Detroit Edison Co. (DECo), like many utilities, had an efficient method of circuit protection, but new thinking and an effort known as the Recloser Team Supply Chain Initiative is improving that circuit protection method and also lowering costs. The initiative reduces the installed cost of a three recloser loop scheme from approximately $120,000 to about $80,000. This cost reduction is accomplished by an innovative combination of equipment and process improvement. DECo expects to save $1 million annually through supply chain process improvements that have reduced unit cost, substantially reduced inventories through standardization, reduced installation and testing man-hours, extended maintenance intervals from 12 to 24 years, and allowed materials to be shipped directly from the manufacturer to crews at service centers or sites. The savings DECo is expecting will permit it to install 50 percent more loops for the same price. The money saved will be spent on other circuit upgrades further increasing reliability and improving customer satisfaction.
The Three Recloser Loop Concept
The three recloser loop design has been in use at DECo since the late ’70s, however, at that time the design failed because the reclosers had no remote monitoring. In 1992, DECo began a distribution automation (DA) project, which included extensive installation of the three recloser loop design in its automation system. “In 1992, when we began the DA effort, our main goal was to limit the number of customers affected by outages and greatly improve service restoration,” said Tom Roberts, DECo’s system planning and engineering manager. “That goal has not changed. Our strategy for reaching that goal is to prevent trouble. If trouble does occur, our strategy is to reduce the number of customers affected and speed restoration. The three recloser loop has helped us implement those strategies.”
The three recloser loop concept is simple, according to Jim Evans, DECo’s SCADA and distribution automation system principal engineer. Two circuits are joined at the ends with a normally open recloser (see figure). If a fault develops on either circuit, a set of three reclosers operates in a predefined manner to isolate the fault and restore service to a major portion of the customers who would otherwise remain without power under traditional means of circuit protection. To put this in perspective, a typical DECo loop scheme involving two circuits has approximately 4,000 customers. A permanent fault anywhere on either circuit causes a maximum of 1,000 customers to lose service. Under the traditional method of circuit protection, approximately 2,000 customers would lose power for a similar fault condition.
Upgrading and Integrating
Though the original three recloser loop implementation, consisting of VWE reclosers and Form 3 controls, works well, DECo knew its program to improve customer service and reliability was a continuous effort. New DA products have been developed, making DECo’s original solution out of date by today’s standards, as well as expensive to build and expand. In late 1998, the utility was poised to upgrade.
According to Evans, DECo understood the limitations of its DA system as soon as new products, with lower costs and added functionality began arriving in the marketplace. Its challenge was to match existing functionality and integrate new products into the system.
Matching DECo’s communications and automation issues proved to be difficult. In 1992 when the DA effort started, standardized protocols were wishful thinking. Therefore, DECo’s distribution hardware, substation automation equipment and radio communications devices all operated with various proprietary protocols. Having to deal with an existing installed base made moving toward a new approach a monumental commitment. Every new product brought its own custom communications interface.
For pole devices, DECo’s System Northwest S-COMM Protocol populated nearly 63 communications cells surrounding its substations. At the remaining communications cells, where pole RTUs handled the communications chores, each pole control had embedded communications capability, but not through S-COMM. This is a problem that plagues most utilities with older systems-there are almost 80 common SCADA protocols and almost as many intelligent electronic device (IED) protocols as there are IEDs. Integration was a custom blend of proprietary communications interfaces and hardware. Industry standards offer common solutions for new systems, but the legacy remains for those utilities that can’t afford to wipe the slate clean.
Unusual Integration Approach
DECo used an innovative approach to resolve its integration problem. Greg Snyder, DECo Supply Chain’s principal leader, developed a seminar that included a group of DECo’s suppliers that share common technologies, specifically, microprocessors and semiconductor electronics. The distribution automation technology suppliers were told that they had to develop products that could integrate seamlessly into DECo’s existing system. “We couldn’t afford to add extra pieces or to customize our system to make one new product work,” Evans said.
Teamwork and commitment proved to be the key to persuading suppliers to provide products that could operate with DECo’s current embedded base. To emulate a unique protocol just for DECo involved major investment. However, Cooper Power Systems agreed to do so, based on the strong joint relationship and commitment shared with DECo. Cooper developed a state-of-the-art recloser and recloser control that could be easily installed and integrated into DECo’s existing DA system.
A relationship between DECo and Cooper was established and a solid team was put into place. Team members from both companies looked on the strategic alliance as a mutually beneficial partnership. The team focused on fielding the next generation of DA reclosers that would bring better business to both sides.
DECo’s Recloser Supply Chain Initiative team members are (L to R) John Kozarevich, Tom Roberts, Jim Evans, Greg Snyder, Dave Costyk and Sharon Hoscila.
“From our perspective, the issue was how to bring technology to bear on utility issues that have a true cost impact,” said Jerry Yakel, Cooper Power Systems’ Kyle products marketing director. “We participate in a limited number of alliance partnerships. The most effective partnerships, likes ours with DECo, have some critical elements: complete organizational buy-in, saving-sharing, tangible metrics and goals, and a manufacturer/utility process team that investigates and uncovers all aspects of the total cost picture. Technology for technology’s sake is not what makes beneficial automation partnerships. Product technology must eliminate a wasteful process or equipment component.”
Technology was not the only issue driving DECo’s efforts. Supply Chain’s mandate to reduce costs brought the team to a new focus. Life cycle cost, inventory management and process improvements all offered challenges and opportunities for the team. Ultimately, DECo predicts the joint effort will net it a $1 million per year savings-$815,000 per year attributed to direct savings on equipment and installation costs, and another $185,000 per year in indirect savings as a result of changing the way three-phase reclosers are purchased and handled.
The arrangement is also beneficial to Cooper because it brings the company a long-term commitment and access to a great deal of industry knowledge and leadership. Both companies see the supply chain initiative as far more effective than simply focusing on first cost or price. There are several key areas where design features and process improvements resulted in life cycle cost savings.
1. Control/RTU Integration
The new recloser control and automation platform, the Kyle Form 5, has an integral loop scheme and imbedded communications functionality that utilizes S-COMM protocol. A second independent communications port gives DECo the future capability of converting to DNP3. The RTU functions are incorporated into the architecture, thus installation of a separate RTU cabinet and associated wiring is no longer necessary. By eliminating the conventional RTU from the pole, DECo estimates cost savings of $8,500 per installation, or more than $350,000 per year.
Cooper worked to simplify the loop scheme design as well, combining mid-line, sectionalizing and tie controls into one modular design. All existing recloser and loop sectionalizing (LS) functions are supported in a single control. With the LS functions configurable in the control, it becomes virtually impossible to install the equipment incorrectly.
The modular design also eliminates many store items and logistic issues. Since these protection-specific components and automation options are configurable in software, hardware permutations dramatically decline. The Form 5 controller replaces five variations of the Form 3 and Form 3LS controllers currently in use at DECo. The new simplified loop scheme has allowed DECo to eliminate 21 items from its stock shelves, saving another $50,000. Fewer items also mean less possibility of scrambled parts.
Another advantage is that the integration into the DA system is seamless. There are no discernable differences to the distribution management system or the substation submaster.
2. Advanced Planning
Site delivery requires a great deal of emphasis to be placed on lead-time and responsiveness. DECo recognized that for Cooper to successfully shorten cycle time and production turn-around, advanced accurate information on anticipated projects was a necessity. DECo communicates specific equipment requirements to Cooper and will soon be able to provide it with specific application details well in advance of the required delivery date. Cooper will then be able to plan production schedules accordingly, allowing it to procure materials quickly and in the most cost-effective manner.
3. Human Interfacing
DECo has an agreement with its field workers’ union that requires the utility to make sure all workers are completely informed about any new equipment that is to be installed in the field. DECo’s safety directives also mandate that workers be completely trained on the equipment before it is put into service. Both partners were sensitive to these issues. Ergonomic and human issues of using new technology were assessed up front. Design considerations centered on switch panel operability, nomenclature and lock-out/tag-out procedures. To make sure the commitment to provide introductory training sessions prior to technology moving out to the field was met, Cooper brought in experts to coach DECo’s trainers in the technology before the first device was installed.
According to John Kozarevich, DECo’s line engineer, convincing the field workers that the new equipment is an improvement over the old was not difficult. The new recloser, called the NOVA, is smaller and lighter than DECo’s previous recloser-it weighs 600 pounds less and is 30 percent smaller. It is much easier to handle and can be installed much faster than the old reclosers. The recloser can also be installed on most existing poles, eliminating the cost of replacement poles.
“In seven years, Cooper Power Systems (Kyle) products have evolved to offer substantial improvements. Better second-generation microprocessor-based controls and a new oil-less Nova recloser have entered into the marketplace,” Kozarevich said. The new recloser completely eliminates the SCADA control box that was mounted on each pole and allows a reduction in pole size. The Nova recloser requires no oil, so it eliminates the potential risks of oil spills and hazardous material handling. In addition, it requires fewer permutations to build, making it much less likely that field workers will install, or even arrive at the site with incorrect parts.
“The alliance activity helped us understand that front-end price isn’t always economically correct. The cost to acquire, integrate, install and operate a piece of equipment can vary over its lifetime,” said Sharon Hoscila, a DECo supply chain buyer. With the older oil insulated reclosers, DECo’s maintenance cycle was 12 years. From experience, DECo planners generally know a recloser stays where you put it for more than 12 years. Studies demonstrated that the true costs associated with removing, transporting and maintaining a recloser after only 12 years is as much as installing a completely new recloser. By stretching the maintenance cycle on the new recloser to 24 years, the recloser should never need maintenance in its life span. This translates to a $15,000 savings per unit to amortize over 24 years.
Another major advantage is that the NOVA contains bushings made of cycloaloaphatic epoxy rather than the traditional porcelain bushings. The material is an arc resistant material and its use should mean DECo will experience fewer extended outages from flashovers, which normally destroy porcelain bushings.
5. Process Improvements
The DECo/Cooper team also found another source of savings in their warehouse stock and handling process. The NOVA reclosers and Form 5 controls are directly shipped to the service centers and require no additional testing once they arrive. This innovative “drop ship” blanket purchase order coupled with changes to DECo’s traditional materials ordering and handling process has reduced the Materials Transport Adder charged on “stock” goods by 19 percent. In addition, the risk of shipment damage while DECo transports the material dropped.
The first reclosers and controls were installed in early November on two of DECo’s more problematic lines-Royal Oak Center and Pontiac Service Center. According to Evans, the utility plans about 50 installations each year. The first installations are planned at other problematic sites that do not currently have the three recloser loop configuration. Other installation will be at sites that currently use the three recloser loop scheme, but don’t have RTUs installed, said Evans. The remaining installations will be new installations that are required as new distribution lines are built within DECo’s service territory.
Both companies feel that the innovative approach taken with product development and process improvements has had a major impact on the project’s success. “Although Cooper has for some time advocated total cost solutions, Detroit Edison helped us to yet better understand the big picture, the overall cost. Together we focused not merely on product cost but also on things like installation, maintenance and inventory costs,” said Neal Roth, Cooper Power Systems’ sales director and a member of the alliance team.
“This project didn’t start out as a strategic initiative, but that is the way it has turned out,” said Evans. “There are savings on both sides.”
The two companies don’t plan to terminate their efforts with the three-phase recloser design. They are continuing the effort to standardize single-phase reclosers, thus allowing DECo to increase recloser installation efficiency even more and, once again, substantially reduce its recloser inventory. However, the biggest advantage to developing a single-phase recloser will be implementing technology that will allow only one phase, instead of all three phases, to be lost during fault conditions. Such technology will mean even fewer customers will be affected when an outage occurs. Both DECo and Cooper are sure that, thanks to the successful alliance they have formed, the standardized, single-phase recloser will be available soon.
“This is the future,” said Roth. “This type of insight and cooperation is what will allow both our companies to improve and succeed.”
The Nova recloser is smaller and lighter than the reclosers DECo previously used. In addition, it requires fewer permutations to build, making it much easier for field workers to install.