Product Description; Overview - GE D30 Instruction Manual

D30 Line Distance Protection System
Chapter 2: Product description

Product description

This chapter outlines the product, order codes, and specifications.
2.1 Product description

2.1.1 Overview

The D30 Line Distance Protection System is part of the Universal Relay (UR) series of products. It is a microprocessor-based
relay intended for use on transmission lines of any voltage level, without, with, and in the vicinity of series compensation, in
three-pole tripping applications. The primary function of the relay consists of five phase and ground distance zones of
protection, either mho or quadrilateral as per user selection. The distance elements are optimized to provide good
measurement accuracy with a fast operating time, even when used with capacitive voltage transformers, and can be
supervised by detection of power swings. The relay provides directional ground overcurrent elements, which are
commonly used as part of an overall line protection system.
D30 phase distance zones can be configured to work with voltages and currents fed from voltage transformers (VTs) and
current transformers (CTs) located independently from one another on either side of a three-phase power transformer. The
relay compensates accordingly to preserve reach and correct target information regardless of the location and type of
fault. This feature allows backup protection applications for generators and power transformers.
A close-into-fault (or switch-on-to-fault) function is performed by the line pickup element. Out-of-step tripping, three-pole
autoreclosing, synchrocheck, fault location, and many other functions are also available. In addition, overcurrent and
undervoltage protection, fault diagnostics, power metering, and RTU functions are provided. The D30 provides phase,
neutral, and ground time overcurrent protection. The time overcurrent functions can be programmed with multiple curve
shapes or FlexCurve™ for optimum coordination.
Voltage, current, and power metering is built into the relay as a standard feature. Current parameters are available as total
waveform root mean square (RMS) magnitude, or as fundamental frequency only RMS magnitude and angle (phasor).
Diagnostic features include an event recorder capable of storing 1024 time-tagged events, oscillography capable of
storing up to 64 records with programmable trigger, content and sampling rate, and data logger acquisition of up to 16
channels, with programmable content and sampling rate. The internal clock used for time-tagging can be synchronized
with an IRIG-B signal, using the Simple Network Time Protocol (SNTP) over the Ethernet port, or using the Precision Time
Protocol (PTP). This precise time stamping allows the sequence of events to be determined throughout the system. Events
can also be programmed (via FlexLogic™ equations) to trigger oscillography data capture that can be set to record the
measured parameters before and after the event for viewing on a computer. These tools significantly reduce
troubleshooting time and simplify report generation in the event of a system fault.
D30 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL 2-1