Abstract: A motor incorporating a power converter that includes a printed board on which an inverter IC, which converts a voltage of an external power supply into a high-frequency voltage and supplies the high-frequency voltage to a stator, is mounted, wherein on a surface of the printed board opposed to the stator, a high-voltage direct-current input wire, which is a copper foil provided on a surface on a stator side, is disposed. One end of the high-voltage direct-current input wire is electrically connected to a high-voltage input line of the external power supply and the other end of the high-voltage direct-current input wire is electrically connected to a high-voltage electrode of the inverter IC.

Abstract: A lithographic apparatus includes a positioner configured to position a first part of the apparatus relative to a second part of the apparatus, the positioner including a motor having a motor position dependent motor constant defining a relation between a motor input and a motor output, and a control system to drive the motor, the control system including a set-point generator to provide a reference signal based on a desired position of the first part relative to the second part, and a controller to provide a drive signal to the motor based on the reference signal, wherein the controller includes a compensator which is configured to at least partially compensate the drive signal for the motor position dependent motor constant. The invention further relates to a positioner, a method to optimize the positioning system, and a method to derive a motor position dependent motor constant.

Abstract: At least one embodiment of the invention relates to a protective circuit for protection of an appliance, in particular of an electric motor, against thermal overloading. In at least one embodiment, the protective circuit includes a first and a second terminal for connecting a temperature detection element; a detection unit for detecting whether a resistance value of the temperature detector element which is connected between the first and the second terminals, is in a first or a second resistance range; a short-circuit detector for identifying whether there is a short circuit between the first and the second terminals; signaling outputs for emitting signal messages to an evaluation unit when the detected resistance value is in the second resistance range and/or when a short circuit has been identified by the short-circuit detector; and a third terminal, which is connected to the second terminal via a predetermined resistance.

Abstract: Provided is a motor controller and method of controlling a motor with an improved maximum junction temperature rating. In accordance with one aspect of the present invention, a motor is controlled by varying a common mode voltage duty ratio for a plurality of solid state switching devices in a power inverter, generating drive signals for the solid state switching devices based at least in part upon the common mode voltage duty ratio, and changing states of the solid state switching devices based upon the drive signals.

Abstract: In a travel-driving mechanism for a self-propelled working machine such as a self-propelled lawn mower travels by using power of an electric motor 30, the torque of a driving shaft 50, which is driven by the power of the electric motor 30 through a power transmission unit 40, is transmitted to travel-driving wheels 7 through two-way or bi-directional clutches 55 provided at both ends of the driving shaft 50. Power transmission units 61, 62 are provided between the bi-directional clutch 55 and the driving wheels 7. A travel control unit 70 is provided to input an instruction signal produced by the operation of a travel operation member 66, which is operated by the operator, and to control the electric motor 30.

Abstract: A method of controlling an operation of an induction actuated container cover includes the steps of (a) normally retaining a cover panel of the container cover in a closed position; (b) detecting a target movement of a user by a sensor; (c) generating a first actuating signal to an actuation unit when the sensor detects the target movement of the user; (d) generating an actuation output from the actuation unit to the cover panel of the container cover, wherein the actuation output contains a decelerating and torque enhancing force which moves the cover panel of the container cover at an opened position; (e) pivotally actuating the cover panel of the container cover at the opened position via the actuation output to expose a storage cavity, and (f) generating a second actuating signal to pivotally actuate the cover panel of the container cover back to the closed position.

Abstract: A speed controller includes a speed integration compensation low-pass filter, an integral control system, a proportional control system, and a multiplication device means. The speed integration compensation low-pass filter has a transfer function corresponding to a delay of a speed control system. The integral control system 136 is multiplied by an integral gain by a multiplier and integrated by a speed integrator before being supplied to an adder. The adder adds an output of the proportional control system and an output of the integral control system and outputs the result to the multiplier, which in turn multiplies the output of the adder by a proportional gain and outputs the result as a torque command. The multiplication means multiplies the output of the integral control system and the output of the proportion control system by a speed proportional gain and outputting the value of the torque command.

Abstract: In a neutral range preset, there are set a zone for stopping and holding a rotating body only by a mechanical brake, a zone for holding the body only by performing position holding control, and a zone for simultaneously exerting both effects, i.e., the effect of the mechanical brake and the effect of the holding control. On-the-spot holding torque generated when the position holding control is performed is stored. The higher of the on-the-spot holding torque stored and accelerating torque according to an operation amount of the body at a rotation starting time is set as electric motor torque for acceleration. When performing a pressing work including pressing a bucket against an object for work, torque control is carried out according to the operation amount.

Abstract: The invention relates to a device and a method for estimating the speed of a slip ring asynchronous machine. The asynchronous machine includes a stator having a stator winding, arranged to be fed with three-phase voltage and current in order to generate a varying magnetic flux, and a rotor having a rotor winding in which the magnetic flux is arranged to induce a voltage to create an electromagnetic torque. The device includes a measuring member arranged to measure the value of the voltage in the rotor winding during at least one time period and a calculating unit, which is arranged, using the above measured voltage, to calculate a value of the rotor speed.

Abstract: A motor drive circuit and method with frequency setting and correcting functions. The drive circuit includes a speed control device, which simultaneously receives a sense signal and a rotation frequency signal. A pulse width modulation signal capable of modulating a duty ratio may be generated by a pulse width modulation method. The pulse width modulation signal is then transferred to a drive timing controller that generates a timing control signal to control output timing of a power drive signal for the drive circuit. Meanwhile, a sensor is used to detect a motor and to generate a correction sense signal, which is immediately fed back to the speed control device to form a closed loop control, so that the rotation frequency of the motor may be automatically corrected and set.

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: PWM AC power is supplied to an induction motor or other AC load. The frequency and magnitude of the waveforms is controlled by detecting the peak voltage or width of the reverse EMF pulses at the commencement of the power waveform applied to the load, and then adjusting the applied AC power based on the detected peak voltage or width. Alternatively, the depth of width of a notch that follows the reverse EMF pulse can be detected and used to control the applied AC power.

Abstract: An electrical steering system for a vehicle includes an electrically supplied steering motor arrangement which is connected with an inverter arrangement, whose output voltage is influenced by a computer arrangement, and a sensor arrangement. To reduce the cost of the steering system while also allowing the steering system to be steerable during braking in the case of a fault, the steering motor arrangement has a redundant steering motor which is connected with the computer arrangement via two separately run control circuits. The control circuits have separate electric supplies and the computer arrangement is redundant.

Abstract: In an electronic apparatus which includes a power generator and a storage device for storing electric energy obtained thereby, it is detected whether a motor driven by the stored electric energy is rotating by comparing the rotation detecting voltage, which is proportional to the induction voltage generated in the motor caused by the rotation of the motor, with a rotation reference voltage. The generation state of the power generator or the charging state of the storage device is detected. The level of the rotation detecting voltage or the level of the rotation reference voltage is shifted by a predetermined amount based on the detected generation state of the power generator or the detected charging state of the storage device so that the voltage difference between the rotation detecting voltage and the rotation reference voltage is increased during the no-rotation period.

Abstract: A method and apparatus for switching an AC motor between two power supplies such as supply mains and a variable frequency AC motor drive. In a transfer procedure, the motor drive is coupled to the motor to power the motor. When the supply main is connected to the motor, a resulting current spike in the output of the motor drive is detected to disconnect the motor drive from the motor very quickly while limiting current. In a capture procedure, both power supplies are coupled to the motor with the motor drive in an idle mode. When the supply mains are disconnected from the motor, the voltage change in the output of the motor drive is detected to quickly activate the motor drive to power the motor.

Abstract: A rotary induction machine in which operating characteristics of the machine are controlled by adding impedance elements to the rotor windings in which the impedance elements are stationary and connected to the rotor windings by a rotary transformer.

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: An air conditioner having a fan motor brown-out control algorithm for increasing the air conditioner fan speed upon sensing a brown-out under-voltage condition is provided. The air conditioner has a power supply connected to an AC line voltage, a fan motor, a multispeed fan driven by the fan motor and means for sensing a brown-out condition of the AC line voltage. The sensing means is connected to the power supply and provides a signal indicative of a brown-out condition. The air conditioner also has means for increasing the speed of the fan in response to the sensed brown-out condition signal provided by the sensing means. In an embodiment, the air conditioner further has a microprocessor and related circuitry for adjusting the speed of the fan. In another embodiment, logic circuitry is provided instead of a microprocessor. A brown-out control algorithm for an appliance having a multispeed fan and components for operating the fan is also provided.

Abstract: A motor controller for brushless motors operates an inverter in a current-controlled mode for low motor speeds and in a voltage-controlled mode for high motor speeds. By switching from the current-controlled mode to the voltage-controlled mode at higher speeds, the motor can be designed at maximum efficiency, and minimum weight, cost and volume.

Abstract: A motor drive control apparatus having an electrical power amplifier for supplying an electrical power to a motor, and a current control loop and speed control loop for controlling the drive of the motor, which includes a current feedforward component calculation section for creating voltage commands to be imposed on respective phases from current commands for the respective phases for the motor and the impedance model of the motor for carrying out a feedforward control by using the voltage commands to be imposed on the respective phases.

Abstract: An energy conserving device which reduces excess level of alternating current power fed to RUN windings of an a.c. electric induction motor whenever the motor is less than fully loaded. A voltage dropping reactor coupled between an a.c. power source and the motor produces about 10-30% reduction in applied motor terminal voltage under reduced motor load running conditions, while a semiconductor switch acts to instantly shunt out the voltage dropping effect of the reactor and couple an increased portion, or full level of a.c. terminal voltage to the motor whenever the motor load increases. Changes in instantaneous levels of motor loading may be determined by changes in motor speed slip, determined from the motor's operating power factor, or preprogrammed. As a result of less a.c.

Abstract: A control system for controlling the load of an AC motor/generator of secondary AC excitation type connected to a power system in parallel to at least a synchronous machine. The AC motor/generator has the secondary excitation winding thereof controlled in the amount of excitation so as to generate an output in accordance with an external output command. In the case of variation of power flow between the power system and the synchronous machine, the output command is corrected in accordance with the variation, and the amount of the secondary excitation is controlled by the corrected output command, whereby the variation of power flow between the power system and the synchronous machine is absorbed by the AC motor/generator thereby to prevent the synchronous machine from stepping out.

Abstract: A load switching circuit for switching two or more transformer taps under load carrying conditions includes first and second parallel connected bridge rectifier circuits which control the selective connection of a direct current load to taps of a transformer. The first bridge circuit is normally conducting so that the load is connected to a first tap through the first bridge circuit. To transfer the load to the second tap, a switch is operable to connect the second bridge circuit to a second tap, and when the second bridge circuit begins to conduct, the first bridge circuit ceases conduction because the potential at the second tap is higher than the potential at the first tap, and the load is thus connected to the second tap through the second bridge circuit. The load switching circuit is applicable in a motor speed controller for a wound-rotor motor for effecting tap switching as a function of motor speed while providing a stepless motor speed control characteristic.

Abstract: SCR devices replace the usual diodes of the rectifier bridge section of a wound-rotor slip-recovery system motor drive. By controlling the retardation angle of the SCR devices while controlling the line bridge for acceleration from zero speed to normal speed, the rating of the overall system is reduced. By removing the gating signal of the SCR's while operating at a retardation angle in the range between zero and 90.degree., operation is immediately brought to a stop in case of an emergency.

Abstract: An AC motor has polyphase stator windings connected to an AC bus and has polyphase rotor windings connected directly or through impedances to capacitors. The capacitances of the capacitors are selected so as to be such that the AC motor exhibits a small input impedance for a specific frequency to be eliminated, thereby preventing the power factor from being since the fundamental frequency is not affected in any way under a light load. As a result, harmonics can be eliminated without causing any excessive AC source voltage.

Abstract: A mining machine includes drive unit means for driving a haulage winch and a cutting tool of the machine, the drive unit means comprising a multi-phase induction motor with a wound rotor. In order to control the motor speed, the motor is provided with a circuit connected across the rotor windings and means for varying the effective impedance presented by the said circuit to the rotor windings.