GB/T 40096.6-2024Technical specification for on-site relay protection equipment - Part 6: Busbar protection (English PDF)

Introduction Introduction

As the level of equipment manufacture rises, and chip technology in particular develops, on-site protection equipment will be placed close to the primary plant or integrated with it, so as to improve protection performance. The content and depth of the existing technical standards for protection equipment installed indoors are no longer suitable.

GB/T 40096 is planned in seven parts. Part 1, General technical requirements, regulates the technical requirements, test methods, inspection rules and general requirements for marking, packaging, transport and storage of on-site relay protection equipment. Part 2, Connectors and prefabricated cables, regulates the product requirements for connectors and prefabricated cables. Part 3, On-site operation box, regulates the product requirements for the on-site operation box. Part 4, Intelligent management unit, regulates the product requirements for the intelligent management unit. Part 5, Line protection, regulates the functional specification and technical requirements of line protection. Part 6, Busbar protection, regulates the functional specification and technical requirements of busbar protection. Part 7, Transformer protection, regulates the functional specification and technical requirements of transformer protection.

1 Scope

The document fixes the technical requirements, test methods, inspection rules, marking, packaging, transport and storage for on-site busbar protection equipment and its associated devices.

It applies to the development, design, manufacture, testing, inspection and application of on-site busbar protection equipment, referred to below as the equipment, at voltage levels of 110 kV and below.

2 Normative references

The content of the listed documents constitutes indispensable provisions of this document through normative reference in the text; for dated references only the edition cited applies, and for undated references the latest edition, including all amendments, applies.

The list includes GB/T 191 on packaging, storage and transport pictorial marking, GB/T 2423.17, GB/T 2423.22 and GB/T 2423.24 on salt mist, temperature change and solar radiation environmental tests, GB/T 2887-2011 on computer sites, GB/T 4208-2017 on degrees of protection provided by enclosures, 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 11287 on vibration tests for measuring relays and protection equipment, GB/T 12357 (all parts) on multimode optical fibres for communication, GB/T 13384 on the general packaging requirements for 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, GB/T 14598.2-2011, GB/T 14598.26-2015 and GB/T 14598.27-2017 on measuring relays and protection equipment, GB/T 17626.9-2011, GB/T 17626.10-2017 and GB/T 17626.18-2016 on electromagnetic compatibility testing, GB/T 26864 on dynamic model tests of relay protection products for power systems, GB/T 32890-2016 on the IEC 61850 engineering application model, GB/T 32901-2016 on the general technical requirements for relay protection in smart substations, GB/T 37880-2019 on the technical guide for on-site ring network busbar protection, GB/T 40096.1-2021, DL/T 478-2013, DL/T 670-2010, DL/T 860 (all parts), DL/T 860.92 and DL/T 1782.

3 Terms and definitions

The terms and definitions given in GB/T 40096.1-2021 and the following apply to this document.

On-site busbar protection bay unit: equipment which, within an on-site busbar protection scheme, undertakes the acquisition of analogue and binary quantities for a number of bays, receives the acquisition information of the remaining bays through the optical fibre ring network communication, performs the whole of the protection logic computation and the tripping outputs for the corresponding bays, and can be connected to the dedicated on-site protection network for external communication. A note records that the on-site busbar protection bay unit is called the bay unit for short, and that whether a bay unit undertakes management functions is set according to design requirements.

On-site busbar protection: a busbar protection scheme made up of one or more bay units, the bay units sharing information through the optical fibre ring network communication and together realising the complete busbar protection function.

Ring network with major management mode: a mode in which all bay units of the equipment communicate through the optical fibre ring network, all bay units in the ring realise the protection function, and one bay unit is chosen to realise the management function of the equipment. The bay unit that realises the management function, called the managing bay unit for short, consolidates the information of all the protection bay units of the whole scheme and sends it up to the intelligent management unit and the monitoring system, and receives operating commands from the intelligent management unit and the monitoring system for management operations on the whole protection scheme, such as changing settings and putting soft strips in or out of service.

Ring network without major management mode: a mode in which all bay units of the equipment communicate through the optical fibre ring network, all bay units in the ring realise the protection function, and each communicates with the intelligent management unit and the monitoring system, sending up its own events and states and independently accepting management operations from the intelligent management unit and the monitoring system, such as changing settings and putting soft strips in or out of service.

4.1 Environmental conditions

Normal atmospheric conditions of operation. The atmospheric conditions at the place where the equipment is used have to meet the following requirements: ambient temperature from minus 40 °C to plus 70 °C; relative humidity from 0 per cent to 100 per cent; atmospheric pressure from 61.6 kPa to 106 kPa.

Surrounding environment. The surroundings at the place where the equipment is used have to meet the following requirements: an electromagnetic environment lower than the immunity level requirements laid down in Table 3, apart from radiated emission and conducted emission; no vibration exceeding severity class 2 as laid down in GB/T 11287; no explosive substances and no severe mould at the place of use; and earthing conforming to 5.8 of GB/T 2887-2011.

Special environmental conditions. The special environmental conditions at the place of use have to meet the following requirements: the equipment possesses resistance to salt mist corrosion and satisfies the salt mist corrosion test requirements of 5.3.2; the equipment possesses the ability to withstand solar radiation and satisfies the solar radiation test requirements of 5.3.4; and other environmental conditions exceeding those of 4.1.1 are agreed between the user and the manufacturer.

4.2 Rated electrical parameters

Direct-current working supply. The direct-current working supply of the equipment has to meet the following requirements: rated voltage 220 V or 110 V, with the equipment adapting itself; permissible deviation from minus 20 per cent to plus 15 per cent; ripple factor not greater than 5 per cent.

Energising quantities. The energising quantities of the equipment conform to 4.2.2 of DL/T 478-2013.

Binary inputs and outputs. The binary inputs and outputs of the equipment have to meet the following requirements: the binary input supply of the equipment is compatible in hardware with 220 V and 110 V direct current; the other requirements for the binary inputs and outputs conform to 4.5 of DL/T 478-2013.

4.3 Accuracy and variation

The accuracy and variation of the equipment conform to 4.3 of DL/T 478-2013.

4.4 General requirements

The equipment has to satisfy the reliability, selectivity, sensitivity and speed requirements for relay protection laid down in GB/T 14285. It has to possess a complete self-checking function and an alarm function able to reflect faults and abnormal states of the protected plant. The realisation of its protection function must not depend on an external time synchronisation system, and, apart from the output relays, the failure of any single component must not cause a maloperating trip of the protection.

The equipment has to use direct cable sampling and direct cable tripping. Binary input information for its own bay, such as the circuit breaker position, is received over cable connections, while starting, blocking, intertripping and similar signals exchanged with other equipment are transmitted over the dedicated protection network as generic object oriented substation event (GOOSE) signals.

The equipment has to use either the ring network with major management mode or the ring network without major management mode. In the mode with a major manager, all bay units have the protection function and only the managing bay unit has the management function; in the mode without a major manager, all bay units have both the protection function and the management function, all bay units are of equal status and they operate cooperatively.

Each bay unit of the equipment should be connected to eight bays, namely one voltage transformer (PT) bay, three bus-coupler or section bays, which in hardware terms can also serve as branch bays, and four branch bays. For double-busbar and double-busbar double-section arrangements, including single-busbar and single-busbar sectionalised arrangements, and for double-busbar single-section arrangements, including single-busbar three-section arrangements, the correspondence between equipment bays and branches is given in Annex A and Annex B respectively.

Communication between the bay units of the equipment uses a bidirectional redundant double ring network in accordance with the requirements of Annex C, and an N-1 communication interruption in any one ring must not affect the protection function.

The equipment is configured with a number of bay units corresponding to the number of bays on site. Within each ring network the bay units are connected in turn by two pairs of optical fibres, finally forming a closed ring, and the bay unit configuration schemes for the different modes are given in Annex D.

The bay units of one set of equipment have to be identical in hardware and interchangeable, and have to have the same settings downloaded, each bay unit having the complete busbar protection function.

The identification mechanism of the individual bay units has to satisfy the requirements of reliability, ease of use and modifiability. Where the ring network with major management mode is used, one bay unit can be set as the managing bay unit on site through the bay unit parameter settings according to actual needs, and any bay unit can be set as the managing bay unit. Communication between the bay units within the ring network has to be configuration-free, for ease of engineering application.

The equipment has to use two different sets of analogue-to-digital sampled data, transmitted separately in two independent ring networks. When one of the two sets of data is abnormal, the protection equipment has to take measures to prevent a maloperation.

The equipment has to have a communication interface for connection to the intelligent management unit and similar devices, the communication protocol conforming to DL/T 860 (all parts), and the configuration, model and services of the communication network and system conforming to GB/T 32890-2016. Where the equipment is connected to different networks, mutually independent data interface controllers have to be used.

When the intelligent management unit is abnormal, the realisation of the protection function of the equipment must not be affected. The dual protection networks of a duplicated configuration follow the principle of mutual independence, and when one network is abnormal or is taken out of service the operation of the other must not be affected.

The equipment has to be supplied by an independent direct-current to direct-current converter. When the direct-current voltage disappears the equipment must not maloperate. The equipment has to work correctly when the direct-current supply voltage varies within the range from 80 per cent to 115 per cent of the rated value, and the direct-current inverter power supply has to start automatically when the direct-current supply recovers, including slow recovery, to 80 per cent of the rated value. The equipment has to work correctly when the ripple factor of the direct-current supply is not greater than 5 per cent, must not maloperate when the direct-current supply is switched on and off or when repeated breakdown sparking occurs on insertion and withdrawal of the fuse, and must not maloperate when various abnormal conditions such as short circuit, open circuit or earthing occur in the direct-current supply circuit.

During power-up and restart the equipment must not send erroneous information, and after the direct-current supply of the equipment disappears none of the recorded information may be lost. The equipment has to support remote management from the intelligent management unit, including one-key backup and download, uploading of state quantities, setting management, and the consultation of reports, logs and disturbance records.

Basic requirements for the information output of the equipment: the information output should conform to DL/T 1782 on relay protection information for substations; the printed information and the displayed information of the equipment have to be consistent with each other, and their application semantics have to be consistent with those of the station level and the telecontrol information; and the equipment has to provide information reflecting its own state of health, including the internal working environment, the hardware working state, the software running state and the communication state, covering both internal communication and communication between devices.

The equipment has to support remote operation, and when operated remotely it is advisable that two or more indications change correspondingly. Each bay unit of the equipment has to have a unique device identification code, which must not be changed during the life cycle of the equipment.

Interface requirements: the equipment interfaces use dedicated electrical connectors and dedicated optical fibre connectors and are connected to the outside through prefabricated cables and prefabricated optical cables; the electrical connectors and optical fibre connectors carry unique markings that are clear, durable and easy to observe; each connector of the equipment has physical means of preventing wrong insertion; and the cross-sectional area of the cores of the electrical connectors is not less than 1.5 square millimetres except for the alternating-current circuits, which are 2.5 square millimetres, while the optical connector core diameter is multimode 62.5/125 µm.

Requirements for the optical fibre interfaces of the equipment: the fibre type is multimode optical fibre; the fibre core diameter is 62.5/125 µm; the optical wavelength is 1 310 nm or 850 nm.