Abstract: An automated fault injection testing and analysis approach drives fault injection into a processor driven instruction sequence to quantify and define susceptibility to external fault injections for manipulating instruction execution and control flow of a set of computer instructions. A fault injection such as a voltage or electromagnetic pulse directed at predetermined locations on a processor (Central Processing Unit, or CPU) alters a result of a processor instruction to change values or execution paths. One or more quantified injections define an injection chain that causes a predictable or repeatable deviant result from an expected execution path through the code executed by the processor. Based on accumulation of fault injections and results, a repeatable injection chain and probability identifies an external action taken on a processing device to cause unexpected results that differ from an expected execution of a program or set of computer instructions.

Abstract: A method for switching off a current-excited synchronous machine of a motor vehicle, the current-excited synchronous machine having a rotor supplied by an excitation circuit of power electronics and a stator supplied via a bridge circuit of the power electronics, the method including interrupting a current supply to the rotor and the stator. The method further includes switching over the excitation circuit of the power electronics to a first freewheeling position, whereby energy contained in the excitation circuit and in the rotor is fed into a first energy store via a first feedback arrangement, and switching over the bridge circuit of the power electronics to a second freewheeling position, whereby energy contained in the bridge circuit and in the stator is fed into a second energy store via a second feedback arrangement.

Abstract: A voltage application device of a tester includes a voltage setting controller that sets a number of transient steps, step time, and step voltage as transient voltage setting parameters; and a device power supply (DPS) configured to supply power to the plurality of devices under test formed on a substrate. The voltage application device outputs an output voltage having a step-like transient voltage waveform based on the transient voltage setting parameters set by the voltage setting controller. The voltage application device is a high-order lag system of a second-order or higher in which an overshoot occurs in a response with respect to a set voltage. An end point of a step time of each of the transient steps set in the voltage setting controller is set to be a time between an end point of a rising time and an overshoot time.

Abstract: An operating circuit and a method for operating a synchronous machine on a voltage supply network is disclosed. The operating circuit has a converter circuit with controllable converter switches and a controllable switching arrangement to switch the converter circuit between a start converter configuration and a direct converter configuration. The power supply network is connected to a converter output and the synchronous machine is connected to a converter input of the converter circuit. In the direct converter configuration, an AC voltage is provided at the converter output with a preset AC voltage frequency. In the direct converter configuration, the switching of the AC voltage between the converter input and the converter output takes place without intermediate rectification.

Abstract: Provided is a driving system and method for a wound rotor synchronous generator. The driving system for a wound rotor synchronous generator according to the present invention includes: a converter controlling the wound rotor synchronous generator and receiving generated power; and a field winding power supply means supplying the power to a field winding of a rotor of the generator. The field winding power supply means is connected to the converter to receive the power from the converter and supply the power to the field winding, the power supplied to the field winding being electrically insulated from the power received from the converter.

Abstract: A drive circuit for an electric pump motor is provided. The drive circuit includes an inverter and a contactor. The inverter is configured to supply variable frequency current to the electric motor. The contactor is configured to supply the line frequency current to the electric motor.

Abstract: The disclosed embodiments include a method to protect a downhole generator from overvoltage. In one embodiment, the method includes determining a speed of an alternator. The method also includes activating overvoltage protection mode if the speed of the alternator is greater than a threshold speed, where activating the overvoltage protection mode includes converting an alternating current measured at the alternator into a first component and a second component of a direct current. Activating the overvoltage protection mode also includes determining a first current threshold based on at least one component of the downhole generator. Activating the overvoltage protection mode also includes shutting down the downhole generator if the first component of the direct current is greater than the first current threshold and decreasing a magnetic flux of the downhole generator if the first component of the direct current is not greater than the first current threshold.

Abstract: An electric motor apparatus may include a rotor and a stator. The apparatus may include a main field motor stage having a set of stator armature windings positioned on the stator and a set of main field windings positioned on the rotor, where the set of stator armature windings is configured to receive a main multiphase power signal from an alternating current power bus having a first current that causes a first rotating magnetic flux that rotates relative to the stator, where the set of main field windings is configured to receive a secondary multiphase power signal having a second current that causes a second rotating magnetic flux that rotates relative to the rotor, and where a combination of the first rotating magnetic flux and the second rotating magnetic flux causes the rotor to turn at a predetermined reference frequency.

Abstract: Provided is a method for controlling a zero sequence voltage of a voltage source converter. When an alternating current system ground fault occurs, a zero sequence voltage at an alternating current (AC) side or a zero sequence voltage at a direct current (DC) side of a converter is detected. If the detected zero sequence voltage is greater than a set value V0ref, a DC side voltage of the converter can be increased to a set value Udc0, thereby generating an appropriate reference wave at the AC side of the converter to match an AC voltage, and accordingly controlling overmodulation of a reference wave at a faulty station to suppress fluctuation of a DC voltage.

Abstract: In a wind-powered thermal power generation system, an induction motor includes a field (rotor) which has a field core coupled to a rotation shaft of the wind turbine and a field conductor, and an armature (stator) which has an armature core arranged on the outer side of the field with a spacing therebetween and an armature winding, and the induction motor is housed in the heat insulating container. A heating medium circulation mechanism circulates, inside the heat insulating container, a heating medium that receives heat generated by the induction motor. A magnetic field control means controls an input current to the armature winding so as to result in slip that produces load torque at the rotor rotating due to rotation of the wind turbine. A power generation portion converts, into electricity, the heat of the heating medium heated by the induction motor.

Abstract: Overvoltage protection apparatuses, systems and methods for variable frequency motor drives are disclosed. In an exemplary embodiment, a variable frequency motor drive system including a rectifier, a DC bus electrically coupled with the rectifier, and an inverter electrically coupled with the DC bus is provided. A protection device electrically coupled with the rectifier and configured to interrupt power supply to the system based upon fault conditions is provided. A controller is provided and configured to receive information indicative of a voltage of the DC bus, process the received information to model a condition of at least one component of the variable frequency motor drive, and control the protection device to interrupt power supply to the variable frequency motor drive if the modeled condition meets a fault criterion.

Abstract: An electric machine includes a phase lead and a winding set with first and second windings. The first and second windings are connected to the phase lead and are connected electrically in parallel with one another. A current sensor is coupled to the first winding and is arranged to measure a portion of current flowing through the phase lead which flows through the first winding.

Abstract: Embodiments include a technique for controlling aircraft VFG over voltage under fault or load-shed, the techniques includes using a control unit for generating signals to maintain a terminal output voltage and frequency, and a variable frequency generator, coupled to the control unit, for generating the terminal output voltage. The variable frequency generator includes a stator having a set of primary stator windings and a set of secondary stator windings for generating the terminal output voltage, and a switch coupled to the set of secondary stator windings, the switch is configured to operate at a threshold frequency of the VFG to regulate the terminal output voltage by supplementing the terminal output voltage produced by the set of primary stator windings reducing the VFG fault over-voltage.

Abstract: An electric power transmission system and method that provides a power electronic interface system for connecting a plurality of alternating current transmission lines by one or more direct current transmission lines. The system includes dc-link converters, frequency transformers connected to the converters, and multilevel converters are connected to a direct current transmission line.

Abstract: According to one embodiment, an over-voltage prevention device includes a first short-circuit device provided between a secondary side of a wound-rotor induction machine and a frequency converter configured to excite the secondary side by a three-phase AC current and having a function of short-circuiting between phases of the three-phase AC current, resistors each connected between the first short-circuit device and the frequency converter for each phase, and second short-circuit devices connected respectively to the resistors in parallel and having a function of short-circuiting between the frequency converter and the secondary side of the wound-rotor induction machine.

Abstract: A double wound rotor type motor with a constant alternating current or direct current power supply input and a control method thereof is disclosed. The wound rotor type motor includes: a stator in which a coil directly connected to a single phase grid power supply or a direct current power supply is wound; a rotor that is rotatably supported in the stator; a power conversion device that is attached to the rotor and controls a rotor current without connection of a separate external power supply; and a control circuit that is connected to the power conversion device and controls the power conversion device.

Abstract: As described herein, a drive circuit for a three phase AC motor comprises an AC/AC converter. The converter has an input for receiving multiphase AC power from an AC source and converting the AC power to variable voltage and variable frequency from the AC source for driving the AC motor. A filter circuit is connected to the AC/AC converter and comprises at least one inductor per phase and at least one capacitor per phase. The capacitors are connected in a broken wye configuration with one side connected to one of the inductors and an opposite side connected via a three phase diode bridge rectifier to a switch. The switch is controlled by a converter control to selectively open or short a neutral point of the broken wye capacitor configuration.

Abstract: A single external power supply variable speed induction motor and a control method thereof are disclosed. An induction motor includes: a stator in which coils directly connected to a single-phase or 3-phase or more systematic power supply are wound; a rotor that is supported to be rotatable in the stator; a power conversion device that is attached to the rotor and controls a rotor current without connection of a separate external power supply; and a control circuit that is connected to the power conversion device and controls the power conversion device.

Abstract: An inverter device according to an embodiment includes a constant power controller. The constant power controller computes and outputs, when a value of a voltage reference to an AC motor exceeds a predetermined threshold value, a d-axis current reference correction value on the basis of the value of the voltage reference and the predetermined threshold value. Moreover, the constant power controller generates the d-axis current reference correction value by using a constant power model determined by a torque reference or a speed reference and a supplied direct voltage at an output switching timing determined based on a winding switching signal and outputs the d-axis current reference correction value for a predetermined time.

Abstract: A control system for an electric motor having a first control device arranged to control current in a first coil set for generating a first torque on a rotor and a second control device arranged to control current in a second coil set for generating a second torque on the rotor, the system comprising a controller arranged to instruct the first control device to control current in the first coil set to generate a torque on the rotor to allow rotation of the rotor; and means for measuring a characteristic associated with the second coil set resulting from the rotation of the rotor from the torque generated by the first coil set while substantially no current is flowing in the coils of the second coil set.

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 device and a method for supplying electrical power to at least one induction machine on board an aircraft. This device includes at least one CVFR type source, in which the voltage and frequency are both variable but in a constant ratio, that supplies power to at least one induction machine.

Abstract: An induction motor control device includes an inverter circuit for driving an induction motor by outputting a command voltage, a current detector for detecting an output current, a magnetic flux estimation observer for generating an estimated magnetic flux, an estimated current, and a phase command for the motor using the command voltage and the output current, a primary angular speed estimator for estimating a primary angular speed using the estimated magnetic flux, a slip compensator for calculating a slip angular frequency using the output current, a first angular speed estimator for estimating a first angular speed using the primary angular speed and the output current, a second angular speed estimator for estimating a second angular speed using the output current, the estimated magnetic flux, and the estimated current, and a resistance estimator for estimating a secondary resistance value of the motor using the first and second angular speeds.

Abstract: A system and method for starting and regulating a wound rotor motor (120) including a phase-controlled SCR converter (150) and a drive circuit (130, 140) having a voltage source inverter (140) and a voltage source converter (130). The SCR converter (150) regulates power transmitted to the drive circuit from the rotor of the motor (120) so that the ratings of the drive circuit are not exceeded.

Abstract: A system and method for starting and regulating a wound rotor motor (320) including a phase-controlled SCR converter (350) and a drive circuit (330, 340) having a voltage source inverter (340) and a voltage source converter (330). The SCR converter (350) regulates power transmitted to the drive circuit from the rotor of the motor so that the ratings of the drive circuit are not exceeded. A shorting contactor (390) is employed in various embodiments to increase the efficiency of the circuit.

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: An alternating current, multiphase, squirrel cage induction electric motor in a unique inverted design, including a method of applying the motor with controls, operator interface, batteries, and peripheral devices to propel a non-polluting electric vehicle.

Abstract: An improved variable speed fan controller for use in devices such as laser printers. The controller automatically adjusts its output signal to fans such that a fan quickly settles into an appropriate operating speed, even if the fan has been newly installed into the equipment. The controller can store values in non-volatile memory, if desired, to keep track of recent changes in the fan's operating parameters and corresponding control signal values. The controller is able to control relatively inexpensive fans that don't necessarily operate at a predictable fan rotating speed under repeatable conditions and control signals, by controlling the fan to an initial or predetermined rotating speed; if the fan isn't running within a suitable range of rotational speeds, then determining whether a fine or coarse adjustment should be made to the fan's rotational speed. The controller makes appropriate adjustments until the fan's rotational speed is within acceptable operating tolerances.

Abstract: It is an object to provide a winding switching device of a three-phase AC motor having a small size at a low cost in which a time required for switching a winding is shortened and the number of semiconductor switch units is decreased as much as possible.

Abstract: Processor-based field oriented control for brushless doubly-fed induction machine having first and second polyphase stator windings is programmed to operate the machine in various modes, as a motor or a generator, with bumpless switching between operating modes. An electronic power converter controls a current supplied to the first stator winding to control the torque of the machine, with the second stator winding selectively connected to an AC line. Stationary coordinates for in-phase and quadrature current commands are coordinate transformed using a voltage vector for voltage induced on the first polyphase stator winding to control current in the first stator winding, with or without a position sensor. The electronic power converter controls the voltage supplied to the first stator for generating, with the second stator selectively connected to a load. The machine can also be controlled to operate as a singly-fed motor at lower speeds, with the second stator winding shorted.

Abstract: A motion control system comprises both a stepper motor and a DC motor. The motors are coupled, and may be operated independently or in concert for various scan types. The stepper motor may be used as an encoder for measuring the position of the mechanism.

Abstract: A motor combination system with operating method for operating as an induction motor or a stepping motor is disclosed. The disclosed system basically encompasses a switch device, an induction motor control module, and a stepping motor control module. Driving signals generated by the induction motor control module and the stepping motor control module are fed into the switch device. The induction motor control module receives a feedback signal for compensating simulation distortion when the disclosed system operates as an induction motor. The switch device is responsive to a mode selection signal to decide which driving signals being selected for driving the disclosed system for operating. In the beginning, the disclosed system operates as a stepping motor for providing torque enough for switching purpose. According to the mode selection signal, the disclosed system may switch to operate as an induction motor when the torque is large enough.

Abstract: Disclosed is an improved three-phase direct-current (DC) brushless motor with Hall elements, in which two Hall elements instead of three Hall elements are placed upon the driving circuit of the DC brushless motor to sense the variation of the magnetic flux during the operation so as to reduce the manufacturing cost and also improve the operation precision.

Abstract: A prime mover such as a microturbine generator is operated to generate dc power, and an inverter is controlled to convert the dc power to ac power. The ac power is supplied to an electric motor. The frequency of the ac power is ramped up during motor startup to reduce motor inrush current. The frequency or current of the ac power may be varied in response to process requirements during normal operation of the motor.

Abstract: A variable frequency motor starting system has a variable frequency AC power supply for generating an AC power output signal applied to an AC motor. A controller is coupled to the variable frequency AC power supply for producing a control signal for adjusting the frequency of the AC power output signal produced. Upon initially applying power to an AC motor or detection of a starting current for an AC motor, the controller adjusts the frequency of the power output signal applied to the AC motor. The frequency of the power output signal is adjusted to a value below the value of the typical operating frequency. The value of the frequency can be increased to the final operating value.

Abstract: Latching components of a padlock are driven by a motor between latched and released positions. An encoder element with associated optical elements provides position information to a control circuit. The control circuit correlates the position information with the signal directing power to the motor so that the motor is precisely controlled for moving the latching elements between release and latch. If the motor jams (sensed by overcurrent), it is operated briefly in alternating directions to try and dislodge the grit or ice causing the jam. The padlock shackle is latched into place by balls which are driven into recesses in the shackle legs. The use of plural balls on at least one side helps isolate the drive motor and gears from grit that may enter through the padlock's top shackle holes.

Abstract: To control the output from an induction motor with a main winding and an auxiliary winding with multiple taps, varying output stages of the motor are adjusted by the activation of the auxiliary winding or one of its part-windings. According to the invention, the coarse adjustment of the power to be output by the motor is effected by the selection of a certain output stage and a repeating digital m-bit keying pattern generated simultaneously for the purpose of fine adjustment, so that the motor is driven alternately at the set output stage and the next higher or next lower output stage as a function of the sequential logic values of the keying pattern. By means of the process complying with the invention, precise power control is possible which can be used to advantage for the adjustment of output.

Abstract: The DC link current from one leg of a DC link of an inverter is provided to a primary winding of an AC current transformer, and a voltage across the secondary winding of the current transformer is integrated for providing an envelope indicative of the DC link current.

Abstract: A doubly-fed reluctance motor (10) has a primary winding set (20) and a secondary winding set (22). A drive control (32) for the motor includes a connection (36) to the primary winding so primary winding current and voltage signals (i.sub.p, V.sub.p) can be developed. A further signal representing the phase relationship (.PHI..sub.p) between the primary winding current and voltage is developed using these signals. A processor module (42) is responsive to these signals to determine the magnitude and phase of a secondary winding current (I.sub.s) of the motor for a predetermined motor operating speed (w.sub.r). The desired current value is as a function of the primary winding current and the phase relationship between the primary winding current and voltage. A switching module (60) operates to regulate the secondary winding currents and opening and closing of switching elements of the module is controlled by an output from the control module.

Abstract: A switched stepping motor for use in a computer-controlled processing system, the motor being capable AC or DC operation in a continuous or stepwise manner for completing a variety of operations such as lathe cutting, drilling, planning, milling, abrading, and boring.

Abstract: As a method for energizing a three-phase stepping motor of Y-connection, driving current values are set to be values resembling sine wave input approximation, thus making it possible to effect driving at small vibration. Energizing of the three-phase stepping motor is performed by a two-three phase driving scheme which calls for alternately effecting a two-phase excitation of the coils in the motor and a three-phase excitation of the coils in the motor. The driving current flowing through each of the coils approximates a sine wave having normalized values defined by .+-. 1, .+-. 0.87, .+-. 0.5 and 0.

Abstract: An electric machine system includes a number of improvements that heighten the performance provided by the system. In particular, the electric machine system may include bypass capacitors for filtering and storage. Further, the electric machine system may include bidirectional power switches for coupling different phase current signals to respective windings in the electric machine system. These switches control which phase signals are connected to the respective windings of the electric machine system.

Abstract: An electric machine system includes a resonant switching system for selecting a resonant frequency of at least a portion of the circuit of the system. The electric machine system includes a first pair of windings for generating force to actuate a moving body and a second pair of windings for exciting the first pair of windings. The resonant switching system includes a resonant inductor and a resonant capacitor. The carrier signal used to excite one of the pairs of windings may have a frequency that is substantially equal to the resonant frequency of the circuit. Preferably, the air gap magnetic flux distribution for the pairs of windings are substantially alike. The electric machine system may employ a rotating body or alternatively may employ a linearly actuating body.

Abstract: This invention proposes an operating control device and method for a winding type induction machine that ensures that the harmonic components naturally present in the primary voltage of a winding type induction machine, do not correspond to the antiresonance point of the impedance characteristic of the transmission system to which the winding type induction machine is connected. Those corresponding harmonic components are eliminated from the primary winding of the winding type induction machine by applying appropriate voltage command values to a PWM controlled inverter if there is distortion of the primary voltage or if the transmission system is being changed over.

Abstract: The problem of detecting low frequency faults is solved in a VSCF control system which is operated in a start mode to start an engine (18) using a brushless synchronous generator operating as a motor (12). The motor (12) receives power through a feeder (52) from a converter (36) which is coupled through an additional feeder (44) to a source (42) of AC power. During normal, non-fault conditions, the sum of the input currents to the converter (36) and the sum of the output currents from the converter (36) must each be zero. When a fault condition exists, then one or both of these currents will be non-zero, depending upon the location of the fault. A single current sensor (56) is used to sense feeder faults by positioning the sensor to read the current through the converter input feeder (44). As long as no feeder to ground fault condition exists, then the current sensor (44) senses zero current. If a non-zero current is sensed, then it is assumed that a fault condition exists.

Abstract: An a.c. variable speed drive system which can switch between a driving operation and regenerative operation of an inverter in accordance with the operation speed.

Abstract: An electrical machine driven by a pulse-controlled a.c. converter contains multiple phases subdivided into a number of n.gtoreq.2 equivalent phases sections that are extensively magnetically decoupled relative to each other. Each phase section is fed by a separate frequency converter. The clocking of the frequency converters for the n phase sections ensues out of phase by an angle of 2.pi./n relative to each other phase section.

Abstract: A circuit for changing the poles of a rotor of a synchronous machine having contact brushes in operative connection with first and second slip rings includes a switch for reversibly connecting the contact brushes to an electrical current source, reversible pole coils operatively connected to one of the slip rings and connected through a first diode to a circuit portion which is formed by irreversible pole coils, and by a second diode and a third diode, and which is operatively connected with the other of the slip rings, and a circuit branch including a fourth diode having a polarity reversed with respect to the polarities of the first, second and third diodes. One terminal of the fourth diode is connected between the reversible pole coils and the first diode and the other terminal of the fourth diode is connected between the irreversible pole coils and the second diode.

Abstract: There is disclosed a protecting apparatus for a secondary excitation type variable speed AC generator/motor having a primary winding connected to an electric power system and a secondary winding each phase of which is AC excited by an independent power converter unit. The protecting apparatus is arranged to detect an electrical event which includes at least one of an overvoltage and overcurrent appearing at each phase of the secondary winding of the AC generator/motor, to decide whether the detected electrical event meets a predetermined condition and to close, when the electrical event detected in respect to any of phases of the secondary winding is decided as meeting the predetermined condition, a switch circuit connected in the corresponding phase of the secondary winding.