Maria Dems

Finite-Element and Analytical Calculations of No-Load Core Losses in Energy-Saving Induction Motors

This paper presents a no-load core loss analysis of a three-phase energy-saving small-size induction motor supplied by a sinusoidal voltage. In the field-circuit approach, the distribution and changes of magnetic flux density in the motor are computed using a time-stepping finite-element method. The discrete Fourier transform is used to analyze the magnetic flux density waveforms in each element of the motor model. The rotational aspect of the field is included by introducing a correction to the losses generated by the first harmonic of magnetic flux density. The core losses in each element are evaluated using a loss curve measured on a toroidal core at different frequencies. Finally, an approximate analytical formulation is derived for rapid field computation. The results are compared with measurements.

Performance Characteristics of a High-Speed Energy-Saving Induction Motor With an Amorphous Stator Core

This paper presents operational characteristics of a small induction motor with the stator core made of amorphous laminations, supplied from mains or a frequency inverter at 50, 100, and 200 Hz. Calculations were performed using field-circuit and equivalent circuit approaches, taking account of nonlinearity and additional losses, both in the core and in the windings. Data for mechanical losses, magnetization curves, and magnetic losses of the amorphous material were experimentally obtained; magnetic measurements were taken as a function of magnetic flux density in the frequency range up to 2000 Hz. Calculated results are compared with measurements.

The highly efficient three-phase small induction motors with stator cores made from amorphous iron

Applies the field/circuit two‐dimensional method and improved circuit method to engineering designs of the induction motor with stator cores made of amorphous iron. Exploiting of these methods makes possible computation of many different specific parameters and working curves in steady states for the “high efficiency” three‐phase small induction motor. Compares the results of this calculation with the results obtained for the classical induction motor with identical geometric structure.

Application of circuit and field‐circuit methods in designing process of small induction motors with stator cores made from amorphous iron

Purpose – To investigate the use of amorphous iron as the stator core material to increase the efficiency of electric machines in serialised production.Design/methodology/approach – In the design process of a new structure for the induction motor with a stator core made from amorphous iron it is necessary to apply the circuit method and the field‐circuit method. The use of the circuit method allows quick calculations of many versions of the designed motor, but the use of the field‐circuit method is necessary for verification of the maximal value of the flux density in the entire area of the cross‐sections of the motor core.Findings – A new construction for the small induction motor with the stator core made from amorphous iron was designed based on the classical structure of the four‐pole induction motor. In the designed motor a decrease of the electric energy costs was observed, which is much bigger than the material costs, and in effect lower total costs for the designed motor were obtained.Practical im...

Field and circuit calculation of the core losses in the energy-saving small-size induction motor

This paper presents no-load core loss analysis of 3-phase energy-saving small size induction motor supplied by sinusoidal voltage. In field-circuit part the distribution and changes of magnetic flux densities of the motor are computed by using time-stepping FEM. Discrete Fourier Transform is used to analyze the magnetic flux density waveforms in each element of the motor model. Rotational aspect of the field is included by introducing correction to first harmonic of alternating losses. Core losses in each element are evaluated using core loss curve measured on toroidal core at different frequencies. In addition, rapid circuit method is presented. The results are compared with the measurements.

Optimization of big power low voltage induction motor using Hybrid Optimization Algorithms

This paper presents results of optimization calculation of the big power low voltage induction motor. The results received by new three hybrid algorithms: GA-R, ESmu+lambda-R, PSO-R were compared. These hybrid algorithms were created by connecting three algorithms of global optimization, i.e. genetic algorithm GA, evolutionary strategy ES and particle swarm optimization PSO with a suitable modified Rosenbrocks method.

Numerical modeling of 3D intelligent comb drive accelerometer structure: Mechanical models

Purpose – This paper aims to focus on the numerical modelling of 3D structure of surface micromachined (MEMS) accelerometers.Design/methodology/approach – The paper focuses on the methods of mechanical design and analysis of electrostatic accelerometers (comb drive structure) and uses computer simulation procedure leading to final structure design, then to be defined as a basic structure for stress analysis.Findings – The strategy in computer modeling of accelerometer MEMS is satisfactory in order to simulate the electromechanical characteristics of different accelerometer structures (IMEMS).Originality/value – A novel complex strategy in computer modeling of accelerometer MEMS, based on solid modeling is proposed.

Comparison of no-load and load core losses for a wide range of nominal power induction motors

This paper presents a comparison of no-load and load losses for six different nominal power induction motors ranging from 3 kW to 280 kW. For loss calculations, field-circuit and analytical methods are used. The results show a significant increase in core losses concomitant with motor load increases. Additionally, analytical methods were employed to calculate the curves of core losses versus load power.

The 3D-Analysis of the Field Distribution of Fractional Power Induction Motor

In the paper, three-dimensional analyses of the electromagnetic field of a fractional power induction motor are presented. The results of these analyses for different discretizations were compared with 2D analyses to determine the proper discretization. The skewing effect of the rotor slots was taken into account using solid modelling of the motor.

Hybrid optimization algorithms in designing of induction motor at occurrence continuous and discontinuous decision variables

In the paper, a new hybrid optimization algorithm, using genetic and modified deterministic Rosenbrocks algorithm in designing big power induction motor is presented. The continuous and discontinuous decision variables and a big collection of limitations were used.