Revamps of power projects are now key to automation contracts

Paul Boughton

Although some greenfield power projects are still proceeding, revamps are dominating the project scene in 2009, especially migrations from old technology and the installation of self-organising wireless networks.

Barking Power Station near London is one of the largest, independently-owned generating plants in the UK. It is capable of generating 1000MW of electricity, or about two per cent of the peak electricity demand in England and Wales.

The station was constructed between 1992 and 1995 and was the first major generating station in the English capital for many years.

Now Emerson Process Management has been selected to replace outdated operator interface stations at the facility.

Under the contract, Emerson will replace the ABB Bailey operator interface stations that are connected to the existing Bailey INFI 90 system (Fig. 1). The Ovation expert control system will interface directly or via OPC to the existing proprietary controllers and other third-party products.

This will provide Barking Power with freedom of choice for future automation upgrades as it will be able to easily integrate other systems and software, enabling tighter control and improved reliability, availability and efficiency.

Emerson will supply an Ovation system with operator workstations and data historian software, as well as perform installation and commissioning services, including graphics and database conversions. The contract also includes Emerson's SureService customer support. This is a programme that offers an array of support services designed to help companies achieve their business objectives, reduce or contain operating and maintenance costs, and keep systems running at peak performance.

According to Emerson, its Ovation migration for Bailey systems programme offers power generators a flexible and cost-effective alternative to traditional control system replacement. It uses the latest hardware and software to bridge communications between the Ovation expert control system and Bailey Command Series, Network 90 or INFI 90 systems, allowing Bailey users to take advantage of the latest control technology without the initial cost of a full control system replacement.

Ovation's technology will allow Barking Power to take advantage of FOUNDATION fieldbus, HART and other digital bus technologies that are used in Emerson's PlantWeb digital architecture.

This upgrade path allows parallel operation with no shutdown and offers fully-featured interoperation between the Ovation workstations and the Bailey controllers as well as alignment with other plant IT infrastructures for flexible control monitoring functions.

"Following a series of meetings and site visits, Emerson demonstrated its technology leadership, vast experience and excellent service and support," said Ian MacDonald, senior CS/IT engineer with Barking Power. "We are confident that Emerson's experience at carrying out this type of project, including their graphics and database conversion tools, will speed the implementation of the upgrade and provide many operational benefits not just for this project but for the future too."

Also in the UK, Emerson's Smart Wireless technology is helping EON UK to accurately monitor and measure treated water usage, allowing trending and analysis to formulate target values at its Kingsnorth dual-fired power station. Using Emerson's Rosemount wireless transmitters, EON is now able to collect flow measurement data from new flowmeters installed throughout the turbine hall. The self-organising wireless network delivers the data for trending in an OSIsoft PI historian that helps personnel monitor water usage within the system.

EON Kingsnorth, a 1940MW generating facility located on the Medway Estuary in Kent, needed a solution to monitor and measure water usage within its main plant. The company decided to install new non-intrusive ultrasonic flow meters to carry out this task. The high cost of wiring associated with a conventional cabled solution and a desire to embrace the very latest networking technology led EON to evaluate wireless technologies that could meet its needs.

"EON is keen to adopt the very latest technology to help improve productivity, efficiency and availability, and wireless technology provides the ideal networking solution to access the flow measurement data from the turbine building without having to install new cabling," said Chet Mistry, EON UK team leader.

Having initially undertaken extensive trials of Emerson's Smart Wireless technology, EON selected the Emerson solution because it offered high levels of reliability and long transmitting distance, as well as the ability to add additional devices to the network without the need for additional infrastructure.

The turbine hall at Kingsnorth is around 500m long and presents a difficult working environment for wireless as it houses large turbines, vast amounts of metal piping and a number of metal walkways that could interfere with the wireless signal.

Such an environment would not be suitable for a line of sight wireless solution, but Emerson's Smart Wireless self-organising technology encountered no problems in terms of routing data back to the gateway or reliability of connection.

With self-organising technology, each wireless device can act as a router for other nearby devices, passing messages along until they reach their destination. If there is an obstruction, transmissions are simply re-routed along the network until a clear path to the smart wireless gateway is found. As conditions change or new obstacles are encountered in a plant, such as temporary scaffolding, new equipment, or a parked construction trailer, these wireless networks simply reorganise and find a way to get their signals through.

All of this happens automatically, without any involvement by the user. This self-organising technology optimises data reliability while minimising power consumption. It also reduces the effort and infrastructure necessary to set up a successful wireless network.

Fourteen Rosemount wireless transmitters have been installed to provide access to flow percentage readings from the new non-intrusive ultrasonic flow meters monitoring different sections of the turbine hall. The Rosemount wireless transmitters are transmitting flow measurement data every 15 seconds to an Emerson Smart Wireless gateway, situated in the main administration building on the other side of the road from the turbine hall. The 14 transmitters took around two hours to configure and then less than six hours to fully install within the plant. In contrast, a wired solution would have taken between one and two weeks to complete.

DCS to China

However, while revamps account for much of the major investment at the moment, there are still some greenfield opportunities for automation companies. For example, Invensys Process Systems (IPS) has signed a multi-million Dollar deal with Shandong No 3 Electric Power Construction Corporation (SEPCO III) of China, a major Chinese contractor in power plant construction, to implement its Foxboro I/A Series distributed control system (DCS) technology for a 3300 MW generating station being built in Kutch district, Gujarat state, India.

Under the terms of the contract, IPS will provide I/A Series automation hardware and software, as well as a range of installation, engineering, training and field services.

The systems will be used to control the new plant's boilers, turbines and generators, utilising IPS' Performance Plus co-ordinated control system technology.

Subsystem applications will include a data acquisition system, furnace safety supervisory system, boiler and turbine sequence control system, turbine digital electro-hydraulic control system, feed water pump mechanical electro-hydraulic control system, and electric control systems.

The Gujarat power plant is part of the 'Power for All' initiative, an aggressive Indian government plan to sustain economic growth with significant additions of power generation capacity in the next few years. It is one of the largest power plants under construction in India and represents a new generation of mega-sized power plants being built to help meet India's bourgeoning demand

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