Automated tool cuts I&C migration time to days20 December 2000
While no-one denies the advantages of upgrading power plant instrumentation and control systems to the state of the art it can be a painful and complex business, to say nothing of the potential for downtime during the transition period. However recent projects in the USA suggest migration can be done surprisingly quickly, given the right tools.
On 7 October 2000 the 1500 MW Midland Cogeneration plant, which accounts for up to 11 per cent of the power used in Michigan’s Lower Peninsula, started an outage during which its entire process control system, one of the largest such installations in the world, was upgraded from WDPF technology to Ovation. Ovation is an open PC-based platform, which not only reduces risks related to component obsolescence, but also provides enhanced system functionality and process efficiency.
Midland’s upgrade outage began on Saturday, and by Monday, only two days later, the plant was generating power again. By Tuesday it was up at full power.
This rapid transition was achievable through use of a new “automated migration tool” allowing owners of WDPF technology to migrate to the Ovation control & information system with minimal re-engineering. The automated migration tool reduces the amount of time needed to convert WDPF graphics and logic codes to Ovation’s advanced open architecture, helping plants to avoid the lengthy outages usually necessary for a technology migration of this kind.
As in a traditional WDPF-to-Ovation migration without help from the automated tool, customers are able to retain WDPF’s Q-Line I/O and its cabling when using the automated tool, significantly lowering the cost of updating technology. Customers have the option of later moving to the Ovation I/O, also designed for fast, easy installation. WDPF cabinets stay in place, and are updated with an Ovation Controller Fieldkit – based on a standard, industrial Pentium PC configured to provide reliability, fault-tolerance and full redundancy. The tool can be used to migrate both Classic and WEStation-based WDPF systems, although while some WEStation workstations can be retained, Classic workstations must be replaced.
It has always been possible to upgrade existing WDPF systems to the newest WDPF hardware available, with little change required to the graphics, control and database because the basic architecture remained the same. However the new automated migration tool enables WDPF users to upgrade to Ovation even though the architecture is quite different.
Another vital factor in getting the upgraded plant back on-line quickly is the ability to reatin a plant’s system tuning parameters during the migration. Tuning the process can often take months of on-site time, and generally is done when a system is changed out.
The Bay County project
A major step in developing the automated tool used at Midland was a smaller project earlier in the year at Bay County Resource Recovery Facility, a 10.3 MWe waste-to-energy power generation plant in Panama City, Florida. The facility burns 490 t/d of municipal waste.
Operating on a Classic WDPF system, Bay County needed additional control equipment and technology to meet the federal Clean Air Act but could not afford a lengthy outage. The plant therefore offered to field-test the migration tool technology for Westinghouse.
Bay County’s older process control system, purchased from Westinghouse over a decade ago, could not support any additional equipment functions, so the plant approached Westinghouse about upgrading its control technology.
Westinghouse Process Control’s new product, the Ovation information & control system, was available, and met all of Bay County’s system requirements. However, the technology to convert the information locked in Bay County’s proprietary Classic WDPF control system to the advanced Ovation open platform was still in development at Westinghouse. Working against a schedule to install the new equipment, but also interested in Ovation, Bay County offered to serve as Westinghouse’s test and development site for an automated migration tool.
The plant could not have afforded a migration to Ovation without the automated tool.
Hand loading the graphics, logic and algorithms necessary for Ovation would have required extensive startup and checkout time. For Bay County it would have been like starting up an entirely new plant. The plant told Westinghouse it did not mind being the first and was willing to be the guinea pig.
Westinghouse and Bay County began to focus on the automated tool in January 2000. Westinghouse engineers evaluated Bay County’s Classic WDPF system and removed redundant hardware addresses. The Classic system was upgraded to the more advanced WDPF WEStation, allowing operators to become familiar with new workstations before the final migration to Ovation.
Bay County’s Ovation hardware was assembled in Westinghouse’s Charlotte office, where engineers completed tool development and began attempting tool-assisted migrations with a copy of the plant’s system information, including controller codes. By March, the tool was fully developed and capable of a successful Ovation migration.
The Ovation controller used to develop and test the migration tool, and later used to migrate Bay County from WDPF to Ovation, was shipped to the Bay County plant in April. Bay County shut down for installation on 11 April, and work began at 8 am the next day. The Bay County plant and its new Ovation system were functional by 7 pm, 13 April.
Migration at Midland
Midland Cogeneration Venture, located on the site of an abandoned and unfinished nuclear project, is jointly owned directly or through affiliates of CMS Energy, Dow Chemical and Coastal Corp. It uses 15 turbines to generate electricity – 12 are natural gas powered and three operate on steam generated inside the plant. Midland also provides steam to Dow and Dow Corning Corp. for chemical manufacturing and to heat and cool Dow’s corporate headquarters. All three facilities, the cogen plant and the Dow and Dow Corning plants are 7/24 operations so minimising outage time was a major consideration.
In the I&C upgrade at Midland, the 27 controllers were replaced in the plant’s WDPF system, which has been in operation for over ten years on various levels of WDPF, with both Classic WDPF and WEStation components. Six existing data link servers and 11 operator workstations were also replaced. When the WDPF-to-Ovation migration was completed, Midland had a fully functional Ovation system – not an interim or hybrid system that typically results when other process control systems are upgraded.
Among the reasons for the Midland upgrade were obsolescence, spare parts availability, and a desire to increase connectivity between the plant and the business side of the enterprise, which is an advantage of moving to an open system such as Ovation. In addition the existing system was at its limits of its capacity in terms of expansion, but the plant is currently considering the addition of further gas turbines.
The Midland upgrade had been originally planned for May 2001. But in the summer of 2000 a decision was taken to accelerate the schedule to October 2000, with engineering -proper starting on 1 July.
In the words of Scott Woodby of Midland Cogeneration Venture (MCV) the magnitude of the project can be likened to “basically taking out somebody’s brain and putting in a new one” and “the idea of being able to do this in a short time frame, was to me, sort of scary at first.” In addition there were also only three months to prepare, requiring a day-in-day-out effort from both contractor and the plant until the resumption of commercial operation.
It was to be the first time in ten years that plant had gone to a full-plant outage, apart from an eight hour period in 1992. So to “say that we’re going to shut down the whole facility, and do a lot of work, not only in the control system, but a lot of the main steam line and boilers, it was a tremendous undertaking.” The original plan was to complete the work in five days, but in the event however the outage associated with the migration effectively amounted to less than two days, with steam being supplied to the chemical plants from their standby boilers.
A key to the success of the project was that all the existing I/O, cabinets, and field wiring could be maintained, as could the existing control strategy, including graphics and “the whole operational philosophy” – a crucial feature of the approach. The look and feel of the operating system, particularly graphics, were maintained so successive shifts of operators were able to come in and operate the plant in just the way they were used to.
Migration to Ovation also avoided the potential risks and time penalties associated with the re-engineering option, which could have taken up to 18 months of engineering time for a system of Midland’s complexity coupled with much longer on-site time.
The success of the Midland migration project demonstrates that transition to a new I&C system, even in a very complex plant operating on a 7/24 basis can be a relatively quick and painless process.