Transformer High Backup Protection Relay

Description

Product Overview

• The Transformer High Backup Protection Relay is designed for backup protection of transformers in substations at voltage levels of 110 kV and below. It works in conjunction with the AST-441H Differential Protection Unit to perform secondary functions for the main transformer bay.

Product Functions (ANSI)

• Voltage-Dependent Overcurrent Protection｜51V
• Residual Current Protection｜51N
• Thermal Overload Protection｜49
• Undervoltage Protection｜27
• Underfrequency Protection｜81U
• Overfrequency Protection｜81O
• Inverse Overcurrent Protection｜51I
• Current Unbalance Protection｜46
• Overvoltage Protection｜59
• VT (Voltage Transformer)

Communication Mode

• Optional: RS-485, CAN bus, Ethernet, IEC 60870-5-103 (IEC-103)

Main Functional Specifications

• Protection response time (including the response time of the output relay): Average error in response time: not more than 35 ms;
• Precision operating range: Minimum precision current: 0.08 In, Maximum precision current: 20 In
• Current setting error: When the current exceeds 1.00 A, the error shall not exceed ±2.5%; Voltage setting error: shall not exceed ±3%
• Measurement accuracy: Current (I)/Voltage (U): Class 0.2; Power (P)/Reactive power (Q): Class 0.5
• Remote signal resolution: no more than 2 ms

Event Logging, Fault Recording

• The recorded events include protective action events and device malfunctions;
• Record the type of protection trip, the time of the trip, and the operating parameters at the time of the trip;
• The fault recording data includes: the time of the protection operation, the type of protection operation, and the rms values before and after the recording was initiated;
• Data length of the fault recording: 2 cycles before the fault and 4 cycles after the fault;
• The SOE can retain 48 sets of data after a power loss, and the fault report can retain 16 sets of data after a power loss.

Monitoring Features

• The device is capable of measuring analog quantities such as current, voltage, and frequency;
• Collect position signals from circuit breakers, energy storage systems, isolating switches, and remote/local control switches, as well as other digital signals;
• Control functions of the disconnect switch.

Setting Table

No.	Display Name	Range	Step	Remark
1	Three-stage Protection: Stage I Setting
1.1	Stage I Protection Switch	1/0	—	Stage I protection: ON(1) / OFF(0)
1.2	Stage I Composite Voltage Blocking	1/0	—	Composite voltage blocking: ON(1) / OFF(0)
1.3	Stage I Directional Blocking	1/0	—	Directional blocking: ON(1) / OFF(0)
1.4	Stage I Time Delay	0.00～120.00s	0.01s
1.5	Stage I Setting Value	0.10～99.99A 0.10～20.00A	0.01A	In=5A In=1A
1*	Two-stage Two-time-limit Protection: Stage I Setting
1*.1	Stage I 1st Time-limit Switch	1/0	—	Stage I 1st time-limit: ON(1) / OFF(0)
1*.2	Stage I 2nd Time-limit Switch	1/0	—	Stage I 2nd time-limit: ON(1) / OFF(0)
1*.3	Stage I Composite Voltage Blocking	1/0	—	Composite voltage blocking: ON(1) / OFF(0)
1*.4	Stage I Directional Blocking	1/0	—	Directional blocking: ON(1) / OFF(0)
1*.5	Stage I 1st Time Delay	0.00～120.00s	0.01s
1*.6	Stage I 2nd Time Delay	0.00～120.00s	0.01s
1*.7	Stage I Setting Value	0.10～99.99A 0.10～20.00A	0.01A	In=5A In=1A
2	Three-stage Protection: Stage II Setting
2.1	Stage II Protection Switch	1/0	—	Stage II protection: ON(1) / OFF(0)
2.2	Stage II Composite Voltage Blocking	1/0	—	Composite voltage blocking: ON(1) / OFF(0)
2.3	Stage II Directional Blocking	1/0	—	Directional blocking: ON(1) / OFF(0)
2.4	Stage II Time Delay	0.00～120.00s	0.01s
2.5	Stage II Setting Value	0.10～99.99A 0.10～20.00A	0.01A	In=5A In=1A
2*	Two-stage Two-time-limit Protection: Stage II Setting
2*.1	Stage II 1st Time-limit Switch	1/0	—	Stage II 1st time-limit: ON(1) / OFF(0)
2*.2	Stage II 2nd Time-limit Switch	1/0	—	Stage II 2nd time-limit: ON(1) / OFF(0)
2*.3	Stage II Composite Voltage Blocking	1/0	—	Composite voltage blocking: ON(1) / OFF(0)
2*.4	Stage II Directional Blocking	1/0	—	Directional blocking: ON(1) / OFF(0)
2*.5	Stage II 1st Time Delay	0.00～120.00s	0.01s
2*.6	Stage II 2nd Time Delay	0.00～120.00s	0.01s
2*.7	Stage II Setting Value	0.10～99.99A 0.10～20.00A	0.01A	In=5A In=1A
3	Three-stage Protection: Stage III Setting
3.1	Stage III Protection Switch	1/0	—	Stage III protection: ON(1) / OFF(0)
3.2	Stage III Composite Voltage Blocking	1/0	—	Composite voltage blocking: ON(1) / OFF(0)
3.3	Stage III Directional Blocking	1/0	—	Directional blocking: ON(1) / OFF(0)
3.4	Stage III Time Delay	0.00～120.00s	0.01s
3.5	Stage III Setting Value	0.10～99.99A 0.10～20.00A	0.01A	In=5A In=1A
3*	Two-stage Two-time-limit Protection: Reserved	—	—
4	Zero-sequence Overcurrent Setting
4.1	1st Stage Zero-sequence Overcurrent	1/0	—	1st zero-sequence overcurrent: ON(1) / OFF(0)
4.2	2nd Stage Zero-sequence Overcurrent	1/0	—	2nd zero-sequence overcurrent: ON(1) / OFF(0)
4.3	1st Zero-sequence Trip Mode	1/0	—	Trip(1) / Alarm(0)
4.4	2nd Zero-sequence Trip Mode	1/0	—	Trip(1) / Alarm(0)
4.5	Zero-sequence Voltage Blocking	1/0	—	Zero-sequence voltage blocking: ON(1) / OFF(0)
4.6	1st Stage Time Delay	0.00～120.00s	0.01s
4.7	2nd Stage Time Delay	0.00～120.00s	0.01s
4.8	1st Stage Setting Value	0.02～5.00A 0.10～99.99A	0.01A	Low-current earthing system 380V 4-wire earthed system
4.9	2nd Stage Setting Value	0.02～5.00A 0.10～99.99A	0.01A	Low-current earthing system 380V 4-wire earthed system
4.10	Zero-sequence Voltage Blocking Value	0.00～100.00V	0.01V	Zero-sequence voltage blocking setting
5	Zero-sequence Overvoltage Setting
5.1	Zero-sequence Overvoltage Protection	1/0	—	Zero-sequence overvoltage: ON(1) / OFF(0)
5.2	Zero-sequence Overvoltage Trip Mode	1/0	—	Trip(1) / Alarm(0)
5.3	Zero-sequence Current Blocking	1/0	—	Zero-sequence current blocking: ON(1) / OFF(0)
5.4	Zero-sequence Voltage Time Delay	0.10～120.00s	0.01s
5.5	Zero-sequence Overvoltage Setting	5.00～100.00V	0.01V
5.6	Zero-sequence Current Blocking Value	0.02～5.00A	0.01A	Zero-sequence current blocking setting
6	Undervoltage Protection Setting
6.1	Undervoltage Protection Switch	1/0	—	Undervoltage protection: ON(1) / OFF(0)
6.2	Undervoltage Trip Mode	1/0	—	Trip(1) / Alarm(0)
6.3	Undervoltage Time Delay	0.10～120.00s	0.01s
6.4	Undervoltage Setting Value	0.00～100.00V	0.01V
7	Underfrequency Load Shedding Setting
7.1	Underfrequency Protection Switch	1/0	—	Underfrequency protection: ON(1) / OFF(0)
7.2	Underfrequency Trip Switch	1/0	—	Underfrequency trip: ON(1) / OFF(0)
7.3	Frequency Slip Blocking	1/0	—	df/dt blocking: ON(1) / OFF(0)
7.4	Undercurrent Blocking	1/0	—	Undercurrent blocking: ON(1) / OFF(0)
7.5	Undervoltage Blocking	1/0	—	Undervoltage blocking: ON(1) / OFF(0)
7.6	Protection Time Delay	0.10～120.00s	0.01s
7.7	Underfrequency Setting	46.00～50.00Hz	0.01Hz
7.8	Current Blocking Value	0.20～10.00A	0.01A
7.9	F-U Blocking Voltage	5.00～100.00V	0.01V	Undervoltage threshold for frequency blocking
7.10	Frequency Slip Setting	0.00～9.99Hz/s	0.01Hz/s	ΔF/ΔT: frequency change rate
8	Current Unbalance Setting
8.1	Current Unbalance Protection	1/0	—	Unbalance protection: ON(1) / OFF(0)
8.2	Unbalance Time Delay	0.10～120.00s	0.01s
9	Overload Protection Setting
9.1	Overload Protection Switch	1/0	—	Overload protection: ON(1) / OFF(0)
9.2	Overload Blocking Voltage Regulation	1/0	—	OLTC blocking under overload: ON(1) / OFF(0)
9.3	Overload Time Delay	0.00～120.00s	0.01s
9.4	Overload Current Setting	0.10～99.99A 0.10～20.00A	0.01A	In=5A In=1A
10	Inverse Time Overcurrent Stage I
10.1	Inverse Time Overcurrent Stage I	1/0	—	ON(1) / OFF(0)
10.2	Time Constant	1.00～100.00s	0.01s	Time constant for inverse overcurrent
10.3	Inverse Overcurrent Setting	0.50～10.00A 0.20～2.00A	0.01A	In=5A In=1A
11	Inverse Time Overcurrent Stage II
11.1	Inverse Time Overcurrent Stage II	1/0	—	ON(1) / OFF(0)
11.2	Time Constant	1.00～100.00s	0.01s	Time constant for inverse overcurrent
11.3	Inverse Overcurrent Setting	0.50～10.00A 0.20～2.00A	0.01A	In=5A In=1A
12	CT Disconnection Setting
12.1	CT Disconnection Function	1/0	—	CT disconnection: ON(1) / OFF(0)
12.2	Disconnection Setting Value	0.40～99.99A	0.01A
12.3	Disconnection Time Delay	0.00～120.00s	0.01s
12.4	Load Current Setting	0.40～99.99A	0.01A
13	General Setting
13.1	Two-stage Two-time-limit Protection	1/0	—	Function: ON(1) / OFF(0)
13.2	Stage III Trip Opposite Side	1/0	—	Trip opposite side(C8,C9):ON(1)/OFF(0)
13.3	Stage I Trip Section Breaker	1/0	—	Trip section breaker(C06,C07):ON(1)/OFF(0)
13.4	VT Disconnection Detection	1/0	—	VT disconnection detection: ON(1) / OFF(0)
13.5	Blocking Release After VT Fault	1/0	—	1=Cancel blocking；0=Retain blocking
13.6	Control Circuit Break Detection	1/0	—	Control circuit break: ON(1) / OFF(0)
13.7	Insulation Monitoring Function	1/0	—	Insulation monitoring: ON(1) / OFF(0)
13.8	1A Current Mode	1/0	—	1A(1) / 5A(0)
13.9	B17 Maintenance Plate	1/0	—	Maintenance plate: ON(1) / OFF(0)
13.10	Integral Energy Calculation	1/0	—	Enable(1) / Disable(0)
13.11	Harmonic Component Calculation	1/0	—	Enable(1) / Disable(0)
13.12	I-U Blocking Voltage	5.00～100.00V	0.01V	Undervoltage threshold for overcurrent blocking
13.13	Negative Sequence Voltage	5.00～100.00V	0.01V	Negative sequence voltage blocking value
13.14	Mutation Starting Current	0.00～99.99A	0.01A
13*	General Setting
13*.1	Two-stage Two-time-limit Protection	1/0	—	Function: ON(1) / OFF(0)
13*.2	Two-time-limit Trip Opposite Side	1/0	—	Trip opposite side(C8,C9):ON(1)/OFF(0)
13*.3	1st Time-limit Trip Section Breaker	1/0	—	Trip section breaker(C06,C07):ON(1)/OFF(0)
13*.4	VT Disconnection Detection	1/0	—	ON(1) / OFF(0)
13*.5	Blocking Release After VT Fault	1/0	—	1=Cancel blocking；0=Retain blocking
13*.6	Control Circuit Break Detection	1/0	—	ON(1) / OFF(0)
13*.7	Insulation Monitoring Function	1/0	—	ON(1) / OFF(0)
13*.8	1A Current Mode	1/0	—	1A(1) / 5A(0)
13*.9	B17 Maintenance Plate	1/0	—	ON(1) / OFF(0)
13*.10	Integral Energy Calculation	1/0	—	Enable(1) / Disable(0)
13*.11	Harmonic Component Calculation	1/0	—	Enable(1) / Disable(0)
13*.12	I-U Blocking Voltage	5.00～100.00V	0.01V	Undervoltage threshold for overcurrent blocking
13*.13	Negative Sequence Voltage	5.00～100.00V	0.01V	Negative sequence voltage blocking value
13*.14	Mutation Starting Current	0.00～99.99A	0.01A

Outline and Installation Dimensions

   

FAQ

Q：What is transformer backup protection?

A:The primary scope of Transformer High Backup Protection Relay covers the areas outside the bushing. When a fault occurs externally, the transformer backup protection device operates; it also serves as the transformer’s secondary backup protection, activating when the main protection fails to operate.

Q：How to Install and Use a Transformer Backup Protection Device

A:When selecting backup protection devices for transformers, it is necessary to consider their protective functions and other technical parameters. Equipment such as transformer differential protection devices and non-electrical quantity protection devices should be installed together in a single control panel.