Abstract: A brushless motor driving device includes a plurality of motor driving coils and a plurality of driving transistors, coupled to the motor driving coils, for periodically supplying an electric power to the motor driving coils. A power supply switching circuit is provided for generating a power supply switching signal for driving the motor driving coils on the basis of a frequency signal corresponding to an oscillation frequency of a voltage controlled oscillator. A phase difference detector is provided for detecting a difference between the power supply switching signal and a counterelectromotive voltage generated in the motor driving coils during a period in which no electric power is supplied to the motor driving coils. The phase difference detected by the phase different detector circuit is used to control the oscillation frequency of the voltage controlled oscillator.

Abstract: An open loop, volts/hertz motor drive for control of an induction motor adjusts the voltage command to a sine-triangle PWM inverter to compensate for reduction in PWM inverter gain and to compensate for variations in DC bus voltage in the pulse dropping transition region between PWM operation and six-step operation. The drive includes a microelectronic processor interfaces to DC bus voltage sensing circuitry and to the PWM inverter.

Abstract: The present method and apparatus detects the position with an accuracy of .pi./m electrical radians (where m=the number of motor phases) within one electrical period, and provides enough information to be able to start in the correct direction with certainty.More specifically, the position at start is determined by the injection of short current pulses in different motor phases, each phase or pair of phases being energized first by a pulse of one polarity and of the opposite polarity. The sign of the difference between the induced voltage is detected. By performing a succession of these tests on different phases or pairs of phases of the standing motor, a table of results is established which clearly defines the position of the rotor relative to the motor phases. The same table then defines what polarity currents should be applied to each phase to reliably and certainly start the motor in the proper direction.

Abstract: Power conversion apparatus (10) for an n-winding switched reluctance motor (M). A rectifier circuit (12) rectifies line voltage supplied to the motor. A switching circuit (14) supplies, at any one time, electrical energy to the motor winding most capable of converting it to mechanical work. A storage capacitor (C1) stores any unconverted portion of the energy and returns it to the winding during subsequent cycles. The switching circuit provides a substantially long conduction period 2 (.theta.) for supplying electrical energy to the motor during each line voltage cycle. This permits use of a substantially smaller energy storage capacitor and results in a higher input power factor for circuit operation. Circuits for precharging the storage capacitor are eliminated. The switching circuit is capable of more modes of operation than previous circuits, while using fewer components, and therefore provides a lower cost design.

Abstract: A control device for an electric vehicle having a reverse L type first filter circuit composed of a first filter reactor and a first filter capacitor between a current collector and control means for controlling electric motor of the electric vehicle. A second filter circuit composed of a series connected second filter reactor and a second filter capacitor is connected in parallel to the first filter capacitor. The second filter circuit has circuit constants selected such that a composite impedance of the second filter circuit and the first filter capacitor when viewed from the control means becomes small at a specific frequency.

Abstract: Control equipment for motors having two windings and wherein both windings are temporarily connected in parallel to start the motor.

Abstract: A reluctance type electric motor, in which, when the first excitation coil being energized is discontinued of energizing, a reverse current prevention diode is provided to prevent the discharging electric power of the magnet energy of the first excitation coil from returning to DC power source so as to change accumulated magnetic energy into the magnetic energy of the second excitation coil to be energized next, and to quickly discharge the magnetic energy of the first excitation coil and as well as to quickly accumulate the magnetic energy of the second excitation coil. Furthermore, the magnetic energy of the first excitation coil is charged into a small capacity capacitor to obtain high voltage, the magnetic energy of the second excitation coil is accumulated by utilizing such high voltage, and the magnetic energy is quickly discharged and accumulated so as to prevent generation of the reduced torque and counter torque.

Abstract: A method and apparatus directly regulate the output currents (i.sub.RX, i.sub.SX, i.sub.TX) of an inverter that feeds a predetermined number of induction machines. This method and apparatus is applicable to an inverter feeding one or more induction machines without rotational speed actual value sensors. The regulation is achieved by means of a secondary current control to which is supplied a current command variable system (i.sub.RW, i.sub.SW, i.sub.TW). According to the invention the current command variable system (i.sub.RW, i.sub.SW, i.sub.TW) is determined from the inverter output currents (i.sub.RX, i.sub.SX, i.sub.TX) and the state signals (S.sub.R, S.sub.S, S.sub.T) of the current switches of the inverter, from a calculation of the actual values of the active and reactive powers (P/U.sub.d, P.sub.q /U.sub.d) supplied to the motor, and a given rotational speed setpoint (n.sub.set), using field-oriented variables and simulating the actual rotational speed (n.sub.act).

Abstract: An operation control circuit for pump motor which is made such that driving condition of pump motor is checked and then when its driving condition is abnormal than driving of the pump motor can be stopped.The operation control circuit includes a pump environmental temperature detecting and heater energizing section, an overload and no-load detecting section, an overload driving count section, a no-load driving count section, latch sections, a reset section, a pump motor driving control section, and an operating state display section.According to the invention, using life time can be extended by preventing overload and no-load operation of pump motor, and freezing break down of pump motor can previously be prevented, and opening and closing noise of switch can be reduced.

Abstract: The invention is a direct current bus voltage regulator for an alternating current inverter, where draws direct current from a DC bus, and the inverter supplies alternating current having a controlled frequency to an AC motor. The alternating current frequency controlled by a signal received through a precedence determining circuit that determines which signal will control the AC current frequency. This circuit receives signals from a ramp generator, an AC current limiting circuit and a DC bus voltage sensing circuit. The precedence determining circuit passes the signal with the highest priority on to a voltage control oscillator which in turn controls the AC current frequency delivered to the AC motor, thereby controlling the motor speed. The ramp generator signal indicates an operator input motor control command and has the lowest priority of the three signals.

Abstract: A control circuit for alternating current motors comprises a bidrectional controlled diode (TRIAC) connected in series to the motor and with its own control terminal connected to a fixed-phase actuating network in order to supply partial power to the motor. The control terminal is also connected to a switching device, piloted by a control signal to supply it, when closed, with a bias current which causes the continuous operation of the TRIAC, so as to supply full power to the motor. The control circuit can be used in conjunction with circuits which measure the current absorbed by the motor and give said control signal to make it switch from the full power condition to the partial power condition and vice versa whenever said current reaches pre-established thresholds. One of these circuits supplies partial power to the motor whenever the current it absorbs is too high, which indicates a mechanical overload.

Abstract: High speed fast response PWM current control regulation methodology and circuitry samples the required peak motor current value from a previous PWM cycle and calculates the required peak motor current value for the present PWM cycle and repeats the sampling and calculating every PWM cycle and updates the new required peak motor current value every PWM cycle. The required peak motor current value for the present PWM cycle is calculated according to the equationI(peak present)=I(command)+0.5I(peak last)-0.5I(turn-on),where I(peak present) is the required peak motor current value for the present PWM cycle, I(command) is the commanded motor current value, I(peak last) is the previous required peak motor current value from the immediately preceeding PWM cycle, and I(turn-on) is the turn-on motor current value.

Abstract: A motor control method and apparatus for a hoist is disclosed in which a drive motor is connected to an adjustable frequency power supply in which the frequency of the power supplied to the motor can be selectively varied. At the initiation of a hoist operation, when the hoist brake is holding the motor and an object constituting a load on the motor stationary, power is supplied to the motor at a predetermined low frequency which is sufficient to provide load holding torque upon release of the brake. The actual current level of the power supplied to the motor is sensed at the initiation of the hoist operation and a signal representative of that current level is compared with a reference signal representative of a current level which is sufficient to provide the load holding torque. If the signal representative of the actual current level of the power supplied to the motor exceeds the reference signal, an output signal is provided which will result in the release of the hoist brake from its holding condition.

Abstract: The invention provides a cushioning control circuit which restricts the initial flow of current to a D.C. permanent magnet motor by providing a neon control lamp in series with a pair of triac control circuits which drops the initial voltage imposed on the motor windings.

Abstract: An energy efficient electric motor is provided with a supplementary run winding arrangement which operates in conjunction with the motor's main run winding to produce a combined magnetic field with sufficient strength to operate the motor under full load. Less than full load operation obtains increased efficiency through a reduction of power flow to the supplementary run winding arrangement, which brings about a significant reduction in stator core structure (eddy current) losses and winding (resistance) losses. A controller may predetermine the normal amount of magnetic field strength necessary during each portion of the motor's usual operating cycle and variously modulate the instant level of power coupled with the supplementary run winding arrangment.

Abstract: A drive system for an automatic washer or dryer having a rotatable drum about a horizontal axis. An induction motor drives the drum and is connected to and disconnected from a source of alternating voltage by a microprocessor to control the speed of the motor. The microprocessor senses the zero crossing of the alternating voltage and the zero crossing of alternating current flowing in the motor to determine the time to connect the motor to the alternating voltage. The microprocessor analyzes successive readings of the motor's back emf to detect undesirable load distributions and effect redistribution.

Abstract: A control system for an alternating current motor, such as an elevator hoisting induction motor, in response to failure of power supply, such as service interruption, phase open and so forth, performs in a first emergency control mode and in a second emergency control mode. In the first emergency control mode operation, dynamic braking is used to decelerate the motor. On the other hand, in the second emergency mode, triggered while the motor is driven in regeneration mode to recirculate regenerated power to decelerate the motor, a mechanical brake is applied. During second emergency control mode operation, power supply condition is monitored to detect failure of the power supply for switching control mode from the second emergency control mode to the first emergency control mode.

Abstract: An induction motor is controlled using a control device having a current control loop by detecting a current of the induction motor, and by detecting a current error corresponding to a difference between the detected current of the motor and a current command signal of the control device. The current error is processed to obtain a slip frequency. A field speed control command is generated based on the slip frequency and a motor speed of the induction motor.

Abstract: A starting system for a rotary dynamoelectric converter is disclosed. The converter is of the type having three sets of windings wired in either delta or wye configuration. Each set of windings consists of two coils normally connected in parallel within the respective winding, and the converter has three leads connected to the delta or wye configurations. Two of the leads are to be connected to a source of single-phase, alternating current, and a run capacitor is connected between one of the first two leads and the third lead, such that three-phase current can be drawn from the three leads when the dynamoelectric converter is running at its normal operating speed. The starting system comprises a mechanism for connecting the two coils in each respective winding in series with each other when single-phase current is initially connected to the first two leads to start the converter.

Abstract: Apparatus for controlling phase commutation of a brushless DC motor. The apparatus is comprised of a back EMF detection technique to determine the current position of the rotor, an error rejection circuit to prohibit commutation noise from causing errors in determining the present rotor position, a means for determining the next phase set to energize and proper energization timing to maintain a lead angle between the physical rotor position and the magnetic wave, and a means for driving the appropriate brushless DC motor phases with current.