Power transfer stabilization of the three-phase contactless energy transfer desktop by means of coil commutation

In this paper, a method for removing the "dead spots" and stabilizing the position-sensitive power transfer efficiency in a three-phase contactless energy transfer desktop is presented. "Dead spots" result from the non-uniform distribution of the primary coils’ magnetic field intensities and the out-ofphase currents they are excited with. When the secondary coil is inside a "dead spot" there is no induced voltage, secondary current, or power transfer. The primary controller can not distinguish between a "dead spot" and a fully charged "receiving device" drawing no current. In this work it is shown, that a temporary unbalancing of the currents inside an activated primary coil cluster will result in an induced secondary voltage. The resultant secondary current flow will produce changes in the primary coils’ voltage and phase which can be detected by the primary controller. Following this method, the primary controller can detect "dead spots" and remove them by disabling and energizing different primary coils

Brushless traction PM machines using commercial drive technology, part II: Comparative study of the motor configurations

In Part II a comparative analysis of the different brushless PM motor configurations, including exterior and interior rotor arrangements, salient and non-salient surface-mounted PM rotors, concentrated and distributed armature windings is presented. The comparative study is based on the developed design methodology given in the Part I of this paper. These motor configurations are investigated to be exploited for the particular automotive application - in-wheel hub traction motor of 80 kW, 1000 rpm base speed and constant power speed range of 4.5:1. It is shown that the interior surface-mounted non-salient PM motor with the concentrated winding is the most appropriate machine type for the considered application

Modeling of Ironless Permanent Magnet Planar Motor Structures

In this paper, finite element analysis is used to develop a fast model that includes end-effects and allows performance and controllability analysis without specifying a commutation scheme or control method is for ironless permanent magnet planar motor structures

Electric field control methods for foil coils in high-voltage linear actuators

This paper describes multiple electric field control methods for foil coils in high-voltage coreless linear actuators. The field control methods are evaluated using 2-D and 3-D boundary element methods. A comparison is presented between the field control methods and their ability to mitigate electric stress in coreless linear actuators

Active electromagnetic suspension system for improved vehicle dynamics

This paper offers motivations for an active suspension system which provides for both additional stability and maneuverability by performing active roll and pitch control during cornering and braking as well as eliminating road irregularities, hence increasing both vehicle and passenger safety and drive comfort. Various technologies are compared to the proposed electromagnetic suspension system which uses a tubular permanent magnet (PM) actuator together with a passive spring. Based upon on-road measurements and results from the literature, several specifications for the design of an electromagnetic suspension system are derived. The measured on-road movement of the passive suspension system is reproduced by electromagnetic actuation on a quarter car setup proving the dynamic capabilities of an electromagnetic suspension system

Tubular permanent magnet actuators: cogging forces characterization

Tubular permanent magnet actuators are evermore used in demanding industrial and automotive applications. However, these actuators can suffer from large cogging forces, which have a destabilizing effect on the servo control system and compromise position and speed control accuracy. This paper focuses on the identification of the cogging forces by means of finite element software, where an approach is introduced within the 2D finite element analysis to model the linear tubular permanent magnet actuator compared to conventional axisymmetrical models. This gives that the contribution of the stator teeth and finite length of the ferromagnetic armature core to the total cogging force can be separately analyzed. The cogging force predictions is characterized and the effectiveness of the new method is verified comparing the results of the tubular structure in both the axisymmetrical model and 2D finite element model, normally used for rotary machines

Analytical force, stiffness, and resonance frequency calculations of a magnetic vibration isolator for a micro balance

The accuracy of a micro balance is highly dependent on the level of floor vibrations. One strategy to reduce floor vibrations is a magnetic vibration isolator. Magnetic vibration isolators have the possibility to obtain a zero-stiffness region, which is beneficial for attenuating vibrations. In this paper a 3D analytical magnetic surface charge model is used to calculate the spring characteristics of a cone-shaped magnetic vibration isolator for different angles

Design tool for a 6-DOF planar motor with moving permanent magnets and standstill coils

This paper describes a fast design tool, which can be used for the rapid modelling, evaluation and optimisation of a moving magnet planar motor. It can be used as an alternative to slow three-dimensional finite element simulations and can calculate forces and torques on the moving platform, which can be positioned in 6-DoF with respect to the stationary part. The force calculations are validated using finite element simulations