AQ-T257 Transformer protection device
Home Protection relays Transformer protection & control AQ-T257 Transformer protection device
Description
AQ-T257 is a transformer protection device with a differential protection function and an integrated automatic voltage regulator function. The relay also provides complete current-based and voltage-based protection functions as well as full measurements. You can add up to nine (9) I/O or communication cards into the device for extensive monitoring and control applications. AQ-T257 communicates using various protocols, including communication according to the IEC 61850 standard.
The AQ-T257 transformer protection device has two software options: the “A” variant (AQ-T257A) includes all the protection functions for transformers including differential protection, while the “B” variant (AQ-T257B) also includes the automatic voltage regulator that allows you to control more than one transformer at the same time. For more details on the software options, please see the order code below.
Configure AQ-T257A in the Product Configurator
Configure AQ-T257B in the Product Configurator
Highlight:
A large I/O capacity.
Automatic/manual voltage regulating (AVR) and/or parallel voltage regulating.
Complete transformer protection.
2nd and 5th harmonic blocking.
Automatic verification of a connection group and nominal value settings.
Overloading and through fault statistics for preventive maintenance.
Power and energy measurement accuracy of up to 0.2 %.
Technical data
AQ-T257A – Standard transformer protection functionality
AQ-T257B – Standard transformer protection functionality + Transformer AVR (automatic voltage regulator)
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)
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 or DT)
Power protection (P, Q, S>/<; 32) - 4 stages (DT)
Volts-per-hertz overexcitation (V/Hz>; 24)
Underreactance (X<; 21/40)
Pole slip/Out-of-step protection (78)
Resistance temperature detectors (RTD)
Transformer status monitoring
Transformer thermal overload (TT>; 49T)
Generator/transformer differential (Idx>; 87T/87G/87M/87N)
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
Cold load pick-up
Switch-on-to-fault
Vector jump (Δφ; 78)
Synchrocheck (ΔV/Δa/Δf; 25)
Number of object to contol and monitor: 10
Number of indicators to monitor: 10
Number of setting groups: 8
Cold load pick-up
Switch-on-to-fault
Vector jump (Δφ; 78)
Synchrocheck (ΔV/Δa/Δf; 25)
Automatic voltage regulator – parallel control (AVR; 90)
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)
Current transformer supervision - 2 instances
Voltage transformer supervision (60)
Circuit breaker wear monitoring
Total harmonic distortion (current)
Total harmonic distortion (voltage)
Fault locator (21FL)
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 input module (8 x DI) (optional)
Digital output module (5 x DO) (optional)
High-speed high-current output module (3 x out) (optional)
Milliampere input module (4 x mA in, 1 x mA out) (optional)
Milliampere output module (4 x mA out, 1 x mA in) (optional)
RTD input module (8 RTD inputs) (optional)
Arc protection module (4 x channels, 2 x HSO, 1 x 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 SFP Ethernet & IRIG-B communication module (optional)
Double LC (HSR/PRP) Ethernet communication module (optional)
Double RJ-45 (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
AX020 SFP module (2 km, MM)
AX021 SFP module (40 km, SM)
AX022 SFP module (120 km, SM)
