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

Volume

11

Issue

1

fYear

1996

fDate

1/1/1996 12:00:00 AM

Firstpage

305

Lastpage

311

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;

fLanguage

English

Journal_Title

Power Delivery, IEEE Transactions on

Publisher

ieee

ISSN

0885-8977

Type

jour

DOI

10.1109/61.484029

Filename

484029