摘要:

The paper investigates the use of various mathematical models to represent saturation in a synchronous machine. For the first time special attention is given to quadrature axis saturation. Calculated transient-response results are compared in order to find an accurate and computationally economical method of allowing for saturation.

DOI:10.1049/ip-b.1980.0001

出版商:IEE    

年代:1980

数据来源: IET

摘要:

The paper describes the construction and principle of operation of a permanent-magnet-excited linear oscillatory motor. As part of an automated frequency adaptive drive, the motor is suitable for driving smaller resonance mechanisms.7It points out the prerequisites for the use of permanent magnets in the construction of the motor and shows the advantages of the Alnico types of material. The demagnetisation effect, which is controlled by shielding the magnets, is estimated. The magnets may be designed for the standard operating mode. Finally, the components of the magnetic field of the motor are analysed and used for the determination of the main parameters of the magnetic circuit of the motor. The basis for the determination and optimisation of the motor characteristics is given in the references to other papers by the authors.

DOI:10.1049/ip-b.1980.0002

出版商:IEE    

年代:1980

数据来源: IET

摘要:

Armature voltage waveforms of synchronous generators with bridge rectifier loads are distorted to a degree determined by the generator transient (or subtransient) inductances. A generator with zero transient saliency (z.t.s.) has a true sinusoidal waveform, apart from commutation disturbances occurring four times a cycle. The disturbance level is reduced by decreasing the generator transient inductance. Reduced waveform distortion becomes important when the generator is loaded with parallel d.c./a.c. loads and when the a.c. load is sensitive to waveform harmonics. A z.t.s. generator is recommended for such mixed-load applications. The operating equations for the z.t.s. generator have been simplified from previous work and performance predictions are readily made. To some extent, the behaviour of a z.t.s. generator with a rectifier load closely resembles simple constant-source-inductance rectifier operation. Some experimental results are given for a cylindrical-rotor z.t.s. generator and for a salient pole generator with two different damper winding arrangements.

DOI:10.1049/ip-b.1980.0003

出版商:IEE    

年代:1980

数据来源: IET

摘要:

The development is described of a new range of eddy-current dynamometers with capacity ranging from 70 kW at up to 12000 rev/mm to 500 kW at up to 4500 rev/min. These are dry-gap, homopolar, disc-type inductor machines in which the excitation coils and water-cooled lossplates are stationary and only a toothed steel member rotates. A design analysis procedure is presented which was used in the development, taking due account of eddy-current penetration and lossplate thickness, magnetic circuit saturation, temperature variations and end effects. Some fundamental points are made concerning conditions at maximum torque, and the performance of machines having two loss members in a single field system is analysed. Measured and computed performance of representative machines under operational conditions show good agreement.

DOI:10.1049/ip-b.1980.0004

出版商:IEE    

年代:1980

数据来源: IET

摘要:

Conditions for the validity of scaling of nonlinear magnetic fields are presented and applied to an idealised form of the fundamentally important saturable overlapping rectangular-pole configuration. This allows the dependence of force on other problem variables to be expressed in a surprisingly simple and generalised way and economises very significantly on tedious numerical work. Results confirm and more extensively quantify the curious force-augmenting effects of saturation and the tendency to linear rather than square-law dependence of force on m.m.f.

DOI:10.1049/ip-b.1980.0005

出版商:IEE    

年代:1980

数据来源: IET

摘要:

The paper describes the principles of d.c. arc extinction using cold-cathode arc chutes, a type originally designed for use with a.c. circuit breakers. Design details are given for the coil-less cold-cathode arc-chute circuit breaker, illustrating the fundamental requirements of the arc chute, contacts, mechanism and withdrawable circuit breaker in its metal enclosed cubicle for use up to 3 kV d.c. The application of the d.c. circuit breaker to the various types of traction circuits is described, and particular reference is given to the rectifier and feeder circuits. The various types of basic protective devices, inherent in high-speed d.c. circuit breakers, are the direct-acting electromagnetic overcurrent releases, which are described in detail. Coverage is given to the testing of d.c. circuit breakers to meet the onerous conditions of a traction application, and these are supported by details of test and service experience.

DOI:10.1049/ip-b.1980.0006

出版商:IEE    

年代:1980

数据来源: IET

摘要:

The paper describes the application of a microcomputer to improve voltage levels and motor starting performance in rural locations by controlling power consumption according to some predetermined stategy. Results obtained with a prototype installation are given and the direction being taken in present and future work is described.

DOI:10.1049/ip-b.1980.0007

出版商:IEE    

年代:1980

数据来源: IET