The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 20, 1988
Filed:
Oct. 14, 1986
Yoshifumi Oura, Ichihara, JP;
Kunio Matsuzawa, Sagamihara, JP;
Kazuyoshi Yoshida, Tokyo, JP;
Keizo Inagaki, Hitachi, JP;
Hiroyuki Kudo, Hitachi, JP;
Yoshihiro Sano, Katsuta, JP;
Hitachi, Ltd., Tokyo, JP;
The Tokyo Electric Power Co., Tokyo, JP;
Abstract
In a transformer protection system, data of voltages and currents detected at individual terminals of a transformer connected to an electric power system are supplied to a computer. The computer computes driving point admittances or shunt admittances of the transformer on the basis of the voltage and current data and predetermined transfer admittances of the transformer and decides that an internal fault has occurred in the transformer when the values of the driving point admittances or shunt admittances deviate from pre-set reference values, thereby disconnecting the transformer from the electric power system.