Title :
Evaluating harmonic-induced transformer heating
Author :
Bishop, M.T. ; Baranowski, J.F. ; Heath, D. ; Benna, S.J.
Author_Institution :
Syst. Eng. Group, Cooper Power Systems, Franksville, WI, USA
fDate :
1/1/1996 12:00:00 AM
Abstract :
The proliferation of nonlinear loads on power systems has increased the awareness of the potential reduction of a transformer´s life due to increased losses. Over the past few years, several manufacturers and users have been applying a harmonic rating system to specify transformers based on relationships developed in ANSI/IEEE C57.110. The specification or evaluation of transformers in a harmonic environment requires a knowledge of the load mix as well as details of the load current harmonic content. The additional heating experienced by a transformer depends on the harmonic content of the load current, and the design of the unit. A heat run circuit was devised to produce harmonic rich load current on a 25 kVA oil-immersed distribution transformer. The test was conducted at 100% of nameplate current using a purely resistive load, and a 2.4 ms current pulse. The temperature rise experienced under harmonic excitation was observed and documented
Keywords :
distribution networks; load (electric); losses; power system harmonics; power transformer insulation; power transformer testing; power transformers; thermal analysis; transformer oil; 2.4 ms; 25 kVA; ANSI/IEEE C57.110; harmonic excitation; harmonic rating system; harmonic-induced transformer heating; heat run circuit; load current harmonic content; load mix; losses; nameplate current; nonlinear loads; oil-immersed distribution transformer; power systems; temperature rise; transformer life; Electrical equipment industry; Energy efficiency; Frequency; Heat engines; Heating; Manufacturing; Oil insulation; Power system harmonics; Power transformers; Senior members;
Journal_Title :
Power Delivery, IEEE Transactions on
