EDS MW AND MVAR TRANSDUCER CONNECTION

Transcription

1 Document Number: EDS Network(s): Summary: ENINEERIN DESIN STANDARD EDS MW AND MVAR TRANSDUCER CONNECTION EPN, LPN, SPN This standard details the convention to be used when wiring MW and MVAr transducers so that power flow direction can be ascertained. Owner: James Ford Approved By: Paul Williams Approved Date: 13/09/2016 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 All UK Power Networks Asset Management Capital Programme Connections HSS&TT Network Operations UK Power Networks Services Other External 81 Website Contractors ICPs/IDNOs Meter Operators THIS IS AN UNCONTROLLED DOCUMENT, THE READER MUST CONFIRM ITS VALIDITY BEFORE USE

2 Revision Record Version 3.0 Review Date 31/08/2021 Date 31/08/2016 Author James Ford Why has the document been updated Periodic review What has changed - 11kV and LV network added and diagrams within appendices refreshed Version 2.0 Review Date 17/12/2015 Date 12/11/2012 Author Azzam Al-Riyami Document reviewed and minor modification to cater for the preference to have the transducer functions within the protection devices. Version 1.4 Review Date Date 16/07/2012 Author Lee Strachan Document reviewed for publishing on 81 Version 1.3 Review Date Date 25/08/2011 Author Chris Anderson Re-classified from EI to EDS Version 1.2 Review Date Date 16/03/2011 Author Don Fossett Document re-branded Version 1.1 Review Date Date 10/08/2010 Author Reviewed and review date extended James Ford / Steve Spencer Version 1.0 Review Date Date 06/12/2006 Author James Ford Original UK Power Networks 2016 All rights reserved 2 of 8

3 Contents 1 Introduction Scope Details Actions Required... 4 Appendix A Example Diagram Appendix B Example Diagram Appendix C Example Diagram Appendix D Example Diagram UK Power Networks 2016 All rights reserved 3 of 8

4 1 Introduction Throughout the EPN area of UK Power Networks, MW and MVAr transducers have been installed and connected to the SCADA system, however, there was no set convention agreed for the connection of the transducers. This has resulted in the transducers being connected in various different ways which means that it is not possible to accurately tell which direction the power is flowing. This is a particular problem where there is embedded generation connected to the network. In the SPN area of UK Power Networks the transducers have been installed to a standard (the same standard as used by National rid (N)). This standard shall be adopted for use with the EPN transducers. The LPN area also has a standard that differs from SPN and N; however, this will not be changed. 2 Scope The scope of this standard is to detail the site output polarity for the given MW and MVAr value based on the direction of flow of the power and to detail the scale range of the transducers to be used. The convention is to be applied at all voltage levels. This standard does not detail how the MW and MVAr values are to be displayed on ENMAC. 3 Details The MW and MVAr transducers should be set up to show a positive output on site when power is flowing away from busbars or specific reference point and a negative output on site when power is flowing towards the busbars or specific reference point. At circuit mid points such as West March rid, the side of the circuit breaker the transducers are connected to needs to be ascertained so the convention can be applied correctly. With reference to the position of the MW and MVAr transducers, a power flow towards the circuit breaker will show a negative output and a power flow away from the circuit breaker will show a positive output. The ENMAC (UK Power Networks Electrical Network Control System) network diagram will need to indicate which side of the circuit breaker the transducers are connected so the convention can be correctly applied. Alternatively, a symbol incorporating an arrow to display the direction of power flow could possibly be developed in the future. The method of displaying the MW and MVAr value on ENMAC is not covered by this standard. The preference is not to use discrete transducers but where available, to use built in functionality within the protection devices. Depending on local RTU capability, the transducer output shall be connected either via serial communication or via discreet hardwired analogue communication, the former being the preference where possible. The analogue output of these transducers shall have the following scale range: -10 / 0 / +10 ma. For reference, please refer to the example diagrams in Appendix A to Appendix D. 4 Actions Required The output of all new MW and MVAr transducers shall be installed as detailed within this document. Any modifications to the output wiring of existing transducers will be covered by a specific project. The locations of the CTs the transducers are connected to need to be recorded so that the analogue can be correctly placed on the ENMAC diagram. UK Power Networks 2016 All rights reserved 4 of 8

5 Appendix A Example Diagram 1 Reference point for direction convention Primary Substation Direction of power flow Transformer Current Transformer (CT) enerator enerator Substation rid Substation Switching Station UK Power Networks 2016 All rights reserved 5 of 8

6 Appendix B Example Diagram 2 Reference point for direction convention Primary Substation Direction of power flow Transformer Current Transformer (CT) enerator enerator Substation rid Substation Switching Station UK Power Networks 2016 All rights reserved 6 of 8

7 Appendix C Example Diagram 3 Primary Substation Reference point for direction convention Direction of power flow Transformer Current Transformer (CT) enerator rid Substation Switching Station UK Power Networks 2016 All rights reserved 7 of 8

8 Appendix D Example Diagram 4 Reference point for direction convention Direction of power flow Transformer Current Transformer (CT) enerator LV Bar HV Bar UK Power Networks 2016 All rights reserved 8 of 8