Vladimir Kindl

Key construction aspects of resonant wireless low power transfer system

The paper discuses an important construction aspects of resonant wireless power transfer (WPT) system for small portable devices. It focuses mainly on key electrical parameters of the systems resonant linkage and its proper construction shape. All presented theoretical presumptions are consequently verified by detailed measurement.

Concept, design and coupled electro-thermal analysis of new hybrid drive vehicle for public transport

The paper deals with a study of new synchronous machine for use in hybrid vehicle. The synchronous machine is projected as permanent magnet synchronous motor with outer rotor embedded into rear rim of a bus. The main target of the study is design of an air self-cooled hub-wheel PMSM from electromagnetic point of view and using finite element analysis of electromagnetic field and thermal distribution. The analysis of losses in permanent magnets is also mentioned.

Design and FEM analyses of an electrically excited automotive synchronous motor

The paper deals with design of an electrically excited automotive synchronous motor and follow-up finite element method analyses. The machine is designed for water cooling of outer cover and enclosed inner air cooling circuit. The paper deals with complete design and analyses of the machine - calculation of losses, ventilation and cooling conditions.

Electromagnetic Coil Gun – Construction and Basic Simulation

A single-stage, sensorless, coil gun was designed to demonstrate the capability to accelerate a ferromagnetic projectile to high velocity. This paper summarizes all important steps during coil gun design, such as physical laws of the coil gun, preliminary calculations, the testing device and the final product. The electromagnetic FEA model of the capacitor-driven inductance coil gun was constructed to be able to optimize the coil’s dimensions. The driving circuit was implemented as a dynamic model for the simulation of current. The coil gun was not designed for really shooting applications, i.e. the projectile is accelerated to a relatively low speed.

A comprehensive approach to calculation of the air gap magnetic flux density in induction machines with eccentrically placed rotor

This article presents a possible way of calculation of air gap magnetic flux density in induction machines with eccentrically placed rotor. In the text a method of analytical calculation is presented and results are compared with finite element analysis outputs.

Determination of the force caused by broken rotor bar and static eccentricity in an induction machine

The paper deals with the force acting in the air-gap of an induction machine within unusual operating states, e.g. static eccentricity and broken rotor bar. Force is determined via FEM model of real induction motor. The study focuses on two special faulty operating states. First, the motor is under static eccentricity only. Second, static eccentricity and broken rotor bar are present simultaneously in the machine. The comparison of both cases is discussed in the paper.

Analysis of rotor's eccentricity influence on bearing load of induction machine

To ensure reliable drive with an induction machine requires deep insight in electro-mechanical dynamics during its operation. The flexible multibody modeling technique enables the simulation of dynamic loads on all drive components. This paper focuses on complex modeling of machines behavior in case of eccentrically placed rotor. The life time of machines bearing becomes very important issue of machines maintenance and reliability and is markedly influenced by any unbalanced forces acting on the rotor. The rotor eccentricity is one of the most significant aspects making machines bearing loaded by strong unbalanced magnetic pull. Only the complex flexible model of the rotor considering all unbalanced rotor forces can provide us the very detailed information about the bearing load. The methodology of determination of such loading is applied to the 11 kW squirrel-cage induction machine.

Basic operating characteristics of wireless power transfer system for small portable devices

Recent research in wireless power transfer using resonant inductive coupling has made a significant progress and reached very high efficiency (usually above 85 %) at large distances. This paper offers a methodology for the basic analysis and prediction of efficiency of the wireless power transfer system for small portable devices. It also gives an overview of operating characteristics of the system for different positions of transmitting and receiving elements. All presented theoretical presumptions are consequently verified by detailed measurement.

Key construction aspects of low frequency wireless power transfer system using parallel resonance

The papers deals with the wireless power transfer (WPT) system using parallel resonance at low frequency. Two different construction arrangements of two-coil resonant system - with and without impedance conversion - are presented. Impedance conversion is carried out via linkage autotransformer. Both systems are consequently measured and the theoretical presumptions are verified.

Benefits of upgrading insulating materials to operating temperature of induction motor

Development of new material contributes to increasing the load of electric machines, while maintaining the dimensions. This article examines the influence of the material properties of the components of induction motor to its warming. The work carried out thermal calculation asynchronous traction motor. The calculation results are verified by measurements on existing machines. These measurements led to define itself the material properties and the boundary conditions. The computational model are used to predict warming of machines, with the use of new insulation materials.