EDS GAS ZONE IDENTIFICATION AND ALARMS ON GAS INSULATED SWITCHGEAR

Transcription

1 ENGINEERING DESIGN STANDARD EDS GAS ZONE IDENTIFICATION AND ALARMS ON GAS INSULATED SWITCHGEAR Network(s): Summary: EPN, LPN, SPN This standard sets out the system of gas zone identification and associated alarms to be used on all 145kV and 72.5kv Gas Insulated switchgear. Author: Paul Dyer Approver: Paul Williams Date: 05/10/2017 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 Management. 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 Management G81 Website Capital Programme UK Power Networks Services Connections Contractors Health & Safety ICPs/IDNOs Legal Meter Operators Network Operations Procurement Strategy & Regulation Technical Training THIS IS AN UNCONTROLLED DOCUMENT, THE READER MUST CONFIRM ITS VALIDITY BEFORE USE

2 Revision Record Version 3.0 Review Date 05/10/2022 Date 03/10/2017 Author Paul Dyer Reason for update: Periodic review What has changed: No content changes, document transferred onto a new template and rules applied. Document title revised. Version 2.0 Review Date 04/04/2017 Date 02/04/2014 Author Paul Dyer Reviewed, no content changes Version 1.0 Review Date Date 14/02/2006 Author Lionel Mackay Original UK Power Networks 2017 All rights reserved 2 of 8

3 Contents 1 Introduction Scope Numbering System Busbars Other Zones Gas zones which contain a numbered item of plant (circuit-breaker, disconnector or voltage transformer) Gas zones which do not contain any identified plant (other than an earthing switch) Labelling SCADA Alarms Actions Required Diagram Implementation on Existing Sites Assessment Agreement with National Grid Site work... 8 Figures Figure 3-1 Gas Zone Labelling for Busbars... 5 Figure 3-2 Gas Zone Labelling for Double Busbar Feeder Bays... 5 Figure 3-3 Gas Zone Labelling for Bus-Section and Bus-Coupler Circuit Breaker Bays... 6 Figure 3-4 Gas Zone Labelling for Standalone Bay... 6 UK Power Networks 2017 All rights reserved 3 of 8

4 1 Introduction This standard sets out the system of gas zone identification and associated alarms that is to be used on all 145kV and 72.5kV gas-insulated switchgear (GIS). The purpose of this standard is to assist Senior Authorised Persons and Control Engineers to clearly relate gas zones to the electrical configuration of the switchgear, and to identify zones of work. 2 Scope This standard applies to all new switchboards where UK Power Networks owns the busbars. On switchboards where individual bays are owned by other parties (e.g. National Grid) this system is to be applied by agreement to all bays to ensure consistency. On new switchboards where UK Power Networks does not own the busbars, UK Power Networks should seek to have this system applied to the whole switchboard. For existing GIS equipment, individual site assessments shall be made to establish the benefits and costs of applying this Standard. UK Power Networks 2017 All rights reserved 4 of 8

5 3 Numbering System 3.1 Busbars MB1VT1G1 MB2VT1G1 MB1G4 MB1G2 MB1G1 MB2G1 MB2G2 MB2G4 MB1G3 MB2G3 Main busbar section 1 Main busbar section 2 Figure 3-1 Gas Zone Labelling for Busbars Main busbar RB1Gn MB1Gn Reserve busbar 104G C D 106G1 105G G1 105G3 101B G1 101A 103G2 103VTG1 Figure 3-2 Gas Zone Labelling for Double Busbar Feeder Bays On double busbar equipment busbars shall be designated Main Busbar or Reserve Busbar. The ID code of gas zones shall be in two parts: For double busbar equipment Main and Reserve Busbars shall use the designations MB and RB respectively, followed by the section number e.g. MB1, RB3, etc. On each section of busbar gas zones shall be consecutively numbered G1, or G01 where any section of busbar may have more than nine compartments. UK Power Networks 2017 All rights reserved 5 of 8

6 The complete gas zone ID code shall combine these designations, e.g. MB1G3, RB3G04, etc. On single busbar equipment the designation for the Busbar shall be BB For Section 1 the sequence of numbering shall start from the bus-section. For other sections the sequence numbering of gas zones shall be in the same direction as the numbering of the busbar sections. This scheme will not apply to any compartments in the busbar run which contain switching devices other than earthing switches. Compartments containing busbar VTs shall combine the busbar section number, the VT number, and G1, i.e. MB1VT1G Other Zones A B MB1Gn 124G1 120G2 120G1 120G3 128G1 MB2Gn or RB1Gn Figure 3-3 Gas Zone Labelling for Bus-Section and Bus-Coupler Circuit Breaker Bays 124G2 101A A 124G1 120G G1 120G B 128G1 101B 128G2 Figure 3-4 Gas Zone Labelling for Standalone Bay UK Power Networks 2017 All rights reserved 6 of 8

7 3.2.1 Gas zones which contain a numbered item of plant (circuit-breaker, disconnector or voltage transformer) The first part of the code shall be the identification number of the principle item of plant. The second part shall be the designation G1. Where a gas zone contains more than one item of plant, including at least one disconnector or circuit breaker, the ID code of the zone shall include the designations of all disconnectors and circuit-breakers; no other items of plant will be included in the code. Where the designations include a common bay reference this may be omitted from the designation of the second device i.e. a zone containing disconnectors 1104B and 1106B would be designated 1104B/6BG1. At the junction of a busbar with a circuit the compartment containing the busbar disconnector shall be identified using the disconnector plant number, e.g. 104G1, even if the zone includes a section of busbar. Voltage transformers shall be assigned a designation in the form NNNVTnG1, where NNN represents the switching device most closely associated with the VT, and n is a sequence number. Earthing switches shall not be used for identifying gas zones Gas zones which do not contain any identified plant (other than an earthing switch) The identification of these zones shall follow the form NNNGn, comprising: The most closely associated switching device; compartments on the CB side of a disconnector shall use the CB number; compartments on the line side of a disconnector shall use the disconnector number. A gas zone identification sequence number, starting with G2. The sequence shall start from: The busbar (for feeder and incomer bays). The lower numbered section of busbar (for bus-section bays). The main busbar (for bus-coupler bays). The source side (for stand-alone bays). 3.3 Labelling Labels with the gas zone ID code shall be fixed to: Each gas zone. Each gas filling valve. Each gas monitoring point. UK Power Networks 2017 All rights reserved 7 of 8

8 3.4 SCADA Alarms The gas alarms shall be segregated such that it is possible for a Control Engineer to identify those plant items which are affected by a low gas alarm. Individual gas alarms shall be provided for each compartment containing a circuit-breaker or a disconnector. Common alarms shall be provided for: SF 6 falling alarm for each section of busbar (other than compartments containing disconnectors). SF 6 low alarm for each section of busbar (other than compartments containing disconnectors). SF 6 falling alarm for each bay (other than compartments containing circuit-breakers or disconnectors) SF 6 low alarm for each bay (other than compartments containing circuit-breakers or disconnectors) SF 6 high alarm for each bay (this will be provided where a leak from a circuit-breaker into an adjacent lower pressure compartment could result in the failure of the bursting disc). 4 Actions Required 4.1 Diagram A diagram showing the gas zones, and the busbars and plant items within each zone, shall be displayed in each substation and shall be provided to UK Power Networks Control Centre. 4.2 Implementation on Existing Sites Assessment An assessment shall be made of each site. The chief criterion for assessment shall be whether zones containing disconnectors and circuit-breakers are identified by the device number. This shall be undertaken by Region Managers, with support from Asset Management Agreement with National Grid This will be required for each individual site. This should be undertaken by Region Managers, with support from Asset Management Site work This should be implemented by Region Managers once agreement with National Grid has been obtained (for sites with NGT bays). 5 Dependent Documents This document is referenced in the following document, any of which may be affected by updates. DSR Operation of SF 6 UK Power Networks 2017 All rights reserved 8 of 8