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Sensorless feedback circuit

Subclass of:

318 - Electricity: motive power systems


318400010 - Brushless motor closed-loop control

Patent class list (only not empty are listed)

Deeper subclasses:

Class / Patent application numberDescriptionNumber of patent applications / Date published
318400340 Electromotive force sensor (e.g., back or counter EMF sensor, etc.) 81
318400330 Voltage injection detection (e.g., voltage injected at startup to determine position, etc.) 50
318400360 With center-tap feedback circuit 3
20100213884ELECTRIC DRIVE SYSTEM FOR AN AUTOMOTIVE VEHICLE - 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.08-26-2010
20110050140Driving system of permanent magnet synchronous motor - When applying a high frequency voltage which alternates on positive and negative sides to a permanent magnet synchronous motor, a driving system of synchronous motor switches the applied voltage phase by 120 degrees successively and applies resultant voltages to three phases. A pulsating current generated by applying a high frequency voltage is detected at timing of elapse of a predetermined time Δt since an output voltage of at least one phase has changed from a state in which all output voltages of the three phases of a power converter are positive or negative. Current detection is conducted by using a DC resistor or a phase current sensor provided on a DC bus. A magnetic pole estimation unit calculates the rotor magnetic pole position of the permanent magnet synchronous motor on the basis of differences between positive side and negative side change quantities in three-phase currents obtained from detected current values.03-03-2011
20120074888MOTOR CONTROL DEVICE - A motor control device includes an inverter circuit including a plurality of switching elements connected into a three-phase bridge configuration and converting a direct current into a three-phase alternate current, a current detecting element connected to a direct current side of the inverter circuit, thereby generating a signal corresponding to a current value, a PWM signal generating unit which determines a rotor position based on phase currents of the motor and generates a three-phase PWM signal pattern so that the signal pattern follows the rotor position, and a current detecting unit detecting phase currents based on the signal generated by the current detecting element and the PWM signal pattern. The PWM signal generating unit generates the three-phase PWM signal pattern so that the current detecting unit is capable of detecting two phase currents in synchronization with advent of two fixed time-points within a carrier period of the PWM signal respectively.03-29-2012
20100052586DETECTOR CIRCUIT - The invention relates to a detector circuit for detecting a change in voltage at a terminal or node with respect to a reference potential. The detector circuit comprises an electronic switch with a control terminal, which has a predetermined switching potential at which the switch operates, and with a detection signal output for outputting a detection signal, and a voltage matching circuit, which provides a control potential at the control terminal of the switch which corresponds to a potential of the terminal which has changed by a predetermined, fixed potential absolute value. The predetermined fixed potential absolute value is selected in such a way that the control potential corresponds to the switching potential or approximately to the switching potential when the reference voltage is applied to the terminal in such a way that the change in voltage to be detected causes the switching potential of the electronic switch to be exceeded or undershot.03-04-2010
20130082630DETERMINING ROTOR POSITION IN SENSORLESS SWITCHED RELUCTANCE MOTORS - A method for determining the position of a moving rotor in a switched reluctance motor includes the steps of applying a voltage to a phase winding of the reluctance motor, sampling a signal representative of the current magnitude in this phase winding, detecting a feature of the second temporal derivative of the signal, and determining the position of the moving rotor taking into account the occurrence of this feature. Apparatus for carrying out the method is described.04-04-2013
20120181962Method and Device for Monitoring and Correcting a Sensorless Rotor Position Detection in Permanently Excited Motors - The invention relates to methods and devices for monitoring and correcting a sensorless rotor position detection in permanently excited motors, comprising a control device and a current converter. The invention is especially characterised in that the ambiguity of the rotor position determined from the inductance ratios of the motor, in permanently excited motors, can be resolved in a simple manner without a sensor, and a defectively determined angle can be corrected as required. To this end, during the operation of the motor, the rotor position is detected by means of an inductance-based detection device. Furthermore, the rotor position is monitored in relation to the ambiguity of the inductance-based signals by means of a monitoring/correcting device, and where necessary, an occurring angle error corrected, the currents in the motor being modified.07-19-2012
20090009114SYNCHRONOUS MACHINE - The invention relates to a synchronous machine provided with a stator and rotor, wherein the stator comprises stator teeth (01-08-2009
20090309528Motor driving system and controlling method of the same - A plurality of current sensors are provided to correspond to a plurality of inverter circuits for driving a plurality of motor generators, respectively. Zero point adjustment of each current sensor is executed in a non-energized state recognized based on a stop of operation of the corresponding inverter circuit and when noise influence is determined to be small based on stops of operations of the other inverter circuits in the same casing. As a result, it is possible to avoid a risk of performing the zero point adjustment in a state in which an output of the current sensor is not exactly a value corresponding to zero current due to the noise influence from the other inverter circuits. In this way, it is possible to highly accurately execute the zero point adjustment of the current sensor for measuring motor driving current.12-17-2009
20110169438METHOD AND SYSTEM FOR CONTROLLING AN ELECTRIC MOTOR USING ZERO CURRENT OFFSET VALUE CANCELLATION - Methods and systems for controlling an electric motor are provided. The electric motor includes at least one winding. A winding current flowing through the at least one winding is monitored. The winding current has an oscillating component and an offset component. The offset component of the winding current is isolated from the oscillating component of the winding current. The electric motor is controlled based on the offset component of the winding current.07-14-2011
20110062909POSITION SENSORLESS CONTROL OF PERMANENT MAGNET MOTORS - Methods and apparatus are provided for sensorless control of a permanent magnet motor. The method includes the step of determining a sensorless position signal and a sensorless speed signal in a torque-speed plane in response to phase currents corresponding to currents on one or more of the plurality of phases.03-17-2011
20080309268Initial Pole Position Estimating Apparatus and Method for Ac Synchronous Motor - 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 (12-18-2008
20090033262Sensorless controlling apparatus of brushless motor - A sensorless controlling apparatus for controlling a brushless motor includes a speed calculator for calculating speed of a rotor ω, an angle calculator for calculating rotor angle θ at a predetermined time interval, and an angle controller for calculating correction angle Δθ based on the current value of a d-axis current (d-axis current value i02-05-2009
20110006714Apparatus and Method for Providing Information Relating to a Motor - This invention relates to an apparatus and method for deriving speed and position information for an electric motor. Apparatus for and a method of controlling a motor 01-13-2011
20110006715Control Unit and Control Method for Permanent Magnet Synchronous Motor - If magnitude relations between the output terminal voltage based on a DC negative terminal of the inverter and a threshold voltage that is a fixed value are compared, polarity thereof is changed at a predetermined rotor phase. The magnitude relation, for example, is detected by an inexpensive and simple apparatus such as a level shift circuit and a NOT circuit. The rotor phase of the permanent magnet synchronous motor is inferred on the basis of changes in the magnitude relation and if it is differentiated, a rotation speed is inferred. If the inferred values of the rotor phase and rotation speed are fed back to synchronous operation or vector control, the free-running permanent magnet synchronous motor is restarted.01-13-2011
20090195200ELECTRIC MOTOR DRIVE SYSTEM AND ELECTRIC MOTOR CONTROL METHOD - An electric motor drive system having current detecting sections for detecting the currents flowing into electric motors, speed variation calculating sections for calculating the speed variation estimating values for the electric motors in accordance with the motor currents detected by the current detecting sections and the current command values for the motors corresponding to the detected currents and a speed uniformizing voltage compensating section for delivering the values that serve to compensate the amplitudes of the voltages applied to the electric motors in such a manner that the speed variation estimating values calculated by the speed variation calculating sections become equal to a predetermined value.08-06-2009
20090256511Direct Flux Regulated Permanent Magnet Brushless Motor Utilizing Sensorless Control - A permanent magnet rotor for use in a flux regulated permanent magnet brushless machine is constructed such that the inductance along the direct and quadrature axes is markedly different to provide sensorless position feedback for the rotor.10-15-2009
20120194112Electrical Brushless Motor - An electrical brushless motor is described, as well as a ceiling fan utilizing the electrical brushless motor.08-02-2012
20110084638METHODS, SYSTEMS AND APPARATUS FOR DYNAMICALLY CONTROLLING AN ELECTRIC MOTOR THAT DRIVES AN OIL PUMP - Methods, system and apparatus are provided for sensorless control of a vector controlled motor drive system that includes an electric motor used to drive an auxiliary oil pump.04-14-2011
20090218973CONTROL OF SWITCHED RELUCTANCE MACHINES - A flux switching electric motor (09-03-2009
20120242266SENSORLESS BLDC MOTOR SYSTEMS AND DRIVING METHODS OF SENSORLESS BLDC MOTOR - Provided is a sensorless BLDC motor system. The sensorless BLDC motor system includes a BLDC motor, a comparator, a motor controller, a three-phase inverter, and a mode selector. The BLDC motor includes first to third coils. The comparator compares a voltage of a specific coil of the first to third coils with a neutral-point voltage to output the compared result. The voltage of the specific coil becomes equal to the neutral-point voltage and a specific time elapses, and then the motor controller generates first and second coil control signals based on the compared result. The three-phase inverter supplies a source voltage or ground voltage to the specific coil, or floats the specific coil, in response to the first and second coil control signals. The mode selector selects a driving mode of the BLDC motor by adjusting the specific time.09-27-2012
20110175560MOTOR MAGNETIC-POLE-POSITION ESTIMATING APPARATUS - A motor magnetic-pole-position estimating apparatus includes a command voltage output device and a current detector. A model-current calculator is configured to calculate a model current corresponding to a voltage equation for a predetermined model of a motor based on a command voltage and an actual current. A current-difference calculator is configured to calculate a current difference between the model current and the actual current. Each of first and second magnetic-pole-position-difference calculators is configured to calculate a magnetic-pole-position difference between an actual magnetic-pole position of the motor and an estimated or designated magnetic-pole position based on the current difference depending on whether or not a rotation speed of the motor is lower than a predetermined value. A magnetic-pole-position calculation device is configured to calculate the magnetic-pole position of the motor based on the magnetic-pole-position difference calculated by the first or second magnetic-pole-position-difference calculator.07-21-2011
20100295489MOTOR DRIVE CONTROL APPARATUS - There is provided a motor drive control apparatus that includes a resistor, which directly or indirectly detects a driving current supplied to a motor and generates a voltage corresponding to the driving current, converts, with an AD converter, the voltage corresponding to the motor driving current detected by the resistor into a numerical value, and reflects the motor driving current converted into the numerical value on driving control for the motor, wherein a plurality of the resistors is connected in series to form a resistor string, and voltage between arbitrary two points of the resistor string is AD-converted.11-25-2010
20090174354Method for determining the position of a rotor of an electric motor without sensors - Disclosed is a method for detecting the current position of a rotor, in particular the angle of rotation of the rotor, an electromotor and a method for detecting the speed and/or the angle of rotation of an electromotor. The speed of the electromotor is hereby implied inter alia from the number of zero crossings of a comparison signal of the armature resistances or respectively conductances determined continuously in time and the average values of the armature resistances or respectively conductances determined continuously in time.07-09-2009
20090224712HEAT-EXCHANGE COOLING DEVICE AND POWER SUPPLY CIRCUIT DRIVER USED THEREFORE - A heat exchange cooler capable of eliminating continuous radiation of high-frequency noise waves and reducing the man hour for the installation work, and a power circuit driving device used for it are provided. A commercial power transformer (09-10-2009
20080252244SENSORLESS SPEED DETECTION OF A PM BRUSHLESS MOTOR WITH PHASE TERMINALS SHORTED - A method of determining the speed of a spinning sensorless brushless motor driven by an inverter when the phase terminals of the motor are shorted including determining a voltage related to the voltage developed in a phase leg of the inverter; from the determined voltage, determining the direction of current and providing a first signal determining transitions between current flowing in each of two directions; and from the first signal, determining the frequency of the current and thus the motor speed.10-16-2008
20110304290CONTROL APPARATUS AND CONTROL METHOD FOR ELECTRIC ROTATING MACHINE - A controller outputting voltage instructions for drive control of an electric rotating machine adds, by using adders, position estimation voltage instructions for estimating the rotor position generated by a position estimation voltage generator, to drive voltage instructions, and outputs the resultant signals as voltage instructions. A position estimation device includes current extractors for extracting position estimation currents having the same frequency components as that of the position estimation voltage instructions, from electric rotating machine currents detected by a current detector, a position estimation current amplitude calculation section for calculating position estimation current amplitudes from the position estimation currents; and an estimation position calculation unit for calculating an estimated position of the electric rotating machine, based on the position estimation current amplitudes. The position estimation current amplitude calculation section calculates the position estimation current amplitudes, based on an autocorrelation obtained by squaring the position estimation currents.12-15-2011
20120249033SENSORLESS MOTOR CONTROL - An method for driving a motor is provided. A plurality of pulse width modulation (PWM) signals are generated from a commanded voltage signal and a commanded angle signal, and these PWM signal are used to drive a motor (which has a plurality of phases). Currents through the phases of the motor are measured, and a Park transformation is performed on the measured currents to determine a projection current measurement. Based at least in part on the projection current measurement, the adjusting the commanded voltage signal and the commanded angle signal can be adjusted.10-04-2012
20100007297Sensorless Drive for Unipolar Three Phase Brushless DC Motors - 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. The system is compatible with high side and low side switching configurations.01-14-2010
20090134826CONTROLLER OF MULTI-PHASE ELECTRIC MOTOR - A controller of a multi-phase electric motor has a drive section, including a pair of upper arm switching element and a lower arm switching element, for driving the multi-phase electric motor, a single current detection section for detecting a current value of the multi-phase electric motor, a pulse width modulation signal (PWM) generation section for generating a PWM signal of each phase based on the current value detected by the current detection section and a saw-tooth signal having a predetermined frequency, a current detectability determination section for determining whether or not the current value is detectable in the current detection section based on the PWM signal of each phase generated by the PWM signal generation section, a switching number determination section for determining whether or not conducting number of the upper arm switching element is an even number or an odd number based on the determination that the current is not detectable by the current detectability determination section, a phase movement section for moving a phase of the PWM signal of a predetermined phase generated by the PWM signal generation section based on the determination result of the switching number determination section and outputting to the drive section, and each phase current calculation section for calculating a current value of each phase based on the current value detected by the current detection section and the PWM signal of each phase generated by the PWM signal generation section.05-28-2009
20120169264METHOD AND APPARATUS FOR COMMUTATING A BRUSHLESS DC MOTOR - Traditionally, controllers for brushless, sensorless direct current (DC) motors (in, for example, Hard Disk Drive applications) would use one of the phases of the DC motor to measure a back electromotive force (back-EMF) voltage. This measurement would generally cause a discontinuity in the current waveform for a motor operating at a generally constant rotational speed (i.e., at “run speed”), which would result in poor acoustic performance (i.e., audible hum). Here, however, an integrated circuit (IC) is provided that uses coil current and applied voltage measurements to substantially maintain a predetermined phase difference between the phase of the applied voltage and back-EMF voltage, eliminating the need for a back-EMF voltage measurement and improving the acoustic performance.07-05-2012
20100052587DETERMINING A POSITION OF A MOTOR USING AN ON-CHIP COMPONENT - An embodiment of a motor controller includes first and second supply nodes, a motor-coil node, an isolator, a motor driver, and a motor position signal generator. The isolator is coupled between the first and second supply nodes, and the motor driver is coupled to the second supply node and to the motor-coil node. The motor position signal generator is coupled to the isolator and is operable to generate, in response to the isolator, a motor-position signal that is related to a position of a motor having at least one coil coupled to the motor-coil node. By generating the motor-position signal in response to the isolator, the motor controller or another circuit may determine the at-rest or low-speed position of a motor without using an external coil-current-sense circuit.03-04-2010
20100231154MOTOR CONTROL DEVICE AND MOTOR SYSTEM - A motor control device has first to third amplifiers which amplify voltage generated at first to third shunt resistances connected to first to third drivers to supply driving current of each of three phases to a three-phase brushless motor, first to third sample-hold circuits which sample and hold voltage amplified by the first to third amplifiers, a multiplexer which sequentially selects and outputs voltage values held by the first to third sample-hold circuits, an A/D converter which performs A/D conversion on output signals of the multiplexer, and an arithmetic unit which calculates the driving current through an output signal of the A/D converter, estimates a magnetic pole position of the motor based on the driving current, and performs pulse width modulation (PWM) control on the driving current by controlling the first to third drivers.09-16-2010
20100231153Driving apparatus for three-phase AC synchronous motor - In a driving apparatus for a three-phase synchronous motor, in which a battery is connected between a neutral point of a stator coil and a negative-pole bus, a control circuit acquires three-phase AC currents. The control circuit checks whether a neutral-point electric current is contained in an electric current detected by an electric current detecting section. Based on the check result, the control circuit checks whether electric current values for three-phases containing the neutral-point electric current are set together or electric current values for three-phases excluding the neutral-point electric current are set together to acquire the three-phase AC currents for driving the motor.09-16-2010
20110248658APPARATUS AND METHOD FOR DETERMINING ANGULAR POSITION - The position of a rotor of a motor is determined. The motor includes the rotor and a stator and the stator includes a plurality of coils. The rotor further includes at least one rotating magnetic field device. When the rotor is moving below a threshold speed, the current in each of the plurality of coils of the stator is measured. A pre-programmed data structure is accessed. The pre-programmed data structure stores a plurality of stator currents associated with a plurality of predetermined rotor positions. A first absolute position of the rotor is determined from the data structure according to the measured current from each of the plurality of coils. When the rotor is moving above the threshold speed, one or more rising or falling edges of magnetic field strength associated with the at least one rotating magnetic field device of the rotor are sensed. At least one timing aspect of the rising and falling edges of magnetic field strength are compared to determine a second absolute position of the rotor.10-13-2011
20130193887MOTOR CONTROL DEVICE - The present invention provides a motor control device including a feedback control system that generates a torque command for reducing a difference between an operation command signal for commanding an operation of a motor and a detection signal of a detector attached to the motor to detect a position and speed of the motor and drives the motor. The motor control device includes a correcting unit configured to estimate an amplitude and a phase of a correction amount for suppressing the detection error included in the detection signal and sequentially update estimation values of the amplitude and the phase and a post-correction-detection-signal calculating unit configured to generate a post-correction detection signal, which is a difference between the detection signal and the correction amount, instead of the detection signal.08-01-2013
20130193886SENSORLESS CONTROL APPARATUSES OF MOTORS AND CONTROL METHODS THEREOF - A sensorless control apparatus of a motor may include: a position estimator configured to compensate for a resistance and a magnetic flux of a permanent magnet of the motor according to a temperature of the motor, and/or configured to generate an estimated speed of a rotor of the motor based on the compensated resistance and the compensated magnetic flux of the permanent magnet; and/or a speed controller configured to generate a command current based on a command speed of the rotor and the estimated speed of the rotor.08-01-2013
20120086374INVERTER DEVICE, MOTOR DRIVING DEVICE, REFRIGERATING AIR CONDITIONER, AND POWER GENERATION SYSTEM - An inverter device, a motor driving device, a refrigerating air conditioner, and a power generation system, which can reduce the recovery loss thereof, are obtained. A plurality of arms that can conduct and block current are provided. At least one of the plurality of arms includes: a plurality of switching elements each having a parasitic diode and being connected in series with each other; and a reverse current diode connected in parallel with the plurality of switching elements.04-12-2012

Patent applications in class Sensorless feedback circuit

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