For more than 100 years, Hamburgische Electricitäts-Werke AG (HEW) has provided a reliable electricity service to the city of Hamburg, Germany. Today, the company supplies electricity to some 1.7 million inhabitants via 285,000 connections.

During 1999, the year the energy market was started in Germany, HEW needed to operate and maintain a safe and reliable network cheaply. The development and implementation of a distribution management system (DMS) is key to the success of HEW.

Distribution Management System

Previously, HEW used two different systems to manage its low-voltage network: the Network Operating Resources Information System (NEBIS), in place for nearly 25 years, and a system for network and customer substations (NSKS). HEW operated these internally developed systems on a mainframe computer.

In April 1999, when further development of these older systems no longer seemed practical, HEW introduced a geographic network information system. The density of the city made more rapid reaction times necessary to provide higher levels of customer service. Also, the increasing customer-orientation efforts in the area required a modern network management system.

HEW's project team sought to find a comprehensive re-engineering solution to optimize standard tasks, as well as to collate and rationalize the existing distributed data of the HEW network in a format for applications over the complete spectrum of the company's activities.

HEW identified the various task areas from each business activity to integrate with the network management system. This effort established a comprehensive requirements catalog that provided the framework for the tendering process. One key engineering requirement of the management system included the capability to georeference the existing HEW distribution network database.

Selection of the DMS Supplier

This company-wide IT system was a major investment decision requiring a demanding selection criteria. The utility considered along with cost factors such as proof of performance, system capacity, ease of expansion and long-term reliability. HEW's strategy was to obtain efficient new software for network management that also offered a good platform for future applications. Following a pilot and prequalification phase, HEW invited several companies to process the requirements catalog and to submit a detailed tender.

The network information management system, Xpower, developed by Tekla Oyj, successfully passed HEW's test program and satisfied all the performance and system capacity requirements. The system met all HEW's conditions by presenting the reality of a network with the attributes of the operating resources. Thus, Tekla Oyj received the contract to supply and install the system in April 1999.

HEW's Distribution Statistics
Parameter System Voltage
110 kV 25 kV 10 kV 0.4 kV
Overhead lines km (miles) 697 (433) Nil 25 (16) 204 (127)
Underground cables km (miles) 344 (214) 86 (53) 5770 (3590) 8121 (5050)
Service area km2 (miles2) 760 (293)
Distribution substations 8000
Switchboxes 8500

Installation Phase

In the beginning, HEW had to analyze the existing data from its mainframe applications and migrate it to the new system. During this stage, HEW considered a flowing migration process able to process all business sequences of network system management, interfaces and database reports using an Oracle database.

The 30-member project team started the implementation of the new system followed by an in-depth analysis of the data. The team transferred the data from the existing two systems to the new system. This work, which took the team 13 months to complete, included these conversions:

  • NEBIS: Alphanumeric data for network devices (nodes for distribution substations, switchboxes and customer connections, cables and lines between nodes)

  • NSKS: Technical data for distribution substations

  • Microstation: Coordinates

  • SAP RIVA 2: Interface to customer data and billing information.

The low-conversion error rate of less than 1% proved a significant benefit throughout each of the three phases of the project.

The team completed the final modules in June 2000, after the 13-month introduction phase and the system became fully operational. During the introduction phase, the team transferred into the new system the data from 8000 network and customer substations, 50,000 cables, 15,000 low-voltage assemblies and 285,000 customer connection points, including all the spatial information and the material attributes together with the background maps.

HEW installed the distribution management system in three phases providing the utility with the opportunity to gradually integrate applications into its engineering disciplines.

Briefly, the engineering activities linked to each implementation phase were as follows:

  • First Phase: Convert low-voltage network topology from NEBIS.

  • Second Phase: Import consumption data into load-flow calculation.

  • Third Phase: Convert detailed asset information from NSKS.

Hardware and Training

The new system resides on a database server and five application servers available at four operating locations in the HEW network. With the object-oriented graphic display of the network systems, all users have access to a central information medium that makes special applications in the areas of operating management and network planning possible. This includes functions such as the execution of comprehensive network analysis, short circuit and load-flow calculations. Furthermore, important bases designed to aid decisions on network operational and maintenance investment is also available from display and modification of the network topology functions.

M.O.S.S. provided personnel training and service. HEW used some 60 workstations for test purposes during the trial phase. Currently, nearly 200 HEW employees are trained and fully equipped to use the new system, all processes and work sequences are established and use of this system has increased the competency levels of employees.

Into the Future

HEW is committed to supporting the development of the technical and economic calculation modules following the commissioning of DMS in 2001. Furthermore, with the development of applications to enhance the performance of call centers, HEW is confident that they will meet the desired goal of being a customer-orientated power service provider.

Bernd Rienecker who has a degree in computer science with a subsidiary subject cybernetics awarded in 1991, began his professional career in Siemens Central IT Research Section. In 1993, Rienecker joined HEW and is currently working in the information processing department.

Uwe Kiesel was awarded a degree in electrical engineering, specializing in the installation and operation of distribution networks. He joined HEW in 1996 and, following three years in the distribution network planning team, was appointed project manager of Network Information Systems.