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Managing Pipelines at Con Edison: Maya's Real-Time, Large-Screen Systems Make the Difference Charles R. Salerno, Manager, Gas Controls Con Edison, New York City Lights flash and alarms sound. That means there is a problem somewhere along the hundreds of miles of our gas pipelines in Manhattan, the Bronx, Westchester, or the parts of Queens we serve. It could be a low pressure condition, a high flow rate-or perhaps a rupture. Whatever the emergency, a sensor immediately telemeters an analog reading that our system converts to a digital signal and displays as data in our Energy Control Center. That, in turn, enables us to immediately implement corrective emergency procedures. Public utilities usually have some system in place for handling emergencies. But few systems have the capability of visually informing control personnel-in real time-of the nature of the problem. That's important when every lost second can inconvenience customers or cost money. Most critically, saved seconds can mean minimizing additional damage to the gas supply system and maintaining service to customers. Up until the winter of 1995, Con Edison Gas Control Operations had a static, hard-wired, mimic board system utilizing one screen in a tiled 12 foot by 8 foot enclosure. Some pressure and flow points were tied into metering stations and remote terminal units (RTU's) throughout Con Edison's gas system and data was telemetered through leased lines. When an anomaly occurred, red indicator lamps flashed on the static mimic board and basic information was then digitally displayed on our Supervisory Control and Data Acquisition (SCADA) desktop computer. But we lacked the ability to query the data. When a problem occurred, indicators intermittently emitted either a slow or fast flashing glow. Slow flashes indicated a low pressure condition and fast flashes a high pressure condition. In any case, Gas Control would refer to SCADA to see where the alarm was being generated and what action had to be taken. This was a slow and cumbersome determination process that offered little flexibility, especially during an emergency. Another circumstance compounded the problem. Three companies tied by pipelines (Con Edison, Brooklyn Union and Long Island Lighting Company) share Con Edison's New York Facility Group System; the only cooperative arrangement of its kind in the industry. This legal agreement gives each participant the ability to receive gas outside of its franchised area. It is imperative that all parties know immediately of any changes in the flow of gas. Therefore, in keeping with our policy of utilizing the latest technology to improve operations, we were determined to replace the static, hard-wired system. We contracted with Maya Video Communications, a New York City-based company that had installed a large-screen, computerized graphical display at Con Edison's Staten Island electric facility. Maya worked with us to install a large-screen projection system (Stacker Screen Enclosures of one over one) with each screen having a near seamless display measuring 67 inches and three stacks holding six screens. This gives us the ability to display multiple events in the Con Edison gas system. Each screen can provide multiple display segments or one display can be viewed on up to four screens. The latter capability permits two operators and a supervisor to simultaneously view the field-a real time overview-without needing to take turns peering over an operator's shoulder. There are some 160 transducers along our pipeline system. Our dynamic system enables us to look at values (different points on the system) graphically displayed. This offers us a better interpretation of occurrences at any point than we were able to obtain with the static board. These new displays look at changes in our gas transmission system and monitor any disruptions. If and when a disruption occurs, flashing lights and values will appear and alarms sound. We can then call up, on one or more screens, Con Edison's established contingency procedures which give step-by-step explanations of what to do. The new system also enables us to generate significant reports through SCADA such as the actual daily accounting of quantities of gas consumed and the status of our contractual obligations with our pipeline interconnects, based on bi-directional metering at the borders between territories. Audit reports cover all gas deliveries coming into the system, and we check them against Con Edison's telemeter readings. A special report details alarm activity. Another generates daily work sheets (a gas day is 8 A.M. to 8 A.M. the next morning) and details all transactions for that day. Our new capability will enable us to integrate all gas operations at the gas control center, improve service by logging in and being more responsive to customer requests and record compliance information. When a water main broke in the Bronx recently and threatened the integrity of our system, we were able to bring up multiple screens depicting all of our contingency cases. By enlarging the graphic display of the location and showing what was happening at the disruption point across a number of screens, everyone in the gas control center could see and react. Based on our observations and following established contingency procedures, we were able to dispatch crews in much shorter time than before. Since we have five more of the larger screens than before, we can designate one screen to display values. This allows us to quickly determine whether we have a system failure or telemetry problem. And we can designate one screen to display contingency planning procedures. We can also query data by Graphical User Interface (GUI) and immediately see on a screen a graphic presentation of whatever is being reported. The system includes help menus, which makes training simple and determinations and reaction time quicker. Also helpful is the system's ability to display more critical information and its modularity, which allows expansion to accommodate additional screens and data sources. |