Title :
A new scheme for power transformer protection
Author :
Yang, J.C. ; Yin, X.G. ; Chen, D.S. ; Zhang, Z. ; Wang, Z.H.
Author_Institution :
Dept. of Electr. Eng., Huazhong Univ. of Sci. & Technol., Wuhan, China
Abstract :
In this paper, a new transformer protection scheme is proposed which is based on the combination of virtual 3rd harmonic restrained and sampled value differential principles. The differential protection restrained by virtual 3rd harmonic can identify asymmetric and symmetric inrush currents with semicycle data window and accelerate the protection tripping speed. The sampled value differential protection can overcome some disadvantages of harmonic restraining with a long delay in the case of high content of harmonic components during internal faults. The combination scheme takes advantages of these two methods and improves the protection performance effectively. Test results in electrical power dynamic laboratory (EPDL) illustrate the proposed scheme. Now the protection system has been put into trial operation in GeZouBa hydroelectric power plant.
Keywords :
combinational circuits; harmonics; hydroelectric power stations; power transformer protection; GeZouBa hydroelectric power plant; asymmetric inrush currents; combination scheme; differential protection; electrical power dynamic laboratory; power transformer protection; protection tripping speed; semicycle data window; symmetric inrush currents; virtual 3rd harmonic; Circuit faults; Delay; Fault currents; Power generation; Power system dynamics; Power system harmonics; Power system protection; Power transformers; Surge protection; Testing;
Conference_Titel :
Power Engineering Society General Meeting, 2003, IEEE
Print_ISBN :
0-7803-7989-6
DOI :
10.1109/PES.2003.1270932
