Trouble Order System Improves Utility`s Service
By Harold Wildgoose, EUA Service Corp.
Eastern Utilities Associates (EUA), serving more than 300,000 customers in Massachusetts and Rhode Island, needed to improve the availability of power outage information to its customer information services (CIS). EUA executives realized this need existed six years ago; however, EUA`s outage response system was outdated and lacked the graphical capabilities needed to locate problems quickly and provide timely feedback to affected customers.
In 1996, EUA was ready to make the switch to a more sophisticated system. EUA has had tremendous success using the new graphical trouble order system (GTO) for all major power system disturbances. In fact, the system is presently being updated for use in the system operations department for daily operations tasks.
After investigating numerous options, EUA chose Intergraph Corp.`s graphics and mapping system to develop its GTO. Based on Intergraph`s FRAMME AM/FM/FIS software running on the Microsoft Windows NT operating system, GTO was completed in June 1997.
“With the project design in place, we started implementation in December 1996. We had the analysts trained and GTO in service by June 1997, all in time for the hurricane season. The training issues alone saved about $100,000 on the overall budget,” said Ray Jenness, software project leader.
Using GTO, EUA analysts receive trouble calls in a centralized location and have immediate access to critical information during power outage conditions. And as a bonus, analysis is performed with fewer employees and other resources than were needed before. This is particularly important during major storm activity, when loss of power can affect thousands of customers and result in significant restoration costs for EUA.
Jean Poisson, EUS`s distribution engineering manager and head of the storm analyst center, has been impressed with the results of GTO. “Intergraph`s technology has greatly contributed to a reduction of the inside storm restoration staff,” he said. “Three years ago, we analyzed trouble calls in four separate areas with nearly twice as many people as we now need in one centralized location.”
By sorting trouble calls and identifying problem feeders graphically, analysts can quickly provide information to dispatch work crews and reassure customers. “Not only is the job performed by fewer people, but the information is more accurate, timely and available simultaneously throughout the organization,” said Poisson.
When a customer reports a power problem, the CIS department enters the call in the trouble order (TO) system, which resides on a mainframe computer. The CIS operator enters the type of problem, such as no power/no lights or wire down, and issues a TO. Each customer is cross-referenced to a secondary power transformer using a transformer load management (TLM) number for geographical identification of the area where the outage has occurred. Every two minutes, TOs are automatically transferred to the graphics computer running FRAMME.
Using the graphics-based system, power system analyst request unanalyzed TOs for the date, time and time span (generally one to four hours). GTO responds with a list of all feeders in descending order, from the most to the least outstanding TOs. Analysts may alternately request TOs affecting feeders that supply power to critical customers such as hospitals, police and fire stations and water works.
Once an analyst identifies a problem feeder, FRAMME displays the selected feeder map, which shows transformer symbols with associated TOs highlighted by color. Colors represent vital information about each transformer: light green denotes a single TO; light blue denotes multiple TOs; light yellow identifies a priority TO (critical customer, medical priority or unconfirmed wire down); and red identifies a confirmed wire down. Analysts view the highlighted transformers and make judgements about restoration priorities from the patterns they observe.
With graphical information about feeders and affected customers displayed, the analyst can zoom into the area with a suspected problem device, such as a blown fuse or open recloser. When the analyst initiates the master trouble order (MTO) and the problem device is selected, that device is highlighted in red and an MTO symbol is placed near it. Additional symbols can be placed to indicate that police are on the scene, a wire is confirmed down and other information important to the ongoing analysis.
Using a custom interface designed with PowerSoft PowerBuilder, restoration dispatchers can sort and view MTOs by whatever criteria they choose, such as geographical location, critical customers or number of customers affected. MTOs are dispatched in priority order to restoration crews via radio transmission. When truck numbers are assigned the status of associated MTOs changes to dispatched.
When the ultimate goal of the process–power restoration–is accomplished, the dispatch crew enters the time and date, and the status of that MTO, which the system notes as complete. This feedback from the crew is critical, because while each MTO is in progress, new TOs related to that outage have been analyzed and categorized under that MTO. Once an MTO is marked complete, any further TOs received and entered for that area will be treated as unanalyzed and subsequently investigated.
Now that GTO is being effectively utilized for all major power system disturbances, using GTO to transfer specific customer information back to CIS is the next phase. This implementation will provide customers with up-to-date progress reports, including when a work crew was dispatched, if a crew is on location, estimated time to restore power and when power is restored. Also in the works are plans to proactively notify customers that EUA is aware of a power outage, a valuable service to customers such as owners of businesses that store perishables, relatives of persons with special medical needs and others with specific power requirements. Mobile Data, the latest GTO project, will include the installation of computer terminals in field vehicles.
As GTO expands and improves, EUA is recognizing the system`s tremendous potential. By focusing on customer needs and taking advantage of FRAMME`s powerful features, EUA is serving customers better and more quickly during difficult outage situations.
Harold Wildgoose is EUA`s technology development supervisor in the engineering department, where he has worked for more than 33 years. He is the GTO project manager.
Intergraph Corp.–Inquire R.S. 140
Battery Life and AMR: A Ten-Year History
By Kindle Smith, Hexagram Inc.
Hexagram Inc., an automated meter reading products company, was concerned with the battery life in its meter transponder units (MTU). Hexagram`s concerns are shared by other AMR companies since many AMR systems require a long-life battery. Because field battery change out is extremely expensive, battery lifetime is critical when evaluating AMR technology. To determine the longevity of the batteries that are installed in Hexagram MTUs, the company analyzed a sample of lithium batteries that were installed in remote-reading modules 10 years ago.
Results of the analysis revealed that when lithium cells are selected by a rigorous screening process and are properly applied, they reliably perform in the AMR environment. The tests that Hexagram performed proved that lithium batteries can provide the 10 to 15 year life that is required in the utility industry.
The battery life of the popular lithium thionyl-chloride cell is a function of circuit current requirements, internal self-discharge of the cell and age-related chemical and mechanical degradation. Circuit current requirements are relatively easy to determine. They include quiescent, or stand-by current, as well as larger currents drawn briefly during communication and processing. It should be noted that standby current may change with temperature.
According to Hexagram, batteries in AMR products must operate for at least 10 to 15 years. A concern to AMR companies is that battery self-discharge is a significant factor in determining the life of a battery. Although a battery vendor may specify a nominal value, self-discharge is strongly related to temperature, current-drain profile and battery quality control. Because of this, its value may vary significantly from the specified value.
To ensure long battery life, Hexagram evaluates every battery placed in its MTU systems. Hexagram AMR products use a single AA thionyl-chloride cell. Before assembly, individual cells are evaluated according to a proprietary procedure which analyzes chemical and electrical properties. Only cells that meet the company`s criteria are accepted.
A small sample of cells, recovered from Hexagram remote-reading MTUs that had been in indoor service for 10 years or longer, were tested. A sample of archived cells that had been stored and unused for ten years were used as a control group. Both groups of cells were slowly discharged to determine their remaining capacity. Subtracting the remaining capacity from the presumed original capacity of 1.8 amp-hour (Ah) allowed the company to estimate the energy consumed during the previous 10 years of storage or service.
The batteries removed from Hexagram`s MTUs were found to have a remaining capacity of 0.9 Ah. This means that only about one-half of their capacity was consumed during 10 years of operation. Since no corrosive or mechanical failure patterns have become evident, these cells could theoretically power the MTU for an additional 10 years. It is not valid to assume, of course, that there are no unforeseen phenomena that might accelerate failure. The company has not, however, seen an increasing failure rate among cells as they age.
When batteries from the control group were analyzed, the remaining capacity was about 1.6 Ah. Thus, only 0.2 Ah of capacity was consumed during 10 years of storage at room temperature. This corresponds to a self-discharge of 1.1 percent per year, which is consistent with the battery vendor`s specification.
Hexagram also found it interesting to compare the self-discharge rate of the control group with that of the operating cells. Since it is known that the module circuitry consumes 0.4 Ah over 10 years, then the self-discharge of the operating cells was about 0.5 Ah. This is greater than the 0.2 Ah self-discharge that was found with the non-operating control group. This difference is due to the fact that self-discharge increases with circuit current drain. It is important to note that high temperatures will also increase self-discharge. This may be important in outdoor applications such as electric meter products.