenata i dr.). Takođe, i algoritami za procenu radnog veka i preostalog životnog veka se oslanjaju na verovatnoću ishoda, prag napona parcijalnih pražnjenja – PDIV (Partial Discharge Inception Voltage), probojni napon – VBD (Voltage Breakdown) kao mere degradacije (starenja) odnosno pouzdanosti izolacionog sistema visokonaponskog (VN) objekata tokom vremena eksploatacije. Metode istraživanja su teorijske i eksperimentalne. Teorijski su izučavani izolacioni sistemi, stohastičnost posmatranih ishoda, matematička statistika. Tako su određeni koncepti eksperimenata (uzorci, merna oprema). Za obrtne mašine korišćeni su reprezentativni uzorci izolacionih sistema (formirani karakteristični uzorci prema skali 1:n, određene celine sistema i celi objekti). Za srednjenaponske kablove je korišćen veći broj formiranih uzoraka. Rezultati ispitivanja su pokazali da je moguće formirati modele izolacionih sistema i na pouzdan način ekstrapolirati ispitivane veličine na realan objekat. Takođe, rezultati su pokazali da je moguće procenjivati životni vek izolacionih sistema u složenim uslovima eksploatacije. Istraživanja su aktuelna i u skladu sa trendovima razvoja savremenih izolacionih sistema. Rezultati istraživanja su doprinela boljem razumevanju osobenosti visokonaponskih izolacionih sistema, unapređenju metoda i postupaka ispitivanja i dijagnostike stanja kako novoproizvedenih, tako i VN jedinica u pogonu. Takođe su unapređene metode i postupci procene radnog i preostalog životnog veka. To može doprineti racionalizaciji i finansijskim efektima u proizvodnji i eksploataciji VN objekata i korektivnom održavanju na produženju životnog veka.

The subject of the doctoral dissertation research is modeling and aging processes of insulation systems of high-voltage objects (rotating machines, cables). Modeling refers to determining the validity of the law of increasing probability of outcomes for a model and a real object enlarged n times (increased area, number of elements, etc.). Also, the algorithms for estimating the working life and the remaining life rely on the probability of the outcome, Partial Discharge Inception Voltage – PDIV , Breakdown Voltage - VBD) as a measure of degradation (aging) of the insulation system during the operation period. Research methods are theoretical and experimental. Isolation systems, stochasticity of observed outcomes, mathematical statistics were theoretically studied. This is how the concepts of the experiments (samples, measuring equipment) were determined. For rotation machines, representative samples of insulation systems were used (characteristics samples formed according to the 1:n scale, individual parts of the system, and entire objects). A larger number of formed samples were used for medium voltage cables. The test results showed that it is possible to form models of insulation systems and reliably extrapolate the tested quantities to a real object. Also, the results showed that it is possible to estimate the lifetime of insulation systems in complex operating conditions. The research is according to the development trends of modern insulation systems. The results of the research contributed to a better understanding of the peculiarities of high-voltage insulation systems, improvement of methods and procedures of testing and diagnostics of the state of both newly manufactured and HV units in operation. Methods and procedures for estimating service life and remaining life have also been improved. This can contribute to rationalization and financial effects in the production and exploitation of HV facilities and corrective maintenance to extend the life span.

starenje, životni vek, izolacioni materijali, električne mašine, srednjenaponski kablovi, zakon porasta, parcijalna pražnjenja, probojni napon

ageing, lifetime, insulating materials, electrical machines, medium voltage cables, growth law, partial discharges, breakdown voltage

621.313:621.315.61(043.3)

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