Abstract: An inverter circuit contains a first and second DC sources for providing a DC voltage, a common boost converter for boosting the DC voltage, an intermediate circuit capacitor connected between the outputs of the common boost converter, and an inverter for converting the DC voltage provided by the capacitor into an AC voltage. The common boost converter contains a series circuit having a first inductance and a first rectifier element and is connected between an output of the first DC source and one side of the intermediate circuit capacitor as well as a series circuit which includes a second inductance and a second rectifier element and is connected between an output of the second DC source and another side of the intermediate circuit capacitor. The common boost converter further contains a common switching element formed by at least two circuit-breakers which are connected between the first and second DC sources.

Abstract: A capacitor discharger applied to a power conversion system including a DC voltage source, a power conversion circuit having a pair of input terminals via which the DC voltage source is electrically connected to the power conversion circuit, and a capacitor electrically connected between the pair of input terminals of the power conversion circuit. The capacitor discharger includes a first series connection of resistive elements and a second series connection of resistive elements. In the capacitor discharger, a parallel connection of the first and second series connections of resistive elements is electrically connected between the pair of input terminals of the power conversion circuit. This can ensure a discharge path for discharging the capacitor even in the presence of an abnormality in a portion of the parallel connection of the first and second series connections of resistive elements.

Abstract: Systems for controlled resonance in electrical power devices are described. A programmed signal processor generates output control signals from input electrical signals based on resonant control parameters for a target power device. Analog electrical control systems for controlled resonance, power devices incorporating controlled resonance, and opto-programmed controllers for use in controlled resonance applications are described, with example embodiments for electro-mechanical systems with resonant constructive power drive action for electric motors.

Abstract: A switching element driver IC has one or more photocouplers, a driver circuit, a detection circuit and a setting circuit. The photocoupler receives setting data transmitted from a microcomputer, and transmits the received setting data to the setting circuit, wherein an input side as a high voltage side is electrically insulated from an output side as a low voltage side in the photocoupler. The setting circuit transmits the setting data to the driver circuit and the detection circuit. The driver circuit and the detection circuit operate on the basis of the received setting data. The setting data can be provided to the driver circuit and the detection circuit through the photocoupler and the setting circuit. This structure makes it possible to suppress increasing the number of terminals at the high voltage side of the switching element driver IC, and decrease the entire size of the switching element driver IC.

Abstract: A solar module has a solar cell which generates a DC voltage. The module has a converter for converting a DC voltage fed into its input. The module contains a semiconductor switch and a controller which drives a switching input of the semiconductor switch. The controller drives the semiconductor switch variably so that the semiconductor switch switches more slowly during the transition operation than during normal operation, thereby reducing a dynamic overvoltage on the switch such that the voltage present on the switch does not exceed the blocking voltage of the switch.

Abstract: A method for controlling a power supply device for at least one electrical machine, having at least one storage device for electric energy (battery) and an inverter equipped with at least one reactor, the inverter having dual functions, being provided for charging (charge operation) the storage device from an in particular stationary power supply system, and for supplying the electrical machine with an alternating current in driving operation. A setpoint charge power is specified for the charge operation, and the reactor current is set accordingly by the inverter. Furthermore, a power supply device is also described.

Abstract: Converter control system coupled between a wind turbine generator and the electric power distribution grid, comprising at least two converter modules connected in parallel which are enabled/disabled by out-of-phase pulse-width modulation (PWM) patterns. The control device guarantees dynamic switching of the converter modules irrespective of the enabling or disabling of at least one converter module, constantly delivering electric power to the distribution grid.

Abstract: The systems, methods, and devices of the various embodiments provide single phase inverters that may be cooperatively controlled to provide one, two, or three phase unipolar electricity. In an embodiment, a solar panel may be connected to a DC to DC converter and a unipolar power converter. In an embodiment, the unipolar power converter output may be a single phase signal approximating a desired voltage waveform and frequency, offset from the ground electrical potential such that the voltage output signal may be always positive, thus “unipolar”. In an embodiment, the unipolar power output of each string of solar panels may be connected to a dedicated, predetermined phase of a load, such as a three phase grid system. In an embodiment, the DC output of a DC to DC converter may be connected in parallel with other DC to DC converters and other unipolar converters.

Abstract: The invention is a bipolar solar photovoltaic to three-phase AC power converter with a novel non-isolated power conversion topology which allows multiple power converter outputs to be directly paralleled without the need for synchronized switching or galvanic isolation. The invention directly supports a new approach to solar photovoltaic system design wherein a large number of distributed lower power converters are used in lieu of one large central inverter.

Abstract: A single-phase inverter and a three-phase inverter are disclosed. The single-phase inverter includes a first and a second inverting topology unit, a first and a second direct-current voltage boost circuit, and four diodes. The first inverting topology unit is connected between a positive output end and a negative output end of the direct-current power supply; the second inverting topology unit is connected between a cathode of a diode and an anode of another diode; and a middle point of the first inverting topology unit is connected to a middle point of the second inverting topology unit and serves as an alternating-current output end of the single-phase inverter. The first and the second inverting topology unit work in a parallel structure to reduce a conduction loss of a switching transistor when the direct-current power supply outputs a high voltage.

Abstract: A system for converting a first voltage into a second voltage, comprising: input terminals and output terminals; switching members disposed between the terminals, which can convert voltage; and a device for controlling the switching members, said device comprising a cell for controlling a switching member and a member for managing and supplying the control cell, said member being connected to the control cell by a link allowing the simultaneous transmission of a control signal and electrical energy. The member comprises means for generating a pulse comprising at least two different control intervals. During the second control interval, the pulse has a substantially constant value different from a reference value corresponding to the absence of control commands, the value of the pulse different from one control interval to the other and, during the first control interval, the pulse has a value strictly greater than the value during the second control interval.

Abstract: A converter device for an uninterruptible power supply, the device having first and second main switching units connected to first and second voltage lines of a first type and each equipped with a first main switch; a main switching point connected to a voltage line of a second type and connected to the first and second main switching units; and a third main switch common to the first and second main switching units, and connected between the main switching point and a third voltage line of the first type; first, second and third capacitors connected between the main switching point and each of the first, second and third voltage lines of the first type; a first auxiliary switching unit connected by individual auxiliary switches between the first and second voltage lines of the first type, and a first auxiliary switching point; a second auxiliary switching unit connected between the first, second and third voltage lines of the first type, and a second auxiliary switching point; and a transformer having windin

Abstract: A multilevel inverter device comprises: a series circuit of a first switching element 21 and a second switching element 22 connected between a terminal at a high voltage side and a terminal at a low voltage side of a DC electric power supply 2; a series circuit of two capacitors 11 and 12, which is connected in parallel with the first switching element 21 and the second switching element 22, to generate an intermediate voltage of the DC electric power supply 2; and a single bidirectional switching element 100 connected between a connection point P1 of the two capacitors 11 and 12 and a connection point P2 of the first switching element 21 and the second switching element 22; and wherein the bidirectional switching element 100 has a horizontal transistor structure using GaN/AlGaN.

Abstract: In a light power generation system, a control device, a control method, and a program, efficient power can be supplied. The maximum power detection unit operates a MOSFET in a power converter circuit and open-circuits both ends of a solar cell panel in the maximum power detection mode. After that, the maximum power detection unit short-circuits both ends of the solar cell panel, detects a maximum power by monitoring the output power of the solar cell panel during a period from the open state to the short-circuited state, and defines the voltage of the solar cell panel as an optimal voltage when detecting the maximum power. In a tracking operation mode, the control unit performs PWM control with respect to the MOSFET by defining the optimal voltage to be a reference signal. Operations are repeated between the maximum power detection mode and the tracking operation mode.

Abstract: An inverter may include an inversion unit for converting a direct current bus voltage into an alternating current voltage, a first snubber unit, and a second snubber unit. The inversion unit may include a first external switch, a first internal switch, a second internal switch, and a second external switch which are connected in series in order between a direct current bus positive voltage terminal and a direct current bus negative voltage terminal. The first snubber unit may be connected between the direct current bus negative voltage terminal and the first internal switch for suppressing voltage stress of the first internal switch. The second snubber unit may be connected between the direct current bus positive voltage terminal and the second internal switch for suppressing voltage stress of the second internal switch.

Abstract: A method for operating a converter circuit is provided. The converter circuit includes a converter unit and a transformer. The transformer includes at least one winding set with a primary winding and a secondary winding. The converter unit is connected, on the AC voltage side, to the primary winding of the respective winding set. In order to compensate for undesirable saturation of the transformer, the converter unit is used to deliberately apply a DC voltage to the primary winding of the respective winding set of the transformer.

Abstract: A stacked switched capacitor (SSC) energy buffer circuit includes a switching network and a plurality of energy storage capacitors. The switching network need operate at only a relatively low switching frequency and can take advantage of soft charging of the energy storage capacitors to reduce loss. Thus, efficiency of the SSC energy buffer circuit can be extremely high compared with the efficiency of other energy buffer circuits. Since circuits utilizing the SSC energy buffer architecture need not utilize electrolytic capacitors, circuits utilizing the SSC energy buffer architecture overcome limitations of energy buffers utilizing electrolytic capacitors. Circuits utilizing the SSC energy buffer architecture (without electrolytic capacitors) can achieve an effective energy density characteristic comparable to energy buffers utilizing electrolytic capacitors.

Abstract: This power converter (1) is provided with: unit cells (11-M) having a semiconductor switch, a DC capacitor (C) and a charge/discharge current I/O terminal; a first arm (12-P) and a second arm (12-N) comprising multiple unit cells (11-M) connected to each other in cascade; an arm connecting unit (13) which has a first terminal to which the first arm (12-P) is connected, a second terminal to which the second arm (12-N) is connected, and a third terminal to which a DC power source is connected; and a transformer (14) which has an AC I/O terminal on the primary side and an intermediate terminal on the secondary side winding, and in which the terminal of the first arm (12-P) and the terminal of the second arm (12-N) are connected to the two end terminals on the secondary winding, and the DC power source (Vdc) is connected to the intermediate terminal.

Abstract: The invention may enable provision of a method for facilitating operation of an induction heating device, and a pot detection method for an induction heating device and to an induction heating device. The induction heating device is characterized by determining a low point of a resonant cycle on a linking node of a parallel resonant circuit and a switching element, determining a low point voltage at the low point of the resonant cycle and switching on the switching element at the low point of the resonant cycle for a cycle duration that is determined depending on the low point voltage in such a manner that a low point voltage does not exceed a predetermined maximum value in the following resonant cycles.

Abstract: A photovoltaic (PV) control system generates a power output rate control signal based on a monitored rate of change of collective power output generated via a plurality of PV subsystems and a desired collective output power change rate for the plurality of PV subsystems and communicates the power output rate control signal to the plurality of PV subsystems to control a rate of change of one or more operating parameters of individual PV subsystems in order to control a rate of change of collective output power of the plurality of solar PV subsystems.

Abstract: A power supply circuit for a gate driving circuit for driving semiconductor switching devices of a power converter that is configured to perform a DC to AC conversion. The power supply circuit includes a DC power supply including a plurality of serially-connected single DC power supplies, a flying capacitor type power conversion circuit including a plurality of flying capacitors connected in parallel to a plurality of the semiconductor switching devices, and a plurality of serially-connected circuits each having an insulating device, a middle part of the series-connected circuits being connected to a middle potential point of the flying capacitors, and to a fixed potential point of the DC power supply.

Abstract: An apparatus for controlling a converter has an ignition unit connected to power semiconductors in the converter and provides control signals for actuating the semiconductors. The apparatus has a control unit whose input is connected to measuring sensors providing actual values and whose output side is connected to the ignition unit. The control unit provides a reference variable for the ignition unit based on setpoint values and the actual values and the ignition unit actuates the power semiconductors such that the actual value corresponds to at least one of the setpoint values. A pilot unit has an output connected to the ignition unit and measures for calculating a step change reference variable for the ignition unit on the basis of at least one of the setpoint values. The ignition unit actuates the power semiconductors based on the step change reference variable.

Abstract: A power supply unit for a press machine having a converter (converter circuit) connected to a commercial AC power supply, and an inverter (inverter circuit) connected to a press motor, includes an electrical energy bank, an inrush prevention circuit, an inrush prevention instruction signal generation section, and a contactor switch section, wherein contactors of the inrush prevention circuit are switched from on ON state to an OFF state and inrush prevention resistors of the inrush prevention circuit are connected to AC phase current paths on condition that the inrush prevention instruction signal generation section has generated and output an inrush prevention instruction signal (Sres) during press operation.

Abstract: A power inverter includes a DC/AC inverter having first, second and third phase circuitry coupled to receive power from a power source. A controller is coupled to a driver for each of the first, second and third phase circuitry (control input drivers). The controller includes an associated memory storing a phase skipping control algorithm, wherein the controller is coupled to receive updating information including a power level generated by the power source. The drivers are coupled to control inputs of the first, second and third phase circuitry, where the drivers are configured for receiving phase skipping control signals from the controller and outputting mode selection signals configured to dynamically select an operating mode for the DC/AC inverter from a Normal Control operation and a Phase Skipping Control operation which have different power injection patterns through the first, second and third phase circuitry depending upon the power level.

Abstract: A system, method, and apparatus is disclosed for interfacing and transferring power unidirectionally or bidirectionally between a direct current (DC) line and a single or multiphase alternating-current (AC) line for only half of any given phase and only a single phase at a time when polarity is matched between the DC and the AC system. A circuit with simplified, robust, and reduced-cost components perform the power conditioning and the synchronization as a system that simulates a half-wave rectifier/inverter.

Abstract: A semiconductor device of this invention (an IGBT with a built-in diode) includes: an n?-type drift layer 1; a p-type channel region 2 that is arranged in contact with the surface side of this n?-type drift layer 1; a gate electrode 5 that is provided in a trench T provided so as to penetrate this p-type channel region 2 and reach to the n?-type drift layer 1 through a gate insulating film 3; an n-type source region 4 that is provided so as to contact the trench T on the surface side of the p-type channel region 2; a high-concentration n-type region 6 that is arranged in contact with the back side of the n?-type drift layer 1; and a high-concentration p-type region 7 that is arranged in contact with the back side of this high-concentration n-type region 6; in which a junction of the high-concentration n-type region 6 and the high-concentration p-type region 7 is a tunnel junction. According to this semiconductor device, it is possible to form the IGBT and the diode on a single chip.

Abstract: A multilevel converter includes at least one phase. Each phase of the multilevel converter includes a direct current (DC) link, a first circuit, a second circuit, and a phase capacitor. The DC link includes a first capacitor, a second capacitor, and a third capacitor situated between the first and second capacitors. The first circuit is electrically coupled to two terminals of the first capacitor. The second circuit is electrically coupled to two terminals of the second capacitor. The phase capacitor is electrically coupled between the first circuit and the second circuit.

Abstract: An inverter comprises a first switch coupled to an input of an output filter and a positive dc bus, a second switch coupled to the input of the output filter and a negative dc bus, a first freewheeling apparatus coupled to the first switch, the second switch and ground, a first soft switching network coupled to the first freewheeling apparatus and the first switch, wherein the first soft switching network is configured such that the first switch is of a first zero voltage transition during a turn-on process of the first switch and a second soft switching network coupled to the first freewheeling apparatus and the second switch, wherein the second soft switching network is configured such that the second switch is of a second zero voltage transition during a turn-on process of the second switch.

Abstract: A turn-off overvoltage limiting for IGBT is described herein. The injection of a sample of the overvoltage across the IGBT in the gate drive to slow down the slope of the gate voltage decrease only during the overvoltage above a predetermined value is described herein. Techniques to increase the parasitic inductance to allow the control to limit an overvoltage at turn off of the second IGBT are also described herein.

Abstract: Provided is an efficient inverter driving method. A pulse with very short pulse width is supplied as a primary driving pulse of a transformer, and the secondary output voltage of the transformer caused by a transient phenomenon can be enlarged several times while keeping the power source voltage for input current constant by shortening the time interval of the primary driving pulse.

Abstract: In aspects of the invention, a multilevel conversion circuit can include a configuration for linking capacitors, including diodes, reverse-blocking semiconductor switches, and resistors, and a circuit for clamping the capacitor voltage at a specified voltage. Such a configuration can serve to reduce the number of capacitors that need detection of the voltages thereof and appropriate changing-over operation of semiconductor switches to control the capacitor voltage to a desired value. By way of aspects of the invention, desired voltages can be provided to the capacitors.

Abstract: The present invention relates to a Voltage converter (100) for converting an input voltage (V10) to an output voltage (V20) comprising an input circuitry (102) for receiving the input voltage (V10) from a power supply (112), wherein the input circuitry includes chopper means (110) for chopping a voltage (V12) derived from the input voltage (V10) at a chopper frequency to a chopped voltage (V14), an inductive transformer unit (106) for transforming the chopped voltage (V14) to a chopped AC voltage (V16), and an output circuitry (104) for converting the chopped AC voltage (V16) of the inductive transformer unit (106) to the output voltage (V20) having a lower frequency than the chopper frequency.

Abstract: A multilevel inverter having an efficient structure is provided, the multilevel inverter including a modularized phase-shift transformer including a plurality of modules to provide a phase shifted voltage by receiving a 3-phase input voltage, a plurality of first group unit power cells configured to provide an output voltage of predetermined phase, a plurality of second group unit power cells configured to provide an output voltage of predetermined phase, a plurality of third group unit power cells configured to provide an output voltage of predetermined phase. One of the first group unit power cells, one of the second group unit power cells and one of the third group unit power cells are paired to provide an output voltage of same phase.

Abstract: A static energy supply unit has an energy store connected to an ac supply network by a power converter. A unit controller for the static energy supply unit includes an amplitude controller, a phase controller and a frequency controller. These measure and record characteristics of the supply network and provide output signals indicative of the voltage characteristics for an operating condition of the supply network. A signal generator for generating a simulated output voltage signal for each phase of the supply network is provided. A comparator is used to compare the simulated output voltage signal for each phase and a measured voltage for a corresponding phase of the supply network. The controller controls the operation of the power converter to vary the amount of power that is supplied to the supply network from the energy store based on the comparison of the simulated output voltage signal(s) and the measured voltage(s).

Abstract: A current controller for controlling plural stator currents of plural stator windings of an electrical machine, in particular a generator, is provided, wherein the plural windings are separately connectable to a converter. The current controller includes a positive-sequence current controller configured to provide a first voltage command, in particular in a rotating dq+ frame, based on the plural stator currents; a negative-sequence current controller configured to provide a second voltage command, in particular in the dq+ frame, based on the plural stator currents. Further, the current controller includes a summation system for adding the first voltage command and the second voltage command to obtain a summed voltage command based on which the converter is controllable.

Abstract: A method for controlling a converter including a resonant circuit, where the converter is controlled such that control switches are switched into a first state at the occurrence of an event that is related to a dependent variable of the converter and are switched into a second state at the occurrence of an event that is not related to a dependent variable of the converter. The method may be employed in a converter or an inductive power transfer transmitter.

Abstract: The invention relates to a DC to AC converter circuit. In particular, the invention relates to a half-bridge inverter for converting a DC to an AC voltage. The half-bridge inverter for converting a DC input voltage to provide an AC output voltage at an output terminal, comprising a first switching circuit connected to at least one input terminal and to the output terminal and configured to provide a high or a low voltage level at the output terminal; a second switching circuit connected to the output terminal and configured to provide a connection to an intermediate voltage level, the intermediate voltage level being between the high and the low voltage level; and wherein the second switching circuit is further connected to the at least one input terminal allowing the second switching circuit to provide the high or the low voltage level at the output terminal.

Abstract: An inverter device includes; a switching element; a plurality of flyback diodes each connected in parallel with the switching element; a first conductor plate connected to anode terminals of the flyback diodes and to one side of the switching element; and a second conductor plate connected to cathode terminals of the flyback diodes and to the other side of the switching element. Each of the flyback diodes is formed in a polygonal shape, and the two flyback diodes in each pair of the flyback diodes that are arranged in mutually adjacent positions are arranged so that a vertex of one opposes a vertex of the other.

Abstract: The invention relates to a differential mode and common mode choke comprising: a ferromagnetic core comprising three branches (1, 2, 3) extending between a bottom part (5) and a top part (4), a first coil (b1) wound around the first lateral branch (1), a second coil (b3) wound around the second lateral branch (3), the first lateral branch (1) being separated from the top part (4) by a first air gap (e1) and from the bottom part (5) by a second air gap (e10), the second lateral branch (3) being separated from the top part (4) by a first air gap (e3) and from the bottom part (5) by a second air gap (e30), the central branch (2) being separated from the top part (4) by a first air gap (e2) and from the bottom part (5) by a second air gap (e20).

Abstract: There is provided a gate driving device, including: an inverter arm including a high-side switch and a low-side switch; a gate driving unit receiving an instruction signal to provide switching control to the inverter arm, outputting a control signal to control switching of the inverter arm, and including a plurality of gate drivers; and a balancing unit causing voltage applied to the plurality of gate drivers to be divided to be supplied to respective gate drivers among the plurality of gate drivers, according to the switching of the inverter arm based on the control signal.

Abstract: An inductive component (1a . . . 1e) with at least two coils (2 . . . 4b) in a closed main magnetic circuit (5a . . . 5j) for guiding a magnetic main flux (?H) penetrating all coils (2 . . . 4b) is specified. The inductive component furthermore comprises a leakage field guide component (6a . . . 8c) or a plurality of leakage field guide components (6a . . . 8c), wherein a leakage field guide component (6a . . . 8c) is arranged between two coils (2 . . . 4b) in each case, separated by two air gaps (E . . . J) from the main magnetic circuit and intended for guiding a magnetic leakage flux ?S different from the main flux ?H. The main magnetic circuit (5a . . . 5j) and/or the leakage field guide components (6a . . . 8c) consist of a magnetically isotropic material. Furthermore, the invention relates to a use of a choke (1a . . . 1e) with leakage field guide component (6a . . . 8c) for guiding a leakage flux (?S) arising in the choke (1a . . . 1e) as a PFC (Power Factor Correction) choke.

Abstract: A power conversion device (1) of the present invention includes a power module (4) for converting direct current electricity to alternating current electricity, first and second power supply buses (5, 6) connecting input terminals (12, 13) and the power module (4), and a metal casing (7) for housing the first and second power supply buses (5, 6) and the power module (4). The capacitive coupling between the first power supply bus (5) and the metal casing (7) and the capacitive coupling between the second power supply bus (6) and the metal casing (7) are substantially matched. Thus, radiation noise is reduced by reducing the propagation of switching noise to the metal casing.

Abstract: A drive device driving a power converter that includes a switching element formed from a wide bandgap semiconductor, includes a PWM-signal output unit that generates a drive signal that drives the switching element with PWM; an on-speed reducing unit that, when the switching element is changed from off to on, reduces a change rate of the drive signal; and an off-speed improving unit that, when the switching element is changed from on to off, draws charge from the switching element at a high speed and with a charge drawing performance higher than that at a time when the switching element is changed from off to on.

Abstract: An analog controller is disclosed. The controller has a maximum power point tracking unit and a power factor adjusting unit. The maximum power point tracking unit generates a maximum power tracking voltage which is used to control the magnitude of the output current of the inverter so as to extract the most available power from the power generating device. The power factor adjusting unit, which generates a ramp control voltage that will further determine the duty ratio and switching frequency of PWM signal, gracefully tunes the magnitude and reduces the total harmonic distortion of the current injected from inverter into utility grid.

Abstract: A multi-level inverter having at least two banks, each bank containing a plurality of low voltage MOSFET transistors. A processor configured to switch the plurality of low voltage MOSFET transistors in each bank to switch at multiple times during each cycle.

Abstract: An improved interface for renewable energy systems is disclosed for interconnecting a plurality of power sources such as photovoltaic solar panels, windmills, standby generators and the like. The improved interface for renewable energy systems includes a multi-channel micro-inverter having novel heat dissipation, novel mountings, electronic redundancy and remote communication systems. The improved interface for renewable energy systems is capable of automatic switching between a grid-tied operation, an off grid operation or an emergency power operation.

Abstract: A voltage converter system includes a first DC-AC voltage converter that converts a first DC voltage signal to a first AC voltage signal. A DC link converts the first AC voltage signal to a second DC voltage signal. A second DC-AC voltage converter converts the second DC voltage signal to a second AC voltage signal. In another configuration a DC-AC voltage converter converts a DC voltage signal to a first AC voltage signal. An AC-AC voltage converter converts the first AC voltage signal to a second, lower-frequency AC voltage signal. In yet another configuration a first voltage converter portion converts a DC voltage signal to pulses of DC voltage. A second voltage converter portion converts the pulses of DC voltage to a relatively low-frequency AC voltage signal. The voltage converter system is selectably configurable as a DC-AC voltage converter or an AC-DC voltage converter.

Abstract: A voltage booster allowing for increased utilization of low voltage, high current, unregulated DC power (“LVDC source”), such as, but not limited to, fuel cells, batteries, solar cells, wind turbines, and hydro-turbines. LVDC generation systems employing a variable low voltage DC-DC converter of the present disclosure may be used without a power inverter in applications requiring high voltage DC inputs and can also allow for the employment of common, low cost, reliable, low voltage energy storage chemistries (operating in the 12-48 VDC range) while continuing to employ the use of traditional inverters designed for high voltage power supplies. An embodiment of the DC boost converter includes a plurality of interleaved, isolated, full-bridge DC-DC converters arranged in a Delta-Wye configuration and a multi-leg bridge.

Abstract: An inverter switches input voltage Vin to flow an excitation current to excitation winding Np of a transformer and output to a discharger an alternating voltage Vout from the output winding Ns. In an output circuit flowing a current to the discharger, a voltage-responsive connector is connected in series with the winding Ns to interrupt or connect the output circuit according to a voltage applied to between opposed electrodes. The voltage-responsive connector has characteristics of keeping the electrodes in an insulated state until an instantaneous value of the alternating voltage reaches a predetermined value, and holding the electrodes in a conduction state while the instantaneous value of the alternating voltage has reached the predetermined value and continues to exceed the predetermined value, and quickly returning the electrodes to the insulated state when the instantaneous value of the alternating voltage has fallen below the predetermined value.

Abstract: An inverter includes transformers having identical characteristics. Exciting windings of the transformers are connected in parallel so that the transformers are excited simultaneously. Output windings of the transformers are connected in series so that waveforms of output voltages of the output windings are time-synchronized. Each transformer includes a core having an identical shape and including an inner leg having an independent closed magnetic circuit. The excitation winding and the output winding are wrapped around the inner leg of the core in layers. The inner leg of the core has a gap whose size is steplessly adjustable in a state where the excitation current is applied to the excitation winding. The size of the gap is adjusted to regulate exciting inductances of the transformers to a same predetermined value.