AQ-G257 Generator Protection Device
Home Protection relays Generator protection & control AQ-G257 Generator Protection Device
Description
AQ-G257 is well-suited for large machines that require complete generator protection and differential protection. You can add up to nine (9) I/O or communication modules into the device for extensive monitoring and control applications. You can also connect up to sixteen (16) RTD signals for thermal alarming and tripping. AQ-G257 communicates using various protocols, including communication according to the IEC 61850 standard.
AQ-G257 has two software options: the “A” variant (AQ-G257A) includes all the standard generator protection functions, while the “B” variant (AQ-G257B) also includes the synchronizer function. For more details on the software options, please see the order code below.
Configure AQ-GS257A in the Product Configurator
Configure AQ-G257B in the Product Configurator
Highlights:
Complete synchronous machine protection
Integrated differential protection
Power measurement accuracy of up to 0.2 %
Technical data
Non-directional overcurrent (I>; 50/51) - 4 stages
Non-directional earth fault (I0>; 50N/51N) - 4 stages
Directional overcurrent (Idir>; 67) - 4 stages
Directional earth fault (I0dir>; 67N/32N) - 4 stages
Negative sequence overcurrent/ Phase current reversal/ Current unbalance (I2>; 46/46R/46L) - 4 stages
Harmonic overcurrent (Ih>; 50H/51H/68H) - 4 stages
Circuit breaker failure protection (CBFP; 50BF/52BF)
High-impedance or low-impedance restricted earth fault/ Cable end differential (I0d>; 87N)
Overvoltage (U>; 59) - 4 stages
Undervoltage (U<; 27) - 4 stages
Neutral overvoltage (U0>; 59N) - 4 stages
Low-voltage ride-through (LVRT; 27T)
Sequence voltage (U1/U2>/<; 47/27P/59PN) - 4 stages
Overfrequency and underfrequency (f>/<; 81O/81U) - 8 stages
Rate-of-change of frequency (df/dt>/<; 81R) - 8 stages
Power protection (P, Q, S>/<; 32) - 4 stages
Generator/motor/transformer differential (Idx>; 87T/87G/87M/87N)
100 % stator earth fault (U03rd>; 64S)
Underexcitation (Q<; 40)
Underimpedance (Z<; 21U)
Underreactance (X<; 21/40)
Voltage-restrained overcurrent (Iv>; 51V)
Inadvertent energizing (I>U<I.A.E.; 50/27)
Volts-per-hertz overexcitation (V/Hz>; 24)
Power factor protection (PF<; 55)
Pole slip/Out-of-step protection (78)
Machine thermal overload (TM>; 49M)
Resistance temperature detectors (RTD)
Programmable stage (PSx>/<; 99)
Arc protection (IArc>/I0Arc>; 50Arc/50NArc) (optional)
Number of objects to control and monitor: 10
Number of indicators to monitor: 10
Number of setting groups: 8
Vector jump (Δφ; 78)
Synchrocheck (ΔV/Δa/Δf; 25)
Number of objects to control and monitor: 10
Number of indicators to monitor: 10
Number of setting groups: 8
Vector jump (Δφ; 78)
Synchrocheck (ΔV/Δa/Δf; 25)
Synchronizer (ΔV/Δa/Δf; 25)
Current transformer supervision - 2 instances
Voltage transformer supervision (VTS; 60)
Circuit breaker wear monitoring
Total harmonic distortion (current)
Total harmonic distortion (voltage)
Measurement recorder
Measurement value recorder
Event recorder (max. 15,000 permanent event records)
Disturbance recorder (max. 100 records á 5 seconds at 3.2 kHz sampling)
Phase, sequence and residual currents (IL1, IL2, IL3, I01, I02)
Phase, sequence and residual voltages (UL1, UL2, UL3, UL12, UL23, UL31, U0)
Frequency (f)
Power (P, Q, S, pf) and Energy (E+, E-, Eq+, Eq-)
Power and energy measurement accuracy of 0.5 %
Power and energy measurement accuracy of up to 0.2 % (optional)
Standard hardware
Current inputs: 10
Voltage inputs: 4
Digital inputs: 3
Digital outputs: 5
Number of empty slots: 9
Optional hardware modules
Digital input module (8 x DI)
Digital output module (5 x DO)
High-speed high-current output module (3 x out)
Milliampere input module (4 x mA in, 1 x mA out)
Milliampere output module (4 x mA out, 1 x mA in)
RTD input module (8 RTD inputs)
Arc protection module (4 x channels, 2 x HSO, 1 x BI)
Communication media (see "Communication" below)
External I/O modules (see "Accessories" below)
Standard communication ports
RJ-45 100 Mbps Ethernet (front panel)
RJ-45 100 Mbps Ethernet and RS-485 (rear panel)
Optional communication modules
Double RJ-45 Ethernet & IRIG-B communication module
Double ST Ethernet & IRIG-B communication module
Double SFP Ethernet & IRIG-B communication module
Double LC (HSR/PRP) Ethernet communication module
Double RJ-45 (HSR/PRP) Ethernet communication module
RS-232 & serial fiber communication module
Communication protocols
IEC 61850 (edition 1)
IEC 61850 (edition 2)
IEC 60870-5-101/104
IEC 60870-5-103
Modbus/RTU and Modbus/TCP
DNP3
SPA
AX007 External 6-channel 2-/3-wire RTD input module (pre-configured)
AX008 External 8-channel thermocouple and mA input module (pre-configured)
AX013 Raising frame (120 mm)
AX014 Raising frame (40 mm)
AX015 Wall mounting bracket
AX020 SFP module (2 km, MM)
AX021 SFP module (40 km, SM)
AX022 SFP module (120 km, SM)
