The evolution of the traditional distributed control system (DCS) into today's more capable and more all-encompassing process automation architectures has been chronicled by the analysts at the ARC Advisory Group as the advent of the collaborative process automation system, or CPAS. In simplest terms, "collaboration" implies the need for systems to share the information needed to perform optimal control actions—and for people to make sound business decisions.
From a functional point of view, the CPAS model recognizes only two systems in a process plant: the business system and the CPAS, each with different classes of applications, writes Dave Woll of the ARC Advisory Group in Martin Hollender's 2010 book Collaborative Process Automation Systems. The CPAS vision leverages a single, non-hierarchical Ethernet/TCP-IP communications backbone such that field devices, controllers and applications "are able to exchange data and information without barriers," Woll notes. Indeed, the CPAS guiding principles of a common infrastructure that is "functionally transparent, logically concise and based on standards" go a long way toward describing the optimal automation architecture that makes possible the seamless integration of plant systems.
The ABB Approach
At its core, ABB's System 800xA is designed to provide the collaborative environment necessary for the formation and execution of sound business decisions. Based on "Aspect Object" technology, ABB's integration architecture relates all plant data, the Aspects, to specific plant assets, or Objects.
The platform's client-server architecture streamlines controller communications, centralizes configuration and back-up tasks, and provides system-wide management of data for trend, history and audit trail purposes. System 800xA also provides hardware freedom of choice when it comes to the server and workstation computer hardware, even leveraging virtualization technology to streamline and simplify computer systems maintenance.
Engineering is done on a system level and provides significant time savings since configuration of each tag or object is done only once. Personalized workplaces can be configured so that each user has only the information necessary for their function. Licensing is done on a system level so all information and applications in the system are available at each workplace.
A central benefit to using the System 800xA architecture is that once all data and information are plugged into the architecture, a relatively simple, browser-based thin client can be used to seamlessly retrieve and display data from the control system itself as well as any connected third-party systems. Displays are available inside or outside of the plant facility, as long as a secure connection to the plant network exists.
In the case of ABB's System 800xA, this cpmPlus Smart Client provides intelligent data access and viewing functions to assist all levels of personnel in making quick, informed decisions to improve overall plant performance. Among the configurable dashboards that can be easily deployed are trending and statistical process control charts, alarm and event notifications, and even an Excel interface for exporting plant data.
And while collaborative information sharing has broad-ranging benefits that carry into every corner of a process plant's performance, a closer look at the power of integration along two specific dimensions helps to illustrate integration's true potential: the integration of process automation with process safety and with electrical power systems.
Safety Integration Features Flexibility
On the safety front, an integrated approach to safety and control is yielding more cost effective safety instrumented system (SIS) implementations while simultaneously delivering operational benefits. ABB's System 800xA architecture offers the flexibility of hosting both safety and process critical control applications in the same controller or on separate hardware if desired.
Either way, the user still gains many of the same integration benefits, including common operator interface and engineering tools, plant-wide sequence-of-events (SOE) lists for consolidated root cause analysis, as well as centralized historian and data archiving. A common, integrated platform also has the advantage of requiring fewer spare parts, less training and provides a comprehensive, integrated platform for asset management.
"Common safety and automation tools, such as for SOE or alarm management, reduce time to decision and action, while improving plant operations," says Luis Duran, safety business development manager for control systems in ABB's process automation division. "They reduce risk more quickly and allow safe start-up after shutdown because root causes can be quickly identified."
"Similarly," Duran continues, "having a common HMI increases operator familiarity with systems, and this reduces training needed. Seamless integration on all levels reduces complexity and simplifies system design, spare parts and maintenance procedures. Having one engineering environment reduces the engineering required, and this enables simplified application programming, upgrades and modifications to be managed through that one engineering environment. Also, having one supplier means users only need one support organization and lets them have a common life-cycle policy."
ABB's System 800xA SIS solutions comprise not only the 800xA HI (High Integrity) logic solver, but the entire safety loop of SIL-rated field instruments, controllers and I/O modules, valve positioners and actuators. Highly scalable, System 800xA SIS solutions provide the flexibility to match specific safety functions with actual plant needs. 800xA HI systems are delivered and supported in accordance with the strictest current standards. Among others, System 800xA HI complies with IEC 61508, IEC 61511, EN 954, NFPA 85 and NFPA 72 standards.
Electrical Integration Boosts Performance
ABB's object-oriented control and information architecture allows users to readily integrate historically disparate functions, ranging from process electrification to safety instrumented systems.
While the potential benefits of a unified approach to process automation and power management have long been recognized, past integration efforts often were made both painful and expensive by a hodgepodge of communication protocols as well as barriers among disparate plant departments and supplier organizations. The end result typically was two separate systems awkwardly tied together through complex, custom gateways or hard-wired signals used to bridge the gap for a few select parameters. This methodology had high integration costs, high project risks and high lifecycle costs as well.Today, however, standardization of process electrification and power distribution systems around the IEC 61850 communication standard has opened the door to using an integrated, collaborative system to accomplish both process automation and power management tasks—and to do them both more effectively.
ABB, an innovator in both power and process worlds, is leading the way with its approach to what it calls "electrical integration." And a growing number of energy-intensive industries already are using this approach to improve plant uptime, increase energy efficiency and even lower capital project and lifecycle costs relative to separate, un-integrated systems.
"Electrical integration," explains Mats Pettersson, ABB product manager for electrical integration, "doesn't replace power distribution SCADA systems, but complements them on the plant site. It provides a common platform for unified operations and allows extended asset management and additional applications like power management to be included in the plant control system."
"Electrical integration saves electrical and installation cost, reduces the possibility of blackouts and minimizes operational costs by non-duplication of systems and staff", Pettersson asserts. "It can reduce investments cost by as much as 20% over the non-integrated, two-control system approach," he adds.
With an integrated approach, energy efficiency can be gained through improved visibility into power consumption as well as through faster plant start-ups. Shell Oil, for example, has reported a 20% productivity improvement through better operator visibility of plant assets. Plant upsets can be resolved more quickly with a plant-wide SOE list. And a smaller combined system footprint can reduce spare part inventories, lower training time, and make for a simpler overall system design with fewer wires but more connectivity.
New energy savings opportunities also can be explored, while existing energy reduction programs can be enhanced. For example, an increase in power consumption by a unit or in an area can indicate equipment malfunction or wear. A recent ARC Advisory Group report indicates that in many cases the potential energy savings attributable to increased visibility can equal 10% of total energy consumption.
"Tighter integration between power and process systems has the potential to increase both efficiency and productivity," adds Peter Terwiesch, ABB chief technology officer. And in this day and age, it's hard to imagine a process manufacturer that couldn't use a generous dose of both.
Electrical Integration Pays for Petrobras
Faced with the need to expand and modernize the power substation infrastructure at its Repar refinery 400 km south of Sao Paulo, Brazilian oil giant Petrobras recently implemented ABB's integrated process and power architecture. The combination of the substation automation system with the System 800xA process automation system has brought benefits to Petrobras in many arenas—starting with project execution and continuing with daily operations and maintenance.
For starters, simplification of the overall system design resulted in a 25 to 30% reduction in overall project execution time. Critical data is now shared between the DCS and the substation automation system via Ethernet instead of using hundreds of hard-wired signal cables. Operationally, the use of a common, integrated platform already has allowed Petrobras to reduce training costs by 20%. Next up is the integration of maintenance practices among instrumentation, motors, power devices, and IT systems to yield further productivity improvements. The ultimate goal is to reduce unscheduled downtime and increase availability through online monitoring of critical assets using both real-time and historical data collected via the integrated system.
Petrobras has a long-term vision for energy efficiency and is looking to improved visibility to help it deliver. The top areas of concern are motor systems, combined heat and power systems, steam systems, and energy recovery systems. Integrated process and power automation systems as well as high performance drives, advanced controls, emission controls and modernization are key elements of the company's efficiency improvement strategy moving forward.
