Capacitance and loss angle measurement of power transformer winding

U ovom radu ukratko je opisan standardni set dijagnostičkih metoda za ocjenu stanja transformatora, a posebna pažnja je data mjerenju kapaciteta i kuta gubitaka (tan δ) izolacije namota transformatora. Transformator je tokom svog životnog vijeka izložen raznim mehaničkim, kemijskim i toplinskim naprezanjima te je znanje o stanju izolacije od velike važnosti. Mjerenje kapaciteta i tan δ vrši se pomoću specijalnih mjernih uređaja koji svoj rad temelje na mjerenju kapaciteta Scheringovim mostom. Mjerenje se u pravilu izvodi jednom u pet godina kod transformatora većih snaga, dok se kod transformatora manjih snaga ta mjerenja provode prema potrebi. Rezultati mjerenja kapaciteta i tan δ uspoređuju se sa prethodno izmjerenim ili sa referentnim. Izmjereni podaci su vrlo važni jer sam životni vijek transformatora uvelike ovisi o stanju izolacije.In this paper briefly describes the standard set of diagnostic methods for evaluating the state of transformers, and special attention is paid to measuring the capacitance and loss angle (tan delta) of transformer winding insulation. The transformer is exposed to various mechanical, chemical and thermal stresses during its lifetime, and knowledge of the state of insulation is of great importance. Capacitance and tan delta measurement is performed using special measuring devices that base their work on capacitance measurement with Schering bridge. As a rule, the measurement is performed once in five years for higher power transformers, while for lower power transformers these measurements are performed as needed. The results of capacitance and tan delta measurement are compared with the previously measured or with the reference. The measured data is very important because the life of transformer itself largely depends on the state of insulation