Abstract: A method of controlling the torque of a rotary machine powered by means of an inverter and servo-controlled by a system having sensors, an observer, and a computer which delivers controls to the switches of the inverter on the basis of values supplied to the observer by the sensors, in the form of sequences of three vectors to bring the torque &Ggr; and the stator flux &PHgr;S of the machine towards reference values for &Ggr;ref and &PHgr;Sref. The measurement sampling period is selected to be equal to the sequence period DTML which corresponds to half the switching period of the inverter.

Abstract: According to this invention, there is provided a motor control apparatus comprising a field weakening device for converting a velocity feedback signal obtained from the rotational speed of a motor into a secondary magnetic flux reference signal by using a field pattern, a field pattern selector for comparing a predetermined signal with a q-axis torque current reference signal obtained on the basis of the secondary magnetic flux reference signal converted by the field weakening device, the velocity feedback signal, a velocity reference signal, and a torque reference signal, and outputting, on the basis of the comparison result, a control signal for switching the field pattern, and a field pattern storage section for switching, on the basis of the control signal output from said field pattern selector, the field pattern to be used in the field weakening device. Since the selector can switch the field pattern, an accurate torque output can be realized.

Abstract: An estimated rotation angular velocity □r0 and an estimated secondary resistance Hr0 are processed using a first feedback gain H1 under a condition that a first state deviation E1 is in phase with a quadrature component of an estimated secondary magnetic flux □r01. An estimated primary resistance Rs0 is processed using a second state deviation H2 under a condition that a second state deviation E2 is in phase with an estimated primary current 02. These values are used to control the speed of an induction motor without an angular velocity detector.

Abstract: A controller for an electric motor, includes a reference circuit and control circuitry. The reference circuit generates a reference signal having a phase and frequency determined in accordance with a set of motion parameters input to the circuit. The control circuitry receives the reference signal and receives a feedback signal from a rotation detector coupled to the motor, the detector having a predetermined rotational resolution, and compares the reference signal and the feedback signal to generate a drive signal used to drive the motor at a speed and phase of rotation determined by the frequency and phase of the reference signal. The phase of rotation of the motor is locked to the phase of the reference signal such that deviation of the phase of rotation relative to the phase of the reference signal at steady state is substantially smaller than the rotational resolution of the rotation detector.

Abstract: A high voltage, single-stage variable speed motor power supply utilizes direct AC-to-AC converters that do not have any intermediate DC link, along with a multi-level, multi-phase, multi-circuit variable speed motor drive and a motor in which a stator is wound with a number of multi-phase circuits. Each multi-phase circuit includes semiconductor switches arranged in drive switch pairs which are operated to produce an effective DC supply with the switches being controlled so that the most positive line-to-line source voltage is utilized for the inversion process.

Abstract: In vector control apparatus and method for a three-phase multiplex winding motor, a plurality of inverters are installed, each inverter operatively driving a corresponding one of multiplex windings of the motor and a plurality of inverter controllers are installed whose number corresponds to that of the inverters. Each controller includes: a decoupling voltage calculator for calculating d-axis and q-axis voltage setting values V.sub.1 d* and V.sub.1 q* on the basis of an excitation instruction value Io*, a torque instruction value I.sub.T *, d-axis-and-q-axis current instruction values i.sub.1 d* and i.sub.1 q* which are quotients of the excitation instruction value Io* and the torque instruction value I.sub.T * divided respectively by the multiplex number N of the windings of the motor, and a power supply frequency .omega. which is an addition of a slip frequency .omega.s to a rotor revolution frequency .omega.

Abstract: The invention includes: a random number generating unit which outputs a random number in driving of an AC motor by a voltage source inverter, a maximum/minimum triangular wave frequency setting unit which calculates a maximum triangular wave frequency and minimum triangular wave frequency using the inverter frequency, a triangular wave frequency calculating unit which calculates a triangular wave frequency from the random number, the maximum/minimum triangular wave frequency, and a triangular wave peak pulse, a triangular wave generating unit which calculates a triangular wave in accordance with this triangular wave frequency and outputs a triangular wave peak pulse, a voltage reference generating unit which inputs inverter current references and the motor revolution frequency, and which calculates the inverter frequency and voltage references of each phase of the inverter, and a PWM pulse generating unit which inputs the voltage references and triangular wave of each phase which are calculated and outputs a

Abstract: A first DC-linked AC converter with a machine converter (6) with controllable turn-on thyristors is connected in parallel with a second DC-linked AC converter with a machine converter (4) equipped with so-called gate-turn-off (GTO) thyristors which can be turned off. The second DC-linked AC converter with a machine converter equipped with controllable turn-on and turn-off thyristors is particularly adapted to feed a drive for pumps and fans where an exceedingly small torque and a small output power is required at low rotation speeds. The second DC-linked AC converter equipped with GTO thyristors is controlled so as to supply predominantly the reactive power for the asynchronous machine (5) and the commutation reactive power for the normal thyristor converter (6) minus the reactive power of the capacitors (C.sub.R).

Abstract: An apparatus for sensing the rotation of a brushless DC fan includes the fan and a sense/driver circuit and a capacitance. The sense/driver circuit is coupled to the fan to receive a sense input signal including a fluctuating electrical effect caused by fan commutation events. The sense/driver circuit processes the sense input signal to generate a sense output signal indicative of fan operation. The sense/driver circuit includes an integrated circuit. The integrated circuit includes a sense input pin, a ground return pin, a driver circuit, an integrated filter portion, a filter pin and a level detecting circuit. The capacitance is coupled to the filter pin to provide a filter with the integrated filter portion. The driver circuit includes a control terminal, a first current handling terminal coupled to the sense input pin and a second current handling terminal coupled to provide a ground return pat.

Abstract: Torque is distributed by calculating first and second torque commands using a requested torque and a ratio of speeds of first and second wheels and limiting them in accordance with respective torque command approved ranges and approved change rates; converting the limited torque commands to horsepower commands and limiting them in accordance with respective horsepower command approved ranges and approved change rates; and converting the limited horsepower commands to present torque commands. Maximum horsepower available is determined by using an engine speed to determine a nominal amount of available horsepower; applying a desired load status signal and an actual engine load status signal to a proportional-integral regulator; and using the nominal amount of available horsepower and an output signal of the regulator to determine the maximum amount of available horsepower.

Abstract: Method for commutation of a brushless motor being supplied with electrical energy from a DC intermediary circuit via a multi-phase inverter, by which a first current and a second current value are determined and the length of a commutation interval is set in dependence of these current values. With motors being exposed to heavily varying load torques during one rotation, e.g. motors driving a compressor, a stable operation must be reached. For this purpose a correction value is added to the pre-set commutation interval determined by the speed of the motor, said correction value being the result of the difference of the actual value of the intermediary circuit current and a filtered and delayed value of the intermediary circuit current, multiplied by a weighting factor.

Abstract: An induction motor drive uses direct vector control for zero speed start up. According to the invention, a speed sensorless induction motor is controlled at all speeds, including zero or substantially zero speed, using direct vector control. In order to utilize direct vector control at all speeds, it is necessary to derive accurate stator flux vectors at all speeds. This is accomplished in the present invention by calculating two sets of stator flux vectors in diverse manners. A first set of flux vectors is derived from measured stator terminal voltage quantities, and a second set of flux vectors is derived from measured stator current quantities. The first set of flux vectors is valid at non-zero speed and the second set of flux vectors is valid at substantially zero speed. The direct vector control utilizes one of the two sets of flux vectors in accordance with predetermined criteria indicative of zero and non-zero speed conditions.

Abstract: An apparatus for essentially eliminating transmission line reflected waves and standing waves and for reducing common mode transient currents for use with a three phase motor controller, the apparatus including a common mode choke in series with a filter network between an inverter and a motor, the filter including three inductors and three resistors, the inductors and resistors together forming three inductor-resistor pairs, each pair including an inductor in parallel with a resistor, each pair linked to a separate one of three transmission supply lines which link the inverter to the motor, values of the resistors and inductors selected according to transmission line theory.

Abstract: In a motor control system and method controlled by a d-axis current command value i.sub.ds and a q-axis current command value i.sub.qs, a d-axis voltage command value V.sub.d * and a q-axis voltage command value v.sub.q * are computed on the basis of d-axis current deviation .DELTA.i.sub.d of d-axis current value i.sub.d from the d-axis current command value i.sub.ds and q-axis current deviation .DELTA.i.sub.q of q-axis current value i.sub.q from the q-axis current command value i.sub.qs and on the basis of q-axis inductance value L.sub.q and d-axis inductance value L.sub.d wherein the inductance values L.sub.q and L.sub.d are tuned or adjusted so that the d-axis current deviation .DELTA.i.sub.d and q-axis current deviation .DELTA.i.sub.q approach zero.

Abstract: A speed controller for a three phase induction motor using sliding mode control to generate estimates of stator current and rotor flux to control motor speed. The controller receives only the actual operating speed and the desired operating speed as input signals. The controller establishes linked non-linear hyperplaces containing the operating points of each phase and coerces the operating points to move along the line of intersection. A change in operating conditions causes a change in the power supplied to the phase terminals.

Abstract: A control system for a vehicle-mounted battery which, in accordance with the state of a battery, can make a polyphase alternating current rotating machine in a hybrid car assist the driving gear (the internal combustion engine) or charge the battery. The current and voltage during discharge and charging of a battery mounted on a vehicle are measured, and on the basis of this measured current and voltage information, a program control circuit controls the discharge current when an auxiliary driving force is given to the driving gear. This control is performed via an inverter which performs AC-to-DC or DC-to-AC conversion between the battery and the polyphase alternating current rotating machine coupled to the driving gear of the vehicle. Because the charging and discharging currents are limited in accordance with the state of charging of the battery, it is possible to avoid charging and discharging uniformly irrespective of the amount of charging of the battery.

Abstract: A d-phase current in the direction of a magnetic flux generated by a field system and a q-phase current in a direction perpendicular thereto are obtained from a driving current and a rotor phase of an AC servomotor by d-q conversion. DC-mode current control is carried out with this d-phase current adjusted to zero and using the q-phase current as a current command. In this DC-mode current control, the influence of magnetic saturation is restrained to lessen torque reduction by advancing the phase of the q-phase current command, which is effective component of the current command, in case of magnetic saturation.

Abstract: The speed of a rotor in a two-winding, permanent magnet motor can be accurately controlled with a dual-polarity pulse width modulation drive signal. The phase back emf signal generated in the non-excited winding is compared against the phase of a command signal and the results of the comparison are used to vary the duty cycle of the drive signal.

Abstract: A variable-speed control apparatus computes the leakage inductance of an AC motor, correctly compensates the leakage inductance, and controls the variable speed of the AC motor. The variable-speed control apparatus has an AC signal generation circuit for generating an AC signal, and obtains a leakage inductance calculation value of the AC motor based on the AC signal and the measured actual current value. The differential value of the summation of a current command value and the AC signal is multiplied by the leakage inductance calculation value to generate a signal for use in compensating the voltage drop caused by the leakage inductance, and added to a voltage command value to cancel the deviation between the actual current value and the M-axis current command value and to obtain the second voltage command value. The second voltage command value is converted into a 3-phase voltage command value and used in controlling the AC motor, and the voltage drop caused by the leakage inductance can be compensated.

Abstract: A method for stepwise voltage control using thyristors for supplying an induction motor at a fixed frequency and a variable voltage. A time sequence of electromotive force amplitudes corresponding to a predetermined law for torque variation during transient operating conditions is stored. Voltages applied to the motor and the current flow are determined to approximate the electromotive force generated by the motor. Static switch conduction intervals are used to adapt the electromotive force to the stored amplitude during the transient operating conditions.

Abstract: A control system for a multiphase induction motor includes microcontroller control means providing a variable frequency signal and deriving high side/low side phase signals from the variable frequency signal. Power is applied from an AC/DC converter to the motor by an output drive bridge with three pairs of high side/low side semiconductor switches, one pair for each phase. The high side and low side phase signals are applied through high side/low side driver means to control the switches and effectively apply a quasi-square waveform to the motor windings. The motor and the control system electronics are protected from excessive current levels by current sensing means. When the current exceeds a predetermined level, the microcontroller limits the power drawn by the motor by ramping down the variable frequency to lower the speed of the motor. In case the motor or control electronics overheat, a temperature sensor is monitored by the microcontroller to shutdown the motor.

Abstract: An electric current compensation circuit for use with a multiple-phase burshless motor to reduce ripples in the output torque is disclosed. It contains a plurality of electric current compensation loops each for a respective phase winding and each of the electric compensation loops contains: (a) a first input for receiving a line current from the driver; (b) a second input for receiving the compensation current from the motor sensor; (c) a forward rectifying circuit for forwardly rectifying the line current and the compensation current; (d) a reverse rectifying circuit for reversely rectifying the line current and the compensation current; and (e) a summation circuit for summing the forwardly rectified compensation current and the reversely rectified compensation current and outputting a synthetic current to a phase winding of the motor.

Abstract: A commutation control strategy for eliminating torque ripple and noise from a brushless motor which has a plurality of motor phases connected in a bridge, each phase having a top switching device provided between a phase winding and a positive voltage supply and a bottom switching device provided between the phase winding and a less positive voltage supply in which following commutations of the motor, when the current flowing in a first phase is decaying towards zero and the current in a second phase is rising from zero, the switching devices are operative between a state in which the current flowing in the first phase is caused to decay at a first rate, and another state in which the current flowing in the first phase is caused to decay at a second rate which is lower than the first rate so that the rate of decay of the current in the first phase substantially matches the rate of rise of the current in the second phase.

Abstract: The invention concerns an improved system for windshield wipers in vehicles. An induction motor is used, in which speed is accurately controlled by controlling frequency of power supplied to the motor. The induction motor may be of the consequent-pole type, which ordinarily does not produce sufficient torque. Addition of (a) auxiliary tooth slotting and (b) skew has raised the torque produced to acceptable levels.The invention includes a control system, which senses excess load on the motor, which occurs as the windshield dries, and reduces motor speed, subject to a minimum, in response.

Abstract: A reduced vibration and reduced noise controller for a switched reluctance machine system and a method for reducing unwanted vibration and noise produced by a switched reluctance machine system. The energization of the voltage across a phase winding in the switched reluctance machine is controlled such that the voltage across the phase winding varies over time in a controlled manner from a first voltage level to a second voltage level following a predefined switching event. The control of the transition of the voltage across the phase winding from the first voltage level to the second voltage level is accomplished through application of a succession of timed voltage pulses to the phase winding at a fixed point in time after the predefined switching event or through use of a capacitor smoothing circuit.

Abstract: A reduced vibration and reduced noise controller for a switched reluctance machine system. A decoder circuit monitors firing signals which are used to energize a phase winding in the switched reluctance machine over an angular period of rotor rotation. When the firing signals indicate that a predefined switching event has occurred, one or more timed voltage pulses are applied to the phase winding at fixed points in time following the predefined switching event. The timed voltage pulses induce vibration forces in the motor which actively cancel unwanted vibrations in the motor system, thus reducing unwanted vibrations and acoustic noise.

Abstract: A disk drive including firmware for overcoming stiction and breaking free the heads of a disk drive which may adhere to the disk surface when the disk is at rest. Upon start-up of the disk drive, if stiction at the head/disk interface occurs, the voltage to the spindle motor and/or actuator motor may be rapidly fluctuated so as to cause a pulsing of the spindle motor and/or actuator motor. Pulsing both the spindle motor and actuator motor creates forces in a plurality of radial directions to allow the head(s) to break free from the disk(s) in the direction of least resistance. Moreover, as the resonant frequency of the spindle motor varies depending on the number of heads that are stuck, the firmware pulses over a range of frequencies including the various resonant frequencies of the spindle motor corresponding to various numbers of heads stuck.

Abstract: In a motor drive circuit, the collector-emitter paths of two npn-type transistors are connected in series between a power line and ground, and the junction between the two transistors is connected to a motor coil. A control circuit feeds a control current to the base of the transistor connected to the power line so that this transistor supplies a drive current to the motor coil. A current mirror circuit is provided which is constituted of two pnp-type transistors whose emitters are connected to the power line, and the base and collector of the input-side transistor is connected to the control circuit through a diode. The base of another pnp-type transistor is connected to the cathode of the diode, and the emitter of this transistor is connected to the collector of the output-side transistor of the current mirror circuit and to the base of the transistor connected to the power line.

Abstract: The invention relates to a method for positioning a pen in a recording device for recording the time profile of a measurement signal which can be connected. In order to implement the highest possible mapping accuracy of the measurement signal onto the recording signal at a low cost and with DC isolation between the measurement signal and drive means of the pen, it is proposed that the positioning error (300) be phase-width modulated, the pulse-width-modulated positioning error (400) be transmitted in a floating manner to a signal converter (70), and a control voltage for the electric motor (90) be determined using the signal converter (70) from the pulse-width-modulated positioning error (400) by normalizing the difference between the pulse duration and the pulse-pause duration, via the sum of the pulse duration and the pulse-pause duration.

Abstract: In a motor control apparatus for controlling a rotational position of a motor, a rotation detector detects the rotational position of the motor, and outputs first and second detection signals having phases corresponding to a detected rotational position of the motor and different from each other, and a position detecting circuit detects a rotational position in a unit which is less than one cycle of the first and second detection signals based on the first and second detection signals, and outputs a rotational position signal representing a detected rotational position. Further, a motor controller compares the rotational position signal with a reference position signal representing a reference rotational position of the motor to obtain a position error, and controls the rotational position of the motor so that the position error is minimized.

Abstract: In a method for controlling an electric motor the stator voltage frequency of the motor is determined by adding the optimal slip frequency of the motor and the desired rotational frequency of the rotor. The magnitude of the stator voltage is determined by subtracting the actual rotational frequency and the desired rotational frequency of the rotor. The desired stator frequency and magnitude are inputted into a pulse width modulation unit which controls an inverter to supply the appropriate voltages to the motor. The operation of the motor with optimal slip has the advantage that the efficiency is optimal independent of the load.

Abstract: A control system (100) for a five-phase brushless DC motor (102) including a stator having five windings and a rotor (116) mounted for rotation relative to the windings (114). The windings (114) are adapted to be electronically commutated in response to the rotary position of the rotor (116). The control system (100) includes a sensing circuit (106) to sense the rotary position of the rotor (116) using an optical or magnetic sensor or the back electromotive force voltages in the windings (114). Electronic switches (112) control the flow of current through the windings (114) in response to control signals generated by a control circuit (110) in response to the rotary position of the rotor (116). The control circuit (110) includes start-up logic to start the motor (102).

Abstract: A control apparatus for an electric vehicle includes a device for detecting a degree of depression of an accelerator pedal in the electric vehicle, and for outputting an accelerator depression degree signal representing the detected degree of depression of the accelerator pedal. A polyphase ac motor is operative for driving the electric vehicle. A rotational speed of the polyphase ac motor is detected, and a motor rotational speed signal is generated which represents the detected rotational speed of the polyphase ac motor. A battery in the vehicle generates dc power. An inverter changes the dc power into ac power through pulse width modulation responsive to a PWM modulation signal, and outputs the ac power to the polyphase ac motor to drive the latter. A steady torque command value is calculated on the basis of the motor rotational speed signal and the accelerator depression degree signal.

Abstract: A process and device for field-oriented control of a polyphase machine, where a torque-producing quantity is regulated via a speed control circuit and a flux-producing quantity is regulated via a field control circuit that determines the magnitude and angle of the flux. The flux magnitude is injected through the field control circuit. Orientation errors in the field axis are corrected through frequency adjustment, specifically by adjusting the slip frequency according to the difference between the transformation angle used and the flux angle. The voltages and currents that create the rotational field of the machine are generated via a current control circuit in accordance with the corrected reference values.

Abstract: A control system for an induction motor of the present invention independently commands the torque current component and the exciting current component of a stator current group supplied to the stator of an induction motor so as to feed-back control the amplitude and phase of the stator current group. The torque current component is commanded to control the output torque of the induction motor in correspondence with the output of a steering force sensor for detecting the steering force. According to an electric power steering apparatus using an induction motor controlled by the control system, a permanent magnet is not used for the motor so additional equipment such as a clutch is not required. Consequently, the structure can be simplified and the size of the unit can be reduced. Further, manual steering operation can be performed in the case of failure.

Abstract: A three-phase, low-pass filter for use in an electronic speed control system and wherein an adjustable speed drive is disposed in signal transmitting relation relative to an electric motor by an electrical conduit having a predetermined length, and wherein each single-phase circuit of the three-phase, low-pass filter includes an inductor having input and output nodes, a first resistor electrically coupled in parallel to the inductor, a second resistor having input and output nodes, and wherein the input node of the second resistor is electrically coupled to the output node of the inductor, and a capacitor having input and output nodes, and wherein the input node of the capacitor is electrically coupled to the output node of the second resistor, and wherein the low-pass filter is electrically coupled to the electrical conduit and operable to substantially filter out frequencies that tend to excite the natural resonant frequency of the electrical conduit.

Abstract: A method and apparatus for improving the efficiency of operation of polyphase AC induction motors. The method and apparatus utilizes a microprocessor to tune a motor control system such that time interval on at least two phases of a multi-phase power source such that the time intervals between turn-on of bi-directional switches and the time of sensing the resultant inrush currents of the two phases on two motor stators are maintained substantially constant as the load is varied.

Abstract: The present invention provides a protection apparatus in a control system for an electric vehicle which is capable of performing back-up driving by using a back-up control method, without using output from sensors even if the sensor in the control system for ordinary driving is failed. When at least one of the current sensor, the speed sensor and the accelerator sensor is detected to be abnormal, a back-up control voltage v1 is output as an abnormal signal from a running back-up control circuit. As a result, the running back-up control circuit sets the limiter of the output of the current control circuit to zero and switches the control signal to the inverter from vector control to V/f voltage control.

Abstract: An inverter-driven induction motor system having input lines (12,14,16) for receiving a three-phase ac input signal which is converted into a dc signal and transmitted on dc bus lines (24,26) before gated into a three-phase alternating current output signal transmitted to the motor on output lines (34,36,38). A four winding common mode inductance (L1) is connected on the output side with an inductance connected to the motor ground wire (42). A ground wire choke (Lg) is also added to further reduce conducted emitted radio frequency noise or interference. A third order filter and grounding capacitance (C14,C15,C16) are further added to the ac input side to improve EMI performance.

Abstract: A control unit for an induction motor continuously provides a precise output torque without being adversely affected by a magnetic saturation of an iron core, or varying precision of sizes of components constituting the motor or varying temperature of the motor. When a torque command value T* is smaller than a predetermined value Trf, an excitation inductance M is corrected in accordance with a torque voltage command Gq.multidot..DELTA.i1q which is calculated on the basis of a torque current command i1q* and a torque current i1q. Further, a secondary resistance r2 is corrected on the basis of the torque voltage command G.multidot..DELTA.i1q. A slip frequency is calculated on the basis of the secondary resistance r2, a magnetic induction command .phi.*, and torque current command i1q*. An angular frequency command .omega. is calculated. The magnetic induction command .omega.

Abstract: An asynchronous motor is supplied with power from an AC line voltage via a variable speed drive including a rectifier bridge connected to the AC line voltage, a DC voltage intermediate circuit including a capacitor and an inverter including switches and connected to the phase windings of the motor. A system for controlling the power supply to the motor includes a device for controlled resumption of motor speed after supply of power to the motor is interrupted.

Abstract: The invention relates to a method and apparatus for recognizing a standstill condition when restarting a power converter-fed AC motor without a tachometer generator. According to an embodiment of the invention, a standstill recognition method includes first and second active phases decoupled by a passive phase. In each phase, time characteristics of the orthogonal current components of a measured motor current are recorded, and the energy component of current from the second active phase is further evaluated to generate an average value. This generated average value and an upper range value are then compared to a limiting value, which will be exceeded when the AC motor is at a standstill. Thus, through application of a current measurement and a simple evaluation, one can quickly determine the actual state of the power converter-fed AC motor when restarting.

Abstract: Disclosed are methods and apparatus for quickly measuring a primary resistance value of an AC motor without using high precision detectors and detecting malfunctions such as breaking of wire in the AC motor or in a power converting mechanism, open phase, and three-phase unbalance. A voltage drop attributable to the primary resistance of the AC motor can be estimated by using an estimated resistance value R.sub.1.sup.#, which is estimated in turn by an integral or proportional-plus-integral operation on the deviation between a detected magnetizing current value I.sub.M and a reference magnetizing current value I.sub.M *, in place of an actual primary resistance value R.sub.1. The time for the estimated resistance value R.sub.1.sup.# to reach the true primary resistance value is reduced with a varying reference magnetizing current value I.sub.M **. Variations of the estimated primary resistance values R.sub.1.sup.# s between the phases are corrected with a mean estimated primary resistance value R.sub.1M.sup.

Abstract: Provided is a method and apparatus for simulating the behavior and operation of a three-phase induction machine. The present invention provides for a digital simulating device for simulating the behavior and operation of three-phase induction machines in accordance with selected parameters. There is further provided a computer modeling method for behavioral and operational analysis which utilizes blocks and super-blocks connected with signals as in physical systems. The modeling method incorporates an algebraicly simplified set of equations in stationary 2-axes reference frame.

Abstract: A frequency, voltage and waveshape converter is placed between the terminals of an ordinary single-phase power line and the power input terminals of a three-phase induction motor. The converter is operable to provide to the power input terminals of the induction motor a three-phase AC voltage of frequency, magnitude and/or waveshape controllably different from those of the power line voltage, thereby to permit effective control of motor speed and power factor. The frequency of the AC voltage is adjustable over the range of 12-120 Hz, with the effective magnitude of the AC voltage being automatically adjusted in proportion therewith, thereby providing for a very wide range of motor speed control without incurring reduced motor operating efficiency.

Abstract: An apparatus for driving an AC motor at variable speeds facilitates arbitrary setting or adjustment of equivalent primary resistance of an AC motor. In one embodiment of the present invention, a reference AC voltage generator outputs reference AC voltage values for each phase of the AC motor, and signals derived from the reference voltage values are in turn used by a power converter to supply the AC motor with variable voltage and frequency. In this embodiment, two or more phase currents are fed back to, and subtracted from, the reference voltage values via a regulator. In another embodiment, an angular-frequency/biaxial-reference-voltage value generator generates a reference primary angular frequency value and biaxial reference voltage values of the AC motor in a rotating orthogonal coordinate system. In this embodiment, two or more of the AC motor's phase currents are fed back to, and subtracted from, the biaxial reference voltage values via a vector transformer and a regulator.

Abstract: A phase regulated power supply is provided for converting alternating current (AC) to direct current (DC) for powering a DC brushless motor, such as a fan. The power supply includes a full wave bridge rectifier and a driver circuit, which may be an IC chip, controlled by standard commutation circuitry. An output capacitor is connected electrically downstream to the switch for supplying a reduced DC ripple voltage to the motor load. The power supply preferably includes a line filter for removing input power surges. The speed of the motor may be varied by changing the values of bias resistors used with the driver circuit.

Abstract: A motor control apparatus and method is disclosed for controlling a multiphase AC motor by controlling electrical quantities such as voltage or current applied to the stator of the motor. The apparatus includes a motor command unit for defining a reference signal indicative of a desired motor parameter such as torque, speed, or position, a DC voltage link, a controller, a line-side converter including active switches in a bridge configuration for controlling the bidirectional flow of electrical power between the DC voltage link and a source of AC power, and a motor-side converter including active switches in a bridge configuration for controlling stator electrical quantities by controlling the bidirectional flow of electrical power between the DC voltage link and the motor, where the motor-side converter includes control means responsive to the reference signal for controlling the active switches to produce stator electrical quantities that correspond to the reference signal.

Abstract: A power control circuit for improved temperature control of thermoelectric devices to maintain the temperature of thermoelectric devices at a set point.

Abstract: Polarity change of a feed-forward compensation signal for compensating for a dead-time voltage disturbance is synchronized with zero crossings of a load current reference. The load current reference is advanced in time by adding a fixed phase angle, scaled by the synchronous frequency, to the synchronous coordinates angle. The load current reference is time-advanced only for timing the polarity change of the feed-forward compensation signal and not for application to the current regulators; the current regulators still use the load current reference (unadvanced). For a converter, the load current would be an AC mains input current. For an inverter, the load current could, for example, be an induction motor stator current. The shape of the feed-forward compensation signal is approximately trapezoidal and is obtained from the limited, amplified, advanced load current reference.