Martin Mach

Impact of punching on a small induction motor

This article deals with impact of punching processes on a small induction motor performance. Attempt to estimate shape of BH curve in areas damaged by punching is present here. To the estimation, simulations by the finite elements method together with laboratory measurement are used. The effect of punching is studied due to measurement of two samples of a small induction motors. First sample is a serial produced motor and second sample is the same motor except that sheets of its magnetic circuit were annealed after punching. The negative impact of punching can be eliminated by annealing. The results of both laboratory measurements and FEM simulations of the both motors are presented in this article.

Analysis of high speed squirrel cage induction motors

This paper deals with an analysis of three phase, two pole high speed induction machines. Our test motor was supplied from frequency converter and laboratory power supply with very low total harmonic distortion. Test bench was used to experimentally verify the results from simulation. The finite element model of induction motor was created in ANSYS Maxwell software. The model of frequency converter was created in ANSYS Simplorer and connect with ANSYS Maxwell model due to their co-simulation.

Practical testing of methods for improvement of efficiency of a small induction motor

Methods for improvement of induction machine efficiency are nowadays in center of interest many researchers. It is mostly due to requirements on minimal efficiency prescribed by legislation. This article describes results of some practical attempts how to improve a small induction motor efficiency. Six motors with different modifications to efficiency improvement was made and measured. The measurement results of each of them are compared with measurement results of a motor from serial production. In case of a small induction motor, the biggest losses are Joule losses in stator winding. Therefore, the most attention is pay to these losses. But core losses and Joule losses in cage can influence efficiency in considerable way too. The tested modifications are as follow: reduction of stator winding resistance, reduction of core losses by using material with lower specific losses, core lengthening, slots shape optimization, sheets annealing after punching and cooper squirrel cage.

Model of a small induction machine with effects of manufacturing

This article deals with modeling of a small induction machine (output power is 600 W) by the finite elements method. The aims are to create model that take into account effects of manufacturing processes and to analyze their impact on efficiency. The considered manufacturing processes are punching and core building (riveting). Impact of real (non-circular) outer shape of stator sheets is considered too. Several different models were used for this research and results of simulations were compared with results of laboratory measurement.

Permanent magnet DC motor re-design by FEMM

This article describes an adjustment of a permanent magnet direct-current motor. This adjustment has been done in order to reduce manufacturing costs due to allowing of machine-made winding. The size of motor has to be unchanged and motor characteristics should be unchanged as well. A finite elements method program has been used for design of the adjusted motor.

Brushless alternator in automotive applications

This paper deals with reliability problems of common types of generators in hard conditions. It shows possibilities of construction changes that should increase the machine reliability. This contribution is dedicated to the study of brushless alternator for automotive industry. There are described problems with usage of common types of alternators and main benefits and disadvantages of several types of brushless alternators.

Shunt-wound motor parameter estimation by a genetic algorithm

This article deals with estimation of shunt-wound motor parameters with help of a genetic algorithm. Only time waveform of total current drawn from a source (i.e. sum of an armature current and a field winding current) during transient after step-voltage application and corresponding steady-state value of angular velocity are used to all parameters estimation. Results of parameters estimation by a genetic algorithm are compared with results of laboratory measurement.

Identification of Induction Machine Electromagnetic Parameters for a Wide Range of Frequency and Flux Density

The paper deals with the experimental identification of electromagnetic parameters of an induction motor for a wide range of frequency and flux density. The relations for calculation of the iron loss resistance and magnetizing inductance of equivalent circuit alike \(\Gamma \)-network are derived for identification from the no-load measurement. The knowledge of these parameters is necessary for simulation or control of the induction machine over a wide range of speed and torque. Presented procedures were used for identification of induction motor with 600 W rated output power.

Application of acceleration method for evaluation of induction motor torque-speed characteristics

This paper deals with practical application of acceleration method for evaluation of induction machine torque-speed and current-speed characteristics. Influence of measuring time on the shape of evaluated torque-speed characteristics is presented based on the results of measurements. One of the aims of this paper is also calculation and measurement of mechanical losses from deceleration test. A method for determination of distribution of friction and windage mechanical losses from the measurement is described. The influence of a cooling fan on the total mechanical losses is also discussed.

Measurement and evaluation of DC motor starting torque

The paper deals with the measurement and evaluation of starting torque of a DC motor. The torque is estimated from an actual motor speed during starting with the Kalman filter. The actual speed is measured with an incremental rotary encoder. The main aim of this paper is a determination of correct setting of all parameters in Kalman recursive algorithm from the perspective of very good coincident of estimated torque and actual torque calculated based on the mechanical equation of this machine. All theoretical results are confirmed by experiments.