Abstract: An electric drive system in an automotive vehicle includes a controller for determining a condition of the electric drive system. The electric drive system includes only two current sensors and a common-mode current transformer. In response to the current sensors and the common-mode current transformer, the controller determines the condition of the electric drive system. The condition of the electric drive system may depend on a condition of an electrical connection between a drive system inverter and a motor in the electric drive system as well as a calculated amount of error in the electric drive system. In addition, the controller may control various operations of the electric drive system, which may or may not depend on the condition of the electric drive system.

Abstract: A drive system for a compressor of a chiller system includes a variable speed drive. The variable speed drive is arranged to receive an input AC voltage at a fixed AC input voltage and provide an output AC power at a variable voltage and variable frequency. The variable speed drive includes a converter connected to an AC power source providing the input AC voltage. The converter is arranged to convert the input AC voltage to a DC voltage. A DC link is connected to the converter. The DC link filters and stores the DC voltage from the converter. An inverter is connected to the DC link. A motor connectable to the compressor for powering the compressor. An active filter connected in parallel with the motor. The active filter is arranged to generate high frequency currents having a magnitude and opposite polarity, with respect to the output AC power of the variable speed drive. The high frequency currents generated by active filter substantially cancel out high frequency currents flowing into the motor.

Abstract: A drive system includes an electric machine and a current source inverter (CSI). This integration of an electric machine and an inverter uses the machine's field excitation coil for not only flux generation in the machine but also for the CSI inductor. This integration of the two technologies, namely the U machine motor and the CSI, opens a new chapter for the component function integration instead of the traditional integration by simply placing separate machine and inverter components in the same housing. Elimination of the CSI inductor adds to the CSI volumetric reduction of capacitors and the elimination of PMs for the motor further improve the drive system cost, weight, and volume.

Abstract: A variable-flux motor drive system including a permanent-magnet motor including a permanent magnet, an inverter to drive the permanent-magnet motor, and a magnetize device to pass a magnetizing current for controlling flux of the permanent magnet. The permanent magnet is a variable magnet whose flux density is variable depending on a magnetizing current from the inverter. The magnetize device passes a magnetizing current that is over a magnetization saturation zone of magnetic material of the variable magnet. This system improves a flux repeatability of the variable magnet and a torque accuracy.

Abstract: A method and an apparatus are described for determining a field current through a field winding in an electrical machine with a stator and a rotor. The electrical machine includes a field-circuit transformer to produce, by induction of an electrical current on the rotor side, field current with which a field winding is energized in order to generate an excitation magnetic field. The method includes driving the primary side of the field-circuit transformer to produce a field current in the rotor, which is derived from the current induced on the secondary side in the field-circuit transformer; measuring one or more phase currents in one or more primary-side phases of the field-circuit transformer; determining a maximum value depending on the one or more measured phase currents; determining the field current through the field winding depending on the determined maximum value.

Abstract: An apparatus for transmission of electrical power includes an AC voltage source configured to produce AC voltage. A stator includes a primary winding arrangement electrically fed from the AC voltage source, the primary winding arrangement having at least two primary windings. A rotor includes a secondary winding arrangement inductively coupled to the primary winding arrangement of the stator, the rotor being rotatable in a rotation direction about a rotation axis. The rotation axis does not pass through the at least two primary windings, and the at least two primary windings each extend over a predetermined sector with respect to the rotation direction and are disposed offset with respect to one another with in the rotation direction.

Abstract: The present invention provides a superconductive rotating electric machine drive control system that has higher efficiency and is smaller size and lighter in weight than conventional systems, and also provides a superconductive rotating electric machine drive control method to be implemented in the superconductive rotating electric machine drive control system. By the superconductive rotating electric machine drive control system and the superconductive rotating electric machine drive control method in accordance with the present invention, a control operation is performed so that the field current If2 applied to the superconductive field winding of the synchronous rotating electric machine satisfies an equation for the field current If2 in accordance with the variation of the electric power exchanged between the synchronous rotating electric machine and the power unit.

Abstract: An electric motor has a field pole formed by a field current passing through a field winding. A voltage booting converter converts output voltage of a battery and outputs the voltage between a power source line and a grounding line. Field winding is electrically connected onto an electric current channel between battery and power source line and formed so that voltage switched by a switching element is applied to both ends. A controller controls the field current so as to adjust density of magnetic flux between a rotor and a stator by performing switching control on switching element and a switching element connected in parallel to field winding and converts the output voltage of battery into voltage in accordance with a voltage command value.

Abstract: An electric motor driving device that drives an electric motor including a field winding, a rotor and a stator, wherein the rotor and the stator each foam a field pole by passing a field current through the field winding, includes: a power supply device; a converter including a reactor that at least partially serves as the field winding shared with the electric motor, and configured to receive a voltage from the power supply device to carry out voltage conversion between first and second power lines and to pass the field current through the field winding during voltage conversion operation; an inverter configured to convert a direct-current power received from the converter to an alternating-current power for driving the electric motor; and a controller controlling the converter so that a current flows through the field winding in the same direction both during power running and regeneration of the electric motor.

Abstract: Methods and apparatus are provided for aligning a control reference axis with a magnetic north of a permanent magnet motor. The method includes the steps of injecting a predetermined stator current on an estimated reference axis of the permanent magnet motor and introducing predetermined error on the estimated reference axis. The method further includes the steps of determining if a speed of the permanent magnet motor is greater than a predetermined threshold speed and setting the control reference axis to 180° added to the estimated reference axis if the speed of the permanent magnet motor is greater than the predetermined threshold speed or setting the control reference axis to the estimated reference axis if the speed of the permanent magnet motor is less than or equal to the predetermined threshold speed.

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 method and apparatus are provided for operation of a three-phase rotating electrical machine which has at least two stator winding sets and each stator winding set has three phase windings connected in star, and the star circuits of the stator winding sets have a phase shift of 30 degrees electrical with respect to one another, and an associated converting unit is respectively provided for each stator winding set, in which method the respective stator winding set is fed by the associated converter unit, and a respectively associated regulation device is provided for each converter unit, and each converter unit is driven by means of a drive signal from the associated regulation device independently of regulation devices of the respective other converter units.

Abstract: In a separately excited electrical synchronous machine, and a method for operating a synchronous machine, coil windings, in particular in the form of excitation coils, are disposed on the rotor, the electrical supply of the coil windings being achieved with the aid of an inductive rotation transmitter, whose secondary winding is connected to the rotor and whose primary winding, which is inductively coupled to the secondary winding, is stationary, especially connected to the stator of the synchronous machine.

Abstract: A device for determining the position of the rotor of a rotating electrical machine. The invention is characterized in that the device comprises a plurality of magnetic field sensors stationary relative to the stator and adapted to deliver multiphase electric signals representing a magnetic field detected by the sensors, and means for processing the multiphase electric signals by an operator capable of providing diphase signals depending on the position of the rotor. The invention is applicable to rotating electrical machines used in the automotive industry.

Abstract: The present invention relates to a device for controlling the speed of an electric motor, wherein the said motor is arranged to be connected to a voltage source, wherein the said motor comprises a stator winding and a rotor winding, wherein, in operation, a rotating stator field having a first rotational frequency is generated in the stator winding, wherein the said stator field, in operation, is arranged to induce a first rotor field having a second rotational frequency in the said rotor winding.

Abstract: A control circuit of a motor includes at least two sensor chips and at least two winding sets. The sensor chips are electrically connected to each other, and each of the winding sets has a first winding and a second winding. The first end of the first windings and the first end of the second windings are electrically connected to each other, and the second end of the first windings and the second end of the second windings are electrically connected to the sensor chips correspondingly. In addition, a motor having the control circuit is also disclosed.

Abstract: A motor driver system and its control methods are discussed. Even when a command magnetic flux decreases as a motor operates in a field weakening region, a current angle can be maintained always below a limit value, thereby obtaining the stability of the motor control.

Abstract: An improved single-switch control circuit for use in a multi-phase switched reluctance machine is provided. The control circuit includes at least first and second phase windings, a switch, a capacitor, and a diode. The capacitor may have a polarity opposite that of a power source in the control circuit. The first winding may be connected in series with the switch and connected in parallel with a circuit block comprising the second winding. The second winding may be connected in parallel with the capacitor and in series with the diode. In operation, the switch may be used to redirect current from the first winding to the second winding. The capacitor can become charged by the redirected current until it eventually stores enough energy to essentially discontinue current flow in the first winding. Then, the capacitor can discharge its stored energy as a current through the second winding. In this manner, substantially all of the energy from the first winding can be transferred to the second winding.

Abstract: The synchronous motor driving apparatus including position sensors provided in the synchronous motor, a current polarity detection circuit for detecting the polarities of the currents in the respective phase windings of the synchronous motor, an inverter driving the synchronous motor, a motor speed calculation unit calculating the rotational speed of the synchronous motor depending on the output signals from the position sensors, a speed control unit outputting a first voltage adjusting component (q-axis current command value Iq*) to cause the rotational speed of the synchronous motor to approach a speed command value and a phase control unit outputting a second voltage adjusting component (d-axis current command value Id*) to cause the phase differences between the phases of the position sensor signals and of the currents in the respective phase windings of the synchronous motor to become a predetermined value.

Abstract: A method and an apparatus are described for determining a field current through a field winding in an electrical machine with a stator and a rotor. The electrical machine includes a field-circuit transformer to produce, by induction of an electrical current on the rotor side, field current with which a field winding is energized in order to generate an excitation magnetic field. The method includes driving the primary side of the field-circuit transformer to produce a field current in the rotor, which is derived from the current induced on the secondary side in the field-circuit transformer; measuring one or more phase currents in one or more primary-side phases of the field-circuit transformer; determining a maximum value depending on the one or more measured phase currents; determining the field current through the field winding depending on the determined maximum value.

Abstract: A system for controlling a trapezoidally (square wave) driven DC motor includes a unipolar commutation circuit coupled between a DC power supply and a brushless DC motor. The motor has three phases formed by respective stator windings coupled at respective proximal ends to a common node and having respective opposite ends remote from the common node. The commutation circuit drives the motor according to a commutation cycle including three primary steps. During each primary step, one of the phases is driven while the other two phases are not driven. Voltages at the remote ends of the undriven phases are sensed, and timing signals are generated at points where the voltages coincide. The timing signals are used to determine motor position and speed, and to synchronize the commutation cycle with motor position and speed. In one embodiment, the commutation cycle includes transitional steps between the primary steps for smoother operation.

Abstract: Brushless Multiphase Self-Commutation Control (or BMSCC), also known as Real Time Emulation Control (or RTLC), is a contact-less means for powering any electric apparatus with “conditioned” or “re-fabricated” multiphase electrical excitation that is synchronized to the movement of the electric apparatus. BMSCC inherently phase-locks the frequency of excitation to any speed or position of the electric apparatus being controlled by a natural electromagnetic processing means and as a result, the BMSCC is an Electromagnetic Self-Commutator. BMSCC should never be confused with any derivative of Field Oriented Control, which is the other means of conditioning speed-synchronized electrical excitation by iteratively performing “speed-variant-to-speed-invariant” transformations and frequency synthesis by the unnatural processing means of an electronic computer. The control flexibility of BMSCC realizes additional synergistic or complementary electric apparatus inventions as shown in the illustration.

Abstract: An excitation device supplies a three-phase AC excitation current to a variable speed generator-motor, and controls the variable speed generator-motor based on a three-phase AC excitation current command value obtained by vector-synthesizing, based on a slip phase from an exciting phase detector, a torque direction excitation current command value from a power adjustment computing device, and a magnetic flux direction excitation current command value from a voltage adjustment computing device by an excitation current adjustment computing device.

Abstract: An electric motor (10) has a field pole formed by a field current passing through a field winding (50). A voltage booting converter (120) converts output voltage of a battery (B) and outputs the voltage between a power source line (107) and a grounding line (105). Field winding (50) is electrically connected onto an electric current channel between battery (B) and power source line (107) and formed so that voltage switched by a switching element (Q1) is applied to both ends. A controller (100) controls the field current so as to adjust density of magnetic flux between a rotor and a stator by performing switching control on switching element (Q1) and a switching element (Q3) connected in parallel to field winding (50) and converts the output voltage of battery (B) into voltage in accordance with a voltage command value.

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: A method for estimating the state of a system, as well as an extended Kalman filter (EKF), allows nonlinear mathematical models to be used for describing the system. Accurate precision is provided since the method is based on an EKF technique while using a filter that implements a first degree Stirling approximation formula. The method may be used for estimating position and speed of a brushless motor, and may be implemented in a relative device. Such a device may be introduced in a control loop of a brushless motor of a power steering system for a vehicle to provide a countering torque on the steering wheel based on speed of the vehicle and a steering angle of the vehicle.

Abstract: A method to permit the start time of a heat engine of a vehicle to be controlled. The heat engine is mechanically coupled to an induction type polyphase rotary electrical machine connected to an on-board electrical network. The method is of the type consisting of carrying out pre-fluxing by establishing an excitation current in the inductor for a predetermined pre-fluxing time (Tpref) before the phase currents are established. In accordance with the method, the predetermined pre-fluxing time (Tpref is a function of the voltage (Vbat+X) of the on-board electrical network. Typically, the predetermined pre-fluxing time (Tpref) is increased when the voltage (Vbat+X) of the on-board electrical network reduces within a nominal voltage range (V1, V2).

Abstract: A motor driving circuit includes an inverter circuit including switching devices connected in a bridge manner, electric-current detection resistances connected between the lower switching devices in the inverter circuit and the ground, so as to enable detection of the phase currents with the electric-current detection resistances, a PWM circuit which controls ON/OFF of the switching devices and repeatedly causes powering and regenerative time intervals, by alternately turning on and off the upper switching devices and the lower switching devices. During a time interval during which the lower switching devices, the electric-current detection resistances and the motor constitute a closed circuit and a regenerated electric current flows through the circuit, when the electric current values detected are equal to or greater than a predetermined electric current value, it is determined that a ground fault has occurred in the connection lines between the inverter circuit and the motor.

Abstract: A synchronous machine regulator is provided to simplify an adjustment work of current distribution to thyristors, the synchronous machine regulator having a circuit board 32 mounting a gate drive circuit 33 for supplying a gate pulse to each of thyristor bridges constituting a plurality of thyristor rectifiers 44 connected in parallel and supplying excitation current to a field winding 2 of a synchronous machine 1, and phase control means 34 for controlling a phase angle of each gate pulse to be supplied to each thyristor, wherein the current distribution to thyristors is controlled by the phase control means 34.

Abstract: A motor system includes an air core motor having a rotor with opposed permanent magnet poles defining therebetween a magnetic airgap and driving magnetic flux across the magnetic airgap. A stationary armature with air core windings is located within the magnetic airgap. The permanent magnet poles produce a magnetic flux density through the air core windings to produce a back emf in the windings comparable to the voltage of the line power when the rotation of the permanent magnet poles is synchronous with the line power. A electronic variable speed drive coupled by a switch to the air core windings ramps up the frequency of power to the air core windings for accelerating the rotor to near line synchronous speed. When the frequency of the back emf approaches the frequency of the line power, the switch decouples the electronic variable speed drive and couples the air core windings to the line power for synchronous operation.

Abstract: A system and method of controlling the power factor for providing either unity, leading or lagging results for the sensorless control of synchronous machines. The system and method provides an estimated angle of the phase current Park vector and uses a floating synchronous reference frame that is shifted from the estimated angle of the phase current Park vector by an angle ? to allow the active control and change of the power factor during operation for applications such as producing reluctance torque of a salient pole synchronous machine during Main Engine Start (MES), and field weakening for Environmental Control Systems (ECS) and MES applications.

Abstract: An electronic device is provided for controlling a motor having three phases driven by a motor driver. In one implementation, the electronic device includes a detection means and a control circuit. The detection means includes three high-gain differential amplifiers and three A/D converters. The detection means detects back EMF voltages induced by the rotation of the motor and applies corresponding signals to the control circuit. The control circuit computes and filters the position and/or the speed of the motor and then delivers the filtered values of the computed rotor position and/or speed to control the motor driver. The motor may thus be controlled even at near-zero rotational speed.

Abstract: A control device of a rotating electric machine to which an inverter is integrally assembled is downsized, and manufacturing costs are reduced. An inverter for controlling outputs from the rotating electric machine is integrated with a rotating electric machine, and in which a control device forming an inverter is constructed of a switching element and a heat sink, a drain electrode terminal of the switching element is directly joined to the heat sink, and a source electrode terminal and gate electrode terminal of the switching element are joined to a metal pattern formed at a connection member.

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: A method for the control of a wound rotor synchronous motor comprises measuring a plurality of electromagnetic entities indicative of the operation of the motor, generating voltage on a stator of the motor to obtain a stator current, further generating a further voltage on the rotor to obtain a rotor current, before the generating and the further generating, the entities being processed to calculate references for the stator current and for the rotor current, the references corresponding to the generation by the motor of the maximum torque obtainable per ampere of stator current supplied.

Abstract: A general-purpose comparator can be used as a comparison processing module to reduce the costs of a motor drive control apparatus. The apparatus has an electric machine; a magnetic pole position computation processing module; a pattern generation processing module; a switching angle computation processing module which computes a switching angle where switching is done in a next control period based on a pulse pattern; a comparison processing module which compares the magnetic pole position with the computed switching angle to generate a comparison signal; and an on-off output processing module which generates a PWM signal based on the comparison signal indicative of the comparison result. In this case, because the magnetic pole position is compared with the computed switching angle to generate the PWM signal based on the comparison signal, a general-purpose comparator can be used as the comparison processing module.

Abstract: A method is specified for operating a rotating electrical machine (1), which machine (1) has at least two sets of stator windings (A, B), in each case one associated converter unit (2) being provided for each set of stator windings (A, B) and each set of stator windings (A, B) comprising n phase windings, where n?3, in which method the respective set of stator windings (A, B) is fed by the associated converter unit (2).

Abstract: A synchronous motor controller is provided which is designed to diagnose whether a failure is occurring or not in energizing one of phase windings of a synchronous motor which is required to be energized first to start the synchronous motor. When such a failure is found, the controller reverses the synchronous motor slightly to bring one of the phase windings which is possible to energize properly to a starting position where the energization of the phase windings is to be initiated to start the synchronous motor in a required direction, thereby ensuring the stability in starting the synchronous motor even if any of the phase windings is failing to be energized.

Abstract: A synchronous motor driving apparatus having a power converter which applies AC variable voltages having variable frequency to a synchronous motor includes a pulsating current application unit for applying pulsating current to the synchronous motor and a magnetic pole position presumption unit. The magnetic pole position presumption unit detects two current values ?Idcp1 and ?Idcp2 on the positive side and two current values ?Idcn1 and ?Idcn2 on the negative side of the pulsating current and presumes the magnetic pole position of the synchronous motor on the basis of difference between change rates of ?Idcp1??Idcp2 and ?Idcp1??Idcp2.

Abstract: A desired q-axis current is determined based on a desired torque, and a desired d-axis current is determined based on the rotating speed of a synchronous motor when the terminal voltage of the synchronous motor coincides with a predetermined maximum permissible voltage to weaken a magnetic field created by the synchronous motor equivalently and to prevent the drop of the output torque of the synchronous motor. The desired d-axis current is determined based on the desired torque and the rotating speed. Therefore, the desired d-axis current can be reduced when a high torque is not necessary and undesired increase of the desired d-axis current can be prevented. Thus the synchronous motor operates efficiently, heat generation of the synchronous motor is prevented and power factor is improved.

Abstract: Method for the determination of start commutation in synchronous servo-drives by means of two coupled control loops, a current control circuit and an angle control circuit. The angle control circuit contains an incremental position sensor signal. A ramped desired value is predetermined by the current control. A constant angle desired value is predetermined by the angle control. The angle control is embodied in such a manner that is has a faster dynamic than the current control dynamic of the signal which is impinged upon by the current control by rotating the magnetic field. The method can be controlled in all positions by the input of an S-shaped disturbance variable signal in the angle control. The shaft of the electric drive can be mechanically blocked in the position during initialization of the start commutation and is regulated to the same position as in the beginning of the start commutation.

Abstract: For providing a controller apparatus for a synchronous motor and a controlling method thereof, enabling to be manufactured, easily and cheaply, and to obtain a lock mechanism, but without necessity of mechanisms, such as, an electromotive lock mechanism, wherein the controller apparatus for the synchronous motor, which has a stator 20 wound with AC windings 21U, 21V and 21W, and a rotor 30 installed within an inside of the stator, rotatably, therein, comprises an inverter 200 for supplying AC voltages having a predetermined voltage/frequency characteristic to the AC windings, which are wound around poles of the stator of the synchronous motor; and further, the inverter is so controlled that the AC voltages, being supplied from the inverter to the AC windings wound around the poles of the stator is changed into DC voltages to be supplied thereto, when rotation of said rotor is zero (0) and also when a lock function signal is ON in condition thereof, thereby obtaining a lock condition of holding a rotating posi

Abstract: A position sensing apparatus (300) derives rotor position of a synchronous machine (200) from signals output from the machine (200). In one embodiment, the position sensing apparatus (300) comprises: a bandpass filter (322) that filters phase voltage signals output from main stator windings (216) of the synchronous machine (200) during AC excitation, thereby extracting a rotor position-indicating component from the phase voltage signals; a converter (324) that converts the filtered phase voltages into balanced two-phase quadrature signals, the balanced two-phase quadrature signals indicating positioning of the rotor (212); and an excitation controller (204) for controlling AC excitation frequency as a function of rotor speed.

Abstract: Method for defining quadrature-axis magnetizing inductance of a synchronous machine, the synchronous machine being supplied by an inverter. The method comprises steps, wherein the synchronous machine is started without load or with reduced load; the rotor current of the synchronous machine is kept substantially at zero, the synchronous machine is accelerated to initial angular velocity of measurement, the load angle (ds) of the synchronous machine is guided substantially to 90 degrees, the stator voltage (us), the stator current (is) and the electrical angular velocity (?) of the synchronous machine is defined and the quadrature-axis magnetizing inductance of the synchronous machine (lmq) is defined on the basis of the stator voltage (us), the stator current (is) and the electrical angular velocity (?) of the machine.

Abstract: A control unit is provided that controls a motor that opens and closes a door of an electric train such that, if an abnormality is detected by a position sensor, continuation of its open/closing operation can be maintained. The control unit includes an arrangement for computing the actual rotation speed and the magnetic polar position of the motor; a position sensor abnormality-detecting identifier unit for detecting abnormalities in the output of the position sensor; and a first controlling arrangement that generates voltage-instructing values by applying the magnetic polar position so as to cause a speed detection value to correspond to the speed instruction value. The control unit further includes a second controlling arrangement, which in turn includes an F/V arithmetic unit 24 and integrator 25; and a switcher unit 27.

Abstract: In a synchronous motor control device that corrects a deviation in rotational position which is related to a rotational position detector for a synchronous motor on which vector-control is performed, the synchronous motor control device includes: a current instruction generator that disables a torque instruction to set d-axis and q-axis current instructions as zero when a phase correction instruction is inputted; a current controller that outputs d-axis and q-axis voltage instructions based on the d-axis and q-axis current instructions; a phase correction quantity detector for determining the amount of offset in which the d-axis voltage instruction becomes zero when the phase correction instruction is inputted and the d-axis voltage instruction is not zero; an adder for adding a rotor positional angle and the amount of offset; and a voltage converter for determining three-phase voltage instructions based on the additional value, the d-axis and q-axis voltage instructions.

Abstract: A controller monitoring an operating state and performing a suitable process when detecting a magnetic pole position by means of a sensor for detecting a position and velocity of a movable part (rotor or movable member) of a synchronous motor. If tandem control is not employed, PWM of the motor is made enable to commence the operation of detecting the magnetic pole position, thus detecting an operation abnormality based on feedback of the position. In the case of tandem control including two position detectors, either a master or slave motor is brought into a free state, and the other is caused to perform the operation of detecting the magnetic pole position, thus detecting an operation abnormality based on the feedback of the position.

Abstract: The invention provides a method and apparatus for maintaining the force, or torque, delivered by a variable reluctance motor as the speed of the motor increases. The method comprises the steps of sensing the speed of the motor and varying the number of turns of the motor's phase coil based on the sensed speed. The apparatus includes a motor speed sensor for sensing the speed of the motor and an inductance switch for switching the number of turns of the phase coil from a first value to a second value based on the sensed speed. One embodiment of the invention includes an inductance compensation circuit to compensate for the change in load inductance when the number of turns of the phase coil is switched.

Abstract: A method and a device for regulating a polyphase machine, in particular a synchronous machine, in which a direct-axis voltage and a quadrature-axis voltage are determined as manipulated variables of the regulating system, and also including a pulse-width-modulation inverter which generates the phase voltages of the individual phases and is triggered to operate either in PWM mode or in block mode as a function of the operating mode of the electric machine. To simplify the hardware component of the regulating device, PWM control signals and block control signals are generated via software and sent to a PWM/block signal device as a function of the operating mode, the device being capable of generating either PWM signals or block signals as a triggering signal for the pulse-width-modulation inverter as a function of the control signal supplied.

Abstract: A controller monitoring an operating state and performing a suitable process when detecting a magnetic pole position by means of a sensor for detecting a position and velocity of a movable part (rotor or movable member) of a synchronous motor. If tandem control is not employed, PWM of the motor is made enable to commence the operation of detecting the magnetic pole position, thus detecting an operation abnormality based on feedback of the position. In the case of tandem control including two position detectors, either a master or slave motor is brought into a free state, and the other is caused to perform the operation of detecting the magnetic pole position, thus detecting an operation abnormality based on the feedback of the position.