摘要:

The paper briefly describes a major project, recently completed by Shell UK Oil, comprising a single-buoy mooring facility, with storage and pumping installations at Amlwch on the north coast of Anglesey with a 127 km-long connecting pipeline to feed crude oil to its Stanlow refinery on Merseyside. The power installations are briefly described, together with other environmental aspects which influenced the design. These included the installation of pumps and motors ranging in size from 500 kW to 3280 kW, so that they did not exceed a permitted noise level of 29 dBA under full-load conditions; designing a lighting scheme which would not draw undue attention at night to a large storage and pumping complex which by day is well camouflaged by the geography of the land; providing adequate earthing at installations built on rock and ensuring the correct functioning of control equipment on a network subject to frequent lightning storms. The ways in which these and other problems were overcome are described.

DOI:10.1049/ij-epa.1979.0018

出版商:IEE    

年代:1979

数据来源: IET

摘要:

The basic principles of optical methods for measuring voltage and current at high voltage are presented. These include the magneto-optic effect, the electro-optic effect and the electrogyration effect, plus various detection and noise-reduction techniques. Both free-path and enclosed-path devices which have been constructed on these principles are described. The viability of these devices for the electricity-supply industry is assessed.

DOI:10.1049/ij-epa.1979.0019

出版商:IEE    

年代:1979

数据来源: IET

摘要:

An outline is given of the phenomenon of virtual-current chopping in vacuum circuit breakers. A digital-computer program which simulates this process is described and applied in the case of a circuit breaker controlling an arc-furance transformer. The effects on the phenomenon of various circuit elements and of protective measures are demonstrated.

DOI:10.1049/ij-epa.1979.0020

出版商:IEE    

年代:1979

数据来源: IET

摘要:

A tensor method has been developed for the analysis of inverter-induction-motor drives using a digital computer. Good agreement has been obtained between computed and experimental results, over a wide range of transient and steady-state conditions.

DOI:10.1049/ij-epa.1979.0021

出版商:IEE    

年代:1979

数据来源: IET

摘要:

In an earlier paper,1a magnetic rotary-to-linear convertor was described. This device was an extension of the principle of the linear helical reluctance motor in which a rotating magnetic field was achieved by rotating mechanically a set of permanent magnets. The convertor described in this paper is based on a further extension of the helical motor in which the saliency of both stator and armature is obtained in a double-start screw thread having rectangular slots. This modification permits two-way action of the device in its ability to convert rotary to linear displacement or vice versa. It is shown that the new arrangement results in a force/displacement characteristic modified from that obtained previously, and with a significant increase in maximum force. Preliminary theoretical and experimental results from a prototype version of the new device are described.

DOI:10.1049/ij-epa.1979.0022

出版商:IEE    

年代:1979

数据来源: IET

摘要:

The performance of permanent-magnet d.c. disc-armature motors is discussed. Calculation of the field distribution allows this to be accurately predicted, and it also permits study of power losses associated with commutation. It is found that, when several pairs of brushes are used with a wave-wound armarure, and each is located opposite a different pole, then every brush will carry terminal current only intermittently. This effect severely degrades motor performance, and indicates that, whenever possible, only a single brush pair should be used with this winding. If additional current capacity is required, then extra brushes should be added opposite the same two poles.

DOI:10.1049/ij-epa.1979.0023

出版商:IEE    

年代:1979

数据来源: IET

摘要:

A comparison was made between the measured performance of a 3-phase, 400 Hz, 200 V induction motor, using its standard, cast aluminium, cage rotor and a saturistor rotor with idle bars of Alcomax III in the outer portions of the slots. At stall, on full voltage, the saturistor motor had 10% lower line current and 25% lower torque. On load, at rated speed, the saturistor motor operated with about 10% lower current and power than the standard motor, and its efficiency was about 10% greater. The saturistor motor had the operational disadvantages of lower peak torque, and about 5% lower power factor.

DOI:10.1049/ij-epa.1979.0024

出版商:IEE    

年代:1979

数据来源: IET