Dispatch Simulators Aid Utilities in Competitive Environment
By Teresa Hansen, Senior Editor
The U.S. electric power industry is rapidly changing due to both political and economic forces. Deregulation at both the state and federal level is forcing utilities into a competitive arena full of challenges. Electricity generation is being unbundled. Utilities and independent generators are forming pooling companies and power marketing companies are implementing complicated multi-party interchange transactions. These changes are expected to result in a substantial increase in power transaction volume in the next several years. In the past, utilities and transmission operators knew and understood dispatch requirements, however, today`s competitive environment is changing the rules and requirements.
In addition, information supplied through utilities` EMS and SCADA systems is becoming more important to customer service and business practices. Not only is it critical that system operators are prepared to meet the increasingly laborious role of keeping the nation`s power systems running reliably, they must also be able to optimize their utility`s systems to meet its business objectives.
Dispatch operator training will need to be more sophisticated to ensure that system operators can meet their critical role in the deregulated electric power industry. Simulators, long used by the airline and nuclear power industries to train pilots and operators, are expected to play a key role in preparing operators to meet the progressive utility industry`s increased demands.
Dispatch Simulator History
Interest in simulated dispatch training was spurred largely by the Northeastern power blackouts of the 1960s and 1970s. The first generation training simulators, introduced in the 1970s, were used to acclimate operators to a utility`s transmission system. Due to budget and technology constraints, the simulators often did not reflect the utility`s actual EMS. Instead, simulators represented a generic power system and made it possible to display hypothetical situations to dispatchers.
Second-generation simulators were installed during the 1980s in the utility`s EMS standby (backup) computer. Still in use by some utilities to teach fundamental skills and normal, steady-state operation, they fail to realistically model system behavior through the full range of off-normal and emergency conditions. Also, these simulators are often slow, responding to a trainee`s input after many seconds or minutes.
In today`s complex environment, power system simulation must appear realistic to the trainees. The control center representation should be exact, including the same displays, consoles and controls used in the actual control room. Trainees should see, hear and feel what they would in actual operation.
Thanks to the advances in computer hardware and software, near identical representation is now possible. Powerful tools have increased speed, memory and storage capacity and provided user-friendly, high-level and often graphic-based software. In addition, these powerful tools, such as Windows NT and object-oriented technology, have dramatically reduced simulator costs. No longer must long strings of code be written to simulate a chain of events. Money allocated for simulators can now be used to develop a system meeting the utility`s exact criteria. The decrease in cost from just 10 years ago makes today`s simulators much more attractive to utilities.
CP&L`s Dispatch Training Simulator
One utility that is taking full advantage of the new powerful simulators now available is Carolina Power & Light Co. (CP&L). The utility has developed an extensive training program for its system operators with Cegelec ESCA`s Dispatch Training Simulator (DTS) as the backbone.
According to Phil Creech, CP&L`s Power System Operation training and support manager, the utility first started using a dispatch training simulator in 1981. The current system operator qualification program was put into place in 1985. In the early 1990s, CP&L replaced its original simulator, also from Cegelec ESCA, with the current DTS. The DTS is used not only to train new operators, but also for existing operators` “refresher” training. All veteran operators spend three weeks each year training on the DTS. “There is no question that our training program results in a more capable system operator,” said Creech.
CP&L`s DTS is fully integrated with the utility`s SCADA/EMS and other control center functions. However, it resides on a separate CPU so that the integrated configuration processing does not degrade control center software execution. In turn, any control center software changes do not affect the DTS. The utility does have the option, however, of making the same changes by simply downloading control center information onto the simulator.
CP&L`s training simulator is an exact replica of its control center, said Creech. It contains a dynamic mapboard, strip charts and various other equipment identical to that found in the control center. Not only does the DTS look just like the control room, it also responds just like it. The simulator responds in real time just as the control center system would. It uses Institute of Electrical and Electronic Engineers standard long-term dynamic models to simulate the prime movers` and relays` actions. As a result, the DTS represents the control center system under a wide range of frequency and voltage conditions. The increased modeling sizes and accuracy are the biggest improvements over the old simulator, said Creech.
CP&L`s DTS contains an instructional system consisting of software and displays used to set up, initialize, control and review training sessions. The instructor interface includes all the displays required to set up and review a training session. The instructor can alter the initial generation, load, voltage and network state, as well as enter load schedules. The instructor can program the simulation to stop at a specified time or be stopped manually any time during the training session. The instructor can play the roles of plant, substation and neighboring utility operators.
“The ability to take an off-the-shelf product such as ESCA`s DTS and adapt it to the changing system operation environment saved CP&L a great deal of time and money,” said Creech. The simulator has enabled CP&L to prepare its operators for the challenges they are sure to face in the evolving electric utility industry.
Simulator Training Benefits
Randy Wilkerson, CP&L`s Power System Operation manager, said the utility`s training program is an investment rather than a cost. The efficient, professional operators resulting from the training program save the company more money through increased productivity than the training costs, he said.
The simulator allows an operator to obtain years worth of experience in a short time. It also allows the operator to experience events that may or may not be experienced in the control center.
“Not only does the simulator give trainees valuable experience, it also gives us the opportunity to assess a person`s capability to function under stress,” Wilkerson said. “It is very important to know how an operator is going to react in a stressful situation before he actually finds himself in one. We don`t need to wait until a crisis to find out that an operator is not prepared to handle the stress,” he said.
In addition, the simulator allows operators to make mistakes that are not harmful to the power system. This type of training not only helps trainees learn from their mistakes, it helps prepare them to deal with pressures they will most likely face in the control room.
According to Wilkerson, operators are not given “cookbook procedures” for every situation. Instead, they are taught concepts, giving them the knowledge to figure out how to rectify system problems. CP&L has developed Dispatcher Technical Reference Manuals to be used as guidelines, but operators are allowed some flexibility. “Procedures should never take the place of good judgment,” Wilkerson said.
The uncertainties of deregulation and competition have given utilities little incentive to invest in new power generation assets or new transmission lines. In the future, utilities may invest in technology to maintain reliability and provide adequate power rather than invest in lines and new power plants, Wilkerson said. CP&L`s DTS installation is an example of such an investment.
Simulators in the Business World
While maintaining a secure, reliable electric transmission system has propelled simulator use in recent years, competitive issues are also driving some utilities` decision to invest in dispatch training simulators. System operators have long had responsibility for buying and selling electricity. While they have typically been business-minded, they are now confronted with much more complex business decisions due to the onset of competition. “Utilities are under pressure to function as a true business,” said Alex Lekich, GSE Power Systems Inc.`s market and customer development director. “The system operator must be able to make good business decisions. Competent operators will be extremely important in a competitive environment.” Lekich believes dispatch simulators will play a key role in preparing operators to function in the new complex competitive business environment.
It is this notion that has spurred GSE, a long-time nuclear plant simulator developer, to investigate the dispatch training simulator business. In their quest to become more competitive and function as a true business, utilities have eliminated many of the management levels that used to exist between executives and system operators, Lekich said. Operators are not only having to deal in a more complex technical environment, many are faced with decisions that were once someone else`s responsibility. These individuals will be expected to understand the technical aspects of system dispatch, as well as the entire process and how it meshes with the utility`s business goals.
According to Lekich, operators must be aware not only of the information that is available through their utility`s EMS/SCADA system, but they must understand the information`s importance and how it can be used by others throughout the company. Simulators will be instrumental in preparing operators for this job, he said.
If the increased complexity and competition isn`t enough to prompt utilities to step up system operator training and invest in today`s high-powered simulators, the North American Electric Reliability Council`s (NERC) upcoming operator accreditation program may be. NERC, which has responsibility for ensuring the nation`s bulk electric systems operate reliably, is developing a system operator accreditation program, placing even more pressure on system operators.
According to Eugene Gorzelnick, NERC`s communications director, NERC has been contemplating operator accreditation for quite some time. The organization felt that increased system operation complexity required establishment of a set of standards and procedures to guide operators.
Although restructuring had already prompted plans for an accreditation program, last year`s outages across western North America accelerated those plans, Gorzelnick said. Twice last summer, common contingencies in local power systems started wide-area outages in the western United States, interrupting power to millions. “These outages resulted from incomplete understanding and control of today`s complex, stressed power systems,” Electric Power Research Institute`s (EPRI) Dejan Sobajic said in a recent EPRI article. “Although the outages focused public and industry attention, for several years we have been exploring the growing potential for problems stemming from competition, large-scale wheeling and power electronics. Significant advances in power engineering are needed to deal with the evolving industry,” he said.
Highly skilled system operators will be required to operate tomorrow`s systems and keep electricity flowing while meeting new regulations. State-of-the-art simulation technology coupled with a training program similar to CP&L`s has the potential to not only ensure secure, reliable electricity transmission, but also to prepare system operators for the complex tasks that await them in the restructured electric utility industry. As technology improves, costs decline and regulations increase, simulators are sure to play a role in future utilities` success.
If you would like to see more articles on this topic, circle R.S. 105.
For more information on this article, circle R.S. 106.