摘要:

The increasing availability of digital computers now makes the computer-aided design of powerelectronic systems an attractive and cost-effective development tool. The paper describes the detailed development of an extremely versatile PWM computer modelling package which can be used as a ‘stand-alone’ package for harmonic analysis, or alternatively as a ‘building-block’ for developing more complex systems. The capabilities of the package are demonstrated, using a number of examples of single-phase and 3-phase PWM inverters, which serve to highlight a number of important operational characteristics of PWM inverters. The validity and accuracy of the computer simulations are confirmed, using experimental results obtained from a microprocessor-controlled PWM inverter-drive system.

DOI:10.1049/ip-b.1982.0001

出版商:IEE    

年代:1982

数据来源: IET

摘要:

Reversible DC power-supply systems with thyristor inverters are described. Design principles applicable to and technical difficulties encountered by the reversible DC power-supply system are discussed. To give an example of application, the power-supply system of Kobe Metro is described in detail, together with principal designs, solutions adopted to overcome the technical difficulties and some operational results. Some more examples of application in Japan are referred to as further experiences of the system. The designs described are supported by service experience.

DOI:10.1049/ip-b.1982.0002

出版商:IEE    

年代:1982

数据来源: IET

摘要:

A new form of composite-rotor induction motor for variable-voltage fan drives is described. The rotor incorporates a section of unlaminated steel and a conventional cage winding, and is of very simple constructional form. It is designed to achieve reduced values of maximum input current and losses, by virtue of the variation of its effective rotor impedance as a function of applied voltage. The principle of its design and operation is explained and theoretical analyses of its performance are presented. Results are given for a prototype fan drive delivering 2.25 kW output at 1400rev/min, showing stable operation and acceptable maximum losses. Computed results correlate well with those measured.

DOI:10.1049/ip-b.1982.0003

出版商:IEE    

年代:1982

数据来源: IET

摘要:

In a moving linear induction motor, each magnetic-field pole travelling in the gap between stator and track, grows from zero at the stator's stem and decays astern. It follows that, if compared with an induction motor having the same pole size and number, and working at the same crest-gap density, tractive capability is less because of the transient nature of working fields. A linear stator with four fully excited pole pitches has the equivalent of one tractively effective field pole when slip is 10%. To assess the separate influence of stern drag, changes in field-pole energy are examined as stern fields emerge. The paper derives 11 expressions for operating power, some in terms of the stator, others of the track, and these are collectively consistent with power received from the stator at the gap. Results are applied to predict power-slip characteristics for three linear motors.

DOI:10.1049/ip-b.1982.0004

出版商:IEE    

年代:1982

数据来源: IET