Impact of turbine fast-valving on generator and transformer protective relays

Abstract

O n e of tlie most effective niethod to preserve g e n e r a t o r s t ab i l i t y following close-in th ree -phase f a u l t s is t he so cal led "fast-valving" of t h e turbine. 'i'liis action may cause one o r more pole s l i p p i n g s of t l i e g e n e r a t o r b e f o r e r e synchronizing. T h e pape r is a imed to investigate, by tne fns of co inpu te r s i inulat ions o f both tlie power sys t em a n d i t s p ro t ec t ive devices , t h e p os s i I) I e a n 3 I y si s of t he resul ts allows to pu t into evidence wliat re lays a r e likely to ope ra t e d u r i n g pole-slipping, a n d what k ind of coun te r -measu res have to be s tudied to avoid unwished trippings. p ro t e c t ion 111 a Io p e r a t ions. 1' he