Prevention of Cascaded Events of Distance Relay Zone Three Using Logic Controls

Abstract

This paper presents a new method to prevent cascaded events caused by zone 3 elements of distance relays due to transmission line overload by using logic controls. A proposed adaptive distance relay algorithm provides a new concept to distinguish between actual faults and flow transfers and secures time to perform remedial controls by a defense system during cascaded events. Maloperation of distance relay is a very critical situation, leading to more operation of other distance relays and finally partial or total blackout. Logic controls are used to insure the operating decision through observing the system parameters and compare it with a setting already being input to the system. When distance relay is activated and the logic controls find that the system is healthy (unfaulted) and that the activation resulted from transmission line overload not real fault, the operation signal will be blocked to protect the system from maloperation.

Locating Fault on Transmission Line with Static Var Compensator Based on Phasor Measurement Unit

“…However, the FACTS devices may also cause the transmission line to lead to deterioration of distance relay operation resulting in inaccurate estimation of short-circuit fault location in transmission lines such as over-reach and under-reach for different cases [5][6][7]. The improper working of distance relay can lead to incorrect tripping and it not only decreases the reliability and security of the power system but also can institute the cascade tripping and blackouts in the system [8].…”

A new algorithm to prevent maloperation of distance protection zone 3 during wide-area disturbances

“…The re‐examination of the application of zone 3 in power system is carried out in Horowitz and Phadke, where authors give situations where it can be properly used or removed without reducing the reliability of the system protection. Another method to prevent cascaded event blackout caused by zone 3 elements of distance relays using a logic control is described in Henna . Another approach is carried out in Aghamohammadi et al It allows identifying the critical line outages and preventing their undesirable outage by blocking zone 3 of their distance relay.…”