Abstract: Systems and methods are provided for charging energy sources with a rectifier using a double-ended inverter system. An apparatus is provided for an electric drive system for a vehicle. The electric drive system comprises an electric motor configured to provide traction power to the vehicle. A first inverter is coupled to the electric motor and is configured to provide alternating current to the electric motor. A first energy source is coupled to the first inverter, wherein the first inverter is configured to provide power flow between the first energy source and the electric motor. A second inverter is coupled to the electric motor and is configured to provide alternating current to the electric motor. A rectifier is coupled to the second inverter and configured to produce a direct current output. The second inverter is configured to provide power from the rectifier to the electric motor.

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: In a system, a plurality of motors are provided. Each of the plurality of motors has a plurality of phase windings. Each of the plurality of motors is rotated when a unidirectional current is supplied to each of the plurality of phase windings thereof. A motor select unit includes a plurality of selectors connected to the plurality of motors, respectively. The motor select unit selects at least one of the plurality of motors via a corresponding at least one of the selectors. A phase current supplier is connected in series to each of the plurality of selectors. The phase current supplier supplies a direct current as the unidirectional current to each of the plurality of phase windings of the selected at least one of the plurality of motors via a corresponding at least one of the selectors.

Abstract: An apparatus and method are provided for adjusting torque and speed of a motor, while remaining within the voltage limit of a power supply. The invention provides a brushless direct current motor with independently driven and switchable stators. In an aspect, each stator and the rotor is structured to function as an independent motor separate from another stator and the rotor. A first power electronics directs energy to a first stator, and a second power electronics directs energy to a second stator. A rotor rotates relative to the stators. In an aspect, a commutation electronics determines electrical position of the rotor relative to the stators, and synchronizes current pulses directed to a sequentially selected phase of the stators, to generate a rotating magnetic field that communicates with the rotor. A controller sets the connection of the first power electronics in series or in parallel with the second power electronics.

Abstract: A motor drive apparatus has a plurality of motor drive parts and a control unit. The control unit performs first and second failure detection processing for the motor drive parts before starting to drive the motor. If the first motor drive part is determined to have failure by the first failure detection processing, a first power supply relay for the first motor drive part is turned off and the second failure detection processing for the first motor drive part is inhibited. If the second motor drive part is determined to have no failure by the first failure detection processing and then by the second failure detection processing, the motor is started to operate.

Abstract: A motor including a stator, a rotor, and a current supply unit. The stator includes a stator core, which has a plurality of teeth, and a plurality of coils, which are wound around the teeth. The rotor includes a plurality of magnets, which function as first magnetic poles, and salient poles, which function as second magnetic poles. Each of the salient poles is arranged between adjacent magnets spaced apart by a clearance from the magnets. When P represents the number of poles in the rotor and S represents the number of coils, a ratio P/S of the pole number P and the coil number S is represented by (4n?2)/3m (where n and m are integers that are greater than or equal to 2). The plurality of coils includes a plurality of coil groups including coils for three phases. The current supply unit executes a different current control for each coil groups.

Abstract: A control apparatus for a multi-phase rotary machine includes a control unit and a plurality of power supply systems including respective inverter units. When a short-circuiting failure occurs in one of the systems due to an ON-failure in any one of FETs in an inverter unit of the failure system, the control unit stops driving of the rotary machine by bringing all the FETs in the failure system into the OFF state. The control unit controls FETs of the non-failure system such that a brake torque generated in the failure system is cancelled or the influence of the brake torque exerted on the driving of the motor is reduced.

Abstract: If a PWM duty instruction D1 determined by a duty calculation circuit exceeds an upper limit value, a duty signal processing circuit in a motor drive apparatus divides a switching current supply period in each of the phases into a first current supply period and a second current supply period. In the first current supply period, the duty is set to the upper limit value. In the second current supply period, the duty is set to 100%, and the length of the second current supply period is set depending upon the duty instruction.

Abstract: An axial flux electric motor comprising a rotor and a first and second stator. The first and second stators have a first and second air gap located between the first and second stators and the rotor, respectively, and the second air gap is greater than the first gap. In one embodiment, the coils of the first stator and the coils of the second stator are in parallel. The motor further comprises switches which alternatingly energize the coils of the first stator and of the second stator based upon required torque and required speed of the motor. In a second embodiment, the coils of the first stator and the coils of the second stator are in series and the motor further comprises switches which selectively bypass the coils of the second stator in order to reduce the back EMF of the motor and increase the maximum speed of the motor at a given input voltage.

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 five-phase motor includes a stator and a movable member movable relative to the stator in a preset direction. The stator includes a stator core provided with five slots within 360 electrical degrees thereof. The five slots are arranged in the preset direction at preset first pitches. The stator includes at least one set of five-phase stator windings. The five-phase stator windings are arranged in the five slots relative to each other such that each of the five-phase stator windings is wound at a preset second pitch. The second pitch substantially corresponds to two of the first pitches.

Abstract: The invention relates to a method and an arrangement for braking a synchronous motor (4) used with a frequency converter (2). The braking current of the motor (4) is controlled by connecting only the negative changeover contacts (10) of the inverter (16) of the frequency converter (2) or alternatively by connecting only the positive changeover contacts (17) of the inverter (16) of the frequency converter. The arrangement comprises a control (3), which is arranged to control in a braking situation only the negative changeover contacts (10) of the frequency converter (2) or alternatively only the positive changeover contacts (17) of the frequency converter (2).

Abstract: Presence/absence of a failure in a feedback control system of a motor is monitored. When a failure is detected in the feedback control system, the motor is driven by switching to an open-loop control. During the open-loop control, the motor is rotated by sequentially switching the motor current supply phase without feeding back encoder count information. The position count is incremented or decremented every time the current supply phase is switched. When the position count has reached a target count, it is determined that the rotor has reached a target position, whereupon the open-loop control is finished.

Abstract: A load drive apparatus includes a noise filter, which includes a coil connected in series between a power source and a load, and a switching transistor connected in parallel across the coil, and a control circuit which is operated based on a drive signal. The control circuit turns on the switching transistor of the noise filter in case of subjecting the load to a full-on drive, thereby to short-circuit the coil and to form a power supply path including the switching transistor without the coil. The control circuit turns off the switching transistor of the noise filter in case of subjecting the load to a PWM drive, thereby to form a power supply path including the coil.

Abstract: Methods and apparatus are provided for discharging a direct current (DC) bus providing power to a motor control circuit in an electric motor system. The method includes the steps of detecting a predetermined discharge signal and generating operational control signals comprising phase currents for dissipating energy from the DC bus through a passive load in response to detecting the predetermined discharge signal, wherein the passive load includes motor windings of an electric motor of the electric motor system. The method also includes the step of providing the operational control signals to the motor control circuit for discharging the DC bus through the motor control circuit and the motor windings of the electric motor.

Abstract: Methods and apparatus are provided for improved discharge of a DC bus which provides power to an inverter. An electric motor system provided with the improved discharge method for discharge of the DC bus includes an electric motor, the inverter which provides electric control for the permanent magnet electric motor, the direct current (DC) bus which provides power to the inverter, and a processor. The processor generates operational control signals and provides such operational control signals to the inverter. In response to detecting a predetermined discharge signal, the processor generates operational control signals for generating a ripple current in motor windings of the electric motor to dissipate energy from the DC bus through a passive load, the passive load including the motor windings of the electric motor.

Abstract: An axial flux electric motor comprising a rotor and a first and second stator. The first and second stators have a first and second air gap located between the first and second stators and the rotor, respectively, and the second air gap is greater than the first gap. In one embodiment, the coils of the first stator and the coils of the second stator are in parallel. The motor further comprises switches which alternatingly energize the coils of the first stator and of the second stator based upon required torque and required speed of the motor. In a second embodiment, the coils of the first stator and the coils of the second stator are in series and the motor further comprises switches which selectively bypass the coils of the second stator in order to reduce the back EMF of the motor and increase the maximum speed of the motor at a given input voltage.

Abstract: In a motor control device according to the invention, upon velocity control of a motor, a superimposed signal generating unit 9 outputs a superimposed signal idh of a repetitive waveform, such as a triangular wave or a sine wave. A d-axis current command generating unit 10 adds the superimposed signal idh generated by the superimposed signal generating unit 9d to a d-axis current command idc*0 and outputs a d-axis current command idc*. An axial misalignment detecting unit 11 (11a, 11b, 11c, and 11d) receives the d-axis current command idc* and a q-axis current command iqc* and outputs an axial misalignment angle estimation value ??^. An axial misalignment correction unit 12 receives the axial misalignment angle estimation value ??^ and an actual detected position ?m and outputs a position after correction ?m?. Therefore, detection and correction can be performed in real time through calculation at a given timing during a normal operation.

Abstract: A starting system for a single-phase induction motor, comprising: a stator having a running coil (11) and a starting coil (12); a power source (F) which supplies current to said running coil (11) and said starting coil (12); a running switch (S1) and a starting switch (S2), respectively connecting the running coil (11) and the starting coil (12) to the power source (F) when in a closed condition; and a control unit (30) which is programmed to operate the running switch (S1) so as to cause a delay in the supply of the current supplied to the running coil (11) in relation to the supplied of the to the starting coil (12), during the motor start for a determined time interval which is previously defined and considered from the zero-crossing moment of the current supplied to the stator.

Abstract: The present invention restrains high frequency leakage current while reducing ripples of current flowing through a motor having one set and another set of independent phase windings. A plurality of inverter type drive means drives the respective phase windings and a PWM control means controls the respective inverter type drive means, by a switching sequence connecting one end of all phase windings including the other set to the negative side of the power supply when both ends of the phase winding included in one set are connected to the positive side of the power supply and connecting at least one end of all phase windings included in the other set to the positive side of the power supply when both ends of at least one phase winding included in one set are connected to the negative side of the power supply.

Abstract: As a boosting-type motor driving device using no reactor, a motor driving device capable of controlling boosting operation and motor driving at the same time is provided, and an automobile using the motor driving device is also provided. The motor driving device is used for driving a motor with a double-winding structure having a first set of three-phase windings and a second set of three-phase winding which are wound over a stator, and includes first and second inverters, which are connected respectively to the first set of three-phase windings and the second set of three-phase windings, thereby controlling the first and second inverters to control a driving force of the motor with the double-winding structure. The first and second inverters have positive and negative terminals which are connected respectively in common to a high-voltage battery.

Abstract: A device for redundant speed monitoring of a synchronous motor, which is sine-commutated without the use of sensors and which has a permanently magnetically excited rotor, has a first control unit, a drive output stage, a plurality of drive phases, and a second control unit for monitoring an electrical value of at least one of the drive phases and connected to the drive output stage for turning off the drive output stage when an improper speed state is detected.

Abstract: A power converter for a switched reluctance motor (SRM) or a permanent magnet brushless direct current (do) motor (PMBDCM) may include a front-end boost partial circuit for connecting with a first phase winding of the motor to form a front-end boost circuit and a back-end boost partial circuit for connecting with a second phase winding of the motor to form a back-end boost circuit. The front-end boost partial circuit generates a first step-up voltage in cooperation with the inductance provided by the first phase winding. The back-end boost partial circuit generates a second step-up voltage in cooperation with the inductance provided by the second phase winding.

Abstract: A brushless DC motor drive apparatus for driving a rotor includes a drive circuit rotating the rotor, a current shutdown and auto-restart circuit coupled to the drive circuit, and a DC voltage comparison circuit coupled to the current shutdown and auto-restart circuit. The current shutdown and auto-restart circuit detects blockage of the rotor via the DC voltage comparison circuit and shuts off the power to the drive circuit accordingly.

Abstract: In an apparatus using an inverter as a motor drive apparatus, continuous operation can be permitted during a motor open-phase without providing any additional switching element. Especially, in an electric brake apparatus, higher security can be assured. When a motor winding of one phase occurs an open-phase, currents are conducted to the remaining normal phases while taking the position of a rotor of motor into account to thereby generate torque of the motor. Since the motor torque can be generated continuously in the event of a phase malfunction, reliability of apparatus such as the electric brake apparatus can be improved.

Abstract: A direct current motor controlling method includes a mean for transforming a duty signal to computed value by a microprocessor unit. The microprocessor unit computes the computed value and then produces a target value by executing a dichotomy method, a rotation method and a transformed function, capable of reducing executing time and executing load of the microprocessor unit and saving memory space. The microprocessor unit sends a frequency signal to a driving circuit unit according to the target value. The driving circuit unit receives the frequency signal and then provides a driving voltage to a power switch. The power switch provides a voltage to a direct current motor or not according to the driving voltage for controlling output performance of the direct current motor.

Abstract: Presence/absence of a failure in a feedback control system of a motor is monitored. When a failure is detected in the feedback control system, the motor is driven by switching to an open-loop control. During the open-loop control, the motor is rotated by sequentially switching the motor current supply phase without feeding back encoder count information. The position count is incremented or decremented every time the current supply phase is switched. When the position count has reached a target count, it is determined that the rotor has reached a target position, whereupon the open-loop control is finished.

Abstract: A single-phase induction motor and a method for reducing noise in the same, which can eliminate unbalance between magnetomotive forces of main and auxiliary windings in a stator of the motor, thereby implementing a low noise, low vibration motor, and can also achieve balance between the magnetomotive forces of the stator windings in the entire running range of the motor, and can further achieve balance between the magnetomotive forces of the stator windings on the basis of temperature increase of the motor as it runs. The amplitude of a main-winding current flowing through the main winding in the stator is controlled to be equal to the amplitude of an auxiliary-winding current flowing through the auxiliary winding in the stator, and the phase difference between the main-winding and auxiliary-winding currents is controlled to be maintained at a predetermined value.

Abstract: A circuit for controlling a multi-phase machine having a stator with stator windings includes a controller, primary commutation switch pairs, a neutral terminal, and commutation control switches. Each switch pair includes first and second primary commutation switches connected at a node. Each commutation control switch is coupled to a winding so that a stator winding circuit is formed between the neural terminal and a respective one of the nodes. Each commutation control switch includes a first diode connected in parallel with a series switch circuit. Each series switch circuit includes a second diode and a series connected switch element. The controller is coupled to the switch elements and the primary commutation switch pairs to control an on time and an off time of the primary commutation switches relative to a point where a supply voltage is equal to the back emf.

Abstract: It is an object of the invention to provide a method which can detect a magnetic pole position easily and surely by using high-frequency currents such as harmonics of an inverter output and carrier frequency components. The invention provides a method of detecting a magnetic pole position of a motor and an apparatus for detecting a magnetic pole position in which, although high-frequency currents of carrier frequency components or the like are used, a special current detecting circuit is not required, and synchronization between the current detection timing and the position calculation can be easily attained, and also to provide an apparatus for controlling a motor using the same.

Abstract: In a power converter, an overvoltage suppression function of low cost and high reliability is provided. The power converter has a power conversion circuit, when driving a motor, for converting power from a battery and supplying it to the motor and when the motor generates power, converting the generated power of the motor and supplying it to the battery for storage of electricity and a drive circuit for driving the power conversion circuit. The power conversion circuit includes a plurality of paired switching elements, in which one of each paired switching elements is arranged on an upper arm, and the other is arranged on a lower arm, and each pair corresponds to each phase of the motor. The drive circuit, when the voltage applied to the power conversion circuit is increased, turns on all the switching elements on one arm, turns off all the switching elements on the other arm, thereby short-circuits the output terminals of the motor.

Abstract: A system and method for reducing the cost of producing a brushless DC motor (58) is presented. The brushless DC motor (58) provides higher power density and efficiency with an increased tool run time. The brushless DC motor (58) includes a rotor assembly (72) that has an unmagnetized permanent magnet (74) affixed to a shaft. The permanent magnet (74) remains unmagnetized until the motor is partially assembled. A plurality of coils (94) for producing a magnetic field are wound about the rotor assembly (72). The coils (94) include end turns that enclose the rotor assembly (72) such that the rotor assembly (72) is not removable. Since the windings (94) are wound with the rotor assembly (72) already enclosed, the windings (94) do not require large end coils to allow subsequent insertion of the rotor (72). Minimizing the end coils reduces the length of wire required per turn, thereby reducing the resistance of the winding (94).

Abstract: A control system is provided for a multiphase motor having a plurality of stator phase components, each stator phase component comprising a phase winding formed on a core element, and a rotor. A plurality of motor control schemes are stored in memory or calculated dynamically during motor operation. Subject to user or system selection, one of the motor control schemes is selected by a controller for implementation. The controller generates control signals that are applied to energization circuitry for supplying current to the phase windings with a particular current waveform profile in accordance with the selected motor control scheme. The controller has an input terminal for receiving a user initiated torque command signal representing a desired motor torque. Each motor control scheme provides motor driving current that corresponds to torque command signals received at the controller input terminal.

Abstract: A single coil, direct current permanent magnet brushless motor including a stator including six alternately-wound coils connected into a single coil having first and second ends, the oppositely-wound coils forming stator poles, and six magnets of alternating polarity coupled to a rotor and rotatably journaled in the stator. A sensor, such as a dual output Hall sensor, is used for sensing rotation of the rotor. A drive circuit, such as an H-bridge circuit, is coupled to the first and second ends of the single coil to drive the motor. The H-bridge circuit includes two high-side switches for alternately receiving signals from the Hall sensor, and two low-side switches alternately receiving signals from the Hall sensor. A high-side switching signal can be controlled by an inverted low-side switching signal. A voltage boost circuit is also provided, having capacitors to provide a boosted voltage to alternately turn on the high-side switches of the H-bridge.

Abstract: Subject to user or system selection, one of the motor control schemes is accessed from the memory by a controller for implementation. The controller generates control signals that are applied to energization circuitry for supplying current to the phase windings with a particular current waveform profile in accordance with the selected motor control scheme. The controller has an input terminal for receiving a user initiated torque command signal representing a desired motor torque. Each motor control scheme provides motor driving current that corresponds to torque command signals received at the controller input terminal.

Abstract: A single coil, direct current permanent magnet brushless motor including a stator including six alternately-wound coils connected into a single coil having first and second ends, the oppositely-wound coils forming stator poles, and six magnets of alternating polarity coupled to a rotor and rotatably journaled in the stator. A sensor, such as a dual output Hall sensor, is used for sensing rotation of the rotor. A drive circuit, such as an H-bridge circuit, is coupled to the first and second ends of the single coil to drive the motor. The H-bridge circuit includes two high-side switches for alternately receiving signals from the Hall sensor, and two low-side switches alternately receiving signals from the Hall sensor. A high-side switching signal can be controlled by an inverted low-side switching signal. A voltage boost circuit is also provided, having capacitors to provide a boosted voltage to alternately turn on the high-side switches of the H-bridge.

Abstract: The stepping motor driver comprises an inverter for feeding stepped currents to windings of a stepping motor, a position detector for obtaining a detected angle of a rotor of the stepping motor and a current controller for controlling the inverter. In a d-q rotational coordinate system in which the d-axis is in the direction of the magnetic flux of the rotor and the q-axis is in the direction perpendicular to the d-axis, an excitation angle for a winding is determined from a d-axis component and a q-axis component of a command current to the winding, a lead angle control signal is computed from the excitation angle, and a phase of an applied voltage to the stepping motor is controlled using the lead angle control signal.

Abstract: A method of controlling an electronically commutated DC motor having a multiphase stator winding which has an even number m of winding phases which are each connected in series with a controllable semiconductor switch, parallel to one another, in which in a lower power output range of the DC motor the semiconductor switches are cycled using a pulse control factor which is predefinable as a function of the rpm within the consecutive periods when the individual winding phases are energized. To reduce the maximum power losses in the semiconductor switches, a setpoint pulse control factor required for a setpoint rpm is achieved within a selected setting range of the pulse control factor by alternatingly setting a comparatively greater pulse control factor and a comparatively lower pulse control factor, and the setting of the two pulse control factors is varied over time so that a voltage setting the setpoint rpm is set across the stator winding on the average over time.

Abstract: A control system is provided for a multiphase motor having a plurality of stator phase components, each stator phase component comprising a phase winding formed on a core element, and a permanent magnet rotor. A plurality of motor control schemes are stored in memory. Subject to user or system selection, one of the motor control schemes is accessed from the memory by a controller for implementation. The controller generates control signals that are applied to energization circuitry for supplying current to the phase windings with a particular current waveform profile in accordance with the selected motor control scheme. The controller has an input terminal for receiving a user initiated torque command signal representing a desired motor torque. Each motor control scheme provides motor driving current that corresponds to torque command signals received at the controller input terminal.

Abstract: Method and system for controlling a permanent magnet machine are provided. The method provides a sensor assembly for sensing rotor sector position relative to a plurality of angular sectors. The method allows starting the machine in a brushless direct current mode of operation using a calculated initial rotor position based on angular sector position information from the sensor assembly. Upon reaching a predefined mode-crossover criterion, the method allows switching to a sinusoidal mode of operation using rotor angle position based on extrapolating angular sector position information from the sensor assembly.

Abstract: A permanent magnet rotating machine control system and method includes an estimator that calculates an estimate of the machine's rotor speed. The estimator receives energization feed back from the machine in a first rotating reference frame and outputs the rotor speed estimate in a second rotating reference frame. A controller receives a rotor speed demand and the rotor speed estimate, and outputs control signals for controlling energization of the machine in response to the rotor speed demand and rotor speed estimate signals. The first rotating reference frame rotates at the commanded rotor speed, and the second rotating reference frame rotates at the estimated actual rotor speed.

Abstract: This method consists in supplying at least a first alternating signal, at a determined frequency, to one end of a stator coil and recuperating a measurement signal at a second end of said coil, said measurement signal being provided to electronic processing means, which are arranged to extract data relating to a periodic variation of the effective inductance of the stator coil. This variation is a function of the angular position of the rotor. By alternately carrying out such a measurement on the stator coils, three periodic curves can be extracted (SPCA, SPCB, SPCC) defining a zigzag curve (70) allowing the angular position of the rotor to be determined.

Abstract: Object of the present invention is to distribute signals indicating angular position of a rotor from a controller for a brush-less motor to another control device. A controller for driving a brush-less motor has a magnetic-pole detecting circuit (9) that receives from a Hall-effect semiconductor disposed in a motor roller (4) sequential (pole position-representing) signals relating to a rotor's position. These signals are converted into pulses and then supplied to a current-controlling circuit (8), so that currents to stators are controlled based on the signals from the detecting circuit (9) so as to drive the motor roller. A sequencer (20) supplies to a controlling circuit (7) “ON/OFF” and other commands, that are then processed in this circuit and fed to the current-controlling circuit (8) for driving the motor.

Abstract: A control system for a multiphase permanent magnet motor compensates for physical variations among individual motor phase circuit elements. The control system successively develops a control voltage for switched energization of the motor phase windings that is closely matched with particular parameters of the corresponding windings. The system can be applied to a motor in which each stator phase component comprises a ferromagnetically isolated stator electromagnet, the electromagnet core elements being separated from direct contact with each other and formed with separate phase windings. A digital signal processor may be utilized that applies an algorithm incorporating the parameters as constant values, the parameters for a particular phase being accessed for generating the appropriate control signals for energizing that phase.

Abstract: A rotor angle detecting apparatus for a DC brushless motor is capable of detecting the angle of the rotor of the DC brushless motor with accuracy without the need for a position detecting sensor. A motor controller has a high-frequency voltage imposer, an angle detector, a U-phase current sensor, and a W-phase current sensor for detecting the rotor angle of the DC brushless motor. The angle detector detects the rotor angle &thgr; using a current value IU_s detected by the U-phase current sensor, a current value IW_s detected by the W-phase current sensor, and high-frequency components depending on high-frequency voltages vu, vv, vw, when the high-frequency voltages vu, vv, vw are imposed on command values VU_c, VV_c, VW_c for three-phase voltages by the high-frequency voltage imposer.

Abstract: In order to propose an inexpensive and highly precise motor controller, it is structured so as to detect the position of the rotor on the basis of the difference between the real current differential vector and the reference current differential vector, thereby control the motor without using a rotation position sensor.

Abstract: A synchronous motor drive system in accordance with the present invention detects a DC current of an inverter which drives a synchronous motor, and based on the magnitude of the current, estimates torque current components that flow through the motor, and then based on the estimated value, determines the voltage which is applied to the motor, and finally estimates and computes the magnetic pole axis located inside the motor using the estimated value of the torque current.

Abstract: Providing control apparatus with a maximum torque/current ratio control means by which the relationship between the maximum torque and current amplitudes and the relationship between the maximum torque and current phases are converted to numeric expressions including one or more than one linear function with the torque taken as the parameter, then the current amplitude command and current phase command data that yields a maximum torque is computed, and computed data is sent as an output signal.

Abstract: Axial error calculation unit is provided for estimating an axial error &Dgr;&thgr; between a d-q axis and a dc-qc axis by using Ld, Lq, Ke, Id*, Iq*, Idc and Iqc in a range of all rotational speeds except zero of a rotational speed command of a synchronous motor, Ld denoting an inductance on a magnetic pole axis d of the synchronous motor, Lq an inductance on a q axis orthogonal to the magnetic pole axis d, Ke a generated power constant of the motor, Id* a current command of the d axis, Iq* a current command on a q axis, Idc a detected current value on an assumed dc axis on control, and Iqc a detected current value on an assumed qc axis orthogonal to the assumed dc axis. Irrespective of presence of saliency, position sensorless control can be achieved in a wide range a low to high speed zone.

Abstract: Axial error calculation unit is provided for estimating an axial error &Dgr;&thgr; between a d-q axis and a dc-qc axis by using Ld, Lq, Ke, Id*, Iq*, Idc and Iqc in a range of all rotational speeds except zero of a rotational speed command of a synchronous motor, Ld denoting an inductance on a magnetic pole axis d of the synchronous motor, Lq an inductance on a q axis orthogonal to the magnetic pole axis d, Ke a generated power constant of the motor, Id* a current command of the d axis, Iq* a current command on a q axis, Idc a detected current value on an assumed dc axis on control, and Iqc a detected current value on an assumed qc axis orthogonal to the assumed dc axis. Irrespective of presence of saliency, position sensorless control can be achieved in a wide range a low to high speed zone.