EDS HV CUSTOMER DEMAND AND GENERATION SUPPLIES

Transcription

1 Document Number: EDS Network(s): Summary: ENGINEERING DESIGN STANDARD EDS HV CUSTOER DEAND AND GENERATION SUPPLIES EPN, LPN, SPN This standard provides guidelines for new HV customer demand and generation connections at 11kV or 6.6kV and existing supplies where an increase in capacity requires equipment to be replaced. Author: Stephen Cuddihey Approved By: Barry Hatton Approved Date: 28/12/2017 This document forms part of the Company s Integrated Business System and its requirements are mandatory throughout UK Power Networks. Departure from these requirements may only be taken with the written approval of the Director of Asset anagement. If you have any queries about this document please contact the author or owner of the current issue. Applicable To UK Power Networks External Asset anagement G81 Website Capital Programme UK Power Networks Services Connections Contractors Health & Safety ICPs/IDNOs Legal eter Operators Network Operations Procurement Strategy & Regulation Technical Training THIS IS AN UNCONTROLLED DOCUENT, THE READER UST CONFIR ITS VALIDITY BEFORE USE

2 Revision Record Version 5.2 Review Date 28/12/2022 Date 19/07/2018 Author Lee Strachan Reason for update: inor version update What has changed: Rectified typo in Section 6.3 (Earthing) Version 5.1 Review Date 28/12/2022 Date 21/05/2018 Author Lee Strachan Reason for update: inor version update What has changed: References to EDS updated to EDS Version 5.0 Review Date 28/12/2022 Date 22/11/2017 Author Stephen Cuddihey Reason for update: Review of customer demand and generation standards What has changed: Fault levels (Section 4.2) and power quality (Section 4.3) added. Additional generation criteria added (section 7.3) and generation protection (section 6.8). HV elements of EDS incorporated. Renumbered from EDS and title amended. Version 4.0 Review Date 25/11/2021 Date 25/11/2016 Author Stephen Cuddihey Reason for update: Clarification of LV supply provision What has changed: LV supply options amended (Section 6.1 and 6.12). Version 3.0 Review Date 04/11/2021 Date 04/11/2016 Author Stephen Cuddihey Why has the document been updated: Clarification of remote control and LV supplies What has changed: Remote control provision aligned with EDS (Section 6.7). LV supply options amended (Section 6.12). Version 2.0 Review Date 12/11/2018 Date 24/08/2015 Author Stephen Cuddihey Why has the document been updated: Periodic review What has changed: Full settlements metering clarified (Section 7.2). Generation and security requirements included (Section 7.3) Version 1.0 Review Date 01/09/2015 Date 14/08/2014 Author Stephen Cuddihey New standard largely based on existing practices. Incorporating extensive internal and external feedback from the UK Power Networks Technical Review Forum and the Customer Engagement Workshop, this standard gives the first formal approach to the provision of HV customer supplies for all three regions of UK Power Networks. This document also incorporates the security of supply arrangements previously detailed in EDS , which will now be withdrawn. UK Power Networks 2018 All rights reserved 2 of 26

3 Contents 1 Introduction Scope Glossary and Abbreviations Technical Requirements Voltage Fault Level Constraints Power Factor Voltage Control Power Quality and onitoring inimum Scheme Designs Higher than Normal Security of supply Central High Load Density Zone ulti-occupied Buildings Connection Arrangements Overview Hardware Arrangement Overview Ring ain Unit ultiple Ring ain Units Extensible Switchgear ulti-section Extensible Switchgear (ulti-panel Boards) Supply Arrangements Overview Open Ring ultiple Rings Dedicated Feeders ultiple Primary Substations ultiple Grid Substations or Grid Supply Points Installation Requirements Responsibilities Accommodation for Switchgear Earthing Ownership Boundary Switchgear Access Requirements UK Power Networks 2018 All rights reserved 3 of 26

4 6.7 Remote Control and Automation Protection and Control TLF Protection Relay Protection Protection Settings Parallel Operation and Interlocking Standby generation Emergency Trip LV Supplies Commercial Requirements Land Rights and Legal Requirements etering Connection Agreement Site Responsibility Schedule References UK Power Networks Standards National Standards Dependant Documents Figures Figure 5-1 Typical HV Customer Connection Arrangements Figure 5-2 Single RU Connection Figure 5-3 ultiple RUs for Tee and Ring Connections Figure 5-4 Extensible RU and RU with 630A RU Connection Figure 5-5 ulti-section Extensible Switchgear Connection Tables Table 5-1 Hardware and Supply Arrangement Summary Table 6-1 Standard Switchgear for Customer Loads UK Power Networks 2018 All rights reserved 4 of 26

5 1 Introduction This standard provides guidelines for new HV customer demand and generation connections at 11kV or 6.6kV and existing supplies where an increase in supply capacity requires equipment to be replaced. The standard for new and additional customer HV metered supplies shall be used where: The customer s load or generation requires a transformer capacity above 1VA. The customer s site covers a large geographic area which would require HV distribution. Due to disturbing loads, a point of common coupling at LV would result in disturbance to other customers. The customer specifically requests an HV connection. Note: A minimum agreed capacity of 200kVA at 11kV or 115kVA at 6.6kV is required to ensure sufficient metering accuracy at times of reduced customer demand. It is the intention of this standard to provide clear and consistent guidelines to support designers and planners when undertaking new customer connections with specific guidance on HV network arrangement for loads to be provided from the HV distribution network and loads requiring the installation of new HV feeders. 2 Scope This standard applies to all HV customer demand and generation connections at 11kV or 6.6kV. This standard does not apply to customer supplies at 33kV or 132kV; refer to EDS This standard applies to connections provided for licensed Independent Distribution Network Operators (IDNOs), except where otherwise required by EDS UK Power Networks 2018 All rights reserved 5 of 26

6 3 Glossary and Abbreviations Term ENA Firm Capacity GRP HV IDNO LV PR n-1, n-2 etc. PLTU RU RTU TLF Definition Energy Networks Association UK association of Distribution Network Owners A maximum power requirement that shall meet or exceed the requirements of ENA ER P2/6 Glass Reinforced Plastic AC Voltages above 1000 Volts; generally used to describe 6.6kV or 11kV distribution systems but may include higher voltages. Independent Distribution Network Operator AC Voltages up to 1000 Volts; generally used to describe 230/400 Volt or 230/460 Volt distribution systems. aximum Power Requirement (in VA) First, second, etc. feeder outage support Parasitic Load Tripping Unit Ring ain Unit Remote Terminal Unit Time Limit Fuses UK Power Networks 2018 All rights reserved 6 of 26

7 4 Technical Requirements 4.1 Voltage The standard HV supply voltage is 11kV. Supplies shall not be offered at 6.6kV where an 11kV alternative with sufficient capacity, and which meets the requirements of a minimum cost scheme, is available. Customers who are to be supplied at 6.6kV shall be advised to use equipment and cables rated for 11kV and transformers with dual 6.6kV and 11kV primary windings. The Connection Agreement shall include a clause stating that the supply voltage may be changed to 11kV in the future. 4.2 Fault Level Constraints Please refer to EDS Power Factor Unless otherwise agreed the customer shall ensure that the import and export power factor is maintained between 0.95 lagging and 0.95 leading. 4.4 Voltage Control The proposed connection of a generation scheme may affect the correct operation of the automatic voltage control (AVC) scheme at a grid or primary substation. Circumstances where this may arise are: In instances where the grid or primary transformers may be subjected to reverse power flow as a consequence of the generation connection; Where the generator provides a significant proportion of the site maximum demand and the AVC scheme relies on line/load drop compensation. The voltage control scheme shall be assessed to determine if it will continue to operate correctly or whether it needs full or partial replacement. Additionally the reverse power capability rating of the tap changer at the grid or primary substation shall be checked to ensure it is not compromised. Where any necessary replacement, modifications or servicing recommended by the manufacturer shall be carried out as a part of the new connection project prior to the generating plant being connected. All replacement costs shall be apportioned in accordance the provisions of the UK Power Networks Common Connection Charging ethodology. Refer to the voltage control standards for further details. UK Power Networks 2018 All rights reserved 7 of 26

8 4.5 Power Quality and onitoring The customer or ICP shall provide data for the proposed connection in respect of anticipated harmonic levels. A power quality meter shall usually be installed for the long term monitoring of the connection to ensure that planning or compatibility levels of harmonic distortion are not exceeded. Refer to EDS for additional information. 4.6 inimum Scheme Designs Supplies up to 7.6VA at 11kV (4.5 VA at 6.6kV) shall be provided from an existing or new 11kV feeder. Supplies exceeding a firm capacity of 7.6VA at 11kV (4.5 VA at 6.6kV) shall only be provided through the use of dedicated feeders from single or multiple primary substations. Following assessment by UK Power Networks, upstream reinforcement of the distribution network may be needed in order to accommodate the customers requirements. This may include a new feeder or feeders from the local primary substation and/or reinforcement of the primary system. Supplies of 5VA or greater within the LPN Central High Load Density Zone should be considered for connection at the higher distribution voltage of 33kV, dependent upon location and available network capacity. Refer to EDS For all customers the minimum cost scheme shall be the most cost efficient method to provide the customer s maximum power requirement in accordance with EDS UK Power Networks do not consider a tee connection suitable for HV customers; the cost impact of an additional HV cable to provide a ring supply compares favourably against the incurred outage costs for a single customer load. Therefore tee connections are recognised as the minimum scheme for many customers but are not recommended. A single customer shall require a ring connection as the minimum scheme if: The single customer demand is greater than 1W. The single customer demand increases a tee group load beyond 1W. The customer is within 100m (measured from boundary) of the supplying HV network. Where a ring supply is to be provided the customer should be made aware that, whilst this will allow the restoration of supply for the majority of system faults, it will not guarantee restoration or continuity of supply under all outage conditions. Where a tee connection to an existing HV network is the minimum scheme a ring connection shall be considered an increase of security of supply. UK Power Networks 2018 All rights reserved 8 of 26

9 4.7 Higher than Normal Security of supply UK Power Networks HV networks are designed in accordance with EDS which complies with ENA ER P2/6. UK Power Networks recognises that some customers will have requirements beyond an ENA ER P2/6 compliant distribution system, therefore the option exists for a single customer at HV to request a security of supply above that which UK Power Networks would normally provide. The customer shall specify, as part of their application, the required level of supply security i.e. n-1, n-2 etc. Once this is established, the appropriate method of supply can be determined. The customer may request that all or a proportion of their demand is connected as unfirm demand meaning that during a first circuit outage this demand will remain off supply for the duration of the restoration period. This would require additional protection modification to ensure disconnection of unfirm demand during the first circuit outage. Costs associated with a higher than normal security supply shall be in accordance with the Common Connection Charge ethodology. No additions to or revisions of an agreed higher than normal security network arrangement shall be to the detriment of the agreed customer security requirements. 4.8 Central High Load Density Zone For HV supplies in the High Load Density Zone (Central London) reference should be made to EDS Within the Central High Load Density Zone of the LPN region it may be necessary to connect at a higher voltage (typically 33kV) for demands of 5VA or more. Refer to EDS ulti-occupied Buildings Supplies to multi-occupancy buildings shall comply with EDS Particular care is required where multiple supplies are requested or existing supplies are to be augmented. UK Power Networks 2018 All rights reserved 9 of 26

10 5 Connection Arrangements 5.1 Overview The following Table 5-1 and Figure 5-1 provide an overview of the available connection arrangements for an HV customer. Table 5-1 indicates the hardware required at the point of connection for increasing demand/export and feeder complexity along with the pertinent section of this standard. Table 5-1 Hardware and Supply Arrangement Summary Switchgear / Protection / etering Demand or Export PR (VA) RU 200A CB RU 630A CB RU 630A CB ultiple RUs Extensible RU ulti-section Extensible Switchgear up to 630A Extensible Primary switchgear above 630A TLF Relay Relay Relay Relay Relay Relay 200A 200A 400A 400A 600A 600A >600A Hardware Arrangement Demand 0 to (standard) (enhanced) Demand 1.5 to 3.8 Export 0 to to to (standard) (standard) (enhanced) (enhanced) (standard) (standard) (enhanced or unit protection) (enhanced or unit protection) Above 11.4 Feeding Arrangement Open Ring ultiple Rings Dedicated Feeders ultiple Primary Substations ultiple Grid Substations/ GSP Refer to EDS UK Power Networks 2018 All rights reserved 10 of 26

11 Figure 5-1 indicates typical network arrangements, switchgear types and feeder options along with the pertinent section of this standard. Primary Substation1 S Primary Substation 2 NOP S S NOP NOP S S S NOP S Existing New etering (not for IDNO) S. 4.3 Section Number S Figure 5-1 Typical HV Customer Connection Arrangements UK Power Networks 2018 All rights reserved 11 of 26

12 5.2 Hardware Arrangement Overview Approved switchgear types are detailed in EAS Where an HV customer is fed from the Central High Load Density Zone in LPN, with interconnected LV networks, all metering circuit-breakers shall be equipped with a PLTU in order to automatically disconnect the customer when an HV earth fault condition is detected. Supplies provided with unit protection or supplies from dedicated feeders shall use multisection extensible switchgear (refer to section 5.2.5) Ring ain Unit NOP Figure 5-2 Single RU Connection A single RU is capable of supplying from 200kVA up to 7.6VA and may be connected in a variety of methods from existing or dedicated HV feeders, dependent upon network availability. Whilst a single RU may be the sole point of supply between one or two dedicated feeders UK Power Networks strongly recommends at least duplicate RUs (refer to section 5.2.3) or multi-section extensible switchgear which provides greater control, protection and flexibility appropriate to the level of supply security (refer to section 5.2.5). A single RU shall not be accepted between two tee connections, as this arrangement reduces the integrity of more than one feeder for a switchgear related outage. Refer Section 6.8 specific protection and control scheme requirements. UK Power Networks 2018 All rights reserved 12 of 26

13 5.2.3 ultiple Ring ain Units NOP NOP Figure 5-3 ultiple RUs for Tee and Ring Connections If the site to be connected is situated where more than one HV feeder is available then, dependent upon network configuration, two teed connections may be used; however two RUs with a normal open point between them or to either incoming feeder may be required to ensure that the two feeders are not put at risk by a single fault (refer to EDS ). The use of multiple RUs also provides a level of redundancy; should one of the units fail, the supply may be maintained from the other providing the maximum load requirements does not exceed the rating of the switchgear. These supplies shall each be provided from standard arrangements of ring main and metering units to the customer s network. The customer shall be able to operate their customer network to maintain or restore supplies during network outages. The customer network shall run with a normal open point to prevent parallel operation of the two incoming network feeders. echanical or electrical interlocks complying with EDS shall be supplied by the customer such that the normal open point on the customer network can only be closed if another open point is established first. The customer may require the installation of an automatic changeover system. Remote control facilities shall be installed on all switchgear where auto-changeover is provided to enable monitoring and control of the feeding arrangement. The use of more than two RUs may warrant the use of multi-section extensible switchgear and should be considered as an alternative. Refer Section 6.8 specific protection and control scheme requirements. UK Power Networks 2018 All rights reserved 13 of 26

14 5.2.4 Extensible Switchgear NOP NOP Figure 5-4 Extensible RU and RU with 630A RU Connection If a ring connection does not offer sufficient security of supply, two additional options are available: Extensible RU. RU with free standing 630A RU. Both options provide an additional HV feeder into a ring supplied customer substation, increasing the security of supply. For example, if 2VA is available from each of three HV feeders, a single customer could receive a 4VA supply with an n-1 security of supply or a 2VA supply with an n-2 enhanced security of supply; n-2 indicates that the full supply capacity will still be available following two coincident outages on the HV system. Note: EDS requires an additional switching point to be present between the two feeders as shown in Figure 5-4, in order to ensure that only one circuit is affected by a switchgear fault. Refer Section 6.8 specific protection and control scheme requirements. UK Power Networks 2018 All rights reserved 14 of 26

15 5.2.5 ulti-section Extensible Switchgear (ulti-panel Boards) Primary Substation1 Primary Substation 2 NOP Figure 5-5 ulti-section Extensible Switchgear Connection At customer request or, for demands exceeding 7.6VA, a multi-section extensible board shall be used. By comparison to RUs, this switchgear takes the form of individual circuit breakers served by a common busbar with, depending on size, bus-section protection. This increases customer security of supply and allows the termination of several HV feeders to a single customer location. The busbar configuration, normal running and protection arrangements at the primary substation will also determine how multiple feeder HV supplies are connected. If the primary/grid transformers are run in parallel this will influence the type of configuration that can be offered. Where the transformers are running in parallel a feeder or group of feeders may be connected to different sections of the busbar separated by a bus-section circuitbreaker. This may enable the supply to the customer to be maintained in the event of a planned or unplanned busbar outage at the primary substation. A bus-section switch (or circuit-breaker without protection) may be used at the customer s substation if busbar protection is not required. any possible designs and configurations exist for this type of installation and will be bespoke by nature. The most economic design to give the supply capacity and security required will need to be carefully assessed in each individual case. Where the multiple feeder supply is from a primary substation with double 11kV (or 6.6kV) busbars; the feeding arrangement for the customer s supplies will need to match the operating regime of the switchboard. Supplies provided with unit protection or supplies from dedicated feeders shall use multisection extensible switchgear. Refer Section 6.8 specific protection and control scheme requirements. UK Power Networks 2018 All rights reserved 15 of 26

16 5.3 Supply Arrangements Overview All UK Power Networks HV feeders and rings are designed in accordance with EDS This section summarises the available options within the HV distribution network to provide HV supplies; each option builds on the previous one to offer additional security of supply but, the list is not exhaustive. For every HV customer UK Power Networks shall provide the most cost efficient arrangement to meet a customer PR, recognising firm and unfirm requirements. Unless previously agreed with the customer parallel operation of HV feeders and/or primary substations is to be prevented (refer to section 6.9) Open Ring Utilising the existing HV distribution network, a ring connection of switchgear into the existing open ring distribution network is the typical minimum HV feeder option for single HV customers (refer to section 4.2). Typical switchgear is a single RU ring connected into the local HV network. The available capacity will be dependent upon the prevailing network capacity available at the customer location. Note: Ring network running arrangements are not guaranteed beyond the initial connection and can be altered at any time to ensure the safe and secure operation of the distribution network. Any reconfiguration will not alter the security or demand capability of customer connections. Open ring HV network security is within the requirements of EDS ultiple Rings Utilising several existing HV distribution networks, ring connections of switchgear are made into each existing open ring distribution network that is available. Typical switchgear is multiple RUs or extensible switchgear. This option is purely dependent upon the prevailing network capacity available at the customer location and may not be feasible at remote locations. The network security of each open ring is within the requirements of EDS Considerations towards redundant feeders and physical security are limited by the availability and proximity of the existing distribution network. Note: As with open ring connections, the network running arrangements of each open ring are not guaranteed beyond the initial connection and can be altered at any time to ensure the safe and secure operation of the distribution network. UK Power Networks 2018 All rights reserved 16 of 26

17 5.3.4 Dedicated Feeders One or more HV feeders are provided from a single primary substation to the customer point of connection. A firm supply exceeding 7.6VA shall only be provided through the use of dedicated feeders and multi-section extensible switchgear. At this level of higher than normal security of supply the customer may require guarantees regarding the stability of their running arrangements. In these instances consideration shall be given towards outage from maintenance and/or a fault on the primary busbars or transformers. Supplies from alternate busbars and/or primary transformers may be requested, though availability will be dependent upon the prevailing network capacity available at the customer location. Considerations towards the use of redundant feeders and the impact of physical security are available at this level of security and, if requested, shall be considered at the design stage. In addition the customer shall be advised to consider the impact of equipment maintenance and failure at their point of supply; redundant switch gear and switch rooms should be a consideration. An unfirm supply exceeding 7.6VA may be possible using a combination of dedicated feeders for the agreed firm demand and an existing open ring network to contribute a proportion of an unfirm supply with the associated restrictions of the existing open ring supply (refer to section 5.3.2) ultiple Primary Substations Further increasing the security of supply beyond dedicated feeders from a single primary substation; HV feeders are provided from multiple primary substations to the customer point of connection. The requirements of dedicated feeders remain in place (refer to section 5.3.4) with additional considerations. This option may be provided if: A single primary substation cannot meet the firm customer requirement or, Other HV feeder options prove impractical or uneconomical. Where possible this should be on the basis of a normal supply from one primary source with an alternative from another and with a normal open point located at a circuit-breaker or switch under UK Power Networks control. UK Power Networks 2018 All rights reserved 17 of 26

18 5.3.6 ultiple Grid Substations or Grid Supply Points It is possible to increase security of supply at HV further by using HV feeders supplied from different primary substations that are supplied by different grid substations or grid supply points. Considering the impact on cost efficiency that a design of this type will have, a customer should give consideration towards an EHV solution where feasible and practicable (refer to EDS ). Differing grid supply points should only be considered where a customer supply at EHV is not feasible or, for customer reasons, an HV connection is unavoidable and a required level of supply security cannot be met by the use of dedicated feeders supplied by alternate busbars and/or transformers at primary substations. At the earliest stage of development careful consideration shall be given to: Phase rotation. HV and EHV earthing. Voltage regulation. Differing source fault levels. Physical security of dedicated feeders. Redundancy of equipment and switchrooms. Any other restrictions relating to the particular grid or primary sources. UK Power Networks strongly recommends that, in order to remove single point weaknesses, consideration should be given towards diverse routes of supply for dedicated feeders, redundant switchrooms fully equipped with standby equipment and a customer network designed to DNO levels of integrity and reliability. UK Power Networks 2018 All rights reserved 18 of 26

19 6 Installation Requirements 6.1 Responsibilities UK Power Networks, an appointed contractor or suitably authorised ICP is responsible for the following: Supply and install incoming HV switchgear and metering circuit-breaker up to and including the metering unit or CTs and VTs. Supply and install control and protection equipment including (where appropriate) batteries, relays, chargers, RTUs, cabling and auxiliary wiring. Supply and install incoming HV cables, jointing and jointing materials. Supply and install metering facilities including multicore cable, fixings and terminations, meter cabinet including test block. Supply and install an LV supply. Note the LV supply shall be provided in accordance with Section Terminate customer s HV and emergency tripping cables (labour only). Supply and install GRP housing and fixings for all equipment (where required). Supply substation locks or access system to UK Power Networks standard (UK Power Networks will also supply for ICP build). The customer is responsible for the following: Supply and build the substation concrete base to UK Power Networks design including cable entry ducts and all cable ductwork on private property. Supply and install the earthing system for the substation to UK Power Networks approved design. Design, supply and build brick or other construction buildings if a GRP is not used. Supply and install the HV cable and termination kits for connection by UK Power Networks to the metering unit or circuit-breaker and install cable then terminate customer s end. Provide all necessary arrangements to facilitate cable and equipment installation e.g. in exceptional cases winching eyes or posts may be required. Supply and install weatherproof accommodation for metering cabinet and ducts for metering multicore cables. Supply and install emergency trip facility in accordance with EDS Supply and install the internal building services including lighting, power and heating/dehumidification (where required). Note the LV supply shall be provided in accordance with Section Unless otherwise stated, responsibilities for contestable elements shall be decided at the design stage. UK Power Networks 2018 All rights reserved 19 of 26

20 6.2 Accommodation for Switchgear All HV supplies will require a new secondary substation and UK Power Networks designers shall ensure this is recognised by the customer at the initial stages of customer enquiries. The substation location and access arrangements shall comply with EDS For supplies fed by outdoor rated RUs or non-extensible switchgear, a standard GRP housing shall be offered, for additional information refer to EDS Bespoke designs will be required for civil works relating to customer HV supplies where indoor multi-section extensible switchgear is used. The switchroom design shall comply with EDS Earthing Refer to EDS for all aspects of earthing design and construction associated with HV connections including inter-connection of UK Power Networks and the customer's earthing systems. All substation earthing designs shall be approved by UK Power Networks before construction. The customer shall provide a comprehensive earthing report with supporting calculations and associated earthing drawings to enable the design to be assessed. 6.4 Ownership Boundary The ownership boundary shall be at the outgoing terminals of the UK Power Networks switchgear and shall be indicated on site by the use of the approved boundary label EDS The customer shall: Provide, install, own and maintain the HV cable from the UK Power Networks metering circuit-breaker. Fit suitable termination lugs to their HV cable (refer to EAS ). Terminate and connect all cables within their own installation to their equipment. The customer shall not terminate the customer HV cable onto UK Power Networks equipment. UK Power Networks or suitably authorised ICP staff shall connect the terminated HV customer cable to the incoming supply equipment. No customer access to UK Power Networks equipment shall be provided. Bus-section metering shall not be provided. All customer supplies shall be supplied by means of customer cable connected to either the customer s HV switchgear or single transformer. Physical separation shall be maintained between the UK Power Networks equipment and any customer owned equipment. Note: IDNOs shall refer to EDS UK Power Networks 2018 All rights reserved 20 of 26

21 6.5 Switchgear The switchgear options are detailed in Table 6-1 and the approved switchgear types are detailed in EAS Table 6-1 Standard Switchgear for Customer Loads Type Circuit Breaker (A) Protection etering* (A) PR up to RU 200 TLF RU 200 Relay RU 630 Relay Extensible RU 630 Relay ulti-section Extensible Switchgear *Refer to EDS for IDNO supplies. 630 Relay Access Requirements UK Power Networks staff, representatives or ICPs with appropriate authorisation shall be provided with full access to the UK Power Networks substation. 24 hour access requirements for personnel and plant shall be available. The substation shall be suitably located at ground level. There shall be adequate provision for installation and maintenance of cables. The proposed site shall be a safe place of work. Expected activities are: To lay incoming cables into the substation. To install plant and equipment in the substation. To install the metering termination box and the multicore cable from the substation. To operate in an emergency. 6.7 Remote Control and Automation Remote control shall be provided in accordance with EDS All substations shall include an RTU and appropriate communication equipment. 6.8 Protection and Control TLF Protection Provided that no higher than normal level of security is required and no ENA ER G59/3 parallel generation exists, customer supplies not exceeding 1.6 VA connected to a single transformer shall be protected by overcurrent and earth fault protection using time limit fuses (TLF). The TLF sizes are based on the rating of the transformer and specified in EDS UK Power Networks 2018 All rights reserved 21 of 26

22 6.8.2 Relay Protection All supplies in excess of 1.6VA shall be provided with a protection scheme using protection relays. The protection requirements should be discussed with the customer at early stage and include any requirements neutral voltage displacement (NVD) protection and, where required, matching equipment is specified for both UK Power Networks and the customer s switchgear. Protection scheme studies shall be carried out to ensure the viability of any proposed protection scheme before the network design is finalised. Refer to EDS for generic block diagrams and specific protection and control scheme requirements. For unit protected rings also refer to EDS Note: UK Power Networks does not provide overload protection for the customer s equipment Protection Settings Protection settings shall be applied in accordance with UK Power Networks standards. Where overcurrent and earth fault relays are used the settings shall be selected to: Protect UK Power Networks equipment against the effects of fault current due to a fault on the customer s network. Discriminate with upstream protection on the UK Power Networks system. 6.9 Parallel Operation and Interlocking Where multiple incoming supplies create the potential to parallel the UK Power Networks distribution network across the customer s network, the customer shall provide a mechanical or electrical interlocking system in accordance with EDS If automatic changeover between main and alternative supplies is required this shall be accomplished on the customer s equipment. Where the customer requires exceptional security of supply and if the network operates in parallel on the UK Power Networks side of the metering circuit-breakers, parallel operation between metering points may be permitted subject to the approval of UK Power Networks Where parallel operation is permitted the customer shall install unit protection to integrate with UK Power Networks owned and approved protection relays fitted to the metering circuitbreakers. The details of arrangements for interlocking and any permitted load transfer between supplies shall be written into the site responsibility schedule and also into the connection agreement Standby generation If standby generation is installed, at either HV or LV, it shall be connected through an interlocked changeover switch such that it cannot be operated in parallel with the UK Power Networks supply. The changeover arrangements shall comply with ENA ER G59/3. UK Power Networks 2018 All rights reserved 22 of 26

23 6.11 Emergency Trip A customer emergency trip facility shall be provided in accordance with EDS where required LV Supplies An LV supply shall be provided in accordance with EDS The supply shall be monitored by UK Power Networks SCADA system. UK Power Networks 2018 All rights reserved 23 of 26

24 7 Commercial Requirements 7.1 Land Rights and Legal Requirements Necessary land rights shall be secured before starting construction as detailed in EDS etering Boundary metering shall be used for all HV customer supplies unless it is proven that all exit points after the HV circuit breaker use full settlements metering. Where boundary metering is not required, an approved monitoring solution shall be installed. An approved metering termination box incorporating a connection/test terminal block shall be supplied by UK Power Networks; the metering terminals shall be connected to the metering CTs and VTs using a multicore armoured cable installed with customer provided ducting. The metering termination box shall be positioned to keep the length of the metering auxiliary cable connection below the normal maximum length of 20m, based on 7.5VA (minimum) CTs with 5A secondary and 2.5 mm 2 copper cable connections. This distance may be extended up to 50m by using 1A meters or up to 40m by doubling on cable cores of the 2.5 mm 2 copper cables if no practical location is available within 20m. Individual metered RU supplies are limited to 7.6VA using 400/5A ratio CTs (refer to EAS ) When 100/5 CTs are used, for reasons of meter accuracy, the minimum capacity of HV supply that shall be offered is 200kVA (115kVA at 6.6kV) to comply with the relevant Balancing and Settlements Code of Practice (CoP 3 in this instance). Where extensible switchgear is used the metering CTs and VTs will be fitted in the metering circuit-breaker, and selected to match the rating of the circuit-breakers in accordance with the requirements of the appropriate Balancing and Settlement Code of Practice. It should be noted that the supply cannot be connected until an energy supplier and meter operator have been appointed by the customer, and a meter has been fitted and commissioned or a portfolio billing arrangement has been agreed by an IDNO. Note: etering arrangements for IDNOs are detailed in EDS UK Power Networks 2018 All rights reserved 24 of 26

25 7.3 Connection Agreement A site specific connection agreement shall be provided and in addition to the standard clauses, clauses to cover any site specific requirements shall be included. This should include but not be limited to, the following customer specific requirements: The proportion of firm and unfirm PR for export and import. The maximum generation capacity to be connected and run in parallel with the distribution system. Location of generator sites with location plans or where detailed information is not available for projects that are still in a development stage, the nearest accessible boundary position to the point of connection. Generator fuel type (e.g. steam turbine, solar farm etc.). Type of generator i.e. synchronous, asynchronous, inverter connected etc. Rating of generator in both W and VAR. Rating of the prime mover in W. Where generation is inverter connected, the type and fault output capability of the inverter and type test certificate. Customers with more than one intake position. Customers with higher than normal security or lower than normal security where the customer has specifically requested that lower level of security to minimise costs. Customer s supplied from more than one primary substation. Customers opting for connections which do not meet the UK Power Networks requirements for minimum cost schemes. Disturbing loads requiring special conditions and associated constraints such as the maximum frequency of motor starts or equivalent constraints. Seasonal or dynamic demand limits. Waiver of compensation rights if generation customer requests teed supply in place of ringed. Requirements for customers supplied at 6.6kV (refer to Section 4.1). Supplies above 11kV. Supplies to Inset Networks. Special customer load, for example battery load to meet the National Grid fast response to frequency change scheme. Special schemes the customer is part of such as Flexible Distributed Generation or the Kent Active anagement System. 7.4 Site Responsibility Schedule Prior to energisation a Site Responsibility Schedule shall be completed. The Site Responsibility Schedule shall specify that maintenance of the substation building or housing along with the building services shall be the responsibility of the customer. This Site Responsibility Schedule shall also include, where relevant the requirements for interlocking between intake points and requirements for switching procedures when making and breaking parallels between intake points. Refer to CON and NOP for further information. UK Power Networks 2018 All rights reserved 25 of 26

26 8 References 8.1 UK Power Networks Standards EAS EAS EDS EDS EDS EDS EDS EDS EDS EDS EDS EDS EDS EDS EDS EDS EDS EDS CON NOP Cables and Joints V Switchgear Protection and Control Schemes for Customer Demand and Generation Connections Fuse Ratings at Distribution Substations Secondary Substation Earthing Design Sign and Label Drawings Civil Requirements for New Customer Supplies and Generator Connections Between 6.6 & 33kV Pre-design Requirements for Secondary Substations Secondary Substation Civil Design Standards Inset Networks Planning Guidance Supplies to ulti-occupied Buildings Fault Levels Substation LVAC Supplies Guidance for the Connection of Customer s Disturbing Loads System 8 Network Design Guidelines HV Network Design EHV Design 8.2 National Standards ENA ER G59/3 ENA ER P2/6 London 33kV Distribution Network Design and Customer Supplies Procedure for Creating a Site Responsibility Schedule - HV Customer Supplies Site Responsibility Schedules for HV Customer Sites (Internal Use Only) Connection of Generation to Licensed Networks Security of Supply Balancing and Settlement Code of Practice (Re: CoP3 or CoP 5) Published by Elexon, available at: 9 Dependant Documents EDS EDS EDS EDS EDS Protection and Control Schemes for Customer Demand and Generation Connections Supplies to ulti-occupied Buildings HV Network Design EHV Design EHV Customer Demand and Generation Supplies UK Power Networks 2018 All rights reserved 26 of 26