This paper reports about the dielectric tests, which were conducted to prove the reliability of a new modular lead exit for use in 400 kV power transformers. Instead of testing many lead exits, the tests were carried out of few samples but at higher voltage levels and the coltages were applied more times than required according to the IEC standard. An additional series of tests was conducted on smaller, simplified the models, verifying the functionality of the moulding insulation of the electrode and of the copper tube. The measured values were compared with those calculated by applying design curves as used by the power, transformer industry.
Bernhard Heinrich – weidmann transfor board systems
Christoph Krause – weidmann transfor board systems
Kurt wick – weidmann systems international CH-8640 Rapperswil, Switzerland