Abstract:
Electric machine comprising a stator and a rotor, wherein the rotor is adapted to rotate relatively to the stator, and wherein the rotor comprises a rotor-switching- device which is arranged at the rotor.
Abstract:
Uninterruptible power supply system (200) uses a slip-ring induction machine (10) and a flywheel combination. The UPS system (200) comprises a back-up power source connected in parallel to a primary power source such as utility grid. During normal operation of the UPS system (200), the primary power source (130) supplies power to the load and the UPS compensates for voltage drop. Moreover, the primary power source keeps the slip-ring induction machine and the flywheel in an excited state above normal synchronous speed. When the primary power source fails, the flywheel, which is rotating at super-synchronous speed and storing kinetic energy, drives the rotor of the slip-ring induction machine to generate power. Accordingly, the slip-ring induction machine and flywheel combination provides instantaneous, short term power to the load until the back-up power source has powered up and been brought online.
Abstract:
A low inductance electrical alternator or motor (1) with low armature inductance is disclosed. Arrangements of complementary armature windings (40) are presented in which the fluxes induced by currents in the armature windings (40) effectively cancel leading to low magnetic energy storage within the machine (1). This leads to low net flux levels, low core losses, low inductance and reduced tendency toward magnetic saturation. Separately excited field arrangements are disclosed that allow rotor motion to effect brushless alternator or brushless motor operation. An exemplary geometry includes a stator (2) including two toroidal rings (4, 6) and a concentric field coil (8) together with a rotor structure (22, 24, 25) separated from the stator (2) by four air gaps (54, 56). An alternate embodiment allows for counter-rotation of two rotor elements (24) for use as a flywheel energy storage system in which the external gyroscopic effects cancel.
Abstract:
A presente invenção se refere a um sistema de porta-escovas (9) levantável apto a operar como fixo, compreendendo um motor (1) que aciona um redutor de velocidade (2) que aciona um eixo (3) que movimenta um disco com rasgo excêntrico (4), em que o disco com rasgo excêntrico (4) fecha a bucha de curto-circuito (6) e movimenta, de modo independente, os lados (9r, 9l) do porta-escovas (9). Além disso, a presente invenção se refere a uma máquina elétrica girante dotada de um sistema de acordo com a invenção.
Abstract:
La presente invención puede detectar faltas internas en sistemas, tanto si el cortocircuito se produce en el estátor como en el rotor de una máquina de inducción de rotor bobinado (2). Se utiliza como indicador de los defectos, la onda de corriente diferencial calculada como resultado de la comparación de las corrientes medidas en el estátor (9) y en el rotor (10), tras la aplicación de diferentes factores correctores (11) y la transformada de Park (12) y (13). La amplitud de dicha corriente diferencial, permite distinguir entre defectos internos a la máquina y externos a la misma.
Abstract:
The invention proceeds from a rotating electric machine, in particular a double-fed induction machine in the power range between 20 MVA and 500 MVA, which comprises a rotor (14) that rotates about a machine axis, is concentrically surrounded by a stator, and has a rotor plate body and a shaft, which rotor plate body bears a rotor winding that is arranged further outwards and is connected by means of connectors (18a, 18b) to slip rings that are arranged further inwards at the end of the shaft. A flexible and secure connection is achieved in that the connectors (18a, 18b) have mechanical connectors (18b) that run at right angles to the shaft to absorb forces arising owing to centrifugal acceleration, which mechanical connectors are connected on one side to a rotor winding head (14) of the rotor winding and are supported on the other side on an auxiliary rim (13, 22) on the rotor plate body (12).
Abstract:
The present invention generally relates to the use of electrical charge storage devices in the rotors of induction machines. Optimal induction machine rotor electrical field requirements increase with rotational velocity and inversely to frequency. Pseudocapacitance and other inverse frequency capacitance adjustment methods are employed to provide for that need and thereby improve induction machine rotor performance parameters. Optimization of electrical reactance is the foundation for improvements in power transfer, torque, efficiency, stability, thermodynamics, vibration, thermodynamics and bearing life in rotational induction machines. LC rotor methods and designs are outlined herein to achieve these objectives.
Abstract:
The short-circuiting and brush-raising device (13) described includes a rotatable actuating ring (14) with brush-actuating rods (28) which, via levers (31), cause the brushes (15) to be raised after the slip rings (3, 3a) have been short-circuited by longitudinal displacement of the short-circuiting ring (10). In order to make the device wear-resistant and robust, the actuating ring (14) is fitted with three rollers (18) with which the ring abuts, in the starting position, the spring-biased short-circuiting ring (10). The actuating ring (14) is guided to move exactly parallel by three longitudinal guide rods (25) disposed at right angles to the brush-actuating rods (28). All the joints (26, 27, 29, 30) of these rods (25, 28) are positioned in such a way that the freely moving joints (26, 30) pass through their points of maximum lateral excursion at times which are staggered with respect to each other in such a way that the brush-actuating rod (28) passes its point of maximum excursion first, followed by the longitudinal guide rod (25). The distance (20) between the contacts (8) on the short-circuiting ring (10) and the contacts (7) on the slip rings (3) is smaller in the starting position than the longitudinal displacement of the actuating ring (14) during short-circuiting so that the brushes (15) are not raised until after short-circuiting has taken place.
Abstract:
The invention relates to a rotor for a double-fed asynchronous machine with a laminated core, insulated electrically-conductive rods that extend in an axial direction through recesses in the laminated core and exit the laminated core in an axial direction, and which are joined together in pairs at the uninsulated axial ends thereof. The invention is characterised in that a material of limited electrical conductivity is arranged between the exit of the rods from the laminated core and the uninsulated ends thereof outside on the insulation.