AQ-G257 Generator protection device
Home Protection relays Generator protection & control AQ-G257 Generator protection device
Description
The AQ-G257 generator protection device is well-suited for large machines that require complete generator protection and differential protection. The device has an integrated automatic voltage regulator function. 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 the IEC 61850 substation communication standard.
The AQ-G257 generator protection device 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.
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 (INST, DT or IDMT)
Non-directional earth fault (I0>; 50N/51N) - 4 stages (INST, DT or IDMT)
Directional overcurrent (Idir>; 67) - 4 stages (INST, DT or IDMT)
Directional earth fault (I0dir>; 67N/32N) - 4 stages (INST, DT or IDMT)
Negative sequence overcurrent/ Phase current reversal/ Current unbalance (I2>; 46/46R/46L) - 4 stages (INST, DT or IDMT)
Harmonic overcurrent (Ih>; 50H/51H/68H) - 4 stages (INST, DT or IDMT)
Circuit breaker failure protection (CBFP; 50BF/52BF)
High-impedance or low-impedance restricted earth fault/ Cable end differential (I0d>; 87N)
Voltage-restrained overcurrent (Iv>; 51V)
Overvoltage (U>; 59) - 4 stages (INST, DT or IDMT)
Undervoltage (U<; 27) - 4 stages (INST, DT or IDMT)
Neutral overvoltage (U0>; 59N) - 4 stages (INST, DT or IDMT)
Sequence voltage (U1/U2>/<; 47/27P/59PN) - 4 stages (INST, DT or IDMT)
Overfrequency and underfrequency (f>/<; 81O/81U) - 8 stages (INST or DT)
Rate-of-change of frequency (df/dt>/<; 81R) - 8 stages (INST, DT or IDMT)
Power protection (P, Q, S>/<; 32) - 4 stages (DT)
Volts-per-hertz overexcitation (V/Hz>; 24)
Underexcitation (Q<; 40)
Underimpedance (Z<; 21U)
Underreactance (X<; 21/40)
Pole slip/Out-of-step protection (78)
Inadvertent energizing (I>U<I.A.E.; 50/27)
Resistance temperature detectors (RTD)
Machine thermal overload (TM>; 49M)
Generator/transformer differential (Idx>; 87T/87G/87M/87N)
Power factor protection (PF<; 55)
100 % stator earth fault (U03rd>; 64S)
Voltage memory
Programmable stage (PGx>/<; 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)
AQ-G257B – Synchronizer (ΔV/Δa/Δf; 25)
Phase, sequence and residual currents (IL1, IL2, IL3, I01, I02)
Phase, sequence and residual voltages (UL1, UL2, UL3, U12, U23, U31, U0)
Frequency (f)
Power (P, Q, S, pf) and Energy (E+, E-, Eq+, Eq-)
Power and energy class 0.5
Power and energy measurement accuracy of up to 0.2 % (optional)
Current transformer supervision - 2 instances
Voltage transformer supervision (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)
Current inputs: 10
Voltage inputs: 4
Digital inputs (fixed): 3
Digital outputs (fixed): 5
Number of empty slots: 9
Digital inputs: +8/16/24/32/40/48/56/64/72 (optional)
Digital outputs: +5/10/15/20/25/30 (optional)
Milliampere I/O module (4 mA outputs + 1 mA input) (optional)
Arc protection module (4 sensors + 2 HSO + 1 BI) (optional)
Communication media (see "Communication" below)
External I/O modules (see "Accessories" below)
Communication inputs
RJ-45 100 Mbps Ethernet (front panel, fixed)
RJ-45 100 Mbps Ethernet and RS-485 (rear panel, fixed)
Double RJ-45 Ethernet & IRIG-B communication module (optional)
Double ST Ethernet & IRIG-B communication module (optional)
Double LC (HSR/PRP) Ethernet communication module (optional)
RS-232 & serial fiber communication module (optional)
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
Download
AQ 200 series flyer, v2.01 (English)
AQ 200 series flyer, v2.01 (Finnish)
AQ 200 series flyer, v2.01 (Swedish)
AQ 200 series product catalog (ANSI, v2.03, EN, September 2024)
AQ 200 series product catalog (IEC, v2.03, EN, September 2024)
AQtivate PRO flyer, v1.00 (English)
AQtivate PRO flyer, v1.00 (Finnish)
