The following sections examine the current role of information technology within the electricity utilities. More specifically, the communications infrastructure and a range of supporting computer systems are described. In addition, a number of limitations with the current system are highlighted.
4.3.1 Communications Infrastructure
Most of the utilities companies in the U.K operate their own analogue PMR systems (section 2.2.1.2 described PMR systems in more detail) within a dedicated band of frequencies. The PMR systems are based on the MPT 1327 trunking standard which allows analogue point-to-point voice calls to be established and limited status code messages (numbers 0-31) to be sent using the control channel. The status codes are used extensively to operate a call-back queuing system at the control centre. The system is half-duplex and makes use of vehicle mounted transceiver units with push- to-talk hand held microphones.
Anecdotal evidence gathered during the requirements capture suggests three primary criticisms of the current system: coverage, lack of prioritisation and lack of a group channel. These issues are considered in more detail below.
Common channel
The current PMR replaced an earlier system of handheld push-to-talk walkie-talkie style radios. Although the PMR systems are far more sophisticated and offer greater capacity and coverage than the previous system, the connection-oriented communication style has changed the way engineers work. With the original system all traffic was shared with any receivers that were in range. This shared channel had two advantages: firstly, in a real emergency, engineers could hear which messages were truly urgent (for example, an injury) and secondly, by hearing all the communication going on around them, engineers were able to implicitly balance the load of repairs, knowing where colleagues requiring help were located and whether or not they could assist. The MPT 1327 standard does allow for group calls to be established. However, the group establishment procedure is too complicated for everyday use and requires all the parties in the group to be known beforehand (new members cannot be added dynamically to an ongoing call).
Traffic prioritisation
The PMR systems used in the divisions are heavily over subscribed, particularly when engineers have to access the control centre (which is often seen as a bottleneck). Engineers commonly wait for over half an hour before the control centre is able to call them back. Furthermore, the calls are not priority based, therefore an urgent or significant communiqué has to wait on the call queue as long as any other message.
Coverage
The coverage of the system can be very poor; engineers can experience coverage blackspots where they must drive for up to thirty minutes before regaining sufficient coverage to contact colleagues. Indeed, engineers have begun to unofficially carry cellular telephones just for cases such as this. The PMR system represents such a huge investment to the utilities companies that it is difficult to justify the expense of improvements to increase the quality or coverage of the system: the current PMR systems have not been upgraded to use more recent technology. Furthermore, under cases of extreme stress such as emergency situations caused by severe electrical storms, the PMR system can suffer from both insufficient capacity and interference problems from the storm.
There are initiatives within most utility companies to move to newer technology. The most likely candidate is digital PMR technology based on the TETRA standard, although some are conducting trials using public telephone systems such as GSM to examine their acceptability and cost effectiveness.
4.3.2 Computer Systems Support
Historically, the utilities industries have made extensive use of computer technology throughout their companies. A significant number of independent systems have become established for dealing with particular facets of the company’s interests.
System Purpose Location Hardware
Capital investment management
Costing extensions and repairs to the distribution network
Centralised Mainframe Project records
management
Recording and monitoring work project progress
Centralised Mainframe Trouble call Collates faults and customer calls Centralised Mainframe Plant records and
maintenance
Tracking the quantities and location of plant Centralised and depots Mainframe Tele-control load data analysis
Network load analysis and prediction suite
Centralised Mainframe Work instruction
management
Job dispatching and completion records
Centralised Mainframe Geographical
information (GIS)
Recording digitised schematic and geographic records
Centralised Networked workstations Switching schedule
production assistant
Expert system for switching schedule production
Centralised Mainframe or stand- alone workstation Network
representation
Replacement for electronic wall charts
Control centre
Workstations Data in the field Trial of CD-ROM based CMR
records in the field
Mobile Portable computers
Table 4.1 - Overview of divisional computer resources
Table 4.1 illustrates the wide range of systems that are being used within a typical utility company. These systems have been developed over many years, largely as a
result of periodic and massive infrastructure investment. The value of the systems, both financially and in terms of the information now contained within them, prohibits them from being replaced. Hence, the typical utility will have a range of legacy systems which must be integrated with newer systems in order to be viewed as a cohesive unified resource. As a direct result of this incremental development, these systems are based on a wide range of hardware and software technologies. In particular, the mainframe systems are based on wholly proprietary technologies which makes interworking particularly difficult (and hence many utilities are interested in open systems technologies).
In addition to internal system integration, there is often a need to work collaboratively with adjacent divisions. Currently, the utilities industry supports a limited form of inter-divisional cooperation through the adoption of a common PMR system. Subject to authorisation, a field engineer can work under the domain of an adjacent division to conduct ‘out-of-area’ work. While working in the foreign domain, the engineer has access to his home domain through the PMR system. Such a facility is often essential for dealing with HV faults with the national grid since switching operations may affect multiple divisions and thus require coordination. It is anticipated that, in addition to providing support for communication while in the foreign domain, future systems will ensure out-of-area engineers can access their home data services also.
The recent establishment of the common street-works register (CSWR) has led to an external requirement for the electricity utilities to interwork with other utilities such as gas or water. The role of the CSWR is two fold: firstly, it will enable utilities to be aware of each others’ infrastructure to reduce the amount of third party damage and, secondly, it will permit the utilities to loosely cooperate so that jobs on a common area of network are scheduled concurrently. In order to support the CSWR the companies are initially only required to be able to exchange textual messages relating to scheduled work. However, it is anticipated that more complex interchanges will arise as fully computerised public views of the distribution networks are developed. Due to the mix of deployed technologies and the separation of administrative control over each division’s computer systems, it seems clear that open systems technology would be able to assist in the foundation of the CSWR.