As from 1 January, 1999 Vattenfall’s regional and local network companies (forming the “Elnät” division of Vattenfall, which is responsible for electrical network operation) were brought together, with the aim of making better use of resources and lowering operations costs.

There are now four network companies in Elnät – Vattenfall Norrnät AB, Vattenfall Sveanät AB, Vattenfall Östnät AB and Vattenfall Västnät AB – each of which integrates both local and regional network operations in its area and is responsible for all voltage levels, 130-0.4 kV.

An improved customer service system with a new type of service centre for network customers is also being set up. This will work together with the operation centres in a co-operative IT system, decreasing the workflow load in the operation centres.

The new arrangement makes it possible to use the same control room engineers for the whole range of networks – the 130 kV, 70 kV and 40 kV transmission networks, as well as the 20 kV, 10 kV and 0.4 kV distribution networks – and at the same time decrease manning levels in the control rooms.

To support Vattenfall’s new operation process an IT system called DRISS is being introduced. This will be an integrated system over the four regional companies. Thanks to DRISS the number of operation centres will decrease from around 20 down to four, one for each regional network company. The DRISS system is due to be in operation in March 2002.

System goals

The DRISS integrated computerized control system will replace existing obsolete computer systems and provide the conditions for extensive operational and maintenance-related interaction between and within the four network areas. The new system will form a modern platform for economic and efficient network operation by the new companies. Throughput times for running network tasks and fault management will be shortened relative to the present system.

A feature of the new process-orientated organization will be one or more customer service centres where there are call-takers/customer service agents who take calls and assist the customer with questions and problems. The call takers/customer service agents work closely with the dispatcher.

The load dispatch centre, of which there may be more than one, has two different functions, operator and dispatcher. The operator handles all operations in the high-voltage network and works with the people in the field. The operator is also the dispatcher for the high-voltage network. The dispatcher handles all contacts with the call takers/customer service agents in the customer service centre, controls switching in the 10-0.4 kV network, sends out personnel to repair faults in the 10-0.4 kV network and dispatches the 10-0.4 kV network.

For this organization to work, the customer service centres and dispatch centres must be manned 24 hours a day, all year round.

Importance of integration

Vattenfall has placed a contract with GE Harris Energy Control Systems UK for the IT system underpinning DRISS. GE Harris was selected because its technology uses one integrated system for SCADA, EMS, DMS and Customer Service/Trouble Call functions.

The SCADA functions include: monitoring; control; statistical reporting; alarm/events displays; switch faults; follow-up; RTU control.

The EMS includes: pre-dispatch functions (load forecasting, study-mode network analysis); real-time dispatch functions (network analysis); and post-dispatch functions (post mortem review).

The DMS functions include: digital one line diagram 130-0.4 kV; GIS diagram 130-0.4 kV; diagram creation; tracing functions; diagram navigation, tagging etc; planned and unplanned outage and restoration; area of responsibility management.

The Customer Service/Trouble Call functions include receipt of fault calls, cable location, and dealing with voltage problems, fuse replacement and network-related customer complaints. The customer service applications of DRISS include call management, incident management, outage management and work and crew management, with the aim of improving outage management and fault logging, analysis, tracking and rectification.

System characteristics

One of the qualities specified for DRISS is that it will be able to handle future changes, expansion and upgrades of configuration, hardware and software without requiring replacement of large parts of the system or affecting normal operation of the power system.

Also the system is sufficiently flexible, as regards introduction of new functions (which will continuously be required for operation and maintenance of the power network), that there will be no need for future major investments in design and implementation.

The system also includes an operation and maintenance environment which supports effective monitoring, fault tracing and fault correction in hardware and in data. A software maintenance environment is also included for Vattenfall custom software and future any additions to the system that Vattenfall might wish to make.

Other features of DRISS include:

  • Great flexibility in the location and number of control centres.
  • Possibility of operating each region or area independently (islanding) or together in a larger area, regardless of faults in communications or equipment in the other areas.
  • Ability to perform basic remote control functions under all load conditions, including a “major disturbance situation”.
  • Unified data maintenance function, in which data for a particular item is entered once, stored in only one place for the entire system, and which allows maintenance to be done centrally or by local personnel as required.
  • Co-ordinated and consistent data definition.
  • Communication with all existing types of RTU.
  • Communication with DDN (DriftDataNätet – operational data network).
  • Validity of all functions for all voltage levels (130-0.4 kV).
  • Exactly equivalent handling of all functions, regardless of network area.
  • Capability for interchange of data with the Vattenfall facilities documentation system (Powel NETBAS) and measurements processing system (Powel) as well as the business activity support system (SAP /R3). The system is designed to facilitate data interchange with other systems in the company and database maintenance for DRISS uses a common database across the whole company from which operational databases, displays, calculations, statistics and control centre systems reports are generated.

    To ensure that these operational, functional and economic requirements are met the following design goals have been adopted for DRISS:

  • The system platform is based on standard products and the aim is to achieve compatibility with older equipment.
  • It will be an “open system” based on formal and de facto standards which require, among other things: portability of operating system, data access methods, operator interface and compilers; scaleability; well-structured and documented internal interfaces (API) for secure internal communication and the addition of new functions; no deviation in coding of application programs from the standard for the language in question except in documented exceptional cases.
  • Key functions (basic remote control, data acquisition, monitoring and control) must be performable under all load conditions.

    Growth market

    The GE Harris technology as incoporated in DRISS is directly applicable where the intention is to have an integrated network management system monitoring and controlling both transmission and distribution. This is the case in Sweden, and in a growing number of other countries.