Abstract: A method and apparatus for braking an AC motor in the higher portion of its speed range includes substantially reducing flux before applying reverse torque commands to brake the motor. A DC link bus regulator is employed to prevent increases in bus voltage and frequency.

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

Abstract: An interface circuit for actuating an electrical consumer, especially a pole-changing rotary-current induction motor, with a first contact element assigned to a signal line carrying an alternating voltage signal to generate at least two different control signals. A circuit arrangement is provided for actuating an electric motor, especially a pole-changing rotary-current induction motor, with a control switch element having an aforementioned interface circuit, which is connected via a signal line to a motor control of the electric motor.

Abstract: A dc motor drive system with a PWM control system permits a high-accuracy rotation drive control while detecting the currents flowing into the coils without using shunt resistors. The system drives output MOS transistors by the PWM control to make the currents flow into the coils, and drives to rotate the dc motor. The system includes current sensing MOS transistors having a predetermined size ratio 1/m (M>1) to the output MOS transistors that make the currents flow into the coils. The current sensing MOS transistors are capable of making flow reduced currents proportional to the currents of the output MOS transistors.

Abstract: Filter network for the reduction of the voltage switching speed between an electrical motor drive and an electrical motor and/or between an electrical distribution network and a motor drive, comprising for each electrical phase a self-damped inductor having a complex impedance determined by a magnitude (Z) and a phase (?), the phase (?) of the complex impedance being comprised between 80 and 90 degrees in the frequency range of the motor's current, and being less than 60 degrees in the frequency range of the overvoltage oscillations. Using the inventive filter network, it is possible to manufacture low cost and small size du/dt-filters generating low voltage overshoot and low losses.

Abstract: An inverter supply voltage generator comprises an inverter supply voltage computing unit 10, a voltage converter 11 and a battery 12. The inverter supply voltage generator varies inverter supply voltage Vdc in synchronization with motor-application voltages Vu_pwm, Vv_pwm, and Vw_pwm. Thus, the degree of freedom of the switching operation of a PWM inverter 13 is increased, an inverter loss and the size of the PWM inverter 13 can be reduced, and its efficiency can be enhanced without deteriorating the driving efficiency of an IPM motor 14.

Abstract: In a controller for brushless motor which suppresses the generation of abnormal noise when the motor current is controlled by updating voltages applied to the coils, the present values of the applied voltages to the coils are calculated from the d axis target current, the q axis target current, the d axis actual current, the q axis actual current, and the present value of the detected rotational position of the rotor. The updating period of the applied voltages is set as a period that is shorter than this calculation period. The predicted value of the rotational position at a point in time at which the applied voltages are updated until the next calculation of the present values of the applied voltages is determined in accordance with the present value, a past value of the detected rotational position, and the applied voltage updating period.

Abstract: A method and apparatus for use with a controller that supplies voltages to an induction machine via supply lines, the voltages including a fundamental voltage component and an injected voltage component, the line voltages also including harmonic voltage components where the harmonic voltage components include at least a high frequency first harmonic component having a frequency substantially equal to the sum of the fundamental component frequency and the injected component frequencies, the method for identifying the high frequency first harmonic component and comprising the steps of sensing the line voltages, identifying a zero sequence voltage component of the line voltages, rectifying the zero sequence voltage component to generate a rectified signal and using the rectified signal to identify the high frequency first harmonic component.

Abstract: A method of balancing the rotation of a motor is provided. Whether or not the motor is in a balanced rotation is determined by detecting whether the variation of a power-factor angle is less than or equal to a preset balance angle according to the principle that the load on a motor has an effect on the variation of the power-factor angle. The determined balance state of the motor is used to adjust the rotation speed of the motor.

Abstract: A circuit and method provide a back EMF signal that represents a back EMF voltage induced in a coil of a brushless motor. In one embodiment of the invention, the circuit includes an input node operable to receive a tap voltage from the coil, and a network coupled to the input node and operable to generate the back EMF signal by removing a predetermined offset voltage from the tap voltage. Such a circuit provides a signal that more accurately indicates a zero crossing than existing circuits for controlling a sensorless brushless motor.

Abstract: A method for determining the rotor flux vector of an electrical machine, the method comprising the steps of controlling the electrical machine with an inverter, forming an equation for the reactive power (Qinv) at the output of the inverter, forming an equation for the consumed reactive power ({circumflex over (Q)}mot) in the electrical machine, forming a reactive power balance equation (Qerr) between the reactive power (Qinv) at the output of the inverter and the reactive power ({circumflex over (Q)}mot) consumed in the electrical machine, determining the stator resistance ({circumflex over (R)}s) of the electrical machine from the balance equation (Qerr), determining the stator flux estimate ({circumflex over (?)}s) using the determined stator resistance ({circumflex over (R)}s) and the balance equation (Qerr), and determining the rotor flux estimate ({circumflex over (?)}R) using the determined stator flux estimate ({circumflex over (?)}s).

Abstract: A motor variator and a driving method thereof are provided for controlling the operating speed of a fan, which employ an alternate current chopper to change the working cycle and the rotary speed of a stepless motor. The motor variator includes a high-frequency alternate current chopper connected to an induction coil of an induction motor, an alternate current power supply connected to the high-frequency alternate current chopper and a controller connected to the high-frequency alternate current chopper for outputting a switch signal to the high-frequency alternate current chopper, such that the high-frequency alternate current chopper is controlled by the switch signal to perform a chopper action for the alternate current power supply and output a drive voltage, so as to change the rotary speed of the induction motor.

Abstract: A microcomputer includes an actual DUTY value detection section that detects an actual DUTY value ?x by measuring the ratio of time in which an output voltage of each phase becomes a power supply voltage in a cycle of a triangular wave. A dead time compensation computation section subtracts the actual DUTY value ?x from a DUTY instruction value ?x before correction, thereby computing a difference value ?x. Subsequently, the dead time compensation computation section adds the difference value ?x to dead time compensation amounts ?xp, ?xm, which have been used for correcting the DUTY instruction value ?x, thereby determining new dead time compensation amounts ?xp? and ?xm?. The dead time compensation amounts ?xp, ?xm stored in a memory are renewed with the new dead time compensation amounts ?xp?, ?xm?.

Abstract: A motor control apparatus includes a direct-current power source and an inverter circuit, which includes a switching element. The motor control apparatus receives a current command value in every control cycle and calculates a current deviation accumulated value by accumulating the current deviation between the received current command value and the actual current value that flows through a coil of a motor. The motor control apparatus then computes a voltage command value in accordance with the current deviation accumulated value and controls the switching timing of the switching element based on the voltage command value. The motor control apparatus judges whether the computed voltage command value exceeds a range of the voltage that can be output from the inverter circuit and causes saturation. If it is judged that the voltage command value is saturated, the motor control apparatus restricts the accumulation of the current deviation.

Abstract: A method for sensorless estimation of rotor speed and position of a permanent magnet synchronous machine the method comprising the steps of calculating first stator flux vector estimate ({circumflex over (?)}d,i+j{circumflex over (?)}q,i) using the flux model and measured stator currents, calculating second stator flux vector estimate ({circumflex over (?)}d,u+j{circumflex over (?)}q,u) using the voltage model and measured stator voltages, comparing the directions of the first and second flux vectors to achieve a first error signal (F?), using speed adaptation to achieve estimates for the rotor angular speed ({circumflex over (?)}m) and angular position ({circumflex over (?)}m) from the first error signal (F?), injecting a known voltage signal (uc) to the stator voltage, detecting a current signal (iqc) from the stator current to form a second error (?) signal, which is dependent on the estimation error of the rotor position, augmenting the voltage model by the second error signal (?) to keep the first and se

Abstract: To a neutral point of a motor is connected a positive electrode of an auxiliary battery and an auxiliary load. Voltage on a power supply line to the auxiliary load, a neutral point voltage, is detected, and disconnection of the auxiliary battery is determined when an increase of ripples in the neutral point voltage is detected. When a voltmeter cannot be used, control of the neutral point voltage is continued by measuring current of the auxiliary battery and performing control such that the current value becomes 0. A resolver is further provided on the motor for detecting the rotor angle with high accuracy. A control circuit generates, in accordance with an output of the resolver, a voltage control signal for each phase current having the same amplitude as the carrier amplitude during startup, and compares the voltage control signal to carrier to obtain a gate signal having the same frequency as the carrier frequency.

Abstract: Certain circuit faults in a phase of a multi-pole, switched reluctance, rotary electrical machine are detected; and the machine is selectively operated with a detected circuit fault when the nature of the fault permits continued operation of the phase and the operation of the phase is desirable. The fault may be one of certain short or open circuits in which at least one of the two current controlling electronic switches is operable to control phase current within predetermined limits. In the continued operation when a fault is detected, (1) the phase current is switched off earlier than it would be in the absence of the fault and/or (2) the maximum phase current is reduced compared with that permitted in the absence of the fault; and either or both of these modifications may be a function of motor speed. If the circuit fault adversely affects current control by an electronic switch normally controlling current level, another electronic switch is substituted for current 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: An automotive generator/motor is driven by a battery via an inverter. Resistance 2Ra0 is expressed by 2Ra0=Vmax/?{square root over (3)} Iamax, where Vmax is a maximum voltage applicable across any two terminals from the inverter and Iamax is a maximum current which must be fed from the inverter into each of the terminals when the maximum voltage Vmax is applied for maximizing torque produced by the automotive generator/motor at a power factor of 1 under voltage saturation conditions, and the armature winding is configured such that resistance 2Ra across any two terminals satisfies a relationship expressed by 0.8Ra0?2Ra?3.8Ra0.

Abstract: A power conversion device is constituted by: a power converter that receives AC power and uses this to drive an AC motor; a control section for controlling an inverter section of the power converter; a voltage detection section that detects the voltage of the AC power source; a current detection section that detects the input current of the AC motor; and a speed detection section that detects the rotational speed of the AC motor.

Abstract: A motor control device that can reduce electrical noise is provided. A motor control device includes an inverter, a current controller, a high frequency wave superpositioner, and a high frequency wave setter. An inverter applies a current to the motor. A current controller outputs a voltage to the inverter according to a current applied to the motor from the inverter. A high frequency wave superpositioner applies a high frequency wave to the voltage from the current controller as a superpositioned wave to infer a position of a rotor in the motor. A high frequency wave setter varies at least one characteristic of the superpositioned wave applied by the high frequency wave superpositioner.

Abstract: A speed control system of a fan motor of an air conditioner is disclosed. A speed control system of a fan motor of an air conditioner comprises: an inverter having a power output terminal connected to a single-phase power input terminal of the fan motor which has a single-phase stator including a main coil and a sub coil, an induction rotor and a permanent magnet rotor installed between the stator and the induction rotor; and a three-phase driving motor connected to the power output terminal of the inverter and driving a compressor of an air conditioner by power received from the inverter.

Abstract: An induction motor system comprising an induction motor, equipped with a heat recovery and water pumping apparatus and an apparatus for controlling the electrical efficiency and resulting heat generation of the induction motor. The motor is adapted to be coupled to an AC source for supplying an AC signal. The controlling apparatus includes a switching device, user controls and optional inputs. The switching device is connected in series with the motor and is operative in either a high impedance state wherein significant current flow through the motor is prevented or a low impedance state wherein current flow through the motor is substantially undisturbed. The user controls provide motor operational input signals. The optional inputs provide setpoint and sensed water temperature input signals.

Abstract: A motor driver has a plurality of output circuits each having an upper side switch and a lower side switch connected in series for supplying a current to a motor. The motor driver includes a current detection resistor connected in series with the plurality of output circuits in common for detecting a current supplied to the plurality of output circuits, a position detection circuit for outputting a position signal corresponding to a position of a rotor of the motor, a current command generation circuit for generating a target current command signal based on the position signal and a predetermined phase angle in which a phase angle of the target current command signal is determined by the predetermined phase angle, and a space vector modulation based logic control circuit for commanding a plurality of output circuits that are set in a plurality of switches states for control of an electric motor.

Abstract: A method controls a torque of an a. c. motor which does not cause a shortage of torque by using an economical current detection which estimates d- and q-axis currents Idc, Iqc from d. c. current IDC flowing through an input d. c. bus line of a power converter. A value of d- and q-axis motor currents Id, Iq of a rotational coordinate system are estimated from detected input d. c. current IDC flowing through the bus line of the power converter to which power is input from a d. c. power source 21. A output voltages of the power converter 2 are controlled so that the estimated currents Idc, Iqc are equal to respective current instruction values Id*, Iq*. Errors of motor constants are determined from information on the motor currents and the rotational phase errors by an operation.

Abstract: The invention concerns a drive arrangement of a lifting gear and/or a traveling gear, with a pole-reversible rotary-current motor with windings for at least two different actuating speeds, with a pole switching element connecting the rotary-current motor to a voltage supply for changing between the actuating speeds of the rotary-current motor. In order to create a drive arrangement of a lifting gear and/or a traveling gear with a rotary-current motor, whose switching behavior is optimized in relation to the actuation of the rotary-current motor, it is proposed that a power switching element (3) be hooked up in front of the pole switching element (5), and it can be separated from the voltage supply via the power switching element (3) for the pole switching process of the rotary-current motor (2).

Abstract: A unipolar drive includes a booster, an energy storage module, and a unipolar inverter. The booster increase a voltage received from a power supply to produce an energy output. The energy storage module store at least some of the energy output by the booster. The unipolar inverter energizes windings of a motor using energy from the booster and returns energy from the windings to the booster when the windings are not being energized.

Abstract: A compressor having a winding circuit and a driven member being driven in part by a winding of the winding circuit. The compressor further includes an auxiliary circuit connected in a parallel relationship with the winding circuit. The auxiliary circuit has an auxiliary circuit element and an electronic switch assembly connected in a series relationship such that the electronic switch assembly controls the current through the auxiliary circuit element.

Abstract: A control device measures time intervals T1 to T12 from the reference time until when each of the rotational angles ?bn1, ?bn2 output from each of resolvers becomes n×60 degrees (n=1 to 12, i.e., 60 degrees to 720 degrees). Then, the control device calculates a deviation angle ??n at each of the rotational angles at the intervals of 60 degrees by calculating T1/T12 to T11/T12 using the measured T1 to T12. By substituting the calculated deviation angle ??n into an equation, n×60°+??n (n=1 to 11), the control device corrects the rotational angles at the intervals of 60 degrees. The control device generates each of drive signals DRV1, DRV2 using each of the corrected rotational angles, and outputs each of the drive signals DRV1, DRV2 to each of inverters. The inverters drive each of AC motors (M1, M2) based on each of the drive signals DRV1, DRV2.

Abstract: A motor driving apparatus including a regeneration control function and a power storage device for accumulating a regenerative current and for supplying an inverter section with electric power during acceleration. The inverter section is connected to a converter section by a DC link to which regeneration start detecting means and the power storage device are connected. When the regeneration start detecting means detects that a voltage at the DC link reaches a regeneration control start voltage, a controller controls switching elements and starts regeneration control. The regenerative current is accumulated in the capacitor through a diode. When a motor is in a power running state, the switching elements are turned on to apply the voltage at the power storage device to the DC link, and the charged power is utilized for motor acceleration.

Abstract: A method and a system for controlling parallel-connected frequency converters or inverter units feeding an alternating-current motor (MOTOR1) provided with parallel windings or separate parallel motors having their shafts mechanically coupled together via a load, in which method the current supplied to the motor is measured. The frequency converters/inverter units are connected to each other via a data bus, e.g. a fast serial bus, and one of the frequency converters/inverter units (FCON1 or INU1) functions as a master device in such manner that it sends to the other device/devices (FCON2 or INU2) information over the data bus regarding the instantaneous value of the current (IW1) fed by it to the motor, said other devices functioning as follower devices so that they adjust their own current (IW2) on the basis of the current of the master device.

Abstract: A method of measuring a motor constant is provided in a vector control apparatus for an induction motor. A voltage output phase ?v is set at a previously set arbitrary phase. Prior to applying a current, a current command is fed to operate the vector control apparatus with a proportional-plus-integral controller being set operative. After conduction for a predetermined time, the gain of the proportional-plus-integral controller is set to zero to maintain an integrated value constant and accordingly fix a voltage command value. In this state, a current command value and a detected current value are measured. This measurement is performed at two levels of current, and a primary resistance value (or a line-to-line resistance value) is derived from the slope.

Abstract: A method and an apparatus for controlling ride through of an induction motor by detecting a power loss from a power supply connected to the induction motor, disconnecting the induction motor from the power supply, monitoring a line voltage of the power supply, monitoring a back emf voltage generated by the induction motor and monitoring a phase differential between the line voltage and the back emf voltage. It is determined whether the monitored voltages are within a predetermined voltage limit and the phase differential is within a predetermined phase limit and the power supply is re-connected to the induction motor in response to the monitored voltages being within the predetermined voltage limit and the monitored phase differential being within the predetermined phase limit.

Abstract: A control constant adjusting apparatus in a control apparatus of a robot or a machine tool, etc. is disclosed. This control constant adjusting apparatus includes a speed control part (12), an estimation part (13), an identification part (14) and an adjustment part (15). The identification part (14) makes identification of inertia J obtained from a ratio between a value |SFTr| in which an absolute value |FTr| of a value FTr obtained by passing a torque command Tref of the speed control part (12) through a predetermined high-pass filter is integrated with respect to time at a predetermined interval [a, b] and a value |SFTr?| in which an absolute value |Ftr?| of a value FTr? obtained by passing a model torque command Tref? of the estimation part (13) through a predetermined high-pass filter is integrated with respect to time at the same interval only when a speed Vfb? of a model in the estimation part (13) matches with a motor speed Vfb in the speed control part (12) at a value other than zero.

Abstract: An electric machine drive (50) has a plurality of inverters (50a, 50b) for controlling respective electric machines (57, 62), which may include a three-phase main traction machine (57) and two-phase accessory machines (62) in a hybrid or electric vehicle. The drive (50) has a common control section (53, 54) for controlling the plurality of inverters (50a, 50b) with only one microelectronic processor (54) for controlling the plurality of inverters (50a, 50b), only one gate driver circuit (53) for controlling conduction of semiconductor switches (S1–S10) in the plurality of inverters (50a, 50b), and also includes a common dc bus (70), a common dc bus filtering capacitor (C1) and a common dc bus voltage sensor (67). The electric machines (57, 62) may be synchronous machines, induction machines, or PM machines and may be operated in a motoring mode or a generating mode.

Abstract: A method of controlling the torque of a multiphase induction motor includes the step of energizing the stator windings of the motor from a power converter using thyristors, inserted between a multiphase main supply and the windings producing a stator current set point expressed by its amplitude and its phase, predicting phase coincidences between the stator current and the set point, and commanding the power converteer so that the windings receive current waves substantially when such coincidences occur.

Abstract: Apparatus for driving a three-phase compressor assembly from a single-phase electrical power supply having first and second power lines, said three-phase compressor assembly comprising a compressor having a rotatable shaft, an electrical motor having a rotatable shaft coupled to the rotatable shaft of the compressor, the electrical motor having at least first, second and third motor windings and having at least first, second and third terminals connected to the first, second and third windings, means adapted to connect the first and second power lines of the single-phase power supply to the first and second terminals and a torque augmentation circuit for injecting current into the third terminal and including a capacitor and an electrical component in series with the capacitor, said electrical component having resistive characteristics and having means for essentially interrupting the current being injected into the third terminal.

Abstract: An angular position sensor (1) suitable for use in combination with the rotor of an electric motor comprising both absolute and incremental encoders (3) where a first signal of the absolute encoder produces a period corresponding to an electric revolution of the motor and less than a mechanical revolution of the rotor, a second output of the incremental encoder varies periodically over a complete revolution of the rotor, where the two signals provide sufficient information to determine the absolute mechanical position of the rotor. Typically, transitions in the first output signal combined with the state of the second output signal provide such information.

Abstract: A motor control apparatus calculates a current command value based on a torque command value and a rotational speed of the traction motor, and calculates a voltage command value based on a difference between a detected current of a traction motor and the current command value so as to reduce the difference to 0. In addition, the motor control apparatus calculates a preferable voltage range of the traction motor with reference to the torque command value and a motor speed, and performs a feedback control so that the voltage value supplied to the traction motor is within this preferable voltage range.

Abstract: A method for increasing the control response of a drive train of a machine tool or production machine with backlash and/or elasticity is described. A combined signal comprised of the motor speed measured on the motor and the load speed measured near the load of the drive train is supplied to a controller. The combined signal can generated in one of two ways: (1) by weighting the measured motor speed with a first multiplication factor (?), by weighting the measured load speed with a second multiplication factor (1??), and by subsequently adding the weighted motor speed to the weighted load speed; or (2) by first subtracting the measured load speed from the measured motor speed, then weighting the resulting difference by a multiplication factor ?, and finally adding the load speed to the weighted difference.

Abstract: Corresponding to a target torque, the control device calculates a target value of a feature based on at least one of the length of a long axis of a current vector locus and the length of the short axis and further superimposes a superimposed current on a drive current for the motor, the superimposed current having a frequency different from the frequency of the drive current. Further, the control device detects an actual value of the feature based on at least one of the length of a long axis of a current vector locus of the superimposed current and the length of the short axis of the same and finally detects a phase angle of the motor based on the target value and the actual value for the feature. The manipulation of a detecting phase is performed by feedback of a feature obtained by the magnitude of the superimposed current. That is, when the actual feature is more than the target value, the detecting phase is advanced.

Abstract: In an electric motor control system according to the present invention, in restarting, after the effect of transient variation has been abated, a phase-reversal-timing detecting means 31 detects the first maximal value V1, the first minimal value V2, and the second maximal value V3, by comparing a value of the integration term of the d-axis component vds* of the 2-phase-voltage command outputted from the d-axis current control means 28 with its previous value, and then outputs a time at which the value of the integration term of the d-axis component vds* of the 2-phase-voltage command becomes below (the first minimal value V2+the second maximal value V3)/2, as the first specific phase at which the current-commanding phase is turned by 180 degrees, to the current phase commanding means 22.

Abstract: A system and method is described for using a matched reactance machine power generation system (MRMPGS) to provide a constant-voltage power for an electric distribution system. The system and method include a permanent magnet rotor type machine without a field winding for excitation. This type of machine presents much better reliability, as the excitation of the machine is fixed and achieved by a permanent magnet embedded in the rotor assembly. The voltage regulation is achieved through speed and load coordination that is based on a machine reactance specially selected and calculated to achieve compensation between the external voltage variation and the internal machine voltage drop, resulting in substantial savings in electronics hardware.

Abstract: A method of compensation for current-sensor gain errors in an electric machine drive 14 includes a high frequency carrier signal electrically injected into the electric machine 14. A current-sensor signal of the electric machine 14 is determined. The current-sensor signal is separated into current-sensor carrier signal negative and current-sensor carrier signal positive sequence reference frames. A proportional compensator signal for one of the current-sensor carrier signal reference frames is generated in a feedback loop 24. A magnitude signal of another one of the current-sensor carrier signal reference frames is generated in a different feedback loop 26.

Abstract: A control system for a polyphase AC motor having a predetermined horsepower rating is provided comprising a plurality of integrated control systems each rated at less than the hoursepower rating for the motor and having a rectifier section, an inverter section, and a controller section, and a parallel controller interfaced to each integrated control system.

Abstract: A drive circuit for operating a resonant motor includes a motor circuit, a feedback circuit, a control circuit, and a coil drive circuit. A feedback loop includes the motor circuit, the feedback circuit, and the control circuit. The feedback loop in conjunction with the coil drive circuit monitors, maintains, and adjusts the oscillatory motion of the resonant motor. The drive circuit is suitable for operating a resonant motor of an optical code reader.

Abstract: Apparatus including a DC-DC converter that applies a variable voltage to an inductive load, such as a fan motor. The converter has a low-frequency high dynamic output impedance and applies a variable voltage from its output to the inductive load. A transient limiter, such as a capacitor, is connected in parallel with the inductive load to minimize the amplitude of transients generated by the load during the reception of the variable voltage from the converter. The converter has a low frequency of operation to inhibit the generated transients from being extended to a DC power source connected to the input of the converter. This prevents the transients from being applied to other circuits served by the DC power source. The fan may be used to provide cooling for the apparatus of which the DC-DC converter is a part.

Abstract: One embodiment of the present invention is a method to control input to an alternating current (AC) induction motor from a power supply that includes steps of: (a) determining a measure of reactive power (VAR) in two input lines to the motor during a time period; and (b) maintaining an SSR (solid state relay) connected in series between the power supply and the motor in a non-conducting state for a subsequent time period, the length of which subsequent time period is determined by analyzing the measure of VAR.

Abstract: A system and a method for controlling a steering position of at least one rear wheel of a vehicle are provided. The vehicle has both a brushless electric motor with a plurality of electrical phase windings and a steering actuator. The brushless electric motor has a rotor configured to drive the steering actuator. The steering actuator is operably coupled to at least one rear vehicle wheel. The method includes determining a desired voltage value indicative of about one-half of a peak-to-peak voltage to be applied to each of the plurality of electrical phase windings of the brushless electric motor based on a desired rear vehicle wheel steering angle and a measured rear vehicle wheel steering angle. The method further includes determining when the desired voltage value is greater than a threshold voltage level. The method further includes calculating a phase advance angle based on at least the desired voltage value and the threshold voltage level.

Abstract: The present invention offers a novel control system for a multiphase motor. The control system involves energization circuitry for energizing each phase winding, and a control circuit for defining phase currents for individual phases of the motor to generate control signals applied to the energization circuitry for energization of the phase windings. When at least one phase of the motor fails, a mode selection circuit enables the control circuit to operate either in a non-correction mode or in a fault-correction mode. In the non-correction mode of operation, phase currents for phases that remain operational are maintained unmodified. In the fault-correction mode, the phase currents for the remaining phases are modified in accordance with pre-set parameters.