ALSTOM GE Bus Protection

The Multilin B30 bus protection relay features integrated protection, control and metering for MV, HV and EHV busbars, providing cost-effective, feature-focused busbar protection. Use the B30 to protect busbars with up to 6 feeders with up to two three-phase differential zones. The Multilin B30 relay is a cost-effective alternative to high-impedance schemes, ideal for breaker-and-half bus schemes, with integrated feeder backup protection and metering.
Key Benefits

High speed differential protection algorithm for sub-cycle trip times of 0.75 power cycle
Advanced IEC 61850 Ed. 1 and Ed. 2 certified implementation, complete settings via SCL files and highly flexible process bus support (IEC 61850-9-2LE or IEC 61850-9-2 Hardfiber) ensures interoperability, device managing optimization and reduced cost of ownership
Routable GOOSE (R-GOOSE) enables GOOSE messages going beyond the substation, which enables wide area protection and control applications
Superior CT saturation detection with only 2 msec of saturation-free current for enhanced through-fault stability
Advanced automation capabilities for providing customized protection and control solutions
Application flexibility with multiple I/O options including high density I/O, programmable logic, modularity, and specific customization
Robust network security enabling Critical Infrastructure Protection through user command logging, and dual permission access control
Simplified system integration supporting serial and Ethernet interfaces and multiple protocols
An integrated large, full color display, provides real-time visualization and control of the protected bay, via a bay mimic as well as annunciator functionality and graphical visualization of phasors

Use the HID module in conjunction with a high-speed overcurrent relay to provide three phase high impedance differential protection for substation busbars of any voltage level. Additionally, it can also be used to protect electrical machines like transformers, generators or motors against restricted ground faults.

Each HID module includes resistors that provide the associated high impedance relay with stability againstexternal faults, and varistors (MOV - Metal Oxide Varistors) in order to limit the secondary peak voltage below 2 kV during fault conditions.

Use the auxiliary contacts provided by an optional latching relay to short-circuit the resistors once the associated relay has tripped, to prevent the fault current from circulating through the resistors.

The HID front panel incorporates a Reset pushbutton to reset the latching relay once the fault has been cleared, in order to eliminatethe resistors short circuit.

Features & Benefits:

·         Single-zone bus protection, reactor protection, or sensitive restricted earth fault protection on grounded, wye-connected power transformer windings

·         Provides metal oxide varistors (MOV) to clamp secondary peak voltage to less than 2 kV

Applications

·         Single-zone bus protection, reactor protection, or sensitive restricted earth fault protection on grounded, wye-connected power transformer windings

·         High impedance differential protection for electrical machines such as generators or motors, including lockout logic.

Protection & Control

·         The combination of HID module with a high-speed overcurrent relay can be applied for bus protection in most cases where CTs having negligible leakage reactance are used.

·         Additional functionality provided by the additional overcurrent device includes:

o    time stamped sequence of event recorder

o    waveform capture

o    data logger

o    communication to remote control centers

The MiCOM Agile P74x offers high performance, secure and sensitive protection for all types of busbar configurations at all voltage levels. Consisting of the Agile P741, P742 and P743 relays, the P74x platform is engineered to provide a centralized or distributed architecture with CT saturation detection, dynamic topology processing algorithms and a fast reset (less than 1 cycle) circuit breaker failure element.

Key benefits:

Tripping time is constant, less than 1 cycle and independent of the fault current, the substation topology and the number of feeders
Free of charge software tools for easy scheme monitoring
Connection between central and peripheral units is by fiber, eliminating EMC, touch and step potential issues

MCAG relays provide high-speed differential protection for various types of power system plants Including generators, reactors, busbars, motors and the individual windings of power transformers. The relays provide current-calibrated busbar differential and have an attracted armature design with simple and robust construction.

Key features:

High thermal withstand - improved when used with the stabilising resistor
Long service history, over 43,000 delivered since 1984
Design pedigree coming from over a million auxiliary relays in-service