Site Services. Asset Management for Modern Networks

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1 Site Services Asset Management for Modern Networks The core expertise of Fundamentals relates to voltage control for electrical power networks. This comes from a deep understanding and practical experience of on-load tap changers, control schemes and the electrical network itself. Building on this expertise, Fundamentals has developed a comprehensive range of services to fully support customers on site for power control: Protection and Control Schemes Tap Changer Maintenance Transformer Upgrade Solutions

2 Protection and Control Schemes Power transformers and switchgear are critical components in power grid substations. Control schemes relating to these components are equally important and require careful management to ensure optimum performance of the system. Protection, tap changer control and transformer temperature control (fan and pumps) schemes could cause significant issues if not functioning correctly. Many control schemes are operational well beyond their intended design lifetimes; it is easy to find schemes which were installed more than 40 years ago. Such aged schemes become increasingly difficult to maintain as components and spare parts become obsolete. An added problem is that the network has changed since it was built to operate as a passive system with trickle-down power flows. These days, because of increasing levels of distributed generation, the network experiences bi-directional power flows which can cause additional problems with existing control schemes. Features Fundamentals offers upgrade services for tap changer control (voltage control) and protection schemes to ensure optimum performance for the modern network. With all skills, knowledge and capabilities in-house, this service can operate as a turnkey solution to include any of the following: Site Surveys Assessment of the existing scheme and implications for replacement (space issues, multi-core cable routes etc.) Network Studies Power System Analysis Application of intended replacement scheme Assessment of network voltages for generator connections Network voltage optimisation Relay settings Scheme Design and Drawings Control Cubicle Design and Build Marshalling Kiosk Design and Build Site Installation Extensive team of experienced installation specialists Authorised for many UK DNOs Tap Changer Motor Drive Repair and Upgrade Substitution of obsolete parts Maintenance of moving parts Optimisation of operation Commissioning Troubleshooting Investigation of scheme issues Extensive knowledge and experience with common problems 02

3 Benefits Quality engineering designed to last Core expertise leaders in application of voltage control solutions Fewer schemes on fixed-tap repair of old motor drives Accommodate more distributed generation operational voltage control Quicker generation connection offers system analysis for voltage control Reduce customer complaints acceptable system voltages Reduce costs related to site alarms and call-outs optimised network voltages and operational schemes Prompt resolution of issues SME means lean and responsive Turnkey service fewer suppliers to manage 03

4 Tap Changer Maintenance The tap changer is the component of the power transformer which enables voltage regulation and is therefore critical for network management. Each tap changer operation generates switching arcs on contacts which leads to carbonisation of the oil and contact wear. Mechanical components, both internally in the diverter and also externally in the motor drive and shaft arrangements, are under stress during each switching operation. Regular maintenance is therefore required. Fundamentals are the exclusive UK & Ireland agent for MR (Maschinenfabrik Reinhausen). Maintenance technicians have been trained at MR Germany on all types of tap changer and related devices. With many years experience and the direct support from MR, Fundamentals can offer a premium service for tap changer maintenance. Features The normal routine tasks for tap changer maintenance are as follows: Dismounting and mounting of the on-load tap changer insert Cleaning and inspection of the mechanical parts Visual inspection of insulation distances of the on-load tap changer insert and the oil compartment Parts replacement Replacement of the switching oil (unused oil with a breakdown voltage of > 50 kv/2.5mm, in compliance with IEC 60156) Determination of the contact wear Measurement of the transition resistors Inspection of the motor drive, drive shaft and protective surge relays Functional test mechanical and electrical operation of tap changer Benefits Optimisation of operating condition - reduce risk of tap changer problems Premium service - maintenance by qualified technicians according to manufacturer s procedures 2-year warranty on parts genuine spares from manufacturer Record keeping maintenance history managed for customers 04

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6 Transformer Upgrade Solutions With an increasingly aged population of key assets in the electrical grid comes increasing scope for refurbishment funded by operational budgets as opposed to replacement funded by capital budgets. The lifetime of power transformers can be extended by refurbishment involving the upgrade of components such as tap changers, WTIs, PRDs, breathers, protection and control schemes and related cubicles/kiosks. Refurbishment of transformers is viable if the transformer itself is deemed to have substantial remaining lifetime. This can be assessed using diagnostic measurements such as DGA of the oil, SFRA, tan-delta etc. Many asset owners are taking such measurements on a routine basis and are able to assign an asset health index to transformers. The health index may be dramatically improved by refurbishment strategies and can be much more economical and quicker than replacement. The on-load tap changer is a key component of the power transformer and is ultimately the only moving part in a substation. It is a mechanical device and therefore requires regular maintenance. Failure of a tap changer can result in replacement of the transformer itself due to the fact that replacement parts for the tap changer are often difficult to source due to its age. This is expensive and can have long lead times. Most OLTCs in the UK are the bolt-on design which lends them nicely to replacement without modification of the transformer itself. Maintenance-free tap changers can be installed on existing transformers in place of problematic or failed units to give decades more operating lifetime for the transformer. This ultimately delays transformer replacement, significantly reducing expenditure and also removing the requirement for OLTC maintenance. Fundamentals has experience in control system refurbishment services where complete tap changer control schemes are upgraded to modern standards. The company has extended the scope of services to include replacement of other components associated with power transformers and can offer turnkey solutions for tap changer replacement (MR OLTCs) to cover the following: Site Surveys Engineering, Design and Drawings Site Installation Commissioning 06

7 Features Transformer upgrade services offered by Fundamentals include the following: Tap Changer Replacement All voltage levels and ratings High-speed resistor and reactor types Full range of tapping configurations Oil and vacuum switches Motor-drive replacement Control system upgrade Transformer Temperature Control WTI and OTI replacements Upgrade from electromechanical to electronic systems Kiosk replacements Breathers Maintenance-free breathers installed Replaces conventional and regenerative breathers Other Transformer Accessories Oil level indicators PRDs WTIs and OTIs Monitoring systems Benefits Reduce capital expenditure save up to 75% of transformer replacement costs Modernise transformer components upgraded to provide operational benefits Turnkey service fewer suppliers Engineering support from MR worldwide references for retrofit projects Standardised solution retrofit packages suitable for many applications 07

8 Fundamentals Ltd 4 Hillmead Enterprise Park Marshall Road, Swindon Wiltshire, SN5 5FZ Telephone Fax enquiries@fundamentalsltd.co.uk