Abstract:
A method and system for controlling a current regulator motor control for parking a motor rotor in a predetermined position, wherein a first current command and a first angle command are supplied to a current regulator for a first parking time, to move the rotor to an intermediate position; and a second current command and a second angle command are supplied to the current regulator for a second parking time, to move the rotor to a predetermined position. The current regulator may have a normal voltage output range, and a circuit may be provided for limiting a voltage output of the current regulator to a reduced voltage output range for at least a portion of the parking time. Advantageously the motor is a permanent-magnet synchronous motor with sinusoidal back-EMF.
Abstract:
Verfahren zum Betrieben einer Elektromaschine, insbesondere einer fremderregten Synchronmaschine mit zusätzlichem Kurzschlusskäfig, wobei die Elektromaschine einen relativ zu einer Statorwicklung bewegbaren Rotor, insbesondere drehbar gelagerten, Rotor umfasst, insbesondere wobei der Rotor eine Erregerwicklung und/oder einen Kurzschlusskäfig aufweist, wobei von einer die Elektromaschine speisenden Einheit, insbesondere umfassend einen von einer elektronischen Schaltung angesteuerten Wechselrichter, ein Statorspannungsraumzeiger gestellt und ein Statorstromraumzeiger bestimmt wird, wobei unterhalb eines kritischen Drehzahl wertes des Rotors der bestimmte Statorstromraumzeiger auf einen Sollwert hin geregelt wird, insbesondere also der bestimmte Betrag des Statorstromraumzeigers auf einen Sollwert für Betrag hin geregelt wird und die Richtung und/oder Drehzahl des Statorstromraumzeigers auf einen entsprechenden Sollwert für Richtung und/oder Drehzahl.
Abstract:
A starting method and system for a motor where the motor may be started as an induction motor by applying a magnetizing current to build flux through the stator, with the field current set at the maximum permissible exciter stator current (i.e., the current that will cause rated no-load current in the main field at the transition speed). The motor stator currents will be maintained at a value that allows the motor to generate sufficient breakaway torque to overcome any stiction. At a specific transition speed or after a period of time, the drive will initiate a transition from induction motor control to synchronous motor control by removing the initial magnetizing current, and a field current is then applied to the motor through the DC exciter. Once this transition is completed, the drive may ramp up to the desired speed demand.
Abstract:
A power converter circuit for providing maximum utilization of a DC bus voltage to a two-phase Permanent Magnet Synchronous Motor (PMSM) is disclosed. The circuit includes first, second, and third nodes, each node being the junction between series connected high and low side switches connected across a DC bus; a PMSM having first and second windings and a star point at which the first and second windings are coupled to each other, the first winding having a terminal connected to the first node, the second winding having a terminal connected to the second node, and the star point being connected to the third node; and a controller for performing a three-point Pulse Width Modulation (PWM) coupled to a gate of each switch.
Abstract:
A small synchronous motor with high reliability so devised that transition from start operation to synchronous operation is ensured. A microcomputer (22) switching-controls the current application range to a range where the rectified current flowing through a rectifying bridge circuit (20) and a coil (A) alternately is inverted during one turn of a permanent magnet rotor (5) to suppress the input on the inverted side with respect to the non-inverted side and thereby to start a synchronous motor, turns off first to fourth transistors (16 to 19) when the rotational speed of the permanent magnet rotor (5) measured by an optical sensor (12) reaches near the synchronous speed regulated by the power source frequency and measured by a power source frequency measuring section (24), and turns on triacs (SW1, SW2), thereby making a switch to the synchronous operation circuit (21).
Abstract:
Un démarreur-générateur de turbomachine comprend une machine électrique principale (20) ayant un stator et un rotor (22) avec un inducteur rotorique bobiné et des barres d'amortissement formant une cage et une excitatrice (30) ayant un inducteur statorique et un rotor avec des enroulements rotoriques reliés à l'inducteur rotorique de la machine électrique principale via un redresseur tournant (36). Lors d'une première étape de la phase de démarrage, la machine électrique principale (20) est commandée en mode moteur asynchrone en injectant un courant alternatif dans ses enroulements statoriques, un couple de démarrage étant engendré au moyen des seules barres d'amortissement sans contribution notable de l'inducteur rotorique de la machine électrique principale à la génération du couple de démarrage. Lors d'une deuxième étape suivante de la phase de démarrage, la machine électrique principale (20) est commandée en mode moteur synchrone en injectant un courant alternatif dans ses enroulements statoriques tout en alimentant son inducteur rotorique en courant continu via l'excitatrice (30), le passage de la première à la deuxième étape de la phase de démarrage étant commandé lorsque la vitesse de rotation de l'arbre atteint une valeur prédéterminée.
Abstract:
A synchronous machine control device for a polyphase synchronous machine (20) includes a phase detection sensor (32) and a control circuit (30, 130). The phase detection sensor (32) is set to 90° advanced. The control circuit (30, 130) includes phase detection, commutation driver and time delay circuits (38A-38C, 50, 40A-40C, respectively). The phase detection circuit (38A-38C) is coupled to the phase detection sensor (32) and is configured to determine electrical phase of the machine (20). The commutation driver circuit (50) is coupled to the phase detection circuit (38A-38C) and has high-side and low-side outputs for selectively and alternately controlling commutation of the machine (20). The time delay circuit (40A-40C) is coupled to the phase detection sensor (32), the phase detection circuit (38A-38C) and the commutation driver circuit (50). The time delay circuit (40A-40C) provides a control output to the commutation driver circuit (50) based upon an adjustable setpoint compared to a speed of the machine (20) as measured by the phase detection circuit (38A-38C).
Abstract:
A controllable switching mechanism (100) integrally housed within a motor (100) to optimally couple the windings (112, 114, 116) of an AC motor for improved torque-speed characteristics. The switching mechanism (100) includes a plurality of double throw switches (121, 123, 125) each with a first and second closed position. The first closed position results in connecting the windings (112, 114, 116) of the AC motor (102) in one configuration for improved torque at lower rotor speeds. The second closed position results in connecting the windings (112, 114, 116) of the AC motor (102) in another configuration for improved torque at higher speeds. The winding configurations may be wye for lower speeds and delta for higher speeds. An accompanying controller (104), based on various inputs, optimally senses the best time for switching between configurations and sends appropriate control signals to the switching mechanism (100) housed with the AC motor (102).
Abstract:
An AC machine comprises: a motor energized by an AC source subject to irregularities of frequency and voltage; a generator driven by the motor (22) for supplying an AC output signal of substantially constant frequency and voltage, the generator (24) having a rotor with a layer of a re-magnetizable, relatively high coercive magnetic material on the rotor (22) and a stator (4) of a soft magnetic material having a pole piece and an excitation coil on the pole piece, the stator and the rotor (22) rotating relative to one another with a clearance enabling rotor poles to be formed on the re-magnetizable layer by current energizing the excitation coil; and, a control signal generator responsive to at least one of the AC output signal and a signal representative of the current energizing the excitation coil for generating pulses of programmed wave shapes which differ in at least one of width, phase and magnitude as necessary to modify the rotor poles during the irregularities of the AC source to maintain the substantially constant frequency and voltage of the AC output signal.