Piezomotor Uppsala Ab

Magström Ab

Magstöm Ab

Electric Line Uppland Ab

Piezomotor Uppsala Aktiebolag

Johan Abrahamsson

Stefan Johansson

Urban Lundin

Jonas Eriksson

Andreas Danell

J Jose Perez-Loya

Robert Sunnerberg

José Perez-loya

A magnetic flux control system () for controlling the magnetic flux in an electrical machine () with concentrated windings (A-C) has at least one magnetic balancing power supply (A-C), at least one balancing-current controller (A-C) and electrical connections () configured to permit the connection of the balancing-current controller(s) over a segment () of the concentrated windings. The balancing power supply provides galvanicisolation. The magnetic balancing system has further at least one sensor () configured to measure a parameter associated with a magnetic flux, a force, a position, vibrations, voltages, and/or currents. The balancing-current controller(s) (A-C) is(are) connected to the sensor(s) and is(are) powered by the balancing power supply(supplies). The balancing-current controller is configured to control an output current in dependence of a signal representing the measured parameter of the sensor(s). A winding excitation arrangement, an electrical machine and a method for balancing are also disclosed.

Concentrated-winding electrical machines with floating exciter

An electrical machine () comprises a rotor (), a stator (), a rotor power supply (), at least one sensor () and a rotor magnetization control arrangement (). The rotor has rotor windings () for controlling magnetization of rotor magnetic poles (). The sensor is arranged to measure a parameter associated with a relative force between the stator and the rotor. The rotor magnetization control arrangement is communicationally connected to the sensor for receiving a signal representing the measured parameter. The rotor magnetic poles are divided into at least two groups (). The rotor magnetization control arrangement is arranged for controlling the magnetization of the groups individually by providing a respective individually controllable rotor current. The rotor magnetization control arrangement is arranged to individually control the rotor currents in dependence of the signal representing the measured parameter. A method for controlling such an electrical machine is also disclosed.

Arrangement and method for force compensation in electrical machines

An electromechanical motor (), using at least two bimorph, monomorph or multimorph electromechanical actuating elements () interconnected by a common actuator backbone () is disclosed. The actuating elements () are controllable in both a longitudinal direction (L), i.e. in the main extension direction of the actuating element (), and a flexural direction, i.e. bending of the actuating element (), separately. The different actuating elements () can be controlled individually as well. The actuator () dimensions are preferably selected to resonance frequencies in vicinity of a certain frequency. The actuating elements () are provided with interaction portions () at which any contact between the actuator and a body () to be moved is made. In order to operate well both in fine-positioning and resonant motion, the interaction portions () are arranged to partially suppress the transfer of acoustic waves between the actuating elements () and the body () to be moved.

Wide frequency range electromechanical actuator

In manufacturing electromechanical drive elements, vibration properties are defined in a test environment. These properties are found to give a good operation when being arranged in a motor. Two flexural vibration modes are defined. One is an s-mode connected to an element being strapped at two supports at respective outer portions. The s-mode have three nodal points. The other vibration mode is an &#x3b5;-mode connected to an element being strapped at the supports and at a drive pad arranged at a middle portion. The &#x3b5;-mode has one nodal point at each side of the middle portion and the middle portion has a stroke amplitude that is smaller than stroke amplitudes at portions between the middle portion and the nodal points. An average of the resonance frequencies of the s-mode strapped at two and three points, respectively, differs from and the &#x3b5;-mode resonance frequency by less than 25%.

Electromechanical drive element

Growing community of inventors

Uppsala, Sweden

Johan Abrahamsson