Search results

Estimating the punching process’s impact on the operating parameters of an electrical motor is a special problem especially in the case of fractional power motors. The purpose of this paper is to discuss a method of numerical modelling that is useful for this case.

The proposed multi-physical FEM approach is based on using professional software in the process of modelling and determining the operating parameters of a low power motor. The basic elements of the approach are built FEM models for which the parameters characterising the damaged portions of the magnetic material were determined. The material properties of this zone were determined both by measurement and by a new analytical approach described in this paper.

The paper formulates the impact of punching on the operating parameters of a low power motor. Moreover, it formulates the analytical algorithm for the estimation of properties of material in damaged zones.

Experimental verification will still be needed to check the model’s accuracy and applicability to various magnetic materials.

The paper provides an easy approach enabling the calculation of motor operating parameters and a simple and useful algorithm to estimate magnetic material properties in the damaged zone.

The analytical algorithm, as presented here, in conjunction with the measurement results is useful and applicable to estimating the magnetic material properties, which form the basis for accurate FEM calculation.

The calculation of additional power loss components in an induction motor supplied from a PWM inverter has been carried out with the assumption of constant load torque, the frequency of fundamental harmonic being adjusted in the range of 20 to 70Hz. The tests presented refer to a squirrel‐cage induction motor Sf 132 M4: PN = 7.5kW, UN = 380V (&Dgr),ƒN = 50Hz, 2p = 4.

The purpose of this paper is to discuss a new method of iron loss estimation under pulse width modulation (PWM) converter supply. The proposed method concerns the longitudinal magnetisation.

A novel method of iron loss estimation applies values of iron losses that come from a single higher harmonic coexisting with a DC‐bias field. This method considers non‐linearity of ferromagnetic. Results of estimation are validated using experimental results.

The paper formulates that the dependence of iron losses come from harmonics, on DC‐bias field. Moreover, it formulates possibilities of their utilization to iron loss estimation in case of deformed flux. On the other hand, it discusses the influence of DC‐bias field on static hysteresis and classical eddy current losses.

Experimental verification will still be needed as to the accuracy of the proposed model and applicability to various magnetic materials.

The paper provides an easy mathematical method of iron loss estimation, under PWM voltage supply.

The paper explains how to use an analytical method and results of iron losses come from single harmonics, obtained under coexistence with DC‐bias field, to iron loss estimation in case of longitudinal magnetisation where deformed magnetic flux occurs.

The calculation of the power loss in the core of the electrical machines is a special problem. In some areas of the electrical machine core the magnetic fields are neither unidirectional nor sinusoidal. This paper seeks to discuss the rotational power loss calculation methodology.

The proposed methodology is based on the calculation of the field quantities B_x and B_y. In this methodology the rotational power losses are calculated employing the empirical approach directly from these quantities. Moreover, the computational model is the most important element of the proposed methodology because it utilises the FEM to the calculations of the hodographs of the flux density vector in each mesh element.

The paper formulates the dependence of the rotational power losses from the B vector hodograph shape.

Experimental verification will still be needed as to the accuracy of the model and the applicability to the various magnetic materials.

The paper provides an easy mathematical method to the iron loss calculation, under the rotational magnetisation, the excess loss included.

The analytical model, as presented here, is applicable to the iron loss calculation under the rotational magnetisation in devices that have complicated geometrical shapes.

The commonly used power electronic systems in the drives of electrical machines as well as in the nonlinear receivers, being the transformer’s load, are the main origin of the deformation in the voltage supply. Due to these, the voltage curve is not sinusoidally variable. In these cases additional power losses take place in the motor and transformer cores which occur due to higher order harmonics of the flux. This paper presents a method to determine the power losses for the core where there are two fluxes in the steel sheet: one with relatively small amplitude and high frequency, and the other one with relatively large amplitude but low frequency.

Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic community. Observes that computer package implementation theory contributes to clarification. Discusses the areas covered by some of the papers ‐ such as artificial intelligence using fuzzy logic. Includes applications such as permanent magnets and looks at eddy current problems. States the finite element method is currently the most popular method used for field computation. Closes by pointing out the amalgam of topics.