GE Multilin™ 889 Generator Protection System

MULTILIN 889

Advanced Generator Protection and Management

The Multilin™ 889 Generator Protection System, a member of the Multilin 8 Series

protection relay platform, has been designed for the protection, control, and

management of generators and associated unit transformers in critical utility and

industrial applications.

The 889 goes beyond asset protection providing power system engineers with the

data, measurement accuracy, and visibility needed for comprehensive generator

management. These advanced asset monitoring capabilities provides engineers with the

ability to make informed, proactive decisions that enable planned maintenance activities

reducing costs associated with pre- and post-fault analysis, equipment damage, and

unplanned or extended downtime.

With a focus on connectivity and security, the 889 supports the latest in communications

technologies and protocols including IEC 61850 Edition 2. OPC-UA, and IEC 62439/PRP,

and provides advanced, industry standard, cybersecurity tools, ensuring simplified and

secure device integration into new or existing SCADA or DCS systems.

Key Benefits

• Enhanced generator protection algorithms provide sub-cycle differential protection,

ensuring faster fault clearing times for reduced generator damage

• Dedicated generator monitoring and control functions providing mission critical

operational data to enable a pro-active maintenance approach

• Additional overall generator-transformer differential (87O) providing additional

back-up protection

• Advanced generator diagnosis, comprehensive asset monitoring and high-end fault

and disturbance recording, simplifies pre- and post-fault analysis

• Advanced cyber security features including AAA, Radius, RBAC and Syslog enabling

NERC/CIP requirements

• Low insertion force, draw-out design simplifying testing, commissioning, and

maintenance for increased process uptime

• Optional Wi-Fi connectivity minimizes system configuration and facilitates remote

relay programming and diagnostic retrieval

• Patented environmental monitoring, providing visibility to changes in environmental

conditions that can affect relay life

Applications

• Comprehensive protection from small to large generators

• Industrial or utility power generation

• Co-generation and renewable generation applications

• Unit Transformer Protection applications

Protection & Control

The Multilin 8 Series provides comprehensive and field proven

algorithms to ensure asset management and uninterrupted

process and system availability. With a fast protection pass, the

8 Series relays provide fast operating current, voltage, power, and

frequency protection elements. With highly configurable protection

logic, system coordination with upstream and downstream

disconnect devices is greatly simplified. Various forms of I/O

are supported in the 8 Series to ensure protection, control, and

management of critical substation and field assets.

Generator Stator Differential

The 889 provides fault clearing operation at up to sub-cycle speed,

by utilizing a high-speed dual slope differential protection for

detecting and clearing of stator phase faults. Advanced CT saturation

detection algorithms maintain immunity to saturation conditions that

may be caused due to external disturbances. Through the use of

a directional check, additional supervision is provided to ensure

the fault is internal to the generator before triggering it to trip. This

sub-cycle operation translates to less burning, and hence low carbon

dissipation and thermal stress on insulation. This also enables root

cause analysis during diagnosis/maintenance of the winding (sever

longer duration faults burns-out all the evidence and make root

cause analysis extremely difficult or sometimes impossible).

Overall Generator & Transformer Differential Protection

The 889 provides overall generator and transformer differential

protection (87O). It covers the protection zones from the generator

neutral to the Generator Step-Up (GSU) Transformer’s High

Voltage (HV) winding. For mid to large-size machines, the typical

protection philosophy and architecture is to implement a dedicated

transformer protection device along with a single function