Abstract: Systems and methods are provided for detecting and compensating for loss of a phase of a three-phase power source, elements of the system including: a sensing unit, which measures current and voltage levels of each phase of the three-phase power source; a switching unit having three primary relays and three backup relays; and a microcontroller, configured to receive measurements from the sensing unit, to determine from the measurements a lost phase and a less-loaded phase of the two remaining phases, and responsively to activate the switching unit to disconnect the lost phase and to connect the less loaded phase to provide backup power in place of the lost phase.

Abstract: A power inverter for driving an electric machine is configured to apply a voltage to the electric machine based on a high-frequency injection current. Three phase currents are measured and input into a current controller. A voltage command output from the current controller is monitored using a discrete Fourier transform to determine a positive and negative sequence voltage of the voltage command. The sequence voltages are compared to expected positive and negative sequence voltages. A loss of connection diagnostic is output if a magnitude of the difference between the expected and actual sequence voltages is greater than a predetermined threshold.

Abstract: An electric machine assembly has an electric machine having a stator and a rotor. The rotor has a rotor temperature and is configured to rotate at a rotor speed (?). The stator has stator windings at a stator winding temperature (tS) and the electric machine defines a number of pole pairs (P). A controller is operatively connected to the electric machine and is configured to receive a torque command (T*). The controller has a processor and tangible, non-transitory memory on which is recorded instructions for executing a method for determining a total permanent magnetic flux (?T) as a function of the rotor temperature. Execution of the instructions by the processor causes the controller to determine a high-speed magnetic flux factor (?H) and a low-speed magnetic flux factor (?L).

Abstract: A synchronous-machine starting device includes an electric power conversion unit for converting supplied electric power into AC power for supply to the armature of the synchronous machine, a rotor position detection unit for detecting a position of the rotor of the synchronous machine based on an AC voltage in the armature of the synchronous machine detected by an AC voltage detection unit, an electric power conversion control unit for controlling the electric power conversion unit based on the position of the rotor detected by the rotor position detection unit, and an abnormality detection unit detecting a rotation abnormality of the synchronous machine based on the AC voltage detected by the AC voltage detection unit after supply of the field current to the rotor of the synchronous machine is started.

Abstract: The synchronous motors are controlled by a three-phase AC power controller. According to an embodiment of the invention, firing points for the AC power controller are determined. A pair of two or three phases is determined from the angular position of the rotor, for which the firing points can be present for the respective A.C power controller. Actual firing points are determined from the mains voltage phase position of the phases so that only positive torque is produced.

Abstract: A sensor detects position data for a rotor of the motor at a first time. A data processor receives the detected position data associated with a first time delay. A sensing circuit senses an analog current at the motor during a second time delay. An analog-to-digital converter converts the analog current to a digital current data during a third time delay. The fourth time delay is detected between actual current reading instant and position reading instant in a data processor. The digital phase current data is transformed into measured direct and quadrature axes control current data based on synchronization or temporal alignment of the position data with the actual measured analog phase current at the starting time by compensating the position data by a sum of the second time delay, the third time delay and the fourth time delay, where the first time delay is subtracted from the sum.

Abstract: Methods and devices are presented herein for estimating induction motor inductance parameters based on instantaneous reactive power. The induction motor inductance parameters, e.g., the stator inductance and the total leakage factor, can be estimated from motor nameplate data and instantaneous reactive power without involving speed sensors or electronic injection circuits.

Abstract: A manipulator has a working unit including an end effector and a posture axis for changing the orientation of the manipulator, a compound mechanism provided on the working unit, and a controller for actuating a gripper axis, a yaw axis, and a roll axis by respectively controlling movement positions of three motors. The controller includes a torque generation detector for detecting a timing at which torque is generated on the gripper axis. When the controller detects the timing at which a torque ?g? is generated on the gripper axis under operation of a given motor, the movement positions of the plural motors are shifted and set, corresponding to the directions at which interference torques are generated with respect to the yaw axis and the roll axis, and to predetermined positions of the same directions.

Abstract: A system and method are provided for correction of parameters used in determination of stator turn faults of an induction motor. An embodiment may include determining a residual impedance and/or a residual voltage of the motor, and correcting a normalized cross-coupled impedance based on the residual impedance and residual voltage. Additional embodiments may include measuring an operating temperature of the motor and determining a negative sequence impedance of the motor based on the temperature. Another embodiment may include measuring voltages and currents of the motor and determining phasors for the voltages and currents using compensation for variations from a nominal frequency of the motor.

Abstract: A system and method for identifying turn faults in a stator of a motor are provided. The method includes determining a normalized cross-coupled impedance from the symmetrical components of measured voltages and currents of the motor. Additionally, the normalized cross-coupled impedance may be normalized to a negative sequence impedance. The negative sequence impedance may be determined through a regression analysis using parameters of the motor, such as line-to-line voltage, horsepower, and number of poles. A system is provided that includes a device having a memory and processor configured to determine a normalized cross-coupled impedance, compare the normalized cross-coupled impedance to one or more thresholds, and trigger and alarm and/or trip the motor.

Abstract: A method and apparatus to provide estimates of electrical parameters for line-connected induction motors during either steady-state or dynamic motor operations. The electrical parameters are calculated from the motor nameplate data and voltage and current measurements. No speed sensors or electronic injection circuits are needed. The method can be divided into 4 major steps. First, complex space vectors are synthesized from voltage and current measurements. Second, the instantaneous rotor speed is detected by calculating the rotational speed of a single rotor slot harmonic component with respect to the rotational speed of the fundamental frequency component. Third, the positive sequence fundamental frequency components are extracted from complex space vectors. Finally, least-squares estimates of the electrical parameters are determined from a dynamic induction motor equivalent circuit model.

Abstract: An assist drive assembly for adjusting tension in a web generated when the web is moved over a roller in a contacting relationship therewith. A plurality of north and south pole elements are disposed about the roller. A controller is coupled to a magnetic pole sensor and an magnetic coil. The magnetic pole sensor and magnetic coil are disposed adjacent the north and south pole elements such that, when, during rotation of the roller in a direction of rotation, as a result of the web moving over the roller, the magnetic pole sensor observes a south pole element a first signal is generated that actuates the controller to energize the magnetic coil to generate a north pole field that attracts an immediately adjacent south pole element thereby imparting a torque to the roller in a direction of rotation of the roller.

Abstract: A switched reluctance drive is supplied from a power source and has a DC link, across which is a DC link capacitor. The phases of the machine are controlled by a controller which controls the switches connecting each phase winding to the DC link. The controller switches off the switches of each phase in a sequence which minimizes the peak voltage appearing on the DC link capacitor, thereby allowing a reduction in the voltage rating of the capacitor.

Abstract: An electronic device for starting and controlling a permanent-magnet synchronous motor, including logic control means, at least one switch arranged in series between an external power source and a permanent-magnet synchronous motor, and sensor means suitable to determine the polarity and position of the rotor of the motor. The logic control means are suitable to send a driving signal to the at least one switch as a function of a position signal that arrives from the sensor means and of a synchronization signal that arrives from the external power source. The logic control means include processing and filtering means that are suitable to determine a phase shift of the position signal as a function of the rotation rate of the rotor and of the specific application.

Abstract: A method of regulating a rotating electrical machine includes a preparatory step of determining a discrete voltage control law for the machine. The discrete control voltage to be applied at each sampling time is determined in the form of a first term corresponding to free evolution of the state of the machine in the absence of control, between the preceding sampling time and the current sampling time, and a second term dependent on the set point torque and a set point for the magnetic energy consumed by the machine. The method further includes, at each sampling time, a step of determining, with the aid of the discrete control law, the control voltage to be applied to the machine for the torque of the machine to reach the set point torque and the magnetic energy consumed by the machine to correspond to the set point magnetic energy.

Abstract: A method and apparatus are provided for positioning a head over a disc in a disc drive while maintaining servo loop stability. The apparatus includes an actuator-head assembly having a large-scale actuator and a micro-actuator that are both able to move the head over the disc. A saturation adjustment component detects when a micro-actuator controller is producing a micro-actuator control value that will saturate the micro-actuator. Using the micro-actuator control value, the saturation adjustment component generates a saturation error value. An adaptive anti-windup circuit transfers control to the large-scale actuator when the saturation error value is generated by the saturation adjustment component.

Abstract: In a numerical control apparatus 1, a synchronous control management unit 11 manages the dominant relation of plural axes to be controlled synchronously. In case of the position control system, in the axis control unit which controls the reference axis, a synchronous position calculation processing unit 74 calculates the command position to the reference axis. On the other hand, in the axis control unit which control the synchronous axis, the synchronous position calculation processing unit 74 calculates the moving stroke per unit time of the synchronous axis, thereby calculating the command position to the synchronous axis. One axis control unit which controls the reference axis and plural axis control units for controlling the synchronous axes issue the calculated command positions, and control the individual corresponding motors, and therefore control plural axes synchronously to one reference axis, and further control other axis synchronously by reference to the corresponding synchronous axis.

Abstract: An encoder operates in accordance with the transparent scanning principle. The encoder includes a rotating shaft, a partial disk connected nonrotatably concentrically with the shaft, an illuminating unit, and a scanning receiver located axially in front of the end of the shaft. The illuminating unit is connected nonrotatably centrally with the shaft and rotates with the shaft on the side of a partial disk that faces away from the scanning receiver. The scanning receiver includes a monolithic photoreceiver array which is formed with photosensitive sensor areas associated with an angular displacement of the partial disk.

Abstract: Motor current and voltage waveforms are measured and converted to digitized current and voltage waveforms. A weighted discrete fourier transform is applied to the digitized current and voltage waveforms to obtain negative sequence current and voltage phasors; and the negative sequence current and voltage phasors are used to determine the existence of a turn fault. The use of the negative sequence current and voltage phasors can be performed by employing one of several techniques. In a first embodiment, an apparent negative sequence impedance is estimated by dividing the negative sequence voltage phasor by the negative sequence current phasor for comparison with a threshold negative sequence impedance. In a second, related embodiment, a current differential is estimated by dividing the negative sequence voltage phasor by a characteristic negative sequence impedance and subtracting the result from the negative sequence current phasor for comparison with a threshold current differential.

Abstract: A self-synchronous electrical motor comprises a rotor, a stator formed by stator windings, at least one electronic switch series-connected with a stator winding to control a mean current in the winding, a sensor of the angular position of the rotor to control the working of the switch. This electrical motor also comprises a rotating mechanical commutator or change-over switch device to shunt or route a current given by a power supply source into windings selected as a function of the position of the rotor. The commutator device is interposed in a series circuit formed by the power supply source, the stator windings and the electronic switch. Application to the industry of automobiles using electrical traction.

Abstract: A self-synchronous electrical motor comprises one rotor, one stator formed by at least one set of four stator windings, at least one electronic switch connected to a stator winding to control the current in the stator winding and a sensor of the angular position of the rotor to control the working of the switch. It also has a rotating commutator device, driven by the rotor, to shunt a current coming from a power supply source into windings selected as a function of the position of the rotor. The commutator device is connected to a first end of each of the windings, the second end of two of the windings being connected to the power supply source and the second end of the other two windings being connected to the electronic switch. Application notably to electrical traction systems for automobiles.

Abstract: Quieting circuits for synchronous electric motors bypass their phase shifting coils with a minor percentage of the total motor watts input.

Abstract: A control device suitable for synchros comprising three stator windings. The device comprises four circuit branches with the inputs of the first and the second branches interconnected to receive a first voltage from the ends of the stator windings of the synchro transmitter and with the inputs of the third and the fourth branches interconnected to receive a second voltage from the ends of the stator windings of the synchro transmitter. Two adder elements supply control voltages to the stator windings of the synchro receiver. Two inputs of the first adder are connected to the outputs of the first and the third branches, respectively and the two inputs of the secnd adder are connected to the outputs of the second and the fourth branches. These branches have transfer functions in the form sin (.alpha.+.phi.1), sin (.alpha.+.phi.2), sin (.alpha.+.phi.3), sin (.alpha.+.phi.4), respectively, wherein .alpha. represents the information supplied by a digital element and .phi.1, .phi.2, .phi.3, .phi.

Abstract: A control system for a synchronous motor which is employed as a servomotor, wherein a pulse coder is employed for detection of the absolute position of one of the field poles of the motor, the absolute position being a component of the input signals for generating a poly-phase alternating current voltage which generates a rotating field maintaining a fixed amount of phase difference with respect to the absolute position of one of the field poles of the motor, thereby the synchronous motor is controlled to run maintaining a fixed amount of internal phase angle of e.g. .pi.

Abstract: A synchro transmitter having a rotor driven by a compass communicates the heading information from that compass to a plurality of loads via respective synchro receivers whose rotors are energized with direct current or carry permanent magnets and whose stators are supplied with a triad of d-c signals from three modular units each having one input connected to an output lead of a respective stator winding of the transmitter and another input connected in parallel with a winding on the transmitter rotor to a source of alternating current. A demodulator in each unit compares the current of the respective output lead with the reference current from the a-c source and feeds the result to an integrating operational amplifier which emits the corresponding d-c signal.

Abstract: A digital servo system is described in which the error signal is multiplied up to a given maximum before its application to a D/A converter that provides control voltage for the motor, as long as the motor has not reached its final position and its velocity is greater than a predetermined amount.