Abstract: A power converting apparatus includes a timing signal generator and a phase determination signal generator provided in an ON/OFF signal generating unit as well as a detected current correction unit. On the basis of timing signals ts1, . . . and phase determination signals ph1, . . . , the power converting apparatus determines detected current values and phases of the detected current values fed from a DC bus current sensor at timings set in accordance with the timing signals and corrects the detected current values idc1, . . . for the individual phases obtained at the individual timings during PWM cycles to represent values which would be obtained at reference timing t0 to thereby reduce errors caused by differences in the current detecting timings for the individual phases.

Abstract: A sensorless induction motor control device with a function of correcting a slip frequency wherein a slip frequency estimation unit estimates the slip frequency from at least one kind of current flowing through the motor. A voltage command value calculation unit calculates a D-phase voltage command value and a Q-phase voltage command value which are used for controlling a voltage applied to the motor using a Q-phase current command value calculated based on a difference between a speed estimation value, which is calculated using an estimation value of the slip frequency, and an externally supplied speed command value. An ideal voltage command value determination unit determines an ideal voltage command value using the speed command value and the Q-phase current command value. An actual voltage command value calculation unit calculates an actual voltage command value using the D-phase voltage command value and the Q-phase voltage command value.

Abstract: An object of the present invention is to provide a motor control device capable of suppressing voltage composite vector fluctuation to increase the output of a brushless motor, and a motor-driven power steering system using this device. The present control device calculates motor phase current command values based on a target current and a rotor rotational position detection value, calculates voltage command values based on the motor phase current command values and phase current detection values, and supplies phase currents to a three-phase brushless motor based on the voltage command values. The present control device outputs the phase current command values so that the absolute value of a composite vector of respective phase drive voltages is substantially a value ?3/2 times the power supply voltage.

Abstract: An induction motor control device includes an inverter circuit for driving an induction motor by outputting a command voltage, a current detector for detecting an output current, a magnetic flux estimation observer for generating an estimated magnetic flux, an estimated current, and a phase command for the motor using the command voltage and the output current, a primary angular speed estimator for estimating a primary angular speed using the estimated magnetic flux, a slip compensator for calculating a slip angular frequency using the output current, a first angular speed estimator for estimating a first angular speed using the primary angular speed and the output current, a second angular speed estimator for estimating a second angular speed using the output current, the estimated magnetic flux, and the estimated current, and a resistance estimator for estimating a secondary resistance value of the motor using the first and second angular speeds.

Abstract: The present invention provides an induction motor controller which includes: a circuit for generating a d-axis current reference signal from a d-axis current command value and a periodically varying periodic signal; a d-axis current controller for controlling a d-axis motor current flowing through an induction motor to be controlled to match the d-axis current reference signal; parameter determining means for calculating and determining a motor parameter of the induction motor based on a deviation of the d-axis motor current from the d-axis current reference signal, and controlling a voltage applied to the induction motor using a compensation voltage calculated from the calculated and determined motor parameter, in which a control parameter for controlling the induction motor is set based on the calculated and determined motor parameter.

Abstract: A method and apparatus for deriving phase voltage control signals for use in controlling current flow to an induction motor. The method may comprise obtaining an error term; converting the error term into a commanded voltage value; transforming the commanded voltage value into a commanded voltage vector; and converting the commanded voltage vector into the phase voltage control signals via pulse width modulation control. The apparatus may comprise a Park vector converter for converting a first stator phase measurement and a second stator phase measurement into a stator phase current vector; a scalar operator for obtaining a stator phase current value; a summer for obtaining an error term; an error converter for converting the error term into a commanded voltage value; a voltage transformer for transforming the commanded voltage value into a commanded voltage vector, and pulse width modulation control for converting the commanded voltage vector into the phase voltage control signals.

Abstract: In order to create a method and an apparatus for anti-trap protection detection for displaceable window and door elements by means of which faster and more stable adjustment to current physical conditions can be achieved during system actuation, in the system the motor (1) is controlled using parameter values generated in real-time using a closed-loop control unit, preferably a PID controller, to keep the speed in the system constant during a learning run and during operational use and to ensure timely trapping detection.

Abstract: The invention provides a motor for a brushless DC motor, which has small torque ripple even if a trapezoidal wave current is supplied and has a small size and reduced motor noise, and a drive control device for the motor as well as an electric power steering apparatus using the motor and the drive control device. Respective phase current command values are calculated on the basis of vector control. Pseudo-vector control for controlling respective phases separately is used as current feedback control.

Abstract: A method and apparatus for use with a controller for controlling a machine wherein a torque reference value is provided, the method for identifying an error representative of the difference between the torque reference value and the torque applied to the machine and using the error value to modify machine operation.

Abstract: A system for variable speed motor control provides continuous variable speed motor controller for each motor or motor application within a family of multi-tap motors while using a single controller. The single controller utilizes a wave chop technique providing variable speed motor control through the operating range for each motor tap and seamlessly passes the motor control to each succeeding tap to provide smoothly varying and continuous variable speed motor control throughout the operating range of the multi-tap motor. The system can use a small wave chop firing angle for each tap, thus maximizing the signal to the motor for each tap and minimizing heat build up in the motor. By selecting the controller to operate on a tap basis, an entire family of motors or motor applications can be accommodated with a single controller and apparatus.

Abstract: A microprocessor of the motor control apparatus acquires a zero-cross detection signal from a zero-cross detection section and a load current from a current detection section at a prescribed sampling period. The processor obtains a load current instant value every sampling period and a corresponding sine-functional value from a sine-functional value table to calculate a compensation value for the load current instant value. The processor also calculates a load current compensation total value by adding the compensation value by the predetermined number of times of sampling and compares the load current compensation total value with a load current reference value to obtain a difference therebetween. In response to the difference, an instruction value for delay time that determines the output timing of a trigger signal to a switching element is changed so that power consumption of the motor falls within a prescribed range.

Abstract: A speed control circuit for a dc brushless motor includes a switch circuit and a voltage-detection circuit. The voltage-detection circuit is actuated depending upon high or low voltage of power supply to thereby cause the switch circuit to output high or low operating voltage to a driver circuit of the motor in response to changes of the voltage of the power supply. The motor is adjusted and operated at desired speeds by a rated range of input voltages according to the high or low operating voltage.

Abstract: A method and system for the sensorless estimation of the states of the mechanical subsystem of a motor are disclosed. In particular, the method and system split the estimation problem into two sub-problems: the estimation of motor parameters as a function of position, and the determination of the states of the mechanical subsystem of the motor using the estimated parameters via a state observer. Motor current and PWM voltage in a polyphase system is measured or otherwise determined and converted into current and voltage in ?-? coordinates. A least square estimator is constructed that uses the voltage and current in ?-? coordinates and provides an estimate of the motor parameters, and in particular, the inductances of the motor, which are a function of the rotor position.

Abstract: Systems and methods for controlling an induction motor including detecting a field weakening operation state of the motor, wherein the field weakening operation state is detected when a flux current, Id, in the motor is reduced to a predetermined fraction of its normal, non-voltage limited value. The systems and methods also including an overmodulation operation state of the motor before said field weakening operation state is detected and enabling the overmodulation operation state of the motor after said field weakening operation state is detected.

Abstract: An inverter apparatus for converting a DC power converted from an input AC power to an output AC power of a variable frequency and a variable electric power to drive an induction motor at a variable speed. The inverter apparatus includes a rectifying unit, a filter capacitor, an inverter unit having an input connected across the filter capacitor, an input current detector and a gate circuitry for driving the inverter unit. An excitation current detection unit detects an excitation current of the induction motor from an output signal of the input current detector, a gate signal for driving the gate circuitry and a reference phase command. A setting unit sets a limitation level of the excitation current, a torque boost voltage command unit produces a torque boost voltage command, and a torque boost voltage compensation unit changes the torque boost voltage command so that the detected excitation current value is smaller than or equal to the limitation level.

Abstract: A motor speed control circuit includes a switch circuit and a voltage-detection circuit. The voltage-detection circuit is actuated depending upon high or low voltage of a power supply to thereby cause the switch circuit to output high or low operating voltage to a driver circuit of the motor in response to changes of the voltage of the power supply. The motor is adjusted and operated at desired speeds by a rated range of input voltages according to the high or low operating voltage.

Abstract: A speed control circuit for a dc brushless motor includes a switch circuit and a voltage-detection circuit. The voltage-detection circuit is actuated depending upon high or low voltage of power supply to thereby cause the switch circuit to output high or low operating voltage to a driver circuit of the motor in response to changes of the voltage of the power supply. The motor is adjusted and operated at desired speeds by a rated range of input voltages according to the high or low operating voltage.

Abstract: A permanent magnet DC brushless motor control assembly permits a user to select the permanent magnet DC brushless motor operating characteristics by selecting appropriate control circuits to interface with the motor. The assembly includes a permanent magnet DC brushless motor, a commutator electrically coupled to the motor, and at least one control module electrically coupled to the commutator, to control operating characteristics of the permanent magnet DC brushless motor.

Abstract: If a speed instruction value is less than a predetermined value, the output current of a power-conversion unit is controlled to be larger than a current value in an ordinary no-load operation, or a frequency instruction value is calculated based on a speed instruction value in place of an estimated speed.

Abstract: A starting motor for an internal combustion engine, where a control circuit monitors or controls the temperature of the starting motor or the carbon brushes, and if necessary, limits or switches off the primary current. The temperature is indirectly determined by means of a comparison, using the voltage ripple in the primary circuit between the battery and the starting motor. Occurring errors can be stored as status messages in an error storage device, and if desired, they can be interrogated and corrected at the next service interval.

Abstract: The speed control circuit in accordance with the present invention mainly includes a switch circuit and a voltage-detection circuit. The voltage-detection circuit is actuated depending upon high or low voltage of power supply to thereby determine the switch circuit to output high or low operating voltage to a driver circuit of the motor in response to changes of the voltage of the power supply. The motor is adjusted and operated at desired speeds by a rated range of input voltage according to the high or low operating voltage.

Abstract: In order to accelerate an asynchronous motor with a squirrel-cage rotor even under load extremely quickly, and in particular within the time of an electromagnetic rotor time constant, in order to be able to cause it to start with a so-called kick start, while the rotor is not moving, quasi-stationary magnetic conditions are initially produced, like at the start of a synchronous motor with a permanent-magnetic rotor. For that purpose there is briefly produced a high-frequency rotor induction current which occurs electrically and spatially in a quasi-stationary condition when thereupon still within the rotor time constant, a strong unmoving stator magnetic field is produced, with a stator current vector which is displaced through about 90° for an optimum starting torque in relation to the rotor current vector, whereupon the stator rotary field starts with increasing amplitude and frequency.

Abstract: A method and apparatus for generating stator and rotor resistance estimate, the method including the steps of providing high frequency injection voltage signals to a three phase motor, rotating three phase feedback current therefrom, converting the feedback currents to two phase currents that represent the high frequency component of the current vector wherein the d and q axis components are within a two phase voltage coordinate system and driving a regulator via one of the current components to generate a lag angle estimate, the lag angle estimate used to solve any of several different equations to calculate the stator and rotor resistance estimates.

Abstract: A method for shorting rotor windings in a wound rotor induction machine is disclosed. The method includes the steps of monitoring rotor current for a frequency indicative of a desired steady-state operating condition and electronically shorting the rotor windings when the monitored rotor current frequency reaches a defined threshold indicative of the desired steady-state operating condition.

Abstract: A N pulse variable frequency drive for driving two or more motors that is the combination of two or more variable frequency drives with each drive driving an associated one of the two or motors. One application is a decanter centrifuge which has a main motor to drive the bowl and a back motor to drive the conveyor. One of the two variable frequency drives drives the main motor and the other drive drives the back motor. The variable frequency drives are connected to a common buss and to a N pulse phase shifting transformer.

Abstract: A method for controlling an electrical machine while it is connected to an inverter comprising phase-specific switching components generating an output voltage, an optimum switching table arranged to select a switching combination for the switching components on the basis of the stator flux and torque of the electrical machine, the method comprising steps of defining the stator current vector (is) of the electrical machine, and determining the rotation speed of the electrical machine. The method also comprises the step of defining a switching combination for the switching components on the basis of the stator current vector (is) and stator current reference vector (&psgr;s, ref) of the electrical machine when the determined rotation speed is lower than a predefined limit.

Abstract: A monitoring apparatus for monitoring operation of a no-back device of an actuator assembly driven by a motor, the apparatus comprising sensor device operable to sense an operating parameter of the motor for determining when the motor's output drive is in a direction opposite to a selected direction of motor output drive.

Abstract: An exemplary embodiment of the invention is a method for detecting a potentially locked axle on a vehicle propelled by an AC motor. The method includes conducting a speed test by estimating axle speed and comparing estimated axle speed to measured vehicle speed. The existence of a potential locked axle condition is determined based on the comparing of estimated axle speed to measured vehicle speed. Additional tests are disclosed for determining a potential locked axle condition and a sensor fault condition.

Abstract: A control scheme for an surface-mounted permanent-magnet synchronous (SMPMS) drive uses a combination of an open-loop magnetizing current reference calculation and a stabilizing feedback term, which speeds-up the torque transient response. The feedback term increases the stability margin during torque transients by increasing the available voltage margin for current control. The magnetizing current reference calculation takes into account the saturation effects in the SMPMS drive, which occur at peak torque points, and compensates for them. By taking into account saturation effects, stable operation at high speed is achieved, thereby increasing the speed range of the SMPMS drive.

Abstract: At Step Sb3, a duty factor, which was calculated at Step Sb2 on the basis of a data for a feed-back control, is compared with a limit value of the duty factor. If the duty factor is less than the limit value, a pulse for the PWM control is modulated to have the calculated duty factor at Step Sb4. If the duty factor is greater than the limit value, the pulse for the PWM control is modulated to have the duty factor of the limit value at Step Sb5. Accordingly, the duty factor provided for a current value instruction is not in excess of the limit value, so that the secondary battery is prevented from discharging overcurrent in excess of the limit current which can be discharged from the secondary battery. Accordingly, although the capacitance of the secondary battery is not large, the lifetime of the secondary battery is prevented from being shortened.

Abstract: A method and apparatus for controlling a synchronous frame current regulator wherein the apparatus includes a current predictor and a current predictor adjuster, the current predictor predicting the current provided to a plant from both a forcing function and an actual current value and the adjuster adjusting the current prediction based on a difference between the current prediction and the actual current sampled thereby driving the actual current so as to conform with a commanded current value.

Abstract: If a speed instruction value is less than a predetermined value, the output current of a power-conversion unit is controlled to be larger than a current value in an ordinary no-load operation, or a frequency instruction value is calculated based on a speed instruction value in place of an estimated speed.

Abstract: A device for high efficiency motor control includes an induction motor and a controller. The induction motor generates a motor torque and has a given rotor resistance and magnetizing inductance at a specific temperature. The controller is coupled to and controls the induction motor. The controller includes control logic operative to maximize the motor torque using a flux current and a torque current. The controller determines the flux current and torque current based upon a requested torque, a requested speed, the magnetizing inductance, the temperature and the rotor resistance.

Abstract: An induction motor control device includes a power conversion circuit, a current sensor, a current component calculation circuit for calculating first and second current components, a magnetic flux command calculation circuit for calculating a magnetic flux command value such that the amplitude ratio between a squared value of the first current component and a squared value of the second current component takes a preset value, a voltage component calculation circuit for calculating a primary voltage component command value, and a primary voltage component command calculation circuit. The current component calculation circuit calculates first and second current components in phase and 90° out of phase with the primary voltage component command value, respectively.

Abstract: A rotary induction machine having wound primary and secondary windings with resistive means connected in series with secondary windings and inductive reactive means connected across said resistive means, with the inductive reactance means and resistive means selected to provide an effective resistance which controls the current in the generator secondary windings, whereby the generator rated current is reached at the highest slip for the range of desired power output.

Abstract: Electric motors having controllable induced armature fields, such as induction motors and synchronous reluctance motors, are used in power assisted steering systems for motor vehicles. Power is conserved by tailoring induced armature fields or rotor flux in accordance with the speeds of motor vehicles including the power assisted steering system. In particular, one or more flux programs or maps are provided for the power assisted steering system with the flux map or program being accessed or addressed by means of the vehicle speed. During low speed operation of the motor vehicle, for example to perform parking maneuvers where speeds are near zero and steering forces are near or at maximum, the rotor flux is programmed to maximum.

Abstract: An object of the invention is to provide a control device of an induction motor where an inverter circuit can be protected from overcurrent by stable current limitation operation not only at steady operation but also at rapid acceleration/deceleration or at regenerative braking. A current component calculation circuit calculates a first current component from primary current detected by a current detector and output frequency. A correction frequency calculation circuit calculates a frequency correction value using a current limit value and the first current component according to prescribed function calculation. A subtractor subtracts the frequency correction value from a primary frequency command value. A voltage component calculation circuit calculates a primary voltage component command value according to the subtracted output.