Marcel Maier

A novel self oscillating power electronics for contactless energy transfer and frequency shift keying modulation

This paper deals with a combination of an inductive based contactless energy transfer system and a data transfer from the primary side to the secondary side of this system. Therefore, an extension of a self-oscillating power electronics offering the possibility to change the capacity of the resonant circuit during energy transmission is presented. An additional switchable capacitor in the compensation network leads to an immediate shift of the resonance frequency of the circuit. On the basis of this frequency shift a frequency shift keying modulation is implemented to encode binary data in the energy signal.

Modeling and parameter estimation of a three phase permanent magnet excited transverse flux machine

Transverse flux machines are electrical machines offering a high torque density by increasing the number of pole pairs by decoupling the electric from the magnetic design. The field of application includes low speed direct drives if challenges like the complex design and high torque ripple are solved. For the development of sophisticated control algorithms, accurate machine models are required. This paper presents the derivation of an idealized quasi rotor flux oriented dq-model for a three phase permanent magnet excited transverse flux machine. Results are verified on a 17 kW prototype machine with the record of parameter fields for the transverse flux machine.

Operation of an electrical excited synchronous machine by contactless energy transfer to the rotor

This paper deals with the design, the set-up and the operation of a rotating contactless energy transfer system. The system is used to replace the slip rings of an electrical excited synchronous machine and transfer energy contactless on the rotor of the machine. Considering the application and the involved boundary conditions, the optimal topology of the compensation network and the optimal operation range is chosen. Furthermore, the required parameters of the contactless energy transfer system are calculated. Based on these calculations the system, consisting of the power electronics, the compensation network, the magnetic path and the control system, is set up. Finally, the calculations are verified by measurements.

Dimensioning of a contactless energy transfer system for an electrical excited synchronous machine

This paper deals with the electrical design of a rotating contactless energy transfer system. The system replaces the slip rings of an electrical excited synchronous machine and transfers energy contactlessly onto the rotor of the synchronous machine. To operate this machine, the possibility to set the rotor current must be given. Therefore, a topology with an input voltage controlled output current source is designed. Furthermore, the required parameters of the contactless energy transfer system are calculated.

Contribution to the system design of contactless energy transfer systems

This contribution propose a design procedure applicable to many kinds of wireless or contactless energy transfer systems. The design procedure is limited to near field wireless energy transfer systems in resonant operation. Therefore it is well applicable to systems with a primary side power oscillator or systems with a control strategy that forces an equal system behavior compared to a primary side power oscillator. In resonant operation the input impedance and voltage transfer function of different natural frequencies describe the system behavior and will be calculated analytically in this contribution. Not only the knowledge of these transfer functions but also the knowledge of basic magnetic properties lead to a readily applicable design procedure.

Design and construction of a novel rotating contactless energy transfer system for an electrical excited synchronous machine

This paper deals with the design and construction of a rotating contactless energy transfer system. The system is used to replace the slip rings of an electrical excited synchronous machine and transfer energy contactless on the rotor of the machine. Considering the application and the involved boundary conditions, three approaches with non distinctive magnetic flux guidance of the electromagnetic design are presented. Calculation and dimensioning of the system is done by electromagnetic and thermal 2D and 3D finite element simulation. Finally, the results are verified by prototypes, constructed for each presented approach.

Analysis of torque behavior of permanent magnet synchronous motor in field-weakening operation

A variety of efficient control strategies for synchronous motors have been proposed in recent years. Many of them use the rotary or stationary two dimensional axes in order to make the control algorithm easier. However, trying to describe the motor behavior using just two axes is either impossible or at least not complete. Neglecting the real flux density distribution of motors, leads even to wrong or at least naive interpretation about the functionality of the machine. In this paper a new approach for understanding the torque development of a permanent magnet synchronous motor in the field weakening region is developed and verified with experimental results. The description of induced voltage and torque using flux density distribution in the air gap offers a deep insight into the functionality and behavior of a electric machine.