An Algorithm for Transmission Distance Relay Setting Calculation Under Network Topology Change

Abstract

Power systems are being expanded day by day with a more complex structure. The system topology always changes due to faults and/or operation requirements. Therefore; malfunctions might occur in the protection system which is one of the most important components for the system reliability, stability and economic operation. Distance protection relays fulfil the main protection function of the power transmission lines. In this study, an algorithm is created which recalculates the distance protection relay setting values depending on the topological changes of the network. The algorithm verified by testing on a selected area from the Turkish National Power Transmission System which comprises 154 kV 28 buses. Modelling of the power system carried out with Dig silent Power factory software. The algorithm is created in the DPL (Dig silent Programming Language) platform.

Enhancing the performance of distance protection relays using interactive control system

“…If the measured impedance value of relay is smaller than the previously entered relay zone setting then relay operates and generates trip signal. Distance protection relays have different types of characteristics such as impedance, reactance, mho and polygon, the last one is used in this manuscript [7,12]. Purpose of coordination, a basic distance protection scheme consists of three zones of protection, Figure 1 shows the zone impedances and corresponding tripping time.…”

“…Time setting for Zone 1 is usually set to instantaneous trip, Zone 2 protection must be time delayed by 350ms so that discrimination can be achieved with the zone 1 protection on the adjacent circuit, and Zone 3 has a longer time delay than zone 2, typically 700ms. Sometimes this zone is set to look in a reverse direction to provide backup for bus protection systems [7,12,13].…”

“…Nowadays, System topology changes continuously due to the addition of new generation units, transmission lines and multiple switching actions due to maneuverings and maintenance, these actions affect on protection system settings [6][7]. To make DRs diagnosis the fult correct with fast of response and minimum disturbance [2,8,9], a supervisory control and data acquisition system (SCADA) sends correct settings to the protection devices.…”

Distance Protection Relay Performance Enhancement Through Integrated Control System

“…To get benefit from series compensation it is necessary to overcome problems raised by series capacitor in distance protection scheme which are discussed in detail in [7]. Distance relay (DR) basically determines the line impedance by comparing the voltage and current values, if the measured impedance value of relay is smaller than the previously determined relay zone setting, then relay operates and generates trip signal [8,9]. Presence of series compensation operation variety in the relay path, obstructs the impedance value read by DR. An improved approach or setting the protection zone of distance relay in line with series compensation is important concern to make DRs diagnosis the fault to be correct with fast of response and minimum disturbance [2, 3, 10, and 11].…”

“…Zone impedance settings for parallel lines are determined as following: Z1 = Xline1 × 85 % Z2 = Xline1 + Xline2 × 20/2 % Z3 = Xline1 + Xline2 × 20 % Time setting for Zone 1 is usually set to instantaneous trip, Zone 2 protection must be time delayed by 350ms so that discrimination can be achieved with the zone 1 protection on the adjacent circuit, and Zone 3 has a longer time delay than Zone 2, typically 700ms. Sometimes this zone is set to look in a reverse direction to provide backup for bus protection systems [8,9,12]. In this paper scheme is made to achieve the required in two stages.…”