Abstract: Electric motors having variable poles are disclosed herein. In one aspect, an electric motor includes a stator including a plurality of magnetic conductive wires. The magnetic conductive wires are configured to form a plurality of poles. The electric motor further includes a rotor configured to rotate in response to a magnetic field generated by the poles of the stator and an electronic control module electrically coupled to the magnetic conductive wires. The electronic control module is configured to adjust a configuration of the poles of the stator.

Abstract: An electric motor includes: a rotor with a first number of permanent magnets, wherein each permanent magnet encompasses a first circular sector; a stator with a second number of pole feet, wherein a first group of coils is electrically connected via a first star point, wherein a second group of coils is electrically connected via a second star point to be conductive, wherein the second star point is electrically insulated from the first star point, wherein a coil of the first group of coils is arranged between two coils of the second group of coils; and a controller for applying drive signals to the first group of coils so as to provide the rotor with a torque with respect to the stator, and for applying a control signal that differs from the drive signals to at least one coil of the second group of coils.

Abstract: Systems and methods of controlling a length of an air gap in an electric machine using an air gap controller may include: determining an air gap length value for an electric machine at least in part using an air gap controller, comparing the determined air gap length value to an air gap target value using the air gap controller, and outputting a control command from the air gap controller to a controllable device associated with an air gap control system when the determined air gap length value differs from the air gap target value by a predefined threshold. A control command may be configured to impart a change to an operating parameter associated with the air gap control system to adjust a length of an air gap between an outer surface of a rotor core and an inner surface of a stator core of the electric machine.

Abstract: A drive system for a vehicle includes a plurality of electric traction motors, each mechanically coupled to at least one drive wheel to generate traction. At least one traction power converter is connected on an AC voltage side to at least one electric traction motor to supply the electric traction motor with electric power. A traction control unit for controlling at least one traction power converter is provided and is designed to control the at least one traction power converter while the vehicle is moving based on electrical output alternating quantities of the at least one traction power converter. A rotational movement of the at least one drive wheel of the vehicle during standstill of the vehicle is not detected by a separate detection unit based on the output alternating quantities.

Abstract: A system for determining an initial angular position of a rotor of a synchronous machine includes a motor driver module configured to provide a motor driver voltage signal to the synchronous machine, the motor driver voltage signal being sufficient to induce an electrical current in the synchronous machine; and a rotor position determination module configured to receive an indication of the current generated in the machine and to determine the initial position of the rotor based on the indication of the current generated in the machine.

Abstract: Systems and methods for generating mechanical and/or electrical energy are presented. A system generates mechanical energy by using direct current to cause a plurality of rotors to rotate within and/or around a plurality of stators and generate electrical energy by using the rotation of the rotors within and/or around the stators to generate an electromagnetic field. Sensors provide information about the rotors and the stators to a control system which sends commands to alter various properties and conditions for the rotors and stators.

Abstract: A motor driver having an automatic phase switching mechanism is provided. After a three-phase motor is started up, a back electromotive force detecting circuit starts detecting a back electromotive force signal of each of three phases of the three-phase motor. A driving waveform generating circuit extracts parts of a plurality of first wave segment patterns from a first wave segment pattern signal as a plurality of first wave segments of a first waveform signal according to the back electromotive force signal. A motor controlling circuit controls the motor driving circuit to drive the three-phase motor to rotate normally according to the first waveform signal.

Abstract: A robust position control method for a permanent magnet synchronous motor considering current limitation is provided. The method fully considers the influence of current limitation on a closed loop system in controller design, stability analysis and other theoretical analysis phase, can effectively overcome the influence of system disturbances including system parameters uncertainty and unknown load torque, and finally realize a control objective of accurate tracking of the motor position. More importantly, the technology is a continuous control method which can overcome the inherent chattering problem while having strong robustness of sliding mode control. Meanwhile, a controller designed by the present invention also has the advantages of simple structure, etc. The technical solution proposed by the present invention has wide practical application prospect due to the characteristics of excellent anti-disturbance capability, and simple and feasible structure.

Abstract: The present invention relates to a method of determining the magnetic flux ? of an electric machine, based on measurements (MES) of currents and voltages in the phases of the electric machine, on a dynamic model (MOD) of the magnetic flux and on an adaptive Kalman filter (KAL).

Abstract: The invention relates to a method for operating an electric machine which can be operated using PWM control (A1) and using block control (A3), wherein a transfer control (A2) is used for transfer between the PWM control (A1) and the block control (A3), in which method, within the scope of controlling a torque of the electric machine, a d value of a phase voltage is set as a manipulated variable and a q value of the phase voltage is changed continuously.

Abstract: As a configuration of carrying out a turning operation of a brushless synchronous power generation apparatus, there are provided a synchronous generator, an AC exciter, a rotary rectifier attached to an armature of the AC exciter, and short-circuiting means which three-phase short-circuits armature windings of the AC exciter, wherein the armature windings of the AC exciter are short-circuited, causing the AC exciter to operate as an induction motor, thus rotating the rotor shaft of the synchronous generator.

Abstract: A method for operating power semiconductors arranged in converters, includes measuring with a temperature sensor a temperature of at least one of the power semiconductors, performing a comparison of the temperature of the at least one power semiconductor with a reference temperature and providing a result of the comparison; activating a pre-heating phase for preheating the power semiconductors as a function of the result; during the pre-heating phase, defining a pre-heating current; and impressing the pre-heating current into an electrical load.

Abstract: A method of controlling a brushless motor that includes storing a lookup table of control values, periodically obtaining a speed-adjusted control value, and exciting a phase winding of the motor. The speed-adjusted control value is then used to define the phase and/or length of excitation. Obtaining the speed-adjusted control value includes measuring the speed of the motor, increasing or decreasing a speed-adjust variable in the event that the measured speed is greater or less than a threshold, selecting a control value from the lookup table using the measured speed, and adjusting the selected control value using the speed-adjust variable to obtain the speed-adjusted control value. Additionally, a control system that implements the method, and a motor assembly that incorporates the brushless motor and the control system.

Abstract: A motor controller and methods of controlling a variable speed motor using the motor controller after a power-loss event are described. The motor controller is configured to be coupled to a motor. The motor controller includes a computing device configured to determine power is being supplied to the motor controller a power-loss event. The computing device is also configured to operate the motor in accordance with a predetermined operating schedule such that the computing device operates the motor at a first speed for a first time period, and after completion of the first time period, the computing device operates the motor at a second speed for a second time period.

Abstract: The invention relates to a method for determining the angular offset between the rotor and the stator of an electrical machine for driving a motor vehicle, the rotor being supplied with a rotor-energizing current and voltage, the stator being supplied over three phases with stator-phase currents and voltages, wherein the method includes the following steps: verifying that the electrical machine is stopped; applying a rotor-energizing signal for an amount of time capable of causing the partial magnetization of the rotor; applying a rotor-de-energizing signal capable of causing an active and rapid demagnetization of the rotor, while measuring, during the magnetization, the stator-phase currents and maintaining zero voltage among the phases of the stator; determining the direct stator currents and quadrature stator currents corresponding to the stator-phase currents measured by applying Park and Clarke transforms and in accordance with a measurement of the electrical position of the rotor; determining the maximu

Abstract: An electrical controller for electric motors is provided. A control system for an electric motor comprises a supply for supplying excitation current to different windings of the motor at any given time. Furthermore, the amplitude of the excitation current is independently variable of the timing and duration of the application of the excitation current to the windings. This allows increased control of the motor and facilitates the operation of the motor at high mechanical and/or electrical speeds.

Abstract: A slide-out or retractable room for a mobile living quarters, such as a recreational vehicle, is provided with actuating assemblies mounted on opposite side walls of the slide-out room and the adjacent wall of the main living area. The actuating assemblies include a pair of parallel gear racks mounted on the side wall, which are engaged by pinions rotated by torque shafts mounted on the main living quarters. Each torque shaft is rotated by a separate motor. A roller engages a bearing surface on the lower portion of the gear racks. Accordingly, the slide-out room is extended and retracted by rotating the torque shafts to cause the gear racks and the attached slide-out room to extend and retract. The weight of the slide-out room is supported by the rollers, thereby supporting the slide-out room off of the floor of the main living quarters as it extends and retracts. A synchronizing control operates the motors.

Abstract: Design of a T-connected autotransformer based 20-pulse ac-dc converter is presented in this invention. The 20-pulse topology is obtained via two paralleled ten-pulse ac-dc converters each of them consisting of a five-phase (five-leg) diode bridge rectifier. For independent operation of paralleled diode-bridge rectifiers, a zero sequence blocking transformer (ZSBT) is designed and implemented. Connection of a tapped inter-phase transformer (IPT) at the output of ZSBT results in doubling the number of output voltage pulses to 40. Experimental results are obtained using the designed and constructed laboratory prototype of the proposed converter to validate the design procedure and the simulation results under varying loads. The VA rating of the magnetic in the proposed topology are calculated to confirm the savings in space, volume, weight, and cost of the proposed configuration.

Abstract: A line-start synchronous motor has a housing, a rotor shaft, and an output shaft. A soft-start coupling portion is operatively coupled to the output shaft and the rotor shaft. The soft-start coupling portion is configurable to enable the synchronous motor to obtain synchronous operation and to drive, at least near synchronous speed during normal steady state operation of the motor, a load having characteristics sufficient to prevent obtaining normal synchronous operation of the motor when the motor is operatively connected to the load in the absence of the soft-start coupling. The synchronous motor is sufficiently rated to obtain synchronous operation and to drive, at least near synchronous speed during normal steady state operation of the motor, a load having characteristics sufficient to prevent obtaining normal synchronous operation of the motor when the motor is operatively connected to the load in the absence of the soft-start coupling.

Abstract: A method for connecting a second motor to a variable speed drive in parallel with at least one existing motor under load and controlled by the variable speed drive is provided. The method disconnects the existing motor from the variable speed drive and a state estimator calculates transient state of the existing motor including at least the speed of the existing motor based on a previously established load model. The method then connects the second motor to the variable speed drive and the second motor is operated using a suitable directive until the actual state of the second motor attains the calculated transient state of the existing motor at a given time. Upon attaining the calculated transient state, the existing motor is reconnected to the variable speed drive such that no current spike is generated in the aforementioned process.

Abstract: A method comprises providing a line-start synchronous motor. The motor has a stator, a rotor core disposed within the stator, and a motor shaft. In accordance with a step of the method, a coupling for coupling a load to the motor is provided. The coupling has a motor shaft attachment portion configured to provide substantially concentric contact around the shaft at the end of the motor shaft. The coupling has a load attachment portion configured to operatively connect to a load. In accordance with a step of the method, a load is coupled to the motor with the coupling, and driven from start to at least near synchronous speed during steady state operation of the motor with a load coupled thereto. The motor shaft attachment portion may comprise a bushing assembly with matching and opposed tapered surfaces that cooperate to secure the motor shaft attachment portion around the motor shaft.

Abstract: A method for switching the voltage supply for an alternating current electric engine between a supply from an ASD and a supply from an electrical network, the method comprises a stage for determining an ideal speed of rotation for the electric engine and for synchronising the phase and the amplitude of the voltage delivered by the ASD with the voltage delivered by the electrical network.

Abstract: A method for controlling a motor at low operational speed is disclosed, wherein the motor comprises a magnetic rotor and a stator arranged to produce a magnetic field responsive to an applied electric current, wherein the method comprises ramping up an electric current applied to a stator from an initial current level to a synchronisation current level over a period of time. The initial current level is less than a minimum current required by the stator to produce a magnetic field having magnetic flux of a sufficient magnitude for synchronising a position of the magnetic rotor with respect to the magnetic field. The synchronisation current level is greater than or equal to the minimum current required to produce a magnetic field having magnetic flux of a sufficient magnitude to synchronise the position of the magnetic rotor with the magnetic field.

Abstract: A rail vehicle has a powered bogie, wherein the powered bogie has driven wheels. Each driven wheel of the powered bogie can be driven by an electric machine, with a power converter being assigned to the electric machine. As a result, a separate power converter is assigned to each driven wheel.

Abstract: A slide-out or retractable room for a mobile living quarters, such as a recreational vehicle, is provided with actuating assemblies mounted on opposite side walls of the slide-out room and the adjacent wall of the main living area. The actuating assemblies include a pair of parallel gear racks mounted on the side wall, which are engaged by pinions rotated by torque shafts mounted on the main living quarters. Each torque shaft is rotated by a separate motor. A roller engages a bearing surface on the lower portion of the gear racks. Accordingly, the slide-out room is extended and retracted by rotating the torque shafts to cause the gear racks and the attached slide-out room to extend and retract. The weight of the slide-out room is supported by the rollers, thereby supporting the slide-out room off of the floor of the main living quarters as it extends and retracts.

Abstract: A line-start synchronous motor has a housing, a rotor shaft, and an output shaft. A soft-start coupling portion is operatively coupled to the output shaft and the rotor shaft. The soft-start coupling portion is configurable to enable the synchronous motor to obtain synchronous operation and to drive, at least near synchronous speed during normal steady state operation of the motor, a load having characteristics sufficient to prevent obtaining normal synchronous operation of the motor when the motor is operatively connected to the load in the absence of the soft-start coupling. The synchronous motor is sufficiently rated to obtain synchronous operation and to drive, at least near synchronous speed during normal steady state operation of the motor, a load having characteristics sufficient to prevent obtaining normal synchronous operation of the motor when the motor is operatively connected to the load in the absence of the soft-start coupling.

Abstract: A mechanical soft-start type coupling is used as an interface between a line start, synchronous motor and a heavy load to enable the synchronous motor to bring the heavy load up to or near synchronous speed. The soft-start coupling effectively isolates the synchronous motor from the load for enough time to enable the synchronous motor to come up to full speed. The soft-start coupling then brings the load up to or near synchronous speed.

Abstract: The present invention provides a simple, robust, and universal position observer for use with sensorless synchronous machines. The observer may be implemented using an equivalent EMF model of a synchronous machine or, alternately, using a sliding mode controller based on the equivalent EMF model of the synchronous machine. The observer may be used on any type of synchronous machine, including salient or non-salient pole machines such as a permanent magnet, interior permanent magnet, wound rotor, or reluctance synchronous machine. The observer provides low sensitivity to parameter variations and disturbances or transient conditions in the machine. In addition, no knowledge of speed is required as an input to the observer and an estimated position may be calculated using a subset of the machine parameters.

Abstract: There is provided a single-phase AC synchronized motor that does not need smooth of rectifier waves but stably performs shift from a starting operation to a synchronized operation. In the motor, based on detected signals of a position sensor, rectified current is reciprocally flowed to each direction of a single-phase coil which starts the motor. The motor includes a start-up operation circuit with a sensor starting period that increases a rotational speed until reaching to a first predetermined rotational speed; and a control device that controls operation of the motor as that shift to synchronized operation is performed when a rotational speed of a permanent magnetic rotor is reached to a second predetermined rotational speed nearby a synchronized rotational speed but not exceeding the synchronized rotational speed, and when the rise and fall of detected signals of the position sensor and the zero-cross point of AC current are approximately correspondent to each other.

Abstract: A motor magnetic pole position correction method includes preventing a movement of a movable element of a direct drive motor by mechanical brake (step S9), generating a command that designates a position spaced or separated from the present position (step S10), detecting a torque command value of the direct drive motor (step S12), determining a magnetic pole position correction value based on a comparison between the detected torque command value and a predetermined threshold value (steps S14 and S16), storing the determined magnetic pole position correction value in a memory (step S18), and performing motor control using an electrical angle offset value obtained based on the magnetic pole position correction value stored in the memory.

Abstract: A synchronous motor including therein a three-phase inverter and position sensors, having a unit for calculating a digital input current value from the analog output of an input current detection circuit that detects the input current flowing into the DC input terminal of the three-phase inverter, and a digital feedback speed control unit for adjusting the amplitudes and frequency of the AC voltages outputted from the three-phase inverter in such a manner that the motor speed calculated by a motor speed calculation unit 41 on the basis of the outputs of the position sensors approaches a speed command value received by a communication reception unit from outside the synchronous motor. The synchronous motor further includes therein a communication transmission unit for transmitting the input current value and the motor speed to outside the synchronous motor.

Abstract: A rotating electrical machine to be connected to a polyphase power grid, having: a polyphase synchronous motor including a rotor with permanent magnets and a polyphase asynchronous motor axially coupled together, and a switching system arranged so as to electrically connect the asynchronous motor to the grid during the machine starting phase in order to bring the synchronous motor to a speed that enables the motor to operate while connected directly to the grid, and to electrically connect the synchronous motor to the grid during a subsequent phase.

Abstract: A speed-variable field winding type of synchronous rotary electric machine is provided, where a rotor with plural-phase windings faces a rotor with a field winding. A field current is limited to flow through the field winding in one direction thereof. A fundamental component of armature current, which corresponds to a synchronizing current for producing a rotating magnetic field rotating in sync with the rotation of the rotor, is supplied to the armature windings. The synchronizing current is adjusted in frequency to change a rotor rotation speed. A pulsed rotor exciting current is supplied to the armature windings. The exciting current causes the field winding to induce the field current only during a specified current-supply duration shorter than a one cycle of the synchronizing current. The number of current-supply times for the exciting current, per electrical angle 2? and per phase, has a positive correlation with the cycle of the synchronizing current.

Abstract: In a predetermined operating state of an electric motor of an axial air-gap type, control is carried out as follows. A phase difference between an electric current supplied to an armature winding of one of the stators and an electric current supplied to an armature winding of the other stator is set so as to suppress a variation in an output torque of the electric motor, and electric currents having the phase difference are supplied to the armature windings of the stators. A variation in output torque can be suppressed only in an operating state where the variation in output torque of the electric motor is to be suppressed, and the output torque and the energy efficiency of the electric motor can be enhanced sufficiently in the other operating states.

Abstract: The present invention provides an initial pole position estimating apparatus and method for an AC synchronous motor without using magnetic pole detector. The initial pole position estimating apparatus includes a thrust force or torque pattern generating portion for generating a thrust force or torque pattern, a pole position command generating portion for generating a pole position command, and a position detecting portion for detecting a position of the AC synchronous motor. The initial pole position estimating apparatus can estimate an initial pole position in a short time with high precision without depending on a fluctuation in a load. The initial pole position estimating apparatus further includes a pole position correcting portion (8) for correcting the pole position command and a thrust force or torque pattern correcting portion (9) for correcting the thrust force or torque pattern, and an initial pole position is estimated through a repetitive correction.

Abstract: This application describes a motor designed to operate as a reluctance machine at low speeds and as an induction machine at high speeds. The drive waveform is composed of one or more harmonics to be used to match the reluctance pattern of the stator-rotor, causing the rotor to rotate due to the reluctance effect, and one or more other harmonics to induce current in the rotor, causing the rotor to rotate due to the induction effect and the subsequent interaction of the stator and rotor magnetic fields. The two effects are generally not applied simultaneously.

Abstract: A robot control device that controls operation of a robot having an actuator includes a casing, an actuator driver, a drive-control board, a main control board, a main power supply board, a vent passage, a cooling fan, and a holding member. The actuator driver is accommodated in the casing and drives the actuator. The drive-control board is accommodated in the casing and controls operation of the actuator driver. The main control board is accommodated in the casing and controls operation of the drive-control board. The main power supply board is accommodated in the casing and supplies a power to the drive-control board and the main control board. The vent passage is defined by at least the drive-control board, the main control board, and the main power supply board and has an end open to the exterior of the casing. The cooling fan is arranged at an end of the vent passage and causes the air to flow through the vent passage. The holding member is provided in the vent passage and holds the actuator driver.

Abstract: An apparatus, system, and method are disclosed for fault tolerant cooling in a redundant power system. The apparatus receives power from a common power bus to power one or more power supply fans. The apparatus detects a non-functioning redundant power supply. The apparatus receives a fan control signal within a non-functioning redundant power supply. In addition, the apparatus uses the received fan control signal to synchronize a fan speed of a power supply fan within the non-functioning redundant power supply. The fan speed is synchronized with at least one fan control signal of a power supply fan within a functioning redundant power supply. Thus, the power supply fans of a non-functioning power supply continue to operate and are synchronized with power supply fans in functioning power supplies.

Abstract: The present invention relates to electrically magnetized synchronous machine comprising an electrically magnetized rotor, and electrically supplied sator windings, whereby it further comprises non-linear means, optionally controllable, such as rectifying means in a series with three sator phase windings, whereby a rotor field winding is arranged to be fed from said non-linear means.

Abstract: Provided is an air conditioning system comprised of a plurality of indoor units connected to each other in parallel, each having an expansion valve, and an outdoor unit including a plurality of compressors, in which at least one of the compressors provided to the outdoor unit is a capacity modulation compressor including an electromotive driving unit for driving a plurality of compression units capable of selectively compressing a working fluid, and the electromotive driving unit for the capacity modulation compressor has a stator with a coil wound around thereon and a rotor rotating inside the stator, the rotor being an LSPRM including a rotor core, flux barriers, permanent magnets and conductive bars.

Abstract: A motor controller capable of suppressing a large speed change generated at the time of changeover from a synchronous operation mode to a position feedback operation mode and implementing even acceleration characteristics regardless of the load torque by estimating a torque of a permanent magnet motor in the synchronous operation mode for driving the permanent magnet motor and setting an initial value of a current command value in a position sensor-less operation mode on the basis of information of the torque estimated value.

Abstract: For a multiphase alternating current (AC) wound field synchronous machine (WFSM) that has a stator with a selected number of poles, the WFSM having an associated exciter and multiphase AC permanent magnet machine (PMM) directly coupled to the WFSM, a method of sensing the position of a rotor in the WFSM comprises the steps of: configuring a stator for the PMM to have a number of poles that is a sub-multiple of the selected number of WFSM stator poles; configuring a rotor for the PMM to have high saliency; applying multiphase AC power of a selected frequency to the PMM stator; detecting at least one set of stator harmonic currents of the multiphase AC power resulting from the rotor saliency; converting the detected PMM harmonic stator currents from their multiphase coordinates to ?? coordinates; rotating the converted PMM stator currents into a reference frame for at least one selected harmonic to generate ?? coordinate harmonic current vectors; and estimating the position of the WFSM rotor based on the values

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 control system for a synchronous machine including a converter for converting DC voltage to AC voltage or AC voltage to DC voltage. The synchronous machine is driven by the converter. The control system further includes a magnetic pole position presuming device for performing a presuming operation to presume a magnetic pole position of the synchronous machine based on high-frequency components of a voltage applied to the synchronous machine and a current flowing into the synchronous machine, and a control device for controlling the converter based on the magnetic pole position presumed by the magnetic pole position presuming device. The control device controls the converter so as to contain significant high-frequency components in the voltage or the current used in the presuming operation when a mean voltage or a mean current output from the converter is spatially in a region close to a straight line containing starting and ending points of non-zero voltage vector output from the converter.

Abstract: In a control method for a twin synchronization in which two motors for driving two axes (moving elements 3) mechanically fastened to each other by a fastening part (a fastening jig 6) are synchronously operated, one of the two axes is operated at low speed by a position control and the other axis is allowed to freely run and follow the one axis and a return to the origin is performed. A positional deviation between the one axis and the other axis is measured at an arbitrary pitch. The positional deviation corresponding to a position where the one axis travels is stored in a data base as a function. One position command is directly distributed to the one axis as a main position command and the position command is distributed to the other axis as a position command corrected by using the function stored in the data base to perform an operation.

Abstract: A position-sensorless motor control device has a superposer that superposes, on the drive current with which the motor is driven, a superposed current having a different frequency than the drive current, a superposed component extractor that extracts, from the motor current fed to the motor, the ?-axis and ?-axis components of the superposed current, and a controller that controls the motor so that the direct-current component of the arithmetic product of the extracted ?-axis and ?-axis components of the superposed current converges to zero.

Abstract: A method for referencing a polyphase stepper motor by monitoring the current step response in at least one driven phase is presented. The coil current step response is compared to past step responses in order to determine when an increase in or maximum load is present. A combination of step to step variance, step response variance from mean current magnitude, and average current magnitude variance, as well as other measures can be combined to create an algorithm output. The output is compared to a pre-determined threshold and if the value is greater than the threshold, the motor is commanded to halt its position, which remains magnetically synchronous. This position is then used as a reference point to zero, or to home the motor.

Abstract: A vector-control system and method of a “sensorless” type for electric drives with a.c. motors is based upon generation of an oscillating magnetic field and upon measurement of the deviation, with respect to said oscillating field, of the flux generated thereby on account of anisotropy, whether natural or induced, of the magnetic structure of the machine.

Abstract: A control system includes controllers that are coupled mutually by a communications network, on which information, transmitted from a master controller to a slave controller, is used to make timing corrections on the slave controller in order to synchronize event timers on the slave controller with that of the master controller. Timing accuracy for the occurrence of the event commanded by each controller is synchronized in narrow range of time, preferably within a few milliseconds depending on the specific application and system.

Abstract: A method of controlling a power converter (20) of a motor drive system (10)controls the power converter (20) during a first operating mode by applying a current control scheme, which sets power converter commands to control torque current flowing from the power converter (20) to the motor (30) to achieve desired motor speed; and initiates a second operating mode when power supply to the power converter (20) is interrupted. The second operating mode includes controlling negative torque current between the power converter (20) and the motor (30) so that mechanical energy from the motor (30) charges an element (58) on a power supply side of the power converter (20). The first operating mode is resumed when the input power recovers. Torque current between the power converter (20) and the motor (30) is also controlled to limit a maximum transient DC bus voltage.