GE L30 User Manual

GE Multilin L30 Line Current Differential System 2-3
2 PRODUCT DESCRIPTION 2.1 INTRODUCTION
2
2.1.2 FEATURES
LINE CURRENT DIFFERENTIAL:
• Phase segregated, high-speed digital current differential system
• Overhead and underground AC transmission lines, series compensated lines
• Two-terminal and three-terminal line applications
• Zero-sequence removal for application on lines with tapped transformers connected in a grounded wye on the line side
• GE phaselets approach based on the Discrete Fourier Transform with 64 samples per cycle and transmitting two time-
stamped phaselets per cycle
• Adaptive restraint approach improving sensitivity and accuracy of fault sensing
• Accommodates in-zone transformer with a magnitude and phase compensation and second harmonic inhibit during
transformer magnetizing inrush
• Continuous clock synchronization via the distributed synchronization technique
• Increased transient stability through DC decaying offset removal
• Accommodates up to five times CT ratio differences
• Peer-to-peer (master-master) architecture changing to master-slave via DTT (if channel fails) at 64 kbps
• Charging current compensation
• Interfaces direct fiber, multiplexed RS422, IEEE C37.94, and G.703 connections with relay ID check
• Per-phase line differential protection direct transfer trip plus eight user-assigned pilot signals via the communications
channel
• Secure 32-bit CRC protection against communications errors
• Channel asymmetry (up to 10 ms) compensation using GPS satellite-controlled clock
BACKUP PROTECTION:
• DTT provision for pilot schemes
• Two-element time overcurrent and two-element instantaneous overcurrent directional phase overcurrent protection
• Two-element time overcurrent and two-element instantaneous overcurrent directional zero-sequence protection
• Two-element time overcurrent and two-element instantaneous overcurrent negative-sequence overcurrent protection
• Undervoltage and overvoltage protection
ADDITIONAL PROTECTION:
• Breaker failure protection
• Stub bus protection
• VT and CT supervision
• GE Multilin sources approach allowing grouping of different CTs and VTs from multiple input channels
• Open pole detection
• Breaker trip coil supervision and seal-in of trip command
• FlexLogic allowing creation of user-defined distributed protection and control logic
CONTROL:
• One and two breaker configuration for breaker-and-a-half and ring bus schemes, pushbutton control from the relay
• Auto-reclosing and synchrochecking
Event recorder Setting groups (6)
Table 2–2: OTHER DEVICE FUNCTIONS
FUNCTION FUNCTION FUNCTION

GE L30 Specifications

General

Brand	GE
Model	L30
Category	Relays
Language	English