GB/T 40096.7-2024Technical specification for on-site relay protection equipment - Part 7: Transformer protection (English PDF)

1 Scope

The document lays down the technical requirements, the test methods, the inspection rules and the marking, packaging, transport and storage of on-site transformer protection equipment.

It applies to the development, the design, the manufacture, the testing, the inspection and the application of on-site, ring network managed, masterless distributed transformer protection equipment for voltage levels of 110 kV and below that takes its samples through conventional instrument transformers.

2 Normative references

The documents referred to are GB/T 191 on pictorial marking for handling of goods; GB/T 2423.17, GB/T 2423.22 and GB/T 2423.24 on the environmental tests salt mist, change of temperature and simulated solar radiation at ground level; GB/T 2887-2011 on the general specification for computer sites; GB/T 4208-2017 on degrees of protection provided by enclosures (IP code); GB/T 4798.1 and GB/T 4798.2 on the classification of environmental conditions for storage and for transport and handling; GB/T 7261-2016 on the basic test methods for relay protection and safety automatic equipment; GB/T 9771 (all parts) on single-mode optical fibres for communication; GB/T 11287 on vibration, shock, bump and seismic tests on measuring relays and protection equipment, section one, vibration tests (sinusoidal); GB/T 12357 (all parts) on multimode optical fibres for communication; GB/T 13384 on the general specification for packaging of mechanical and electrical products; GB/T 14285 on the technical code for relay protection and safety automatic equipment; GB/T 14537 on shock and bump tests on measuring relays and protection equipment; GB/T 14598.2-2011, GB/T 14598.26-2015 and GB/T 14598.27-2017 on the general requirements, the electromagnetic compatibility requirements and the product safety requirements for measuring relays and protection equipment; GB/T 15145 on the general specification for transmission line protection equipment; GB/T 17626.9-2011, GB/T 17626.10-2017 and GB/T 17626.18-2016 on the immunity tests for pulse magnetic field, damped oscillatory magnetic field and damped oscillatory wave; GB/T 26864 on the dynamic model test of relay protection products for power systems; GB/T 32890-2016 on the engineering application model of IEC 61850 for relay protection; GB/T 32901-2016 on the general technical requirements for relay protection in smart substations; GB/T 40096.1-2021, part 1 of this series, on the general technical requirements; DL/T 478-2013 on the general technical requirements for relay protection and safety automatic equipment; DL/T 860 (all parts) on communication networks and systems in substations; DL/T 860.92 on the specific communication service mapping for sampled values based on ISO/IEC 8802-3; and DL/T 1782 on the specification for relay protection information in substations.

Dated references apply in the dated version only; undated references apply in their latest version, amendments included.

3 Terms and definitions

The terms and definitions given in GB/T 40096.1-2021 apply, together with the following.

3.1 Special network for on-site protection equipment: the dedicated communication network between on-site protection equipment, over which the sampled values (SV) output by the equipment and the generic object oriented substation event (GOOSE) and manufacturing message specification (MMS) information are all transmitted.

3.2 Ring network for on-site distributed transformer protection equipment: the ring network between the sub-units of an on-site distributed transformer protection, which applies to the process level ring communication network made up of the sub-units of a distributed transformer protection. A note states that it is called the ring network below.

3.3 Sub-unit of on-site distributed transformer protection equipment: in an on-site distributed transformer protection, the protection equipment that carries out the collection of analogue and binary quantities, receives the collected information of all the other sub-units, completes the whole of the protection logic operation, is responsible for the tripping output of the bay assigned to it and is connected to the special network for on-site protection equipment for external communication. Note 1 states that when the distributed protection function mode is used, each sub-unit receives the bay sampling information of all the other sub-units and completes the whole of the protection logic operation. Note 2 states that it is called the sub-unit below.

3.4 On-site centralized transformer protection equipment: the transformer protection equipment integrating main and backup protection in which a single on-site protection device completes the collection of the analogue and binary quantities of all the bays of the transformer, completes the protection logic operation, is responsible for the tripping output and is at the same time connected to the special protection network for external communication.

4.1 Environmental conditions

4.1.1.1 The atmospheric conditions at the place where the equipment is used shall meet the following requirements: ambient temperature -40 °C to +70 °C; relative humidity 0 % to 100 %; atmospheric pressure 61.6 kPa to 106 kPa.

4.1.1.2 The surroundings at the place where the equipment is used shall meet the following requirements: the electromagnetic environment shall be below the immunity level of the equipment laid down in Table 2, radiated emission and conducted emission excepted; no vibration exceeding severity class 2 of GB/T 11287 shall occur at the place of use; there shall be no explosive substances and no serious mould at the place of use; and the earthing shall meet the requirements of 5.8 of GB/T 2887-2011.

4.1.2 The special environmental conditions at the place where the equipment is used shall meet the following requirements: the equipment shall have the ability to resist salt fog corrosion and shall satisfy the salt fog corrosion test of 5.3.2; the equipment shall be able to withstand solar radiation and shall satisfy the solar radiation test of 5.3.4; where other environmental conditions go beyond those of 4.1.1, they shall be agreed between the user and the manufacturer.

4.2 Rated electrical parameters

4.2.1 The d.c. working supply of the equipment shall meet the following requirements: rated voltage 220 V or 110 V, to which the equipment shall adapt itself; permitted deviation -20 % to +15 %; ripple factor not greater than 5 %.

4.2.2 The excitation quantities of the equipment shall meet 4.2.2 of DL/T 478-2013.

4.2.3 The binary inputs and outputs of the equipment shall meet the following requirements: the binary input supply of the equipment shall be compatible in hardware with 220 V and 110 V d.c.; the other requirements for the binary inputs and outputs of the equipment shall meet 4.5 of DL/T 478-2013.

4.3 Accuracy and variation

The accuracy and the variation of the equipment shall meet 4.3 of DL/T 478-2013.

4.4 General requirements

4.4.1 The equipment shall satisfy the requirements of reliability, selectivity, sensitivity and speed of operation of relay protection.

4.4.2 The equipment shall have a complete self-checking function and an alarm function able to reflect the faults and the abnormal states of the protected plant.

4.4.3 The equipment shall not depend on an external time synchronization system in order to perform its protection functions.

4.4.4 Apart from the output relays, the failure of any single component of the equipment shall not cause a false tripping of the protection.

4.4.5 A distributed transformer protection is made up of several sub-units forming one protection equipment; the composition of the sub-units and the definition of the channels of the various types of distributed transformer protection are given in Annex A.

4.4.6 The sub-units of a distributed on-site transformer protection equipment communicate by means of a gigabit optical fibre bidirectional double ring network, in accordance with the requirements of Annex B; the interruption of communication of any one ring network, an N-1 event, shall not affect the protection functions. The data flow and the architecture between the sub-units of the distributed transformer protection are given in Annex C.

4.4.7 The hardware of the several sub-units of one distributed transformer protection equipment shall be identical and interchangeable.

4.4.8 All the sub-units of a distributed transformer protection and the centralized transformer protection equipment are connected to the special protection network, publish sampled value (SV) messages and send and receive generic object oriented substation event (GOOSE) and manufacturing message specification (MMS) messages. The SV message contains the analogue information of the bay collected by the sub-unit or by the equipment. The GOOSE message sent contains the operating information of the whole transformer protection and the binary information of the bay collected by the sub-unit; the GOOSE message received consists of the breaker failure inter-tripping signal of the bay where the unit is placed and of the tripping and closing commands of the other relevant protection and safety automatic equipment.

4.4.9 The equipment shall use direct cable sampling and direct cable tripping; the binary inputs of the bay that the equipment receives, such as the breaker position, shall be connected by cable. The signals between bays, such as the tripping of the bus coupler or section breaker, and the starting, blocking, inter-tripping, tripping and closing signals exchanged with other equipment, are transmitted as GOOSE signals over the special protection network; the external communication mode of the special protection network is given in Annex D.

4.4.10 The equipment shall have the function of outputting SV, GOOSE and MMS over a single combined port, and the optical port should use a 100 Mbit/s optical fibre interface.

4.4.11 After the plate of a distributed on-site transformer sub-unit has been withdrawn, the protection function of that sub-unit shall not be affected and the electrical quantities it outputs shall not be counted in the protection calculations of the other sub-units.

4.4.12 When the plate of the intelligent management unit is put in or taken out, the equipment shall decide whether to carry out the remote control command according to the current maintenance quality of the object being controlled; it shall receive and carry out correctly the remote control commands whose maintenance quality matches that of the remote signal.

4.4.13 The protection shall not operate falsely while the settings of the equipment are being changed or the setting group is being switched through the intelligent management unit.

4.4.14 When the settings or the plates of the sub-units are not consistent, a blocking message shall be sent, and the time taken should be not greater than 5 s.

4.4.15 The dedicated networks of a duplicated configuration shall follow the principle of relative independence; when the equipment is connected to different networks, mutually independent data interface controllers shall be used, so that an abnormality in one network or its withdrawal does not affect the operation of the other.

4.4.16 When the intelligent management unit is abnormal, the performance of the protection functions of the equipment shall not be affected.

4.4.17 The communication services, the data model and the configuration process of the equipment shall meet the requirements of GB/T 32890-2016.

4.4.18 The man machine interfaces of the sub-units of a distributed transformer protection are independent, are controlled directly by the intelligent management unit, and the station level data are sent directly to the intelligent management unit.

4.4.19 The centralized transformer protection equipment is controlled directly by the intelligent management unit and its station level data are sent directly to the intelligent management unit; the architecture of the centralized transformer protection is given in Annex C.

4.4.20 The equipment shall supply information reflecting its own state of health, which includes the internal working environment of the equipment, the working state of the hardware, the running state of the software and the state of the communication, internal communication and communication between devices included.

4.4.21 A distributed transformer protection shall be convenient in engineering application, and the communication between the sub-units inside the ring network shall need no configuration.

4.4.22 The protection equipment shall be supplied by an independent d.c. to d.c. converter. When the d.c. voltage disappears the equipment shall not operate falsely. The protection equipment shall work correctly when the d.c. supply voltage varies within 80 % to 115 % of the rated value. When the d.c. supply is restored, slowly restored included, to 80 % of the rated voltage, the d.c. inverter supply shall be able to start by itself. The protection equipment shall work correctly with a ripple factor of the d.c. supply not greater than 5 %. The protection equipment shall not operate falsely when the d.c. supply is switched on and off and when repeated breakdown sparks occur while a fuse is plugged in or pulled out. The protection equipment shall not operate falsely when abnormal conditions such as a short circuit, an open circuit or an earth fault occur in the d.c. supply circuit.

4.4.23 During the powering up and the restarting of the equipment, no false information shall be sent; after the d.c. supply of the protection equipment has disappeared, no recorded information shall be lost, and once the supply has returned to normal the information shall be displayed and output correctly again.

4.4.24 The equipment shall support remote management from the intelligent management unit: one key backup and downloading, the sending of state quantities, setting management, the querying of reports and logs and the retrieval of fault records.

4.4.25 The interfaces of the equipment shall meet the following requirements: the interfaces of the equipment use dedicated electrical connectors and dedicated optical fibre connectors, the external connection being made with prefabricated cables and prefabricated optical cables; the electrical connectors and the optical fibre connectors shall carry a unique marking, which shall be clear, durable and easy to see; there shall be physical means of preventing mis-insertion between the several electrical connectors and optical fibre connectors of the equipment, which include measures against mis-insertion in the different directions of one connector and between different connectors; the equipment uses standard information interfaces, and the definition of the cables, optical cables and terminals is given in Annex A; the conductor size of the electrical connectors is 2.5 square millimetres for the alternating current circuits and 1.5 square millimetres for all the others, and the core diameter of the optical connectors is 9/125 µm for single mode and 62.5/125 µm for multimode.

4.4.26 The optical fibre interfaces of the equipment shall meet the following requirements, of which the scan shows the first three: the fibre type is multimode optical fibre; the fibre core diameter is 62.5/125 µm; the wavelength is 1 310 nm or 850 nm.