remote control equipment - Indian Railways Institute of Electrical ...

The relay continuously monitors the vectorial ∆ - I, the moment ∆ - I current cross the set
value, relay start Trip Time. During the Trip Time if X components of complex
impedence is with in the set blinder limit then relay provides trip command.
The relay allows power transformer changing also starting of multiple locomotives
(EMUs) on the same section without unwanted tripping. For this, the 2 nd and 3 rd
harmonic components of the load current are monitored, and appropriate restraint
of the Relay element is done. if 2 nd harmonics component of current increases
more than 15% then relay blocks the tropping operation. If a 3 rd harmonics
component increases more than 15% of fundamental then relay internally
de-sensitized the - I setting by factor of 0% to 100% (programmable). The
De-sensitized V. Delta - I can be claculated by following formula.
De-sensitized V. Delta I setting = (V. Delta - I setting * De - sensitivity) + V. Dealta I setting
100
The range of measured / computed parameters as well as internal digital flgas
status are dynamically displayed on a pront panel dot - matrix 16 x 2 LCD
display.
Fig. P.F.R.S.
94