Switch on generators
4 Feb 2003
Formerly National Power, Innogy has in recent years been improving the control systems in its coal-fired power stations. Since electricity must be generated as it's needed, these plants have to be capable of a rapid response to extreme and sudden changes in demand. To that end Innogy started to rethink its existing supervisory and control systems.
The generator had five main goals in mind: to increase the flexibility and responsiveness of the power stations; to integrate diverse control systems at all of its sites; to create a uniform operator interface and a managed engineering interface; to create a generic database for plant, business and support data; and to manage plant component life and integrity.
Two distinct choices existed to meet these goals - to replace the existing control systems with a single distributed control system (DCS), or to add a supervisory layer above the control systems. In either case, Innogy was seeking solutions to a broad range of problems faced by most generators. The question was, how to do it?
No single product on the market could satisfy all of its demands instantly, so Innogy looked to create a new system, using existing software packages as building blocks.Adding a supervisory layer above the existing systems would minimise cost and risk, and eliminate extended shutdown periods during refurbishment. Early in 1995, Innogy took the ini tiative and awarded a contract to Thales Information Systems (formerly Syseca) for the development of an 'advanced plant management system' (APMS). The first system was installed at the West Burton coal-fired plant in August 1995 (now owned by the London Electricity Group), closely followed by a similar installation at Didcot.
The APMS software platform has been designed as a generic product, ideal for use across the diverse range of Innogy plants and at any thermal generating company. Based on Thales's OpenPMS Supervisor, with Verano's RTAP at its core (see panel on previous page), the APMS is a system with many flexible capabilities. One of the most valuable of these is the RTAP (Real-Time Applications Platform) database, which is capable of holding data in forms as diverse as coal station plant, business and support data. RTAP provides the control desk with up-to-the-minute operating information, representing all aspects of coal-fired plants.
According to Andrew Lichnowski, Innogy's manager for process control systems, 'the Verano RTAP product is considered to have the best performing real-time database on the market'. It was seen as a solid core upon which to build the rest of the solution and Thales, which is licensed to market APMS worldwide, has further extended its capabilities. As systems integrator, Thales improved the dual-server redundancy capability, while a shaded trend feature for screen displays has also been developed.
APMS is up and running in the UK on 30 generation units, equivalent to 14 500MW of output, at nine power stations. The results have been noteworthy. For example, at the AES coal-fired power station in Drax, Yorkshire, there have been major improvements in controlling the start-up process, and energy costs have been reduced. Access to up-to-the-minute information has led to increased efficiency, better management, and an in-depth understanding of the plant at the touch of a button. In this case the computer-based or soft desk operator interface is the enabling innovation.
The production of the APMS has enabled thermal generators to meet the challenges of today's commercial and market realities. Its key strength is that all thermal-generating plants can generically exploit the advantages of such a system. With the APMS in place, power stations are more flexible and responsive. Operations become more standardized within each plant, and this extends to the cross-site integration of control systems.
A highly interactive control team can manage operations more efficiently and with ease, as illustrated by Innogy's experience.
Sidebar: Lining up with Linux
Founded in 1996, Massachusetts-based Verano has undergone something of a renaissance in its short life. Originally known as Nfold, it acquired the Automation Integration Software division of Agilent Technologies in 2000, and with it the Hewlett-Packard-developed RTAP Unix-based real-time Scada system, along with the Enterprise Link MES software. These products now form the basis of Verano's 'Instant Awareness' branding. More pertinently though, it simultaneously acquired an installed customer base that included over 220 of the world's leading process, utilities and energy operators.
According to Verano's president and ceo, Brian Ahern (previously president of Invensys Process Solutions), 'many of our customers operating large-scale infrastructure assets such as oil and gas pipelines, mass transit systems, water distribution and power generation have mandated the use of commercial Unix platforms to ensure reliability.'
It is this emphasis on reliability in mission-critical applications that has resulted in Verano's latest products launched last month. Described as the first Linux-based plant operations platform, Performux is based on the RTAP/i Scada platform and offers real-time alarm and event management, analysis and visualisation using Java and web-enabled technology.
As Ahern explains: 'All of our customers using commercial Unix are at a point where they are evaluating where to go next with their choice of operating system platforms. Most are evaluating Linux. Our introduction of Performux allows us to be in alignment with our customers and provides them with an option to use a field-proven, mission-critical, real-time software platform on Linux to run their critical operations.'
While Performux is built on the Red Hat Linux Advanced Server, Verano's other new offering, its Secure Scada solution, takes security to higher levels by using SELinux - a version of Linux developed by the US National Security Agency to meet the stringent security needs of top-secret projects. Security Scada is said to offer the multi-level user security needed to address the increasing concern over the threats of 'cyber terrorism' attacks on critical plants and processes controlled by Scada and DCS systems.