Abstract: A method and apparatus are described for compensating input voltage ripples of an interleaved boost converter using cycle times. In an embodiment, a phase compensator receives a first duty cycle measurement of a first converter and a second duty cycle measurement of a second converter, compares the first duty cycle to the second duty cycle and generates a phase compensation in response thereto. A phase combiner combines a phase adjustment output and the phase compensation and produces a phase control output, and a cycle controller is coupled to the first and the second converters to generate a first drive signal to control switching of the first converter and to generate a second drive signal to control switching of the second converter, wherein a time of the second drive signal is adjusted using the phase control output.

Abstract: A power conversion circuit has an inverter circuit including a first node and a second node that output a voltage according to an input voltage, a resonant circuit connected to the first node and the second node and including a third node and a fourth node that output a resonant voltage; and an output circuit connected to the third node and the fourth node and configured to output a DC voltage, wherein the resonant circuit includes a first inductor having one end connected to the third node, a first capacitor connected between the first node and another end of the first inductor, a second capacitor connectable between the second node and the fourth node, a second inductor connectable between the third node and the fourth node, and a first switch that switches whether or not to connect the second inductor between the third node and the fourth node.

Abstract: The present invention allows individual control of an output voltage of a main transformer and an output voltage of a teaser transformer while utilizing output characteristics of the respective transformer when a Scott connected transformer has control equipment arranged on the input side thereof, including first control equipment arranged in one of two phases of the main transformer on the input side in order to control a voltage or a current and second control equipment arranged in one end of a primary coil of the teaser transformer on the input side in order to control a voltage or a current, the control equipment controlling an output voltage of the main transformer and an output voltage of the teaser transformer individually.

Abstract: A power amplifier with supply switching is provided. The power amplifier detects a magnitude of an outgoing broadband communication signal and determines whether the magnitude exceeds a predetermined voltage threshold. The power amplifier applies a first gain to the outgoing broadband communication signal using a first voltage supply rail when it is determined that the magnitude exceeds the predetermined voltage threshold and a second gain using a second voltage supply rail that is smaller than the first voltage supply rail when it is determined that the magnitude does not exceed the predetermined voltage threshold. The power amplifier produces an output signal from the outgoing broadband communication signal with the applied first gain or the applied second gain, wherein a current of the outgoing broadband communication signal is switched between the first voltage supply rail and the second voltage supply rail in response to the magnitude being detected.

Abstract: The present invention allows individual control of an output voltage of a main transformer and an output voltage of a teaser transformer while utilizing output characteristics of the respective transformer when a Scott connected transformer has control equipment arranged on the input side thereof, including first control equipment arranged in one of two phases of the main transformer on the input side in order to control a voltage or a current and second control equipment arranged in one end of a primary coil of the teaser transformer on the input side in order to control a voltage or a current, the control equipment controlling an output voltage of the main transformer and an output voltage of the teaser transformer individually.

Abstract: A power amplifier with supply switching is provided. The power amplifier detects a magnitude of an outgoing broadband communication signal and determines whether the magnitude exceeds a predetermined voltage threshold. The power amplifier applies a first gain to the outgoing broadband communication signal using a first voltage supply rail when it is determined that the magnitude exceeds the predetermined voltage threshold and a second gain using a second voltage supply rail that is smaller than the first voltage supply rail when it is determined that the magnitude does not exceed the predetermined voltage threshold. The power amplifier produces an output signal from the outgoing broadband communication signal with the applied first gain or the applied second gain, wherein a current of the outgoing broadband communication signal is switched between the first voltage supply rail and the second voltage supply rail in response to the magnitude being detected.

Abstract: A method and apparatus for providing multi-phase power. In one embodiment, the apparatus comprises a cycloconverter controller for determining a charge ratio based on a reference waveform; and a cycloconverter, coupled to the cycloconverter controller and to a multi-phase AC line, for selectively coupling an alternating current to each line of the multi-phase AC line based on the charge ratio.

Abstract: A multiphase transformer rectifier unit for converting a three-phase alternating current supplied from a power distribution system to direct current supplied to at least one load. The multiphase transformer rectifier unit includes a magnetic core having a primary winding set and secondary winding set, and a rectifier circuit. The secondary winding set is arranged to generate N substantially equally distributed output phases, wherein N is an odd number multiple of 3, and N>3, and the primary winding set (17) is arranged to provide a positive or negative phase shift equal substantially to 360 ( 8 × N ) degrees of said output phases. Also an arrangement of two inventive multiphase transformer rectifier units for reducing current distortion in the power distribution system.

Abstract: There is disclosed a power conversion apparatus 3 for converting polyphase ac power directly to ac power. A conversion circuit includes a plurality of first switching devices 311, 313, 315 and a plurality of second switching devices 312, 314, 316 connected, respectively, with the phases R, S, T of the polyphase ac power, and configured to enable electrical switching operation in both directions. Output lines 331, 332 formed by a pair of busbars are connected with the conversion circuit. The first switching devices and the second switching devices are so arranged that output terminals are arranged in a row. The output lines 331, 332 are connected with the output terminals and drawn out rectilinearly in one direction.

Abstract: A generator, such as for a gas turbine engine, includes an integrated auto transformer unit having secondary windings connected to a main windings.

Abstract: An integrated magnetic device for low harmonics three-phase front-end (1) comprising three magnetic sub-assemblies (30), wherein each magnetic sub-assembly (30) comprises a magnetic core without air-gaps, three or more wound limbs and at least five windings, three current inputs connectable to a three-phase power grid (100), at least nine current outputs, three for each current inputs, said current outputs being galvanically connected to said three current inputs and connectable to a load (200). The integrated magnetic device is designed for a low harmonics three-phase bidirectional front-end and also for AC/DC rectifier and DC/AC power inverters. Its use enables reduction of the harmonics of the currents absorbed or injected to three-phase power line by using only one device which integrates a splitter and an inductor function. Compared to known solutions, cost, material and dimensions of the integrated magnetic device are reduced.

Abstract: A static converter includes a current converter on the three-phase side and a current converter on the single-phase side, which are electrically conductively linked to one another on the DC voltage side, and which are respectively electrically conductively connected on the AC voltage side to a feeding three-phase network and a single-phase receiving network. According to an embodiment of the invention, one network-commutated current converter is provided as the current converter on the three-phase side, wherein the current converter on the single-phase side has two phase modules which are connected in parallel on the DC voltage side and whose current converter branches each have at least one two-pole subsystem. This results in a static converter which is simpler and costs less than a known static converter.

Abstract: A system and method for power conversion synchronizes multiple phases at a desired phase angle difference. The power conversion involves variable frequency switching, fixed on-time and provides power factor correction. A relative measure of a phase angle difference between two phases permits each phase to be controlled to obtain the desired phase angle difference. The power conversion involves transition mode switching to help reduce switching losses. A phase angle difference detector may be provided for each phase. The various phases may have different inherent frequencies that vary with switching frequency, and are synchronized to an average frequency. Current measures can be taken with a single component, such as a resistor. A maximum frequency control limits period width to avoid high frequency switching. An added switch on time improves input voltage crossover distortion. One or more phases can be deactivated in light load conditions.

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: Electrical power monitoring apparatus comprises a loop and a first conductor. A current sensor coupled to the first conductor provides a current signal that is representative of the current in the first conductor. A voltage sensor coupled at least to the first conductor provides a voltage signal that is representative of the voltage on the first conductor relative to that on a reference terminal. A multiplier coupled to the current sensor and voltage sensor has a power output which provides a power signal that is proportional to the instantaneous value of electrical power carried by the first conductor. A calibration circuit in the loop has an input coupled to the power output and has an adjustable output. A current regulator in the loop has an input coupled to the adjustable output to maintain the current in the loop between predetermined minimum and maximum loop current values.

Abstract: The present invention provides smooth conversion of electric power between an AC line operating at a first voltage and a DC line operating at a second voltage bearing a fixed ratio to the first voltage. In one embodiment, polyphase AC is converted to rippled DC. In one embodiment, switched DC is converted to AC of one or more phases. The electric power converter of the invention uses a single electrical winding can be thought of as derived from the formerly well-known, and now largely forgotten, synchronous converter by locking the rotor, discarding the field winding and its power supply, replacing the AC slip ring contacts with hardwired connections, and replacing the DC commutator taps, bars and brushes with rectifying taps. Thus, the new power converter may be referred to as a single-winding static synchronous converter.

Abstract: Even when a plurality of dispersed power generation systems are connected to a utility gride, an islanding-operation prevention apparatus can easily and assuredly prevent an islanding operation of each dispersed power supply constituting the corresponding dispersed power generation system. The apparatus includes a breaker provided between the utility gride and a dispersed power supply, an electric-power-value detector for detecting a value of electric power from a power line connected to the utility gride, a switch for electrically connecting or disconnecting an electric-power changing device for changing the value of electric power to the power line in accordance with an output from a pulse circuit, and a controller for controlling the breaker in accordance with the width of fluctuations of the value of electric power during the connection or the disconnection. A dispersed power generation apparatus and a dispersed power generation system uses such an apparatus.

Abstract: An electronic system comprises a three-phase transformer, a power conversion circuit, and a control circuit. The three-phase transformer has primary windings and first, second and third secondary windings. The primary windings are connected to three-phase power supply and the first secondary winding is connected in phase with a single-phase load, such as an electric railway. The second and third secondary windings are connected to the single-phase load by the power conversion circuit. The power conversion circuit includes an a.c. to d.c. converter, a d.c. to a.c. converter, and a single-phase transformer. The d.c. to a.c. converter is adapted to convert out of phase power from the second and third windings, into a d.c. voltage signal. The d.c. to a.c. converter is connected to a.c. to d.c. converter and is adapted to convert the d.c. voltage signal into a single-phase a.c. voltage signal. The single-phase transformer has a primary winding which is connected to the d.c. to a.c.

Abstract: A method and apparatus for providing a source of alternating current electrical power to a plurality of loads in an office environment, including a plurality of non-linear loads which draw power for only a portion of the alternating current cycle, includes an input source of three-phase electrical power to a primary side of a power transforming device which provides an output at its secondary side which comprises at least six phases and a shared neutral. The plurality of loads are evenly distributed between each phase of the output power source and the shared neutral so as to reduce by current cancellation the current which would otherwise flow in the shared neutral conductor due to the presence of the non-linear loads. Each of the six phases is separated from the other by 120 electrical degrees, and the fourth, fifth and sixth phases are separated from the first, second and third phases, respectively, by 180 electrical degrees.

Abstract: A three phase inverter (10) in accordance with the invention includes a first phase inverter (12) producing a first phase AC output voltage from a DC power supply; a second phase inverter (14) producing a second phase AC output voltage which is displaced nominally 120.degree. from the first phase from the DC power supply; and a vector adding circuit (32), responsive to the first and second phases, for vectorially adding voltages proportional to output voltages from the first and second phases to produce a resultant voltage which is inverted to produce a third phase having an output voltage which is displaced nominally 120.degree. from the output voltages produced by the first and second phases.

Abstract: A DC to AC sinewave converter having an FET with its gate terminal coupled to a switching signal which turns the FET on and off. A pair of parallel, oppositely conductive diodes couples the drain terminal of the FET to a resonant circuit that is responsive to a source of DC voltage. A clamping diode is connected between the parallel diodes and the source terminal of the FET for preventing the drain and source terminals from being reverse biased.

Abstract: An uninterruptible polyphase AC power supply equalizes an electric power taken out from a polyphase AC power source, even if unbalanced load is connected to output.

Abstract: An inverter apparatus for converting a single-phase A.C. power source to three-phase A.C. outputs is described wherein the single-phase power source is directly connected to a first phase load and is connected through a one-phase converter to a second phase load, and the single-phase power source and the one-phase converted single-phase power source are connected to a third phase load and a fourth phase load, the third and fourth phase loads being formed by dividing a single load, so that three-phase power outputs are provided for the first phase load, the second phase load, and the third plus fourth loads.

Abstract: A circuit arrangement for inexpensive production of three-phase current from dc current contains two dc voltage sources connected in series, the connection point of which is selected as reference voltage. A chopper circuit is provided which is arranged in parallel to the series circuit of the dc voltage sources and which produces two ac voltages phase-displaced by 60.degree. from the dc current provided by the dc voltage sources.

Abstract: This invention relates to an electric supply circuit for a large number of multi-phase a.c. apparatus, particularly hysteresis motors of gas centrifugal machines, having circuits to form three-phase control pulses, control circuits for the through-connection between d.c. forms of the desired alternating voltage for one or a number of apparatus to be energized under the control of the control pulses and circuits for adapting the signal levels of the control pulses to the circuit for the formation of the alternating voltages, wherein a large number of circuits for the formation of the alternating voltage is controlled from a single control circuit.

Abstract: The converter includes a transistor, a transformer having a ferromagnetic core, tuning capacity, and rectification of high frequency oscillations which occur in the converter for producing a voltage for an electrical load different in magnitude from the voltage of an electrical energy source from which the converter takes power. Load voltage and electrical energy source voltage may be direct current voltages or changing voltages. The converter operates to maintain the voltage across the load at a constant value independent of the resistance of the electrical load. The oscillations occur only when transistor bias current is provided, for example by bias current conduction through the load, in which case negligible power is taken from the electrical energy source by the converter when the load is disconnected. High frequency of oscillations in the converter provides certain advantages.

Abstract: In an inverter apparatus including a plurality of parallel branch circuits connected across a D.C. source, each including a pair of serially connected controllable switching elements, and a plurality of semiconductor elements connected in parallel opposition with respective switching elements, a D.C. reactor is connected on the D.C. side or A.C. side of the inverter and a circuit is connected across the D.C. reactor for preventing attenuation of the current flowing through the D.C. reactor during the OFF period of the switching elements. A source of control pulses is provided for rendering ON respective controllable switching elements each for a 120.degree. interval of the output alternating current. The source of control pulse includes means for chopping the current flowing through each controllable switching element at a predetermined modulation frequency for the former or latter 60.degree. of the 120.degree. interval.