National Grid Experience With Management Of Multi-Functional Numerical Relay Settings

Historically, correct application of protection relay settings have been accomplished in accordance with relay settings sheets - which stipulate the calculated settings to be applied to a relay. With the advent of programmable Multi-Functional numerical Relays (MFR), circa 1999, the number of settings sheets expanded dramatically from typically one or two per relay to as many as one hundred. This created both increased complexity and risk for correct settings application, and a significant increase in engineering resource requirements to discharge the settings process.This Paper describes the implementation of a new relay settings process and database system which both enables a reduction in the number of settings sheets, and provides a more rigorous methodology for the management of Multi-Functional Relay (MFR) settings. The paper also considers the challenges and experiences associated with the new arrangements – and addresses the following:Brief history of NGET relay settings systemThe paper examines the importance and requirements of relay settings sheets, and addresses the following questions:- What is the purpose of a relay settings sheet – and are today’s requirements different from the historical requirements- What is the process by which relay settings sheets have been created, modified and stored in National GridThe drivers for changeThe drivers for change emanate from the introduction of Multi-Functional Relay technology – and comprise the following:- The requirement to dramatically reduce the number of settings sheets to a more manageable and meaningful level. – thereby reducing the risk of settings error- The requirement to improve the settings file transfer process from Supplier to National Grid database, and from National Grid database to site- The requirement to ensure that any changes arising from the above are underpinned by a rigorous and holistic governance process – which eliminate the risk of an incorrect protection setting - The requirement to reduce the engineering resources required for settings. - The requirement to replace an ageing database.Type Registration and Relay Settings Process (TP107)NGET Type Registration process confirms the technical suitability of a product. For protection and control it defines and verifies the extensive range of fixed relay settings that will be used on all future applications of a protection relay.The paper illustrates the procedural steps which ensure that a relay which is commissioned on site, and which is subject to circuit specific (variable) settings, also contains the type registered fixed settings. This process is dependent upon relay settings configuration file electronic comparison techniques, both at time of Factory Acceptance Tests (FAT) and during site commissioning. New MARS (Multi Access Relay Settings) SystemThe ethos behind the new MARS system is explained further in detail; including the required level of consultation and challenges during the design, testing and commissioning stage of this new system.Experience to date and lifetime managementWith the new MARS system and supporting procedural governance in place for more than a year, the paper reviews the operational experience specifically focusing on the willingness of both suppliers and commissioning personnel to embrace the new system. Lifetime management (including backup arrangements), technical support, audits, system enhancements, training, stakeholder feedback and management reporting feasibility are discussed.