Abstract: A motor control apparatus includes: a main power conversion circuit that converts power that is supplied from a power supply into alternating current power for driving a motor, and outputs the alternating current power; a counter electromotive force protection circuit including a rectifier unit that rectifies alternating current power based on counter electromotive force of the motor and outputs direct current power, a short-circuit unit that short-circuits terminals on a direct current output side of the rectifier unit, and an alarm signal output unit that outputs an alarm signal at occurrence of an abnormality; a monitoring unit that monitors whether the alarm signal is output from the alarm signal output unit; and a protection operation unit that performs a protection operation for preventing damage to the main power conversion circuit when the monitoring unit determines that the alarm signal is output from the alarm signal output unit.

Abstract: Assemblies for HVAC systems and methods of operating HVAC systems are disclosed, including a method of operating an HVAC system having a condenser motor operatively coupled to a fan and a controllable bus voltage for powering the condenser motor. The method includes increasing the controllable bus voltage from a first voltage to a second voltage to increase a speed of the condenser motor.

Abstract: Detection accuracy of a short circuit state in a load driving circuit is improved thereby operation efficiency of a motor may be enhanced. A gate control circuit 25 turns off NMOS transistors Q1 and Q4, turns on an NMOS transistor Q3, and turns on and off an NMOS transistor Q2 intermittently so as to control rotation of a motor 10. A detection circuit 30a detects a voltage Va at a connection node a between the NMOS transistor Q2 and the motor 10 a predetermined time after the NMOS transistor Q2 is turned on. A control circuit 20 turns off the NMOS transistor Q2 so as to cut off a current from a power supply to the motor 10 if the voltage Va at the connection node a is within a range in which the motor 10 is determined to be short-circuited.

Abstract: A system and method for protecting a motor drive unit from an associated motor includes a motor drive unit protection system. The motor drive unit protection system includes at least one switch configured to be connected between a motor drive unit and a plurality of motor leads of the motor driven by the motor drive unit. The motor drive unit protection system also includes a controller configured to monitor the motor drive unit or the motor to determine a fault condition indicative of the motor potentially operating as a generator. Upon determining the fault condition, the controller is configured to cause the at least one switch to connect the plurality of motor leads together to protect the motor drive unit from the motor when the motor is operating as a generator.

Abstract: A hybrid drive apparatus includes an engine, a first electric motor for generating electric power by using at least a portion of its output and for controlling the speed of the engine and a control unit for controlling the engine and the first electric motor. The control unit performs a prepositioning control for positioning the engine being fuel-cut to a predetermined cranking start position such as a constant crank angle position or a constant cranking load position by the motoring of the first electric motor. As a result, the engine can always be started under identical conditions, and the torque vibrations to be outputted to a wheel have identical waveforms so that a simple torque correction can be made by outputting corresponding waveform data.

Abstract: In a control apparatus for a synchronous motor, a coordinate converter converts a detected current into a current on rotational biaxial coordinates (d-q axis). A current controller outputs a voltage command on the coordinates so that the current follows a current command on the coordinates. Another coordinate converter converts the voltage command into three-phase voltage commands. An adaptive observer calculates an angular frequency so that a q-axis component of an estimated rotor magnetic flux is zero. An inverter applies a voltage to the motor based on the voltage command.

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

Abstract: The present invention is applicable to any a.c. electromagnetic reduction device which is used to change voltage or current levels or to transfer energy between mechanical and electrical systems and includes, for each phase, a combined pair of windings which are conductively and inductively dependent. The dominant winding of each combined pair is electrically connected to an input/output phase, while the reflux winding of each pair is electrically connected in additive or subtractive series with the dominant winding by means of a variable capacitive reactance. The capacitive reactance is then adjusted to minimize the net reactive factor of the coupled windings and the net reflected impedance of the input/output circuitry.

Abstract: An electric motor has a rotor and a stator each of which is provided with a polyphase winding. The rotor and stator have the same number of poles but the number of phases in the winding of the rotor differs from that in the winding of the stator. The motor can operate as a stepping motor by deenergizing one of the phases of one winding while simultaneously energizing one of the phases of the other winding, and the motor advances one step whenever one phase of a winding is deenergized and, at the same time, one phase of the other winding is energized. The deenergizing and energizing steps are performed alternately for each winding. The motor can further operate as a synchronous motor by accelerating the motor, discontinuing the deenergizing and energizing steps for one of the windings while maintaining the excitation of such winding and, simultaneously with the discontinuing step, reducing the frequency of the deenergizing and energizing steps for the other winding.

Abstract: An induction motor starting method comprises the steps of supplying a predetermined low-frequency current to the primary winding of an induction motor through a first cycloconverter having its input side connected to a commercial-frequency power source and its output side connected to the primary winding, supplying a voltage of a frequency from zero up to a first frequency through a second cycloconverter having its first input side connected to the commercial-frequency power source and its output side connected to the secondary winding, controlling the first cycloconverter to increase the frequency of the low frequency voltage supplied to the primary winding to the first frequency when the rotation speed of the induction motor reaches substantially a first rotation speed, and disconnecting the output side of the first cycloconverter with the primary winding to connect the output side of the first cycloconverter to the second input side of the second cycloconverter and connect the primary winding to the commer

Abstract: This invention presents several meters characterized by a novel stator structure having distinct and separated energizing and exciting windings and provided with squirrel cage rotors of conventional design which are energized by induction, replacing rotors having commutator and brushes. Several species are derived in analogy to series, shunt, universal and repulsion motors, which exhibit similar characteristics, as their counterparts with commutators. As no rotating fields are considered, multipole, single phase motors and Multiphase motors are repetitions of the basic single phase two pole design.