germany supplement: INSTRUMENTATION & CONTROL
I&C system that never goes obsolete1 January 2010
Like brain surgery, replacing the I&C system in a power station is complicated, expensive and very stressful. So an I&C system that never goes obsolete should prove a very attractive proposition for plant owner/operators.
An I&C system that never goes obsolete” means that, with the SPPA-T3000 I&C system installed, a power plant owner/operator will never again need to take on the daunting challenge of completely changing out an obsolescent I&C system, eg due to the all-too-familiar problem of lack of availability of spare parts. With SPPA-T3000 the plant can be operated for as long the owner/operator wishes, with station life determined by, for example, the condition of boiler and turbine.
But at the same time the system can be maintained and upgraded, responding to innovations in I&C over its life, “on the fly”, in the course of routine service activities. New components are installed on a plug-out/plug-in basis, without disturbing operation, based on the system’s ability to mix old and new hardware and software.
The key – revolutionary in our view – is the use of what we call ECSTM (embedded component services) within SPPA-T3000 and the crucial concept of software that is independent of hardware.
The result: security of investment for more than forty years and potential savings in excess of 20 million euros over this period.
The classical approach
In classical, third-generation, systems, the HMI (human–machine interface), controller and I/O generally have to be replaced after about fifteen years or so because the technology is phased out by the manufacturer. That means total modernisation from the HMI level right down to the I/O level – with complete re-engineering, recommissioning, and re-optimisation and parameterisation of the controllers and limit values.
With a total I&C modernisation project, everything that has proven itself over decades requires readjustment and adaptation, and has to be optimised and subjected to stress tests. This is intricate and involves high costs, which is why many owner/operators put it off for as long as possible.
The 2007 modernisation of RDK 7, in Karlsruhe, Germany, provides a good – indeed state of the art – example of the conventional approach.
Planning started a good two hundred days before system changeout, in May. Both partners in the project – EnBW and Siemens – were working at full steam on the preparations right up to start of changeout, with the power plant operating at full load. Then a state of emergency lasting fifty-six days, with 110 additional people working on site: dismantling of 157 electronic equipment cabinets; dismantling of more than 100 km of cabling; 40 000 signal tests; re-engineering, continual optimisation, and complete recommissioning. One can imagine the complex problems and solutions that lie behind these bald numbers: the cable clutter in the picture below is just the tip of the iceberg.
The RDK 7 I&C changeout was completed in a world record 56 days, considered an extraordinary result by utility EnBW and a benchmark for the industry as a whole, winning the VGB 2008 quality award, reflecting excellent co-operation between utility and vendor. Nevertheless no-one would want to embark on such a project if they could avoid it.
The basic reason why such total modernisation projects are needed in the case of classical I&C is that software and hardware are intimately fused together, while basic functions such as HMI, engineering, etc, are typically packaged in separate systems, with the usual problems of data consistency, maintenance, etc.
Data, user software, system software and hardware are essentially interlinked in such systems, and the data are matched to the software.
If the hardware is discontinued, there is a problem. New hardware must be procured but generally it will use different software. That may sound pretty harmless, but in fact involves a vast amount of time and expense, as all the power plant and process data have to be ported without any errors and adapted appropriately. And following this, they have to be checked, optimised, and released. The reader will be fully familiar with these problems. That is what makes modernisations so very complex and challenging.
A new approach: separation of hardware and software
We therefore decided to grasp the bull by the horns when developing our new I&C system: fundamental separation of software and hardware.
Given that the key problem with traditional systems was the fusion of data, user software, system software, and hardware, this seemed like a good place to start.
This separation of hardware and software – one of the key innovations of SPPA-T3000 – is a completely new approach and revolutionises the entire modernisation process.
We proceeded in two steps.
The software concept of SPPA-T3000, based on ECSTM technology, employs Java. It is independent of the hardware and executable in different hardware and operating systems. All power plant data are implemented in xml.Java, xml, and ECSTM. They harmonise perfectly with each other and, crucially, as we have already seen, with any certified hardware, too.
The advantages of this approach are obvious: this universal software can be ported simply. It runs on any new item of hardware with a browser without any adaptation problems. The stress associated with starting from scratch, as required in a total modernisation, no longer exists for our new I&C system.
The most important aspect: from now on, it is possible to retain an existing system for the entire life of a power plant while continually innovating, without any necessity to carry out total modernisation, simply as part of maintenance and servicing.
The fundamental separation of software and hardware was only the first step towards “never-goes-obsolete” technology and “plant-lifetime I&C with capability for constant innovation”. What was still missing was a concept for hardware replacement.
This is where the plug-out/plug-in idea comes in. As part of standard service procedures, the latest available technology is installed and not simply an already obsolete component that happens to match the old system concept. We are able to install the latest technology because we can ensure that the old and new hardware match.
This is a really big step forward because it means we do not merely prolong the life of the I&C with “old” components. That would mean the owner/operator would not be able to incorporate any innovative technology over the forty year plant life and his system would effectively remain in its original condition. Instead we are able to provide continuous I&C innovation, but without any need for a total modernisation.
What is more we are also giving a lifetime guarantee of innovations with the new I&C system, the innovations being provided as part of routine service measures without any negative impact on operation.
The principle of plug-out/plug-in hardware replacement is that old, new, and the very latest components work together. Whichever component has to be replaced, we use the very latest technology. Everything we develop after installation of SPPA-T3000 fits harmoniously into the overall concept and is absolutely state of the art. This means: hardware innovation comes with each spare part, as part of service.
Of course, innovations are also possible in the system software, based on the existing hardware. And, conversely, hardware innovations are possible with existing user software.
Following the modernisation project, RDK 7 is now equipped with SPPA-T3000, and the new unit currently under construction at the site, RDK 8, will also be equipped with the new I&C system.
With SPPA-T3000 installed at both RDK 7 and RDK 8, innovation is guaranteed at both plants for 40 years via spare parts replacement and the Siemens “LifeCycleConcept”, without the need for full modernisation.
This means that in the future these units will remain up to speed with developments in I&C technology, with innovation as and when required, but will no longer have to suffer the stresses, and lost power production, associated with total changeout. In the words of Frank-Peter Kirschning, power plant manager at RDK, “total modernisation is now obsolete.”
How to save 20 million euros
As already noted, our calculations suggest that with the “never-goes-obsolete” I&C concept, plant owner/operators will save at least twenty million euros over the forty-year life of a plant. The graph, bottom left, shows how we have arrived at that figure, comparing the costs for the two total modernisation projects typically performed over the life of a plant against the costs of the “never-goes-obsolete” concept with continuous innovations (introduced via a service contract).