DA and DSM help utilities adapt to changing markets

Flexible technologies bend to fit a variety of needs during revolutionary industry developments

Ann Chambers

Assistant Editor

Distribution automation (DA) and demand-side management (DSM) are evolving, blurring the lines that once separated these technologies from traditional customer service and marketing. DA was initially concerned with technology to assist engineers and technicians in the field, and to eliminate manhours in outages and routine tasks. DSM grew from the need to shave peaks and fill valleys, eliminating or reducing the need for additional capacity, saving capital costs.

But DA is becoming more and more concerned with power quality and consistency, and DSM is now often more concerned with offering customers products and technology they seek. As various countries throughout the world are privatized, or prepare for privatization, these one-time monopoly endeavors are rethinking customer service and marketing and finding DA and DSM contain valuable technologies and tools.

This trend was showcased in the international papers at the 1995 DA/DSM(TM) Americas show in San Jose, Calif., USA, and will no doubt continue to be seen in DS/DSM(TM) Asia, held in conjunction with POWER-GEN Asia in Singapore in September.

Free market tools

Ad Brogtrop of N.V. NUON in The Netherlands presented a paper discussing DSM as part of a utility`s product mix in a free market. Production, transportation and distribution were separated in The Netherlands seven years ago as the first step toward a more competitive electric market. At that time, more than 500 companies were active in these three fields. According to Brogtrop, there are now four production companies, one transportation company, and less than 40 energy distribution companies left, with the number of distribution firms expected to fall “dramatically” in the future.

“Four years ago, the Dutch electricity supply companies entered into a covenant with the government directed at reducing the level of CO2, SO2 and NOx emissions,” he said. “A target to be realized by the year 2000 was set for each of the respective companies. The methods to be employed in achieving this objective were left to the companies.”

A free market for electricity is close at hand, and electricity supply companies in The Netherlands are working to ensure their ability to operate successfully in that market when it arrives.

“A key factor for success is that customers come to see the electricity supply company as a preferred supplier. Naturally, price plays an important role in this regard,” Brogtrop said. He also indicated factors such as image, reliability and service will be important. Mergers, takeovers and horizontal integration are leading to savings on supplies and boosting utilities` buying power.

“As a result, it will become possible to offer energy as an increasingly competitive product with respect to price,” he said. “But of equal, if not greater, importance is that the quality of service may be boosted and that further expansion for the range of products and services resulting from installed capacity will become more interesting for suppliers.”

Brogtrop indicated this will shift the focus from products which suppliers wish to sell, to marketing and sales, including DSM products.

In The Netherlands, where electrical power had traditionally been relatively inexpensive, DSM programs had failed to gather the support utilities had hoped for, especially when DSM programs to reduce peak use and marketing campaigns aimed at increasing sales were launched together. Brogtrop said consumers found the objectives of these campaigns contradictory.

“If marketing and DSM activities are carried out in an uncoordinated fashion, not only will the costs involved be higher and the results be lower, but customers` perceptions of the energy supply company will become clouded, thus weakening the existing interrelationship between the two parties,” he said. “Once time-of-use rates become market-based as opposed to cost-based, the difference between DSM and marketing will have disappeared.”

Brogtrop predicts that as the distinction between DSM and marketing dims, DSM will become an instrument to be used to influence customer demand and to realize greater profits on products and services.

Starting small

D. Wood of Norweb plc in the United Kingdom said, “In the United Kingdom, DSM activity to date has been restricted to small-scale, localized programs focused on network investment saving and to activities focused into government-led regulatory programs to reduce carbon emissions by the promotion of energy-efficiency programs.”

Norweb has found small DSM projects can be carried out at relatively low costs and produce avoided or deferred network investment. Norweb is the regional electricity company in the northwest of England, covering 12,500 sq. km from the Scottish border to the Peak District and from the Pennines to the Irish Sea.

The population of the region is 4.7 million, and Norweb has 2.2 million customers. The utility`s 58,000 km of network deliver 21,857 million kWh of electricity annually. Typical DSM measures promoted by this utility include hot-water-tank insulation, loft insulation, cavity wall insulation, draught proofing, energy saving controls, double glazing, energy-efficient lighting and energy-efficient refrigeration, all with a focus on residential customers.

“The number of projects will be relatively small and will generally be restricted to selected areas of our rural network where most of our problems and high cost of reinforcement exists.”

Automated controls

Hitoshi Kakimoto and Kenji Tanaka, both of Kyushu Electric Power Company Inc. (KEPCO), outlined their utility`s load control test plans for rate incentives. “In recent years, electric power demand in Japan has been on the rise. The consumption of electric power is concentrated particularly during daytime hours of the summer season, resulting from the increased use of air conditioners. The disparity between the amount of power consumed in the different seasons and at different times of the day has shown a tendency to increase year by year,” the two stated in their presentation.

In the summer season, power consumption during the daytime peak is more than double that of the nighttime off-peak. This usage disparity makes it difficult to use generating facilities effectively and tends to cause a rise in cost.

Pilot test

KEPCO conducted a pilot test on direct load control of customer equipment in Usuki Town, Kagoshima City, Japan, between 1986 and 1993, focusing on water heaters and air conditioners. Repeaters were installed at branching points of trunk lines, to amplify optical signals. Each repeater can be hooked up to eight distributors, with each distributor designed to accommodate four fiber-optic service wires. Direct-light branching, a passive method, was used instead of electrical conversion, to keep system costs down and to enhance reliability.

Home terminal units were then equipped with functions for controlling multiple load equipment, collecting utility information and measurement. The units reduce the amount of data to be processed at the control center.

Experimental air conditioners were equipped with control units and control overrides. A test was performed on a mix of residential, commercial and industrial areas supplied by a single circuit of 6-kV distribution line. The control units monitor room temperature and work to stagger air- conditioner use throughout the group, decreasing overall maximum load.

KEPCO installed an individual control on water heaters to enlist the heaters in a program to fill the nighttime energy-use valley. The program increased nighttime power use by 7 percent in summer and 6 percent in winter.

The KEPCO tests concluded that automation could have a substantial effect in both valley filling and peak shaving. “It is essential to investigate specific control methods, system components and profitability based on pilot test results,” the two stated.

Yun-Wu Chen and Yuarn-Chau Tseng of Taiwan Power Co. (TPC) in The People`s Republic of China outlined a DA pilot project their company initiated. Limited manpower, traffic congestion and difficult field access to switch operating positions pushed TPC to try line-switch automation in 1984, covering four substations and 25 feeders.

Chen and Tseng report that the systems are performing well and show a variety of benefits, including:

– fault outage time reduction from a 55-minute average to a 5-minute average

– decrease in time spent searching for fault location in distribution lines

– manpower savings in field switch operations and

– faster fault repair, restoring electric service more rapidly when an outage occurs.

Customer service is a growing concern at TPC, and power outages are the primary source of customer complaints. The utility`s supervisory control and data acquisition (SCADA) system monitors fault occurrence and restores healthy distribution segments; however, the SCADA system is not alerted to any faults that do not trip a circuit breaker. These outages require customer notification.

“No matter where the fault happens, the outage occurrence and fault-related information can, however, be reported and confirmed by customers` call-in messages managed in TCA (Trouble Call Analysis) functions,” the TPC paper stated. “Generally speaking, TCA can increase the degree of satisfaction of customer service and reduce the cost of distribution operation.”

TPC reports TCA benefits in a variety of areas, including:

– expedites judgment and repair of distribution faults–increases the energy sale by decreasing outage duration

– enhances operation efficiency by managing the repair crew and vehicles through a computer

– optimizes the management of scheduled outages and

– provides the reliability index of the distribution system for maintenance reference.

Phasing it in

Yorkshire Electricity Group plc (YE), one of 12 regional electric companies in England and Wales, is in the midst of a project developing a computer-based distribution management system (DMS). YE awarded the contract to Westinghouse Systems Ltd. in December 1993, with plans to complete the program in 1996. The DMS will manage the entire high-voltage (HV) network.

M.B. Fox of YE and W.D. Wilson of Westinghouse explained the scope of the DMS.

“The DMS will incorporate many of the latest technical innovations including automatic switching schedule generation and condition-based switchgear maintenance. These will be integrated with a power SCADA system to provide control engineers with fast access to control-center information through a carefully developed graphical user interface,” their report stated. “To meet challenging performance and availability requirements, the DMS will model the HV network in its own integrated database which will be populated with data from existing GIS and plant file systems.”

Future phases will involve hooking the DMS into a new distribution asset management system and the introduction of an expert system for alarm-handling and the validation of SCADA data through a neural network.

SCADA facilities are already installed in 425 major substations, with the switching sequence directed by a control engineer. There are approximately 450,000 switching operations each year, all directed by engineers at the control centers on an HV system of more than 36,000 substations and approximately 14,000 miles of HV underground cables and overhead lines.

Control and management of YE`s HV systems are currently run through three control centers. These centers also monitor and coordinate fault repairs. The DMS will convert the system to one centralized control system, with the three original control centers acting as data-collection sites and standby control centers in case the main center fails.

The main center will be equipped with 16 workstations for engineer use, split across two local area networks. All four sites will be supported by telemetered uninterruptible power supplies, backed up by local standby diesel generators.

The report identified the most important functions of phase one of the project as:

– improved SCADA functionality; new equipment will improve SCADA system integrity and support the existing RTUs

– full graphical schematic representation of the distribution system, supported by a plant and circuits database, which includes connection information to improve contingency arrangements in the event of a system emergency

– automatic switching schedule generation to improve switching schedules for the majority of planned work

– condition-based switchgear maintenance, an improvement over traditional time-based switchgear maintenance and

– a platform for future developments.

Fox and Wilson`s project report concluded, “Replacing the aging central site SCADA equipment with up-to-date but proven technology will not only protect a significant investment already made in RTUs, but it will provide enhanced facilities aimed at meeting the ever-higher customer-service standards demanded by the industry regulator.”

Valuable tools

DA and DSM may not be the ultimate answer for every utility, because every situation and distribution system is unique, but growing numbers of utilities are finding that the time has come to explore the options made available by these relatively young technologies. They have evolved into valuable tools for utilities striving to excel into the future. END

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The DA/DSM Americas conference (left and below) features an exhibit showcasing the latest innovations in DA, DSM, information technology and other rapidly developing areas of the utility industry, giving attendees hands-on access to products and service providers.

Click here to enlarge image

The DA/DSM Americas conference (left and below) features an exhibit showcasing the latest innovations in DA, DSM, information technology and other rapidly developing areas of the utility industry, giving attendees hands-on access to products and service providers.