Abstract: An electric power source in which a plurality of inverters operate on the same frequency and the plurality of inverters are connected in parallel so that a resistance value expressed by (1??·G)/(?·G) where ? is the output voltage feedback gain, ? is the output current feed forward gain, and G is the inverter current gain, is made to be the equivalent output impedance; and is an electrical power source in which the cross-current between the inverters are made to be an acceptable value or below by adjusting the output of each of the inverters by controlling the equivalent output impedance by modifying both or either one of the output voltage feedback gain ? or the output current feed forward gain ?.

Abstract: A multi-phase voltage regulator comprises a plurality of current supplying stages, each current supplying stage configured to supply a local output current equaling at least a portion of a load current output from the multi-phase voltage regulator; and a plurality of control circuits, each control circuit coupled to a respective one of the plurality of current supplying stages, wherein each control circuit calculates a control signal based, at least in part, on a sampled current representative of the respective local output current and a sampled current representative of a master output current. The control signal from each control circuit causes the respective current supplying stage to be disabled gradually over a first time interval if the sum of the local output current and the master output current is detected as being below a respective first predetermined level.

Abstract: An electric energy storage system (EESS) for providing a power management solution for a multi-subsystem energy storage in electric, hybrid electric, and fuel cell vehicles. The EESS has a controller that determines when to draw power from each subsystem as needed by the vehicle.

Abstract: The invention relates to a method for controlling the voltage and power of several HF inverters (2), connected in parallel at the output, of an electrically isolated inverter assembly as well as for distributing the load to these HF inverters (2) each consisting of at least one DC-DC converter (3), one intermediate circuit (4) and one DC-AC converter (5), with a command variable (Ui?) being formed for each HF inverter (2) so as to preset a nominal value for control of an intermediate-circuit voltage (UZKi) at the intermediate circuit (4) of the HF inverter (2). The load of each HF inverter (2) is determined by a control unit (13) by measuring the current or power required, an internal resistance of the HF inverter (2) is simulated via which internal resistance a virtual voltage drop (UVR) is caused which depends on the load determined and is used for controlling the voltage (UZKi) of the intermediate circuit (4) so as to produce a purposive change in the output voltage of each HF inverter (2).

Abstract: In the present invention, when configuring a control system of an inverter performing power conversion between AC and DC, a frequency computation is performed based on biaxial voltage amounts obtained through two current regulators in such a way that each of biaxial component currents obtained by detecting an AC circuit current and performing a rotational coordinate transformation matches each respective command value and phase information in synchronization with an electromotive force power supply of the AC circuit is obtained by integrating the frequency to perform the rotational coordinate transformation of the AC current and also the inverter is caused to operate by generating a PWM switching signal from the biaxial voltage amounts to perform necessary power conversion control.

Abstract: An inverter circuit for generating an AC signal from a DC input is described herein. The inverter comprises a primary inverter for generating a first portion of a signal, the primary inverter using switches that when actuated efficiently produce the first portion of the signal, the first portion of the signal being an approximation of a sine wave, the approximation of the sine wave having an error component; a secondary inverter for generating a second portion of the signal, the secondary inverter using switches to produce a waveform that that attenuates the error component of the first portion of the signal; and combining means such as a transformer which combine the first and second portions of the generated signal to produce a substantially improved approximation of a sine wave.

Abstract: A method and circuit enabling off-the-shelf controllers designed for use with a two-level AC drive inverter bridge (1920) to drive inverter bridges with three-or-more levels. Signals from an ordinary induction motor controller or a two-level induction motor controller (2200) are used to drive the twelve-or-more switches of a three-or-more level inverter bridge (1920), as are used in medium-and-high voltage applications. The proper sequence and timing of switching for the three-or-more-level inverter bridge is based in-part upon either the output of the six pulse-width modulators, or the output of the flux and torque control device, or the voltage control device (2210), of the two-level controller (2200).

Abstract: A voltage transforming apparatus includes a first high voltage side coil, a first low voltage side coil magnetically coupled to the first high voltage side coil, a second low voltage side coil magnetically coupled to the first high voltage side coil, and a first switch switching an externally supplied voltage between being supplied to the first low voltage side coil and the second low voltage side coil and being supplied to the first high voltage side coil. The first low voltage side coil and the second low voltage side coil are provided such that a magnetic flux that is generated by current flowing through the first low voltage side coil and a magnetic flux that is generated by current flowing through the second low voltage side coil cancel each other out when a voltage is supplied via the first switch.

Abstract: An adaptive hybrid energy system is provided. The system includes a first DC energy source that generates a first DC output by converting a first type of energy into an electrical output. Additionally, the system includes at least a second DC energy source that generates a second DC electrical output by converting a second type of energy into an electrical output. The system further includes a cascaded multilevel converter electrically connected to the first and second DC energy sources to convert a DC electrical output into a sinusoidal electrical output when at least one of the first and second DC energy sources is operable.

Abstract: A bi-directional dc-dc converter is provided that may provide voltage conversion for two separate electrical power systems. The two electrical power systems may have different functions, electrical requirements and power transfer directions. The bi-directional dc-dc converter may include back-to-back bi-directional dc-dc converter circuits isolated from each other by a transformer. Multiple such dc-dc converters may be connected in parallel to increase power capability. Phase shift pulse width modulation (PWM) may be used to switch the parallel dc-dc converters so as to decrease both voltage ripple and current ripple. The number of dc-dc converters may be modified to meet the different needs of various electric power systems. A single bi-directional dc-dc converter of the invention may be employed to provide electric power conversion for multiple electric power systems, even where those systems have different power requirements and different power transfer directions.

Abstract: A switchgear cell having a group of connection is disclosed, with the group of connection having a first and a second controllable bidirectional power semiconductor switch and a capacitor.

Abstract: An inverter system for driving electrical loads such as multi-phase induction motors is disclosed utilizing five single-phase inverter cells configured in a wye configuration. Inverter cells such as neutral-point-clamp inverter cells are configured to generate a voltage waveform between two output terminals and further configured with a terminal providing a neutral voltage reference point with respect to each of the two output terminals. The inverter cells may be configured with the neutral voltage reference points connected together and with one output terminal from each inverter cells connected together to provide three outputs of the inverter system at different voltage phases and with the common neutral reference point as the wye connection of the three outputs. The other three single phase inverter cells may be added to each of the three outputs to boost the output voltage of the inverter system and decrease the maximum voltage requirements on each inverter cell.

Abstract: Methods and systems are provided for operating an electric motor having at least one winding coupled to first and second power supplies. A torque command for the electric motor is received. A present power reserve for the first and second power supplies is determined based at least in part on the torque command. An operating voltage for the second power supply is determined based on the present power reserve. The operating voltage for the second power supply is applied to the at least one winding. The application of the operating voltage allowing the present power reserve to flow between the first and second power supplies and the motor.

Abstract: Methods and systems for converting direct current (DC) power to alternating current (AC) power are provided. A first phase of the AC power is generated based on a first carrier signal. A second phase of the AC power is generated based on a second carrier signal.

Abstract: A regulator for converting energy from an input source to a voltage of an output. The regulator comprising at least two conduction switches to conduct energy from the input source to the output. Each of the conduction switches operated at approximately 50% duty cycle. At least two inductors in communication with the at least two conduction switches, the at least two inductors wound together on a common core and each inductor having a polarity such that DC currents in the inductors cancel each other. The inductors having a coefficient of coupling approximately greater than 0.99. At least two freewheeling switches in communication with the at least two conduction switches to provide a path for current during non-conduction periods. A drive signal generator to generate drive signals for controlling the at least two conduction switches.

Abstract: A DC voltage converting device is on the output side connected to a DC voltage source and, on the output side, supplies a converted DC voltage to at least one electrical consumer via a cable connection. To improve such a DC voltage converting device in that also with high DC voltages on the input side, a conversion into another DC voltage is possible without any special constructional efforts and high costs while complicated cooling means or the like, are avoided at the same time, the Dc voltage converting device comprises a plurality of DC voltage converting units of which each is serially connected to the DC voltage source on the input side and connected in parallel with the cable connection on the output side for supplying the converted DC voltage.

Abstract: In a power conversion apparatus that boosts a solar light voltage, converts it to AC and supplies AC power to a load or system, power loss is reduced and efficiency is improved. An inverter unit, in which AC sides of three single-phase inverters receive DC power from respective sources with a voltage ratio of 1:3:9 as respective inputs are connected in series. Gradational output voltage control of an output voltage is carried out using the sum of the respective generated AC voltages. Also, a solar light voltage is boosted by a chopper circuit to generate the highest voltage DC power source. When the solar light voltage exceeds a predetermined voltage, the boosting of the chopper circuit is stopped, thereby reducing power loss due to the boosting.

Abstract: A system for converting at least one electrical input direct current into an electrical output alternating current comprising M phases and supplied to M output terminals includes N polyphase inverters, connected in parallel, each converting the input direct current into an intermediate alternating current comprising M phases and supplied to M intermediate terminals; N×M first electromagnetic coupling coils, each being connected to a respective intermediate terminal; N×M magnetic cores, each first coil being wound around a respective core. This system comprises N×M second electromagnetic coupling coils, each being connected to a respective first coil and wound around a distinct core from that of the respective first coil. The first and second coils of a same core correspond to a single phase, and generate respective common mode fluxes of opposite directions. Each output terminal is connected to the M second coils of a single phase.

Abstract: The invention relates to converters (inverters, pulse or frequency converters) and to the driving of “magnetically active” operating means. An effective switching frequency of the converter is not to be reduced, but nevertheless a reduction in cooling requirements is to be achieved A noise level produced in the operating means is to be kept low as well. The invention proposes, for this purpose, a circuit arrangement for feeding the operating means (electrically operated machine (M)) having at least one winding (L1, L2, L3), which circuit arrangement, in at least one first winding phase (S1), comprises a first branch (Z1) of a frequency converter (WR1) adapted for and operable at a switching frequency of not higher than 5 kHz for outputting a main alternating current generated at said switching frequency and having a substantially lower operating frequency (f1) to a winding (L1).

Abstract: A power conversion apparatus for converting direct current from a power source to polyphase alternating current includes a plurality of carrier signal generators, a plurality of gate signal generators, and a plurality of legs. The carrier signal generators are configured and arranged to independently generate and transmit a plurality of carrier signals, respectively. The gate signal generators are operatively coupled to the carrier signal generators, respectively, to receive the carrier signals, each of the gate signal generators being configured and arranged to generate an on/off signal by comparing a command value of each phase of the polyphase alternating current and corresponding one of the carrier signals. The legs are connected to the gate signal generators. Each of the legs is operated based on the on/off signal transmitted from corresponding one of the gate signal generators to convert the direct current to each phase of the polyphase alternating current.

Abstract: A DC/DC power conversion device with smoothing capacitors including three column circuits share the smoothing capacitors to be connected in parallel, each column circuit have a plurality of circuits connected in series where two MOSFETs are connected in series between both ends of respective smoothing capacitors and LC serial bodies of capacitors and inductors with the same resonant cycle are disposed between the circuits at two middle terminals. Driving signals for the respective column circuits have the same driving cycle identical with the resonant cycle of the LC serial bodies, and are out of phase with each other by 2?/3(rad), and thus charge-discharge currents towards the smoothing capacitors are circulated among the column circuits and ripple currents flowing through the smoothing capacitors are reduced.

Abstract: At least three power converters in a power distribution and power transmission system can be controlled as rectifiers or inverters and are connected together by a direct current network. A measuring direct current voltage and a measuring direct current are measured on each power converter and respectively, transmitted to the respective rectifier control and/or inverter control, and a rectifier desired direct power and/or inverter desired direct power is determined for each power converter.

Abstract: In a power conversion apparatus that boosts a solar light voltage, converts it to AC and supplies AC power to a load or system, power loss is reduced and efficiency is improved. An inverter unit, in which AC sides of three single-phase inverters receive DC power from respective sources with a voltage ratio of 1:3:9 as respective inputs are connected in series. Gradational output voltage control of an output voltage is carried out using the sum of the respective generated AC voltages. Also, a solar light voltage is boosted by a chopper circuit to generate the highest voltage DC power source. When the solar light voltage exceeds a predetermined voltage, the boosting of the chopper circuit is stopped, thereby reducing power loss due to the boosting.

Abstract: A power conversion system includes first and second voltage sources for driving a multiple-phase AC motor and a control unit. The control unit is configured to compute first and second output voltage command values used to drive the multiple-phase AC motor based on a first output voltage command vector corresponding to the voltage source that is charged and a second output voltage command vector corresponding to the voltage source that is discharged. The first and second output voltage command vectors are determined so that a resultant vector of the first and second output voltage command vectors is coincident with a motor voltage command vector corresponding to a motor voltage command value, and a motor current command vector corresponding to the motor current command value is positioned within an included angle formed between the second output voltage command vector and a negative vector of the first output voltage command vector.

Abstract: The present invention comprises a controller for the cascade H-bridge three-phase multilevel converter used as a shunt active filter. Based on the proposed mathematical model, the controller is designed to compensate harmonic distortion and reactive power due to a nonlinear distorting load. Simultaneously, the controller guarantees regulation and balance of all capacitor voltages. The idea behind the controller is to allow distortion of the current reference during the transients to guarantee regulation and balance of the capacitors voltages. The controller provides the duty ratios for each H-bridge of the cascade multilevel converter.

Abstract: An electrical DC-to-AC power conversion apparatus is disclosed that is primarily intended for use with solar photovoltaic sources in electric utility grid-interactive applications. The invention improves the conversion efficiency and lowers the cost of DC-to-AC inverters. The enabling technology is a novel inverter circuit topology, where the bulk of the throughput power, from DC source to AC utility, is processed only once. The inverter does not require an isolation transformer and can be connected directly to a 480/277 Vac utility grid. The invention also allows the power converter to start into photovoltaic array having higher open circuit voltages. The invention also uses active ripple current cancellation to substantially reduce the cost, size and weight of the main filter inductors.

Abstract: An object of the invention is to provide a power converter that is capable of easily constituting a bidirectional power conversion system, and that can realize power regeneration. In a power converter in which cell power modules U1 to U4, V1 to V4, and W1 to W4 comprising single-phase inverters 4A and 4B are serially connected for each phase, and in which three phases are provided, and which converts and outputs power that is input from a power source, isolation transformers are provided between each cell power module U1 to U4, V1 to V4, and W1 to W4 and the power source side, or between each cell power module U1 to U4, V1 to V4, and W1 to W4 and the output side.

Abstract: A voltage transformer, which is placed between a DC power source (B) and a motor (M1), includes: a voltage sensor (10) and an electric current sensor (11), which senses input and output of electric power to and from the DC power source (B); a buck-boost converter (12) having power control elements, which is placed in a path connecting between power lines (PL1) and (PL2) that establish the connection to the DC power source (B) and the connection to the motor (M1), respectively; and a controller (30) for controlling the buck-boost converter (12). The controller (30) monitors the change in the regenerated power that is supplied to the DC power source (B), based on the outputs from the voltage sensor (10) and the electric current sensor (11), and, if the amount of change in the regenerated power is greater than a predetermined amount, the controller (30) changes the operation mode of the buck-boost converter (12) from a rapid operation mode to a slow operation mode.

Abstract: A power conversion system has a three-phase AC input, where each AC input phase is linked to a string of cascaded single-phase AC-DC converters placed in series with a three-phase AC-DC converter. Each single-phase AC-DC converter in one embodiment includes a silicon carbide (SiC) pulse width modulated MOSFET H-bridge that placed in series with the three-phase AC-DC converter that includes a silicon (Si) SCR bridge. The single-phase AC-DC converters and the three-phase AC-DC converter together in one embodiment include a mixed silicon-carbide (SiC) and silicon (Si) device topology.

Abstract: A pulse width modulated half bridge dimming controller is provided for dimming a lighting ballast is described. The top half of the bridge is comprised of two switches, the top switch set, and the bottom half of the bridge is comprised of two switches, the bottom switch set. Each switch also has a diode in parallel with it. The drivers for the switches are configured so that each of the switches can be turned on and off independently of all of all the other switches. Preferably, the controller is capable of operating in all four quadrants. In one preferred embodiment the switches are IGBTs. The switches are controlled in a manner so that when one of the switches sets changes states, the second switch set has one switch on and one switch off, so that one of the diodes in the second switch set is disposed to block shoot through and provide a path to allow current to continue flowing in the inductive load.

Abstract: A control device calculates a voltage command value of a voltage step-up converter based on a torque command value and a motor revolution number and calculates the on-duty of an NPN transistor based on the calculated voltage command value and a DC voltage from a voltage sensor. Under the conditions that the on-duty is influenced by a dead time and the DC voltage is smaller than a predetermined set value, the control device controls NPN transistors to step-up or step-down the voltage while fixing the on-duty at 1.0.

Abstract: A control method for a power converter capable of reducing overall volume of a system and energy loss by using a plurality of power sources and distributing loads to them without a DCDC converter. The power converter has DC power sources and poles formed by connecting various poles of the DC sources. Voltage is applied to a load by switching between poles. The method includes operating a switch between poles of the first DC power source when a voltage command is lower than the electric potential of the second DC power source; and operating a switch between the poles of the second DC source when the voltage command is higher than the electric potential of the second DC source.

Abstract: A power converter circuitry for converting a DC voltage generated by a generator with varying output power in the mean voltage range into an alternating voltage for feeding into a grid, with several series-connected power converters, which are connected in parallel with said generator, as well as with a controllable bridging switch for each power converter, said bridging switch lying in a direct voltage intermediate circuit and bridging the respective power converter in the closed condition, is intended to be used for a photovoltaic generator. This is achieved in that a resistance chopper is connected between each power converter and the generator, no input diode being provided in the current path from the generator to the power converter, and that each bridging switch is connected in parallel with the resistance chopper in the direct voltage intermediate circuit.

Abstract: A 7-level wye-connected H-bridge converter that provides redundancy for continued operation when one bridge phase has failed and more particularly to a topology that includes multiple semiconductor H-bridges and a three-phase semiconductor mid-bridge. The converter may continue operation with failure of any bridge, as a three-phase, wye-connected H-bridge by bypassing the failed bridge. Individual bridges of the converter may be operated at different dc-bus voltages to maximize power output. The converter may employ synchronous gating signals for the semiconductor devices of the bridges, including a zero-current notch waveform for minimizing harmonic distortion of the output waveform.

Abstract: Disclosed is a controller of a grid coupled type doubly-fed induction generator having a multi-level converter topology, which can control the doubly-fed induction generator having a high voltage specification and can perform a fault ride-through function, an anti-islanding function and a grid voltage synchronization function required for a dispersed power generation facility. The controller makes a H-bridge multi-level converter generate a three-phase voltage waveform resulted from the structure that single-phase converters each being composed of a 2-leg IGBT are stacked in a serial manner, and controls a rotor current so as to make the rotor coil of the doubly-fed induction generator in charge of a slip power only. The boost converter is composed of a 3-leg IGBT and a boost inductor generating a direct current voltage of its source required for the H-bridge multi-level converter.

Abstract: The present invention is a method and system for efficiently converting an alternating current (AC) supply to a direct current (DC) output. A power supply in accordance with the present invention may employ variable frequency constant on-time converters whereby switching losses of the converters are approximately proportional with a switching frequency, causing the power supply to be more efficient at light loads. Additionally, a power supply in accordance with the present invention may include multiple-phase converters in which each phase is designed for operation at a fraction of the total maximum load for the power supply.

Abstract: A power modulator comprises a plurality of switched pulse generator sections (22), a power supply arrangement (10), and a transformer arrangement (30). A switch control (24) is connected to said plurality of switched pulse generator sections (22) for providing control signals for turning on and/or turning off them. The switch control (24) is arranged to provide control signals for turning on and/or turning off switched pulse generator sections of a first subset at a first time instant and to provide control signals for turning on and/or turning off switched pulse generator sections of a second subset at a second time instant, different from the first time instant: The second subset is different from the first subset.

Abstract: The present invention is an electric power source in which a plurality of inverters operate on the same frequency and the plurality of inverters are connected in parallel so that a resistance value expressed by (1??·G)/(?·G) where ? is the output voltage feedback gain, ? is the output current feed forward gain, and G is the inverter current gain, is made to be the equivalent output impedance; and is an electrical power source in which the cross-current between the inverters are made to be an acceptable value or below by adjusting the output of each of the inverters by controlling the equivalent output impedance by modifying both or either one of the output voltage feedback gain ? or the output current feed forward gain ?.

Abstract: A photovoltaic (PV) inverter system operates continuously in a buck converter mode to generate a sum of full wave rectified sine wave currents at a current node common to a plurality of buck converters in response to a plurality of full wave rectified sine wave currents generated via the plurality of buck converters. The PV inverter system increases the level of the voltage sourcing each buck converter when a corresponding DC power source voltage is lower than the instantaneous voltage of a utility grid connected to the PV inverter system.

Abstract: There is provided a switching power supply device having one half-wave rectifying circuit made up of switching elements complementarily turned on or off, a reactor, a current resonance capacitor, a transformer, and a rectifying diode and another half-wave rectifying circuit made up of switching elements complementarily turned on or off, a reactor, a current resonance capacitor, a transformer, and a rectifying diode and configured so that the half-wave rectifying circuits commonly charges a smoothing capacitor. The switching elements are turned on or off according to a voltage of the smoothing capacitor and other switching elements are turned on or off based on a difference between a charging voltage of the current resonance capacitor and a charging voltage of the current resonance capacitor. As a result, power energy fed from the half-wave rectifying circuits connected in parallel is made equal.

Abstract: A DC/DC power conversion device includes n-stage circuits comprised of an inverter circuit for driving which is connected between positive terminals and negative terminals of smoothing capacitors, and a rectifier circuit which is connected between positive terminals and negative terminals of smoothing capacitors; a first circuit corresponding to at least one among the n-stage circuits and configured by connecting in parallel cell circuits of m, second circuits corresponding to a plurality of remaining circuits of (n?1) among the n-stage circuits; capacitors for energy transfer connected between middle points of the cell circuits and middle points of the second circuits; and column circuits of m comprised of the cell circuits, the second circuits and the capacitors for energy transfer, wherein the middle points are contact points of high voltage sided elements and low voltage sided elements of the cell circuits and the second circuits; and driving signals for driving the respective column circuits have the sam

Abstract: A discharge lamp ballast apparatus includes a DC/DC converter having a transformer T1 and a DC/DC converter having a transformer T2, which are connected in parallel; a control section 4 for controlling the output voltages of the DC/DC converters by varying their duties with shifting the operation phases of the transformers T1 and T2 of the DC/DC converters; and a voltage-multiplier rectifier circuit having diodes 7-9 and capacitors 10-12 for generating a high voltage used for starting a discharge lamp 22 by utilizing the potential difference between the output voltages of the transformers T1 and T2.

Abstract: A motor controller is provided which can be reduced in the number of the wirings and power semiconductor devices required while maintaining the function equivalent to or higher than that of the motor controller adopting the existing winding changeover scheme, thereby realizing cost and size reduction and life increase. The motor is made in a structure having motor windings opened at both ends. The one end terminals of phase windings are respectively connected to the output terminals of a first inverter circuit while the other end terminals are respectively connected to the output terminals of a second inverter circuit. During power generation, any one of the inverter circuits is driven on all the phases by means of a same control pulse.

Abstract: The present invention is an electric power source in which a plurality of inverters operate on the same frequency and the plurality of inverters are connected in parallel so that a resistance value expressed by (1??·G)/(?·G) where ? is the output voltage feedback gain, ? is the output current feed forward gain, and G is the inverter current gain, is made to be the equivalent output impedance; and is an electrical power source in which the cross-current between the inverters are made to be an acceptable value or below by adjusting the output of each of the inverters by controlling the equivalent output impedance by modifying both or either one of the output voltage feedback gain ? or the output current feed forward gain ?.

Abstract: In a power conversion apparatus that boosts a solar light voltage, converts it to AC and supplies AC power to a load or system, a second inverter is connected in series to one of two terminals on the AC side of a first inverter that uses, as its DC source, a DC voltage boosted from a solar light voltage by a chopper circuit. A third inverter is connected in series to the other terminal. Then, output voltages of the second and third inverters are controlled to be equal, and an output voltage is provided by using the sum of the generated voltages of the first, second, and third inverters. Thus, a mid-point potential of the DC power source is made equivalent to an intermediate potential of the output voltage of the power conversion apparatus, that is, the mid-point potential (ground potential) of a system.

Abstract: The invention relates to a method for controlling the voltage and power of several HF inverters (2), connected in parallel at the output, of an electrically isolated inverter assembly as well as for distributing the load to these HF inverters (2) each consisting of at least one DC-DC converter (3), one intermediate circuit (4) and one DC-AC converter (5), with a command variable (Ui?) being formed for each HF inverter (2) so as to preset a nominal value for control of an intermediate-circuit voltage (UZKi) at the intermediate circuit (4) of the HF inverter (2). The load of each HF inverter (2) is determined by a control unit (13) by measuring the current or power required, an internal resistance of the HF inverter (2) is simulated via which internal resistance a virtual voltage drop (UVR) is caused which depends on the load determined and is used for controlling the voltage (UZKi) of the intermediate circuit (4) so as to produce a purposive change in the output voltage of each HF inverter (2).

Abstract: A control device generates, upon receiving an instruction to start engine while drive wheels of a hybrid vehicle are driven by a motor generator, a signal to output the signal to a voltage step-up converter, and thereby drives and controls the voltage step-up converter to step up a DC voltage that is output from a battery to a maximum voltage of a motor drive apparatus. Then, the control device generates, when an output voltage of the voltage step-up converter reaches the maximum voltage, a signal to output the generated signal to an inverter. Accordingly, the inverter is driven and controlled to drive motor generator in powering mode.

Abstract: A power conversion system comprises a converter coupled to a power source and configured to convert a DC power to a variable AC power signal. The power conversion system may further comprise a process control unit coupled to the converter and configured to control the variable AC power signal. The power conversion system may also further comprise a transformer having a primary side and a secondary side, the primary side receiving the variable AC power signal from the converter and a passive rectifier coupled to the secondary side of the transformer. The transformer may be adapted to provide galvanic isolation between the power source and an electro-chemical process. The passive rectifier is adapted to convert the variable AC power to the variable DC power and to deliver the variable DC power to the electro-chemical processing unit.

Abstract: A power conversion apparatus includes a first single-phase inverter that uses as a DC power source a first DC voltage that is boosted from a solar light voltage by a boosting chopper circuit. The first single-phase inverter is arranged between two single-phase inverters that use second DC power sources that are supplied from the first DC power source. AC sides of the respective single-phase inverters are connected in series. A power conditioner thus configured provides an output voltage using the sum of the generated voltages of the respective single-phase inverters. Chopper circuits are connected between the first DC power source and the second DC power sources, and power is supplied to the second DC power sources from the first DC power source via switching devices in the single-phase inverters.

Abstract: Apparatus for generating a high time-varying AC voltage using low voltage power semiconductors arranged in series bridge circuits, each powered by an independent DC source. At least one bipolar output pulse width modulation bridge circuit and at least a pair of bipolar output square wave generator bridge circuits have their outputs added together and passed through a low pass filter to form a time-varying, typically sinusoidal, AC output waveform. A first square wave generator has an output with a relative magnitude of 6, a second square wave generator has an output with a relative magnitude of 2 and the pulse width modulator has an output with a relative magnitude of 1. Additional square wave generators of relative magnitude 6 may be added to increase the output voltage.