In a migration program that began in 2002 and runs through 2005, Constellation Energy Group is migrating legacy process control systems at a total of six units at three of its Maryland plants with the Ovation expert control system from Emerson Process Management Power & Water Solutions. Staying current with technology was one of the key factors driving Constellation’s migration plan.

While the technology and business of generating electricity have evolved enormously during Constellation Energy Group’s more than 185 years of existence, one thing has remained constant: the company’s focus on growth and improvement. These two factors are also drivers of Constellation’s ongoing program to migrate the older process control systems at several of its Maryland plants to new systems utilizing the latest technology. “Staying current with technology was one of the key factors behind our migration plan,” explained William Collins, Constellation control system analyst.

When the migration program is completed next year, Constellation will have upgraded legacy control systems at a total of six units at three of its Maryland plants with the Ovation ® Expert Control System from Emerson Process Management Power & Water Solutions. At each unit Constellation is migrating Emerson’s WDPF control systems to Ovation, a state-of-the-art system utilizing commercially available (non-proprietary) off-the-shelf hardware, communications and software applications.

From the beginning, Emerson designed the Ovation system to allow a straightforward migration path for users of its WDPF systems. Emerson’s migration path allows WDPF customers to retain much of their investment by allowing them to keep existing I/O cards, field cabling, terminations and cabinets; as well as their system engineering investment in control logic, graphics and the database. “This enables us to increase the functionality of our control systems in a cost-effective way,” said Collins.

In its first WDPF-to-Ovation migration project, Constellation upgraded the process control system at Unit 1 of its coal-fired C.P. Crane power plant in Baltimore County. During a scheduled outage in June 2003, Emerson replaced eight controllers, two data link servers and eight operator workstations at the 190-megawatt unit. In just a few days, the new Ovation system was up and running, according to Collins, who adds that C.P. Crane Unit 2 is scheduled for a Fall 2004 migration, during which Constellation will replace eight operator stations, 11 controllers and three data links, and upgrade its six-level DEH turbine control to Ovation.

In the C.P. Crane Plant Unit 1 migration, all hardware (controller and operator stations) was replaced during one scheduled outage. At two other plants – H.A. Wagner Units 3 and 4 (with a combined capacity of 740 megawatts) and Brandon Shores Units 1 and 2 (with a combined capacity of 1,300 megawatts) – Constellation is taking a two-step approach to migration, in which operator stations were replaced during outages in 2002 and 2003 (Phase One) and controllers are installed during outages taking place in 2004 (Phase Two).

Through careful planning and collaboration with Emerson, Constellation is maximizing plant availability by installing new controllers and operator workstations during regularly scheduled outages that occur on an every-other-year basis. Preparation for the onsite installation begins months earlier, as Emerson uses a proven process to convert WDPF graphics and logic codes to Ovation’s advanced open architecture.

Life Assessment Program Helps Constellation Tailor Migration Strategy
Emerson’s System Life Assessment Program helps users of WDPF and Ovation systems develop the best short- and long-term process automation strategies for their plants. Constellation used this methodology to select the two-step migration plan at H.A. Wagner and Brandon Shores. “With Emerson we were able to tailor our migration strategy at each unit to satisfy our operational and financial requirements,” explained Collins.

At H.A. Wagner Units 3 and 4, Emerson replaced 12 operator stations (six per unit) in 2002, while 13 controllers (Unit 3) and 10 controllers (Unit 4) were replaced during overlapping planned outages in March 2004.

At Brandon Shores, 12 operator stations (six per unit) were upgraded in 2002 and 2003. In October 2004, Emerson will replace 18 controllers on Brandon Shores Unit 2; replacement of Unit 1’s 16 controllers is scheduled for October 2005.

Collins believes that while there are a lot of considerations when determining a migration strategy, long-term vendor support and technical expertise are two aspects that should not be overlooked. “The importance of previous migration experience and technical expertise can’t be underestimated,” explained Collins. “They play a critical role in the successful design and execution of a migration strategy.”