Abstract: A device includes a bidirectional switch circuit 10, a control unit 20 that performs virtual AC/DC conversion processing to acquire a plurality of interline voltage generation sections according to a plurality of modes divided according to a magnitude relation between voltages in each phase and that generates a switching pattern of the bidirectional switch circuit 10 to perform virtual DC/DC conversion processing corresponding to the plurality of interline voltage generation sections based on a second carrier waveform pattern CW2 according to the plurality of modes and a signal level G1 of a P-phase, a current setting unit 50 that inputs a current direction and an amount of current that flows in a power line LU, a current detection unit 51 that detects the current direction and the amount of current of the power line LU, and a current adjustment unit 52 that increases and decreases the signal level G1.

Abstract: An overvoltage is prevented from being applied to a circuit. A full-bridge circuit is provided with a first switch having an output terminal connected to one end of a capacitive load, and switching output to the output terminal between a power supply and a ground, a second switch having an output terminal connected to the other end of the capacitive load, and switching output to the output terminal between the power supply and the ground, a first waveform generation section adapted to output a drive waveform for driving the first switch, a second waveform generation section adapted to output a drive waveform for driving the second switch, a detection section adapted to detect voltages of the drive waveforms output by the first waveform generation section and the second waveform generation section, and a control section adapted to control the output of either of the switches based on the voltages detected by the detection section.

Abstract: Disclosed is a matrix converter that directly converts input three-phase AC power into three-phase AC power and outputs the converted three-phase AC power to a load. The matrix converter includes: a bidirectional switch circuit that switches on or off the supply of the three-phase AC power to the load; and a controller that performs different virtual AC/DC conversion processes according to a plurality of modes which are divided depending on magnitude correlation between respective phase voltages in the input three-phase AC power, with respect to the input three-phase AC power, selects two phases from the input three-phase AC power, and generates switching patterns of the bidirectional switch circuit so as to perform the different DC/AC conversion processes according to the plurality of modes with respect to line voltages of the two selected phases.

Abstract: A method is provided of operating a resonant converter, the converter having a controller and power stage and providing an output voltage, by determining a characteristic frequency of the power stage. The characteristic frequency is defined as a natural oscillation frequency of the power stage observed right after the power stage control signals from the controller are disabled. The converter is operated at the characteristic frequency during ramp-up or ramp-down of the converter output voltage and/or during overload or input overvoltage conditions.

Abstract: A matrix convertor includes a power convertor and a controller. The power convertor includes a plurality of bidirectional switches disposed between a plurality of input phases and a plurality of output phases. The controller is configured to generate a control command and control the power convertor based on the control command. The control command includes a switching pattern that causes a first input phase among the input phases to be connected to one output phase among the output phases and that causes connection of the input phases to be switched between a rest of the output phases. In generating the control command, the controller is configured to set a lower limit to a period of time during which a second input phase among the input phases that corresponds to an intermediate voltage is connected to the rest of the output phases.

Abstract: A matrix converter includes a power converter and a controller. The power converter includes bidirectional switches each having a controllable conducting direction. The bidirectional switches are disposed between input terminals and output terminals. The input terminals are respectively coupled to phases of an AC power source. The output terminals are respectively coupled to phases of a load. The controller controls the bidirectional switches. A first commutation controller performs commutation control when the conducting direction is unidirectional. A second commutation controller performs the commutation control when the conducting direction is bidirectional. A selector selects between the first commutation controller and the second commutation controller to perform the commutation control based on a state of an output current from the power converter.

Abstract: A converter has converting groups with a first stage connected to input lines thereof and a second stage connected to output lines. The first and second stages have positive and negative branches that are connected together.

Abstract: Provided is a power converter 3 that directly converts polyphase AC power to AC power. A converter circuit has a plurality of first switching elements 311, 313 and 315 that are connected to each phase R, S or T of the polyphase AC power to enable switching for turning on current-carrying bidirectionally, and a plurality of second switching elements 312, 314 and 316 that are connected to each phase to enable switching for turning on current-carrying bidirectionally. The converter circuit comprises input lines R, S and T connected to each input terminal, and output lines P and N connected to each output terminal. Parts of wiring 347 and 348 of protection circuits 32 are located between output lines P and N. The wiring distance between each protection circuit 32 and the corresponding switching element can be shortened.

Abstract: Provided is a power converter 3 that directly converts polyphase AC power to AC power. A converter circuit has a plurality of switching elements 311, 313, 315, 312, 314 and 316 which are connected to each phase R, S or T of the polyphase AC power to enable switching for turning on current-carrying bidirectionally. At least three condensers 821 to 826 are provided between phases of the converter circuit. The three condensers are respectively placed at apexes of a triangle on a plane that is in parallel with a part-mounting surface on which the switching elements are actually mounted. The wiring distance between the condensers and the switching elements can be shortened.

Abstract: A control circuit adapted to control a power converting circuit for stabilizing an output of the power converting circuit is provided. The control circuit includes a capacitor, a charging unit, a discharging unit, a feedback control unit, and a duty-cycle adjusting unit. The charging unit has a first current source coupled to the capacitor for charging the capacitor. The discharging unit is coupled to the capacitor for discharging the capacitor. The feedback control unit controls the charging unit to charge the capacitor according to a feedback signal which represents the output of the power converting circuit. The duty-cycle adjusting unit generates a control signal and adjusts a duty cycle of the control signal according to a voltage of the capacitor.

Abstract: A method of controlling a motor is provided. The method may determine a speed of the motor, and engage a soft chopping routine on a first switch and a second switch of each phase if the motor speed is relatively low. The first switch may be driven by a first pulse width modulated PWM signal and the second switch being driven by a second PWM signal. The first and second PWM signals may be alternatingly configured such that at least one of the first switch and the second switch is closed at any point during the distributed soft chopping routine and both the first switch and the second switch are never simultaneously open.

Abstract: A power conversion method including: receiving an input voltage which is a single-phase AC voltage; designating a first target voltage and a second target voltage respectively representing consecutive target values of a first-phase output voltage and a second-phase output voltage which form a two-phase AC voltage; cyclically connecting and disconnecting a pair of input terminals and a pair of first output terminals at a duty cycle corresponding to a ratio |ref1/in| during a time period in which an instantaneous absolute value of the input voltage is greater than an instantaneous absolute value of the first target voltage; and cyclically connecting and disconnecting the pair of the input terminals and a pair of second output terminals at a duty cycle corresponding to a ratio |ref2/in| during time periods in which the instantaneous absolute value of the input voltage is greater than an instantaneous absolute value of the second target voltage.

Abstract: Identification of electrical equivalent circuit parameters (15) of a three-phase asynchronous motor (09) without a shaft encoder. The method comprises—Assumption of a standstill position of the rotor (11);—Equidirectional test signal infeed U1?, U1? in ? and ? in the stator axis direction of the asynchronous motor (09);—Measuring of a measuring signal I1?, I1? of the ? and ? axial direction of the asynchronous motor (09); and—Identification of equivalent circuit parameters of the asynchronous motor (09) on the basis of the test signal voltages U1?, U1? and of the measuring signal currents I1?, I1?; whereby the test signal feed allows the rotor (11) to remain torque-free. Determination of equivalent circuit parameters (15) of an asynchronous motor (09) as well relates to a motor control device (35), whereby the identified equivalent circuit parameters (15) can be used for the determination, optimization and monitoring of a motor control and for control of electrical drives.

Abstract: A bi-power motor controlling apparatus, which is electrically connected with a motor, includes a driver IC having a first pin and a second pin. The first and second pins are used to receive a first power and a second power, respectively, from outside. The second power is supplied to the driver IC, and the first power is supplied to the motor for controlling the rotational speed of the motor.

Abstract: A converter control device includes a converter device formed by three converter circuits connected together in parallel between a secondary battery as a first power source and a fuel cell as a second power source. A control unit includes: a PID control module for controlling the converter device by PID control and executing a desired voltage conversion; a drive phase quantity changing module for changing the number of drive phases of the converter device in accordance with the passing power of the converter device; and an integration term correction function switching module which switches the PID control integration term correction function when changing the number of drive phases.

Abstract: A power supply includes a power source having at least one power source output, and a plurality of drivers connected to the at least one power source output. At least one of the plurality of drivers includes a bridge network having a first switch, a second switch and a bridge network output. The first switch is connected between the at least one power source output and the bridge network output. The second switch is connected between the bridge network output and a ground. The bridge network further includes at least one control input connected to the second switch. The bridge network is adapted to change a state of the first switch based on a state of the second switch.

Abstract: An electrical circuit, in particular a circuit used for generating electric power, wherein this circuit comprises a generator with n phases, a converter and a transformer to which a p-phase load can be connected. The converter comprises m partial converters, each of the partial converters is composed of p units and each of these units is provided with n/m switching circuits. The switching circuits of the individual units are connected symmetrical to the generator.

Abstract: Three coils, each having several serial windings, have selected windings connected in a delta. Input AC power is applied through outrigger windings at the delta apices. At least two strategically located, direct tap, natural output points are provided at each side of the delta. For 6-phase output, only the six natural output points are required. For 9-phase output, an additional central output terminal connects to each side of the delta through a stub winding. The 6-phase or 9-phase output is passed to a rectifier circuit.

Abstract: A power supply includes a power source having at least one power source output, and a plurality of drivers connected to the at least one power source output. At least one of the plurality of drivers includes a bridge network having a first switch, a second switch and a bridge network output. The first switch is connected between the at least one power source output and the bridge network output. The second switch is connected between the bridge network output and a ground. The bridge network further includes at least one control input connected to the second switch to direct electrical current from the at least one power source output either substantially through the bridge network output or through the second switch to ground.

Abstract: Electric storage device is provided which is capable of smoothly charging storage elements and reliably detecting an overvoltage of each of the storage elements. Electric storage device includes charging/discharging limiting circuit. Charging/discharging limiting circuit includes charge element, discharge, control unit, charging current detection unit, voltage detection unit, valuable reference voltage source, and voltage comparison unit. A magnitude of valuable reference voltage source that is connected to an input terminal on a first side of voltage comparison unit is adjusted by charging current detection unit. Detection signal from the voltage detection unit is given to an input terminal on a second side of voltage comparison unit.

Abstract: A power conversion method comprising detecting a three-phase source voltage of the three-phase AC power supply every control sampling cycle. The three-phase source voltage is allocated to a maximum voltage, an intermediate voltage and a minimum voltage as seen from a virtual neutral point voltage. A one-phase fixing switching mode is detected for fixing one of output phases into a predetermined state without switching and switching the other phases during a PWM cycle or a full phase switching mode for switching all of the phases during the PWM cycle based on an output voltage command and the three-phase source voltage. ON/OFF pattern of a bidirectional switch is determined from the switching mode thus selected, the output voltage command and the three-phase source voltage. The bidirectional switch is turned ON/OFF based on the ON/OFF pattern.

Abstract: A device and method for supplying a display, such as a liquid crystal display, for example a bistable ChLCD, with drive voltages for extremely low power operation. The method and the device implementing the method provides an energy storage device and a voltage converter being utilized to store energy in the storage device, such that a display can be driven during an inactive, powered-down phase of the converter by using the stored energy to drive the display.

Abstract: System, method, and apparatus for commutating and controlling a multi-phase motor using one output rotor sensor and circuitry that measures time between rotor pole-to-pole transitions is disclosed. The exemplary system, method, and apparatus may utilize the polarity of the single-output rotor sensor and the measured time between the polarity transitions detected by the single-output rotor sensor.

Abstract: A converter device which is configured by connecting three converter circuits in parallel is provided between a secondary battery serving as a first power supply and a fuel cell serving as a second power supply. A control unit includes a PID control module which controls the converter device by PID control, for executing desired voltage conversion; a module for modifying the number of drive phases which changes the number of drive phases of the converter device in response to an electric power passing through the converter device; and a gain switching module which switches feedback gains in the PID control when the number of drive phases is changed.

Abstract: Systems for converting single phase power to three phase power are well known, however, these systems may be noisy and wasteful of electrical power because they are prone to being left on for long periods of time when three phase power is not required. To overcome these disadvantages, these converters would be manually started and stopped as necessary. This invention solves these problems by providing a system that automatically controls a three phase converter based on electrical characteristics of the connected three phase load. The invention may detect when a three phase load requires power to operate and enables a three phase converter to provide the required power. Upon completion of the requirement of power, the system of the invention may shut down the converter. Additionally, the system of the invention may signal other electrical devices based on various electrical conditions of the connected three phase load.

Abstract: An automatic adjustment system that includes: a transmission device that includes a constant voltage output unit that outputs a constant-voltage signal to a cable; and a reception device that includes a voltage detecting unit and a control unit. The voltage detecting unit receives the constant-voltage signal transmitted through the cable and detects the voltage of the signal, and the control unit determines signal attenuation based on the voltage detected by the voltage detecting unit and adjusts the gain of a receiving unit that receives the signal from the transmission device. This automatic adjustment system performs gain adjustment on the receiving unit when a cable insertion/pull-out sensing unit senses that the cable is connected to a connector.

Abstract: A method of using a cycloconverter switches a first switch of the first topology type to an on state after a magnitude of a current through an output inductor becomes less than a predetermined current threshold, and switches a second switch of the first topology type to an off state a first time after switching the first switch to the on state. The cycloconverter includes nodes on a first port, nodes on a second port, a switch pair coupled between a first node of the first port and a first node of the second port, a switch pair coupled between a second node of the first port and a first node of the second port, a switch pair coupled between a first node of the first port and a second node of the second port, and a switch pair coupled between a second node of the first port and a second node of the second port. Each switch pair includes a switch of each topology type.

Abstract: A matrix converter for converting a polyphase alternating current into a desired alternating output current includes at least two stages; a plurality of controllable bidirectional switches, converts m phases of the polyphase alternating current into alternating output current with n (n<m) phases of a load; and a controllable bidirectional switch controlling each phase of the polyphase alternating current in at least one stage of the converter.

Abstract: The invention provides a T-connected autotransformer for converting three-phase ac input voltages to nine phase shifted ac voltages feeding three sets of three-phase diode rectifier bridges. The nine phase shifted voltages are at an angle of +20 degree or ?20 degree with respect to the supply voltages and their magnitudes are essentially identical. The present design requires substantially fewer coils than other autotransformers for 18-pulse AC-DC converters, resulting in saving in space, volume, weight, size and cost of the converter. The magnetics requirement is only about 30% of the drive rating. The output voltage ratio can also be selected to give an average dc output from the proposed converter same as that of a conventional three-phase diode bridge rectifier. However, it is also possible to step up or step down the output voltage as required.

Abstract: A device and method for supplying a display, such as a liquid crystal display, for example a bistable ChLCD, with drive voltages for extremely low power operation. The method and the device implementing the method provides an energy storage device and a voltage converter being utilized to store energy in the storage device, such that a display can be driven during an inactive, powered-down phase of the converter by using the stored energy to drive the display.

Abstract: A multiple PWM cycloconverter or matrix converter uses reactors to connect various phase output terminals in parallel.

Abstract: A method is described for controlling a matrix converter which includes nine bi-directional circuit-breakers arranged in a 3×3 switch matrix. A commutation sequence is selected based on detected linked input voltages and a predetermined limit value and compared with a calculated commutation sequence. If these two do not agree, the switching states of the calculated commutation sequence are rearranged into the selected commutation sequence. In this way, it is possible to operate a matrix converter without requiring a precise measurement of the polarity of the input voltages, which eliminates the risk of a commutation short circuit.

Abstract: A phase converter that converts single phase AC electric power to balanced three phase AC power. Two input terminals are connectable to a single phase AC power source, and connect directly to two output terminals of the converter. The phase converter has a storage capacitor, a charging circuit for controlled charging the storage capacitor and an output circuit for controlled discharge of the storage capacitor to provide single phase AC power to a third output terminal. The charging circuit controls input to the storage capacitor to provide a sinusoidal input current and to step up the voltage to the storage capacitor. The output circuit provides output power to the third output terminal of a predetermined phase and amplitude, relative to the other two output terminals, to result in balanced three phase AC power at the three output terminals.

Abstract: A method for a frequency converter, when the frequency converter controls a motor and operates torque-controlled partly or entirely in a field weakening region. The method comprises the steps of defining the direction of travel and sector of a stator flux vector ({overscore (&psgr;)}s) in the motor, predicting a torque estimate (Tpred) produced by a voltage vector of the output of the frequency converter at the end of the voltage vector when a voltage vector change occurs at the instant of prediction, comparing the predicted torque estimate (Tpred) with a reference torque (Tref) of the frequency converter, and implementing the voltage vector change when the predicted torque estimate (Tpred) is smaller than the reference torque (Tref) and the stator flux vector ({overscore (&psgr;)}s) is moving in a positive direction of travel or when the torque estimate (Tpred) is greater than the reference torque (Tref) and the stator flux vector ({overscore (&psgr;)}s) is moving in a negative direction of travel.

Abstract: A power unit is provided which can perform stable feedback control by reducing a feedback gain, and sufficiently cope with fluctuations in the output voltage occurring according to fluctuations in the input voltage caused by fluctuations in the rotational speed of an engine. A pair of variable control bridge circuits are connected to three-phase output windings of a three-phase generator driven by the engine, and connected in an antiparallel manner to each other to form a cycloconverter for generating a single-phase alternating current to be supplied to a load. A voltage-detecting circuit detects a voltage of the three-phase alternating current. An effective voltage value-calculating circuit calculates an effective value of the voltage of the alternating current. A reference sinusoidal waveform-forming circuit generates a voltage of a reference waveform for controlling the single-phase alternating current.

Abstract: A power supply, including a resonant circuit having an output voltage and a current oscillating therethrough, and a voltage-fed half-bridge inverter producing a source voltage at an output coupled to the resonant circuit. The inverter is responsive to a driving signal. A driving circuit has a first input representing the sensed current oscillating through the resonant circuit, a second input representing the output voltage, and a reference voltage. The driving circuit includes compensation circuitry for maintaining the output voltage at the reference voltage and commanding a phase shift angle, and phase-shifting circuitry producing the driving signal based on a phase-shift of the sensed current. The amount of phase shift is commanded by the compensation circuitry.

Abstract: A control arrangement for a multilevel convertor employs an AC reference signal which is locked to the AC system frequency and is compared with a number of DC threshold levels. Intersections of the reference signal and threshold levels triggers the firing and turning-off of GTOs within the convertor to produce the desired multilevel voltage output. Normal changes in system voltage, for example, are compensated by variation of the phase relationship of the reference signal with respect to the system voltage, and/or of the voltage values of the threshold levels. Sudden and drastic changes, especially reductions, in system voltage level are sensed and used to alter the amplitude of the reference signal so as to reduce the difference between the convertor multilevel voltage and the system voltage, thereby reducing the stress on the GTOs during faults.

Abstract: A sine wave input converter provided with a phase sequence computation unit which inputs two line voltages or two phase voltages of the three phase ac power supply, computes the phase of a sine wave voltage of one of these two inputs, and determines on the basis of computation using these two input voltages and the phase whether the phase sequence is positive or antiphase, which is determined depending on whether the result of computation assumes a constant value, or becomes a sine wave oscillating between positive and negative values. Power supply interruption can be determined from the same computation result.

Abstract: A phase control system has a stable timebase phase reference generated by an internal phase reference generator which has improved transient response in the presence of spurious noise generated by other external equipment coupled to the same voltage source. A digital phase comparator estimates a phase error between the timebase phase reference and the voltage source. The internal phase reference generator constructs the timebase using a normalized difference between the volt-time-areas between two adjacent quadrants of the internal timebase phase reference. This allows corrections to the phase reference generator to be made on the next cycle of the phase reference generator based on the error estimate of the present cycle.

Abstract: A power supply unit comprises three input terminals connected to a three-phase A.C. power supply, a phase control circuit controlling the firing of the three-phase A.C. for each phase, and a transformer comprising a single-phase iron core wound by first to third coils at the primary side and by a single-phase coil at the secondary side, and in which the first to third primary coils are connected to the three-phase A.C. power supply. It outputs a single-phase A.C. having a frequency three times that of the input current.

Abstract: An emulator which is able to operate on a standard single phase 120 VAC line, generates simulated three-phase alternating current in order to demonstrate the operation of a polyphase electricity meter. The emulator is also capable of demonstrating the operation of the polyphase electricity meter which has been incorrectly wired into the polyphase circuit, i.e., with incorrect or missing connections to the current transformers; or in which there are problems with the phasing of the polyphase circuit, i.e., incorrect phase differences between circuits or between the currents and voltages within any of the phases.

Abstract: A reduced voltage starter for gradually starting a polyphase motor having an acceleration control circuit for gradually applying power to the motor and detector circuits for detecting various fault conditions for terminating power to the motor. A shorted solid state switch detector senses when one of the semiconductor switches applying power to the motor is shorted to terminate the application of power from the remaining phases. A phase angle control circuit insures a uniform application of power to the motor. A phase rotation detection circuit detects when the three phases are in other than their correct sequence and terminates power in the event of such detection. An underload detection circuit senses when the current drops beneath a preselected reference after the motor has reached its full speed and terminates power in response to such detection. A line-to-line-to-line-to-neutral convertor produces signals representative of the line-to-neutral voltages which are necessary for other circuit functions.

Abstract: A rotary phase generator for generating 3 phase voltage is provided which can operate off of 230 or 460 volts A-C. Also provided is a rotary phase generator which has two groups of running capacitors for providing a stable voltage on the third phase at no load and light loads. In addition, a booster system is provided for a rotary phase generator to provide high starting torque to one or more of the motors operated on the rotary phase generator. A plurality of smaller rotary phase generators may be connected in parallel and started in time delay sequence to eliminate the heavy starting current when starting the system on one phase power.

Abstract: A start-up control technique is disclosed for an AC motor. At least one H-switch connects a motor winding to a pair of AC-supplied power lines and is switched between designated states to yield a fundamental frequency component voltage waveform in the winding phase shifted from the voltage waveform in another winding. A rotating field is provided for start-up, without energy-storage phasing capacitors or inductors.

Abstract: A simple combinational technique is disclosed using one or more H-switches for start-up control and frequency conversion in an AC motor. A coordinating logic system provides H-switch toggling timing patterns yielding phase shifted voltage waveforms in the motor windings to afford a rotating field during start-up, and provides irregular switching times yielding a chopped sinusoid output waveform of converted frequency for variable speed operation.

Abstract: A motor control circuit utilizes sample and hold circuitry whose operation is initiated by an analog switch to control the firing angle of silicon control rectifiers, thereby to minimize wasting of power supplied to the motor being controlled.