Abstract:
An aircraft starting and generating system includes a starter/ generator and an inverter/converter/controller (200) that is connected to the starter/generator and that generates AC power to drive the starter/generator in a start mode for starting a prime mover of the aircraft, and that converts AC power, obtained from the starter/ generator after the prime mover have been started, to DC power in a generate mode of the starter/generator. A four leg inverter is coupled with a DC power output (452) of the starter/generator and has an inverter/converter/controller (ICC) (580) with a four leg MOSFET-based bridge configuration that drives the starter/generator in a start mode for starting a prime mover of the aircraft, and converts DC power to AC power in a generate mode of the starter/generator. A four leg bridge gate driver (560) is configured to drive the four leg MOSFET- based bridge (580) during start and generate mode using bi-polar pulse width modulation (PWM).
Abstract:
The present disclosure relates to a synchronous electrical machine (1) that is adapted to alternately work as an electric generator or as an electric motor. The synchronous electrical machine (1) comprises a rotor (2), that is provided with a main rotor winding (25) configured to cooperate with a main stator winding (15), and an excitation system (3) for exciting the main rotor winding (25) to a production of a main rotor magnetic field. The excitation system (3) comprises a first exciter (31), which in the specific case is of conventional type in direct current, and a second exciter (32), which in the specific case is in alternating current. The first exciter (31) is operational when the synchronous electrical machine (1) works as electric generator and it is non-operational when the synchronous electrical machine (1) works as a motor. The second exciter (32) is operational when the synchronous electrical machine (1) works as a motor, by guaranteeing excitation power at each speed; the second exciter (32) is non-operational when the synchronous electrical machine (1) works as electric generator.
Abstract:
A separately excited synchronous machine (1b1k) with an excitation circuit on the side of the rotor includes an excitation winding (3) and a power supply for the excitation winding (3) as well as a switching element (8a, 8e) for connecting the power supply to the excitation winding (3). Further, the synchronous machine (1b1k) comprises a first stator-side primary winding (5a5f) and a first rotor-side secondary winding (6a6f). Moreover, the synchronous machine (1b1k) may comprise a) a tap of the first rotor-side secondary winding (6d) connected to a control element (9a, 9e) of the switching element (8a, 8e) or b) a second rotor-side secondary winding (14d), which is coupled to the first stator-side primary winding (5a5f) and connected to a control element (9a, 9e) of the switching element (8a, 8e).
Abstract:
A protection circuit (44) is disclosed for protecting an electrical generator in case of failure of a power control device in the excitation circuit. The electrical generator comprises a main machine (10), an exciter (18) for providing excitation to the main machine, and an automatic voltage regulator (26), the automatic voltage regulator comprising a power control device (32) for controlling excitation fed to the exciter and a control circuit (42) for controlling the power control device. The protection circuit (44) comprises means (46) for detecting an output of the control circuit, means (52) for detecting an output of the power control device, means (54) for comparing the output of the control circuit with the output of the power control device, and means (34) for reducing the excitation if the output of the power control device does not correspond to the output of the control circuit.
Abstract:
The invention relates to an excitation device for an electric machine having a superconducting load, in which a current control device is provided in the static part of the electric machine. A transmitter comprising a primary winding is provided in the static part of the electric machine and a secondary winding is provided in the rotating part of the electric machine. Said current control device comprises a controllable D.C voltage source. Said D.C voltage of the controllable D.C voltage source is transmitted on the secondary side by means of an inverter, the transmitter and a bridge rectifier, said D.C voltage defining the level of the magnetisation current. Using said magnetisation current level which is predefined by the controllable D.C voltage source, the magnetisation current is controlled by the primary side.
Abstract:
Es wird eine Erregereinrichtung für eine elektrische Maschine mit supraleitender Last angegeben, bei der eine Stromregeleinrichtung im ruhenden Teil der elektrischen Maschine vorgesehen ist. Weiterhin ist ein Übertrager mit einer Primärwicklung im ruhenden Teil der elektrischen Maschine und einer Sekundärwicklung im rotierenden Teil der elektrischen Maschine vorgesehen. Die Stromregeleinrichtung umfasst eine steuerbare Gleichspannungsquelle. Die Gleichspannung der steuerbaren Gleichspannungsquelle wird über einen Wechselrichter, den Übertrager und einen Brückengleichrichter auf die Sekundärseite weitergegeben, wo sie die Höhe des Magnetisierungsstroms bestimmt. Anhand des Gleichspannungsniveaus, das durch die steuerbare Gleichspannungsquelle vorgegeben wird, wird der Magnetisierungsstrom von der Primärseite aus geregelt.
Abstract:
Die Erfindung betrifft ein Verfahren und eine Vorrichtung zum Ermitteln eines Erregerstroms durch eine Erregerwicklung in einer elektrischen Maschine mit einem Stator (2) und einem Läufer (4), wobei die elektrische Maschine (1) einen Erregertransformator (7) umfasst, um durch Induzieren eines elektrischen Stroms läuferseitig den Erregerstrom (I DC ) hervorzurufen, mit dem eine Erregerwicklung (6) zur Erzeugung eines Erregermagnetfelds bestromt wird, mit folgenden Schritten: - primärseitiges Ansteuern des Erregertransformators (7), um einen Erregerstrom (I DC ), der von dem in dem Erregertransformator (7) sekundärseitig induzierten Strom abgeleitet ist, in dem Läufer (4) zu bewirken; - Messen eines oder mehrerer Phasenströme in einer oder mehreren primärseitigen Phasen des Erregertransformators (7); - Bestimmen eines Maximalwerts (l peak_measure ) abhängig von dem einen oder den mehreren gemessenen Phasenströmen (I 1 ); - Ermitteln des Erregerstroms (I DC ) durch die Erregerwicklung (6) abhängig von dem ermittelten Maximalwert (l peak_measure ).
Abstract:
Disclosed herein is an automotive electrical system including a FET based rectifier and method of controlling the FET based rectifier without using either an alternator shaft position sensor or current sensors on each phase of the alternator output to control the switching of the FETs. In accordance with the teachings herein, the voltage and current on the DC bus of the automotive electrical system are sensed and switching of the FETs is controlled by a microcontroller that determines the appropriate switching times based on these sensed parameters.
Abstract:
A system and device for providing AC signal. The system includes: an AC generator that outputs an AC output signal and includes an AC rotor that communicates with a shaft that is rotated at a rotation speed; a speed sensor for sensing the rotation speed; and a controller for controlling a magnetic field of the AC generator in response to the rotation speed; wherein the controller comprises a direct current (DC) generator that generates a current that is provided to the AC generator so as to control the magnetic field of the AC generator.