摘要:

The paper studies the application of conventional two-axis machine theory to the performance analysis of modern permanent-magnet synchronous motors. A representative motor with radially-oriented samarium-cobalt magnets in a rotor of interior type is considered as an example. Full performance data are measured for the full 360° range of load angles at various supply frequencies. Performance computations using constant motor parameters show significant discrepancies when compared with measurements, particularly at low supply frequency. Detailed determinations of parameter values reveal an important variation of quadrature-axis reactance as a function of quadrature-axis current, owing to magnetic saturation on this axis. When this variation is included within the analysis, together with temperature variation of stator resistance, excellent correlation is shown in all respects.

DOI:10.1049/ip-b.1985.0017

出版商:IEE    

年代:1985

数据来源: IET

摘要:

The paper describes a technique for calculating the leakage reactance and resistance per bar of a cage rotor with closed slots. The method is based on the use of a finite-element field calculation which enables the precise slot geometry to be modelled accurately, and includes the effects of tooth saturation and stator magnetomotive force. The method is illustrated by means of two examples, which are also used to provide a comparison with previous work on similar geometries. The method may be used to generate reactance against frequency and current characteristics, for design office use.

DOI:10.1049/ip-b.1985.0018

出版商:IEE    

年代:1985

数据来源: IET

摘要:

The theoretical and practical development of a new suboptimal PWM switching strategy, based on well established regular sampling techniques, is presented. It is shown that this suboptimal PWM strategy closely approximates and exhibits many of the desirable performance characteristics of optimised PWM strategies based on minimised THD. The new suboptimal PWM strategy is based on a well defined modulation process which has the potential for on-line real-time microprocessor generation. This possibility is confirmed using both CAD and experimental results obtained from a microprocessor-controlled PWM inverter-drive system.

DOI:10.1049/ip-b.1985.0019

出版商:IEE    

年代:1985

数据来源: IET

摘要:

This paper describes how the PE2D finite-elements field package is used to calculate the distributedLandCparameters of a multiconductor transmission-line model for the line-end coil of a large AC motor. Under steady-state AC conditions, the package produces field distributions from which self and mutual inductances and capacitances can be calculated. Distributed shunt and series losses are included in the model, and there is no need for any assumptions about surge velocities in evaluating the coil response. Separate parameters are calculated for the slot and overhang regions and the various sections of uniform multiconductor transmission lines are joined in series to represent the complete coil. The coil response is then computed using a Fourier transform technique. The input waveform is broken down into its spectral components and the steady-state transmission-line equations are solved at each component frequency. The response at each frequency is then used in the inverse Fourier transform to arrive at the solution in the time domain. Responses calculated from the model are compared to test responses on a laboratory model of the line-end coil and are found to be in good agreement. Several parameter variations are then investigated on the theoretical model.

DOI:10.1049/ip-b.1985.0020

出版商:IEE    

年代:1985

数据来源: IET

摘要:

A generalised technique for applying harmonic analysis to determine the steady-state performance of a cage induction motor with any stator winding connection and any excitation configuration, is described. Explicit formulas are given for all the impedances required. The method is verified by means of comparison between experimentally measured variations of input power, input current, and electromagnetic torque and those calculated using the technique.

DOI:10.1049/ip-b.1985.0021

出版商:IEE    

年代:1985

数据来源: IET

摘要:

The state-space model of a synchronous phase convertor is formulated by using the nonlinear dynamic equations of both the pilot (synchronous) and the load (induction) motors. A design procedure is presented for computing the parameters of a linear controller for the field exciter of the synchronous motor. The controller parameters are updated according to the selected steady-state operating conditions. The proposed controller is suitable for microcomputer implementation. The validity of the controller design method is further verified by using computer simulation. Numerical experiments indicate that the synchronous phase convertor system can be operated stably under different load and fault conditions.

DOI:10.1049/ip-b.1985.0022

出版商:IEE    

年代:1985

数据来源: IET