摘要:

The paper describes the development of contracting from the early days to the emerging role of the lead contractor in major overseas power projects today. The look at history shows how the role of the contractor has evolved in parallel with the development of the UK power industry. The fall in new business in the UK forced a change in attitude to attack the world market, and some overseas projects are described. The significance of the concept of UK Ltd is discussed together with the important role of the lead contractor with strong project management skills and experience to bring together not only technical and construction activity but also commercial and financial aspects of a large construction project. Developments in opportunities for renewable energy projects at home and overseas are reviewed. The paper concludes with a reference to the challenge facing contractors in the changing scene worldwide in power sector construction projects.

DOI:10.1049/ip-c.1988.0001

出版商:IEE    

年代:1988

数据来源: IET

摘要:

20 years ago, following a period of rapid growth in demand in the UK for electricity, the UK cable makers were world leaders with major installations at 275 kV and 400 kV. In parallel with significant improvements in manufacture, forced cooling of cables had also been introduced. It was forecast that a 750 kV grid would be needed in the future. Both of these latter factors led to extensive research into all types of low loss, high-power cables including superconducting cables, the possibility of which was first demonstrated in the UK in 1967 with a small-scale superconducting link. Progress made since is reviewed and it is found that the UK has lost the lead in all areas of high power cable technology except for paper insulated oil-filled cables. Activities during this period are summarised with special regard to superconducting cables where the recent discovery of high-temperature superconductors has stimulated interest again. The future prospects for the UK high-power cable industry are analysed in the light of the downtrend in the UK in both the supply of research and development staff and of research funding from both industry and Government sources.

DOI:10.1049/ip-c.1988.0002

出版商:IEE    

年代:1988

数据来源: IET

摘要:

An apparatus is developed for monitoring the leakage currents drawn by an insulator chain of a power line or a busbar support in a polluted atmosphere. The apparatus monitors the insulator pollution by sensing and analysing the leakage current bursts. If these bursts are judged by the apparatus as corresponding to a potentially dangerous pollution level, the apparatus transmits an alarm signal to the service crew to allow them to clean the insulators of the line or substation in time before a sudden line outage occurs, with the entailed excessive expense, loss of power supply and annoyance to customers. Line insulator cleaning is thus carried out only when necessary, which adds to the economy of the power system operation. The apparatus design and construction were reported in Part 1 of the paper. It has undergone numerous tests with artificially polluted insulators in the high voltage laboratory. These tests are the subject of the present paper. The following Part, to be submitted, will describe field experience.

DOI:10.1049/ip-c.1988.0003

出版商:IEE    

年代:1988

数据来源: IET

摘要:

This paper deals with the estimation of parameters involved in the classical steady-state modelling of network elements within the context of power system state estimation. A general method is proposed for the identification and correction of the real-time data, based on the sensitivity relationship between the measurement residuals and the parameter error; this relationship is treated as an estimation problem, yielding a parameter error estimate. Special emphasis is put on the real-time correction of erroneous transformer tap positions, the most frequent parameter errors during the real-time operation of state estimators. The proposed method is very simple and efficient, since it merely requires a single substitution in the state estimation linear system. Relationships with other methods are also discussed. Simulation results on a real-life system are reported.

DOI:10.1049/ip-c.1988.0004

出版商:IEE    

年代:1988

数据来源: IET

摘要:

Cape Town City Council is responsible for the supply of electricity to the city area. To achieve this, the council owns and operates thermal and pumped-storage power stations and extensive HV transmission and LV distribution networks. Power is also purchased from the national supply authority. Prior to the introduction of the control system described in this paper limited supervisory control and data acquisition facilities existed to provide some degree of remote control for the network. In addition to duties associated with supervision of both the HV and LV networks, the control centre operators were also responsible for energy management involving generator scheduling and control, and load-shedding when required. To assist the operators in their extensive and onereous duties a new computer-based control centre has been developed and was commissioned in 1984. Because of the unusual mix of power sources special software had to be developed for energy management purposes. Descriptions are given of the functional and practical aspects of the control centre, and of associated hardware and software facilities and also some commissioning experiences.

DOI:10.1049/ip-c.1988.0005

出版商:IEE    

年代:1988

数据来源: IET

摘要:

A new method of numerically modelling coupled heat and moisture flow around power cables in steady state and time varying conditions based on the Philip and DeVries model for flow in soils is presented. The method has been implemented within a computer program for an IBM or compatible personal computer which utilises the Galerkin approach in the finite element method. The program employs advanced, sparsity-based algorithms which can handle large finite element grid structures and calculate accurately the steady state and time dependent temperature and moisture distributions and isothermal contours for power cables buried in media containing complex configurations of soil, boundaries, heat sourcesand sinks. Validation of the program has been achieved with data from field tests. A good comparison between predicted and measured results was obtained.

DOI:10.1049/ip-c.1988.0006

出版商:IEE    

年代:1988

数据来源: IET

摘要:

The paper gives details of development work on a protective scheme based on the travelling waves present on major transmission lines after the incidence of faults. The basic principle of the scheme is outlined. Analytical treatment, based on an ideal single-phase line, is included to indicate how the initial travelling wave propagated from a fault and a later wave resulting from a reflection at the fault position may be identified. The time interval, between the arrivals of these two waves at the transducers which would energise the protective scheme, is proportional to the distance to the fault. Its position may therefore be determined with acceptable accuracy. Indication is given of the differences resulting from faults both on and external to a protected line, and discriminatory checks which could be incorporated are outlined. The application of the scheme to 3-phase lines is considered and a further discriminatory check is described. To demonstrate the potential of the proposed scheme, its responses to a number of fault conditions are provided.

DOI:10.1049/ip-c.1988.0007

出版商:IEE    

年代:1988

数据来源: IET

摘要:

A computer simulation method for predicting the dynamic responses of a marine power system containing both AC and DC subsystems is proposed. The method has two important features. First, it allows modelling of system components in modular form and representation of network relations by utilising Kirchhoff's current law, hence providing flexibility in model building and testing. The second feature is its ability to simulate the performance of DC machines and converters in a combined AC/DC system. The paper contains a description of the method and its application to a practical marine power system. Simulation results are practically verified by comparing with a manufacturer's supplied experimental data.

DOI:10.1049/ip-c.1988.0008

出版商:IEE    

年代:1988

数据来源: IET