GE 745-W2-P5-G5-HI-RE 745 Series Transformer Protection Management Relay

GE 745-W2-P5-G5-HI-RE 745 Series Transformer Protection Management Relay
I. Product Positioning
It belongs to the GE Multilin (now GE Vernova) 745 series transformer protection management relay. It is a core microcomputer protection device used in substations / power plants for comprehensive differential protection, measurement and control, fault recording, etc. of power main transformers, autotransformers, and reactors.
Model Segmentation Explanation Table
Model Segment Meaning
745 Product Series: Transformer Management Relay
W2 Each phase has 2 windings, suitable for double-winding transformer differential protection
P5 Secondary rated current of current transformer: 5A (the most commonly used CT ratio for industrial distribution)
G5 General hardware I/O basic configuration version
HI High-voltage power supply: Control power 90–300 VDC / 70–265 VAC, suitable for substation DC operating power supply, factory power supply AC supply
R Restricted Ground Fault, restricted grounding fault (small current grounding differential protection) Function enabled, precise protection for internal grounding faults of transformer windings
E Enhanced Display, enhanced 40-character large-screen LCD + extended operation keyboard, more convenient for local viewing of faults, setting parameters

Core Protection Functions
Differential Protection: Percentage ratio braking differential, with CT open circuit locking, excitation surge secondary harmonic braking, preventing erroneous tripping of transformer due to excitation surge during closing;
Ground Fault Protection: Includes R restricted grounding fault (R configuration), zero-sequence overcurrent, neutral point gap protection;
Backup Overcurrent Protection: Phase overcurrent, negative sequence overcurrent, thermal overload (life loss Loss of Life) monitoring, evaluating transformer aging;
Overexcitation Protection: Monitoring V/Hz ratio, preventing damage to core due to excessive voltage / low frequency saturation;
Frequency Protection: Overfrequency / Underfrequency Trip Alarm;
Flexible Logic (FlexLogic): Programmable logic input output, customizable interlocks, tripping logic.

 Measurement and Recording Capabilities
Real-time Measurement: Three-phase phase current, differential current, braking current, zero-sequence / residual current, harmonic content, THD total harmonic distortion rate;
Event Recording: Can save 128 events, record action time, fault value, action element;
Fault Recording: Can capture waveform before and after the fault, used for fault review and analysis.

 Communication and Debugging
Front panel RS232: Local computer through EnerVista 745 software for setting, uploading / downloading settings, reading waveforms;
Back panel dual RS485: Supports Modbus RTU, DNP3 protocols for access to SCADA / substation integrated automation system;
Supports multiple sets of settings switching, suitable for different operating conditions of transformers.

Key Electrical Parameters
Rated Frequency: 50Hz/60Hz Adaptive;
Logic Input DI: 16 channels;
Auxiliary Relay DO: 6-8 channels for tripping / alarm output;
Power Consumption: Rated 30VA, maximum 40VA;
Installation: Standard 19-inch panel embedded installation;
Protection: Front panel IP20;
Operating Temperature: -20℃ ~ +60℃, suitable for harsh environments in distribution rooms.

 Typical Application Scenarios
Power plant plant-use high-voltage transformers, main step-up transformers;
10kV/35kV/110kV substation double-winding main transformers;
Large factories self-owned power stations, metallurgy / chemical enterprises distribution transformers protection.