We present a general mesh-free description of the magnetic field distribution in various electromagnetic machines, actuators, and devices. Our method is based on transfer relations and Fourier theory, which gives the magnetic field solution for a wide class of two-dimensional (2-D) boundary value problems. This technique can be applied to rotary, linear, and tubular permanent-magnet actuators, either with a slotless or slotted armature. In addition to permanent-magnet machines, this technique can be applied to any 2-D geometry with the restriction that the geometry should consist of rectangular regions. The method obtains the electromagnetic field distribution by solving the Laplace and Poisson equations for every region, together with a set of boundary conditions. Here, we compare the method with finite-element analyses for various examples and show its applicability to a wide class of geometries.
18 December 2009 in IEEE Transactions on Vehicular Technology
This paper offers motivations for an electromagnetic active suspension system that provides 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 with the proposed electromagnetic suspension system that uses a tubular permanent-magnet actuator (TPMA) with a passive spring. Based on 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.
4 June 2012 in IEEE Transactions on Industrial Electronics
Acoustic energy transfer (AET) is a relatively new form of contactless energy transmission that uses sound waves to wirelessly convey energy. In contrast to inductive coupling, it is suited for energy transmission over distances that are large in comparison to the transmitter and receiver dimensions. The frequencies that are used are low, minimizing losses and keeping the electronics simple. This review summarizes the work done on AET by various researchers.
19 December 2006 in IEEE Transactions on Magnetics
This paper presents three types of magnetostatic models of ironless planar actuators with moving magnets. The models predict the force and torque exerted on the translator of the actuator, which can be positioned in six degrees-of-freedom with respect to the stator coils. The force and torque are calculated with the Lorentz force law. The analytical and numerical models can be used for the design of large planar actuators, for the fast comparison of actuator topologies, and in the decoupling and commutation algorithm. The models have been verified with experiments
Analytical modeling is still a very effective manner to calculate the magnetic fields in permanent magnet devices. From these magnetic fields, device quantities, e.g., force, emf, or inductance, can be calculated. This paper presents a semianalytical technique, based on a 2-D Fourier series to represent the magnetic field, to describe the force components due to permanent magnets in 3-D cylindrical structures. The Maxwell stress tensor method is selected to calculate these force components in the cylindrical coordinate system. The method is analytically evaluated by inserting the analytical expressions describing the magnetic fields. The obtained force equations avoid the use of numerical integration of the magnetic fields resulting in a fast and accurate force calculation method. An example of a 3-D cylindrical structure is modeled and validated by means of a magnetostatic finite element analysis (FEA), and excellent agreement is found.
22 March 2011 in IEEE Transactions on Vehicular Technology
The efficiency and power consumption of a direct-drive electromagnetic active suspension system for automotive applications are investigated. A McPherson suspension system is considered, where the strut consists of a direct-drive brushless tubular permanent-magnet actuator in parallel with a passive spring and damper. This suspension system can both deliver active forces and regenerate power due to imposed movements. A linear quadratic regulator controller is developed for the improvement of comfort and handling (dynamic tire load). The power consumption is simulated as a function of the passive damping in the active suspension system. Finally, measurements are performed on a quarter-car test setup to validate the analysis and simulations.