Abstract: According to one embodiment, the inverter control device includes a signal generator. The signal generator outputs a signal to increase the resistance of the gate when the value of the DC voltage is equal to or greater than a first voltage threshold, and the value of the AC current is less than a first current threshold; and when the value of the DC voltage is equal to or greater than the first voltage threshold, and the value of the AC current is equal to or greater than a second current threshold, and outputs the signal to increase the resistance of the gate when the value of the DC voltage is equal to or greater than a second voltage threshold, and the value of the AC current is equal to or greater than the first current threshold and less than the second current threshold.

Abstract: The present invention relates to a bi-directional DC-DC converter comprising: a first terminal, a second terminal, a transformer circuit, a first high voltage side coupled to said first terminal, and a second low voltage side coupled to said second terminal; wherein said first high voltage side and said second low voltage side are coupled to each other by means of said transformer circuit, and said first high voltage side comprises a resonant tank circuit coupled between a first bridge circuit of said first high voltage side and a high voltage side of said transformer circuit. Furthermore, the invention also relates to a system comprising at least two such bi-directional DC-DC converters.

Abstract: An overcurrent protection circuit includes a load drive portion that drives a load based on a power supply voltage; a wire that connects the load and the load drive portion; a current detection portion that detects a load current showing a value of a current flowing through the load; a voltage detection portion; and a controller that controls the load drive portion to control a drive of the load, the controller determining an addition-and-subtraction value, controlling the load drive portion to cut off the load current, and stopping driving the load to protect a protection target from an overcurrent. The controller subtracts the integration value based on an elapsed time after cutoff of the load current. The controller controls the load drive portion to again start to drive the load, and also calculates a post-correction integration value lower than a pre-correction integration value by correcting the pre-correction integration value.

Abstract: Unique systems, methods, techniques and apparatuses of zero-voltage transition pulse width modulation resonant converters are disclosed. One exemplary embodiment is a zero-voltage transition PWM resonant converter comprising a DC bus, a first switching device, a second switching device, a resonant tank circuit, an auxiliary circuit having a flying capacitor and a plurality of auxiliary switching devices, and a controller. The controller is structured to control the first switching device, the second switching device, and the plurality of auxiliary switching devices to provide resonant operation of the tank circuit effective to provide a substantially zero voltage condition across the first switching device when turning the first switching device on or off and to provide a substantially zero voltage condition across the second switching device when turning the second switching device on or off.

Abstract: A system and methods for reducing common mode leakage current for a three-phase three-level inverter using a single modulation waveform, implemented by a controller using a space vector diagram is disclosed.

Abstract: A semiconductor device can include an insulating substrate on which at least four semiconductor elements forming a three-level power conversion circuit are mounted, a base plate on which the insulating substrate is provided, a positive conductor plate with a positive DC potential which is connected to one semiconductor element among the semiconductor elements; a negative conductor plate with a negative DC potential which is connected to another semiconductor element among the semiconductor elements and an intermediate potential conductor plate with an intermediate potential which is connected to the remaining two semiconductor elements among the semiconductor elements. The positive conductor plate, the negative conductor plate, and the intermediate potential conductor plate are provided on the base plate. The positive conductor plate and the negative conductor plate are arranged close to the intermediate potential conductor plate so as to face the intermediate potential conductor plate.

Abstract: Embodiments of a synthetic test circuit for a valve performance test of high-voltage direct current (HVDC) are presented. In some embodiments, the synthetic test circuit comprises a resonance circuit configured to comprise a first test valve to test an operation of an inverter mode and a second test valve to test an operation of a rectifier mode. The synthetic test circuit may comprise a power supply (P/S) configured to provide the resonance circuit with an operating voltage. The synthetic test circuit may comprise a direct current/direct current (DC/DC) converter configured to bypass a DC offset current of the resonance circuit. The first test valve may be an inverter unit, which may have a positive DC current offset. Further, the second test valve may be a rectifier unit, which may have a negative DC current offset.

Abstract: A power system for an electric vehicle, an electric vehicle and a motor controller for an electric vehicle are provided. The power system includes: a power battery (10); a charge-discharge socket (20); a three-level bidirectional DC-AC module (30); a motor control switch (40); a charge-discharge control module (50) having a first terminal connected with an AC terminal of the three-level bidirectional DC-AC module (30) and a second terminal connected with the charge-discharge socket (20); and a control module (60) connected with a third terminal of the charge-discharge control module (50) and a third terminal of the motor control switch (40), and configured to control the charge-discharge control module (50) and the motor control switch (40) according to a current working mode of the power system.

Abstract: An on-load tap changer has a housing, a switching module inside the housing and having a switch and a cooling conduit, an insulating liquid that surrounds the switching module inside the housing, and a cooling circuit comprising a pump, the cooling conduit and a heat exchanger. The interior of the housing and the cooling circuit are hydraulically connected together for flow of the insulating liquid through the cooling circuit and the housing and cooling of the housing with the insulating liquid.

Abstract: An electric power conversion device includes: a switching element; a collector side wiring connected to a collector side of the switching element; an emitter side wiring connected to an emitter side of the switching element; a detection circuitry configured to detect an induction voltage generated in the collector side wiring or the emitter side wiring when a current flows through the collector side wiring or the emitter side wiring; and a comparison circuitry configured to compare the induction voltage detected by the detection circuitry and a predetermined threshold voltage determined in advance to each other.

Abstract: Disclosed is a drive system for induction motor, including a two-phase induction motor, a power source filter circuit, an H-bridge power drive circuit and a controller MCU. The power source filter circuit is configured to filter out harmonic components of a DC power source, and generate a power source midpoint voltage required for driving; the controller MCU is configured to generate a switch control signal required for operation of the H-bridge power drive circuit; the H-bridge power drive circuit is configured to generate a drive current and transfer the drive current to the two-phase induction motor; and the two-phase induction motor is configured to receive the drive current generated by the H-bridge power drive circuit.

Abstract: A DC-DC converter includes: a clamp capacitor having one terminal connected with a ground terminal of a voltage source; a switching circuit including first and second switches connected with each other in series between a positive terminal and the ground terminal of the voltage source, and third and fourth switches connected with each other in series between both terminals of the clamp capacitor; and a forward-flyback transformer including a plurality of primary coils connected between a first connection node between the first and second switches and a second connection node between the third and fourth switches.

Abstract: A high efficiency multi-mode/multi-phase power conversion device has DC-boost receiving input power from a plurality of DC (e.g., solar) sources, power inverters and an AC grid supply. Power conversion switches are arranged in a stacked configuration with controllable inner and outer switches conveying: in an non-inverting switched mode, an AC voltage from power from the AC grid supply; in an inverting outer switched mode, an AC voltage from power from the AC grid supply; and in an inverting outer and inner switched mode, an inverted voltage from power from the DC-boost circuit. At least one input switch and output to the AC grid supply is coupled to an output of the power inverters and a resonant circuit is coupled to the input switch. A rectifier and/or high voltage AC output tap is coupled to the resonant circuit and a controller is coupled to the power conversion switches and the input switch.

Abstract: A method operates a multilevel converter for power factor correction of a polyphase mains voltage. Each phase of the polyphase main has an associated phase module with a plurality of sub modules which are connected in series and each have an electrical energy store. Each sub module can be connected to the phase of the mains voltage or disconnected there from by an electronic switch. A circuit breaker is provided for disconnecting the converter from the mains voltage. The converter has a regulation system by which the voltages of the phase modules are balanced when the circuit breaker is open.

Abstract: Provided is a power converter in which a magnetic core of a noise filter can be prevented from magnetic saturation and the noise filter can be downsized. A noise filter 140 provided in a power converter includes: a magnetic core 1 formed with a single through-hole 1A and forming a closed magnetic circuit; first wiring 11 having one end 81 connected to a power conversion circuit and the other end drawn out from the second opening 3, and running through the through-hole 1A from one first opening 2 to the other second opening 3; second wiring 21 having one end connected to the other end of the first wiring 11 and the other end 82 drawn out from the first opening 2 as a filter output end, and running through the through-hole 1A from the second opening 3 to the first opening 2; a first capacitor 41 provided between the ground and a connecting portion 31 of the first wiring 11 and the second wiring 21; and the second capacitor 51 provided between the other end 82 of the second wiring 21 and the ground.

Abstract: A converter assembly and method are provided. The converter assembly includes a galvanic isolation device, first switching devices, and second switching devices. The switching devices are conductively coupled with each other and with opposite sides of the isolation device. The first switching devices control conduction of an input voltage, and the second switching devices control conduction of electric power. The first switching devices are configured to switch between an open state and a closed state at frequencies that are faster than frequencies at which the second switching devices switch between the open state and the closed state to control a shape of a waveform of the electric power.

Abstract: An auxiliary power source device for a vehicle is incorporated in an electric vehicle and includes a three-phase inverter that converts an input DC voltage into a desired three-phase AC voltage and applies the three-phase AC voltage to a load. The auxiliary power source device further includes a filter reactor that is connected to respective output terminals of a three-phase inverter, a filter capacitor that is connected in a Y-shape at an end on a load side of the filter reactor and is not grounded at a neutral point, and a three-phase transformer that includes primary windings that are connected in a Y-shape at the end on the load side of the filter reactor and is grounded at a neutral point and secondary windings that are connected in a delta shape.

Abstract: A device for voltage conversion includes a first, transformerless direct voltage converter unit having a first output potential connection and a second transformerless direct voltage converter unit having a second output potential connection. The two direct voltage converter units have a common input potential connection and a common reference potential connection. The first direct voltage converter unit generates, from the input voltage potential, a first output voltage potential on the first output potential connection, which has a higher voltage potential value relative to the reference voltage potential. The second direct voltage converter unit generates, from the input voltage potential, a second output voltage potential on the second output potential connection, which has a lower voltage potential value relative to the reference voltage potential. The device can be cost-effectively produced and provides sufficient safety.

Abstract: Embodiments herein relate to a drive system for an electric motor. The drive system including a DC bus having a positive terminal and a ground terminal, an inverter connected to the DC bus configured to provide a plurality of motor excitation signals, and an interface cable operably connected to the inverter, and configured to transmit the plurality of motor excitation signals. The drive system also includes a motor remote from and connected to the inverter via the interface cable, the motor responsive to the motor excitation signals and a plurality of snubber circuits, each of the snubber circuits having a first terminal connected to a winding of the motor, and a second terminal operably connected to a first end of a transmission line and a second end of the transmission line is connected to the positive terminal of the DC Bus.

Abstract: An electronic half-bridge ZETA converter may include a transformer, wherein a half-bridge is connected to the primary winding of transformer, and wherein a respective capacitance and a respective diode are associated with the half-bridge switches. Moreover, the converter includes a ZETA converter which is connected to secondary winding of transformer, so that the ZETA converter includes a first inductance, which includes the magnetization inductance of transformer, and a second inductance. Finally, the converter includes a control unit which drives the half-bridge switches with four time intervals that are repeated periodically. Specifically, during the fourth time interval the first and the second switch are opened, so that the capacitance associated with said second switch is charged and the capacitance associated with said first switch is discharged, enabling a zero voltage switching.

Abstract: A first conversion circuit switches a magnitude of a voltage generated between a first output point and a reference potential point in three stages. The second conversion circuit switches a magnitude of a voltage generated between the reference potential point and a second output point in three stages. The third conversion circuit includes first to fourth switches in a full bridge configuration and converts a voltage generated between the first output point and the second output point into an alternate current voltage and outputs the alternate current voltage. The third conversion circuit forms a current path including inductors between the first output point and the second output point during a start time period from a start of supplying power from a direct current power supply until a first capacitor and a second capacitor are charged to a specified voltage.

Abstract: A device for monitoring a power semiconductor switch includes a circuit section for applying to the power semiconductor switch an HF voltage having a frequency above a switching threshold of the power semiconductor switch, a shunt resistor for detecting an actual HF current resulting from application of the HF voltage to the power semiconductor switch, a monitoring circuit for comparing the actual HF current with an expected HF current that depends on a switching state of the power semiconductor switch when the HF voltage is applied to the power semiconductor switch, and a comparator for generating a power semiconductor status signal depending on a result of the comparison. A corresponding method for monitoring a power semiconductor switch of this type is also described.

Abstract: The switching power supply device is provided with a high-withstand voltage first transistor, a first electrode of which being connected to a first node; a low-withstand voltage second transistor, a first electrode of which being connected to a second electrode of the first transistor, and a second electrode of which being connected to a second node; and a drive circuit. Each of the first and second transistors has a parasitic diode connected in the forward direction between the second and first electrodes. The drive circuit, in a case where electrical current is to flow from the first node to the second node, turns on the first and second transistors, and, in a case where electrical current is to flow from the second node to the first node, turns on the first transistor, and turns off the second transistor.

Abstract: A step-up/down DC converter applied to achieve a characteristic of zero-ripple voltage, which ripple voltage is near zero, is disclosed. The converter includes a ripple-filtering inductor, a power isolating and converting unit, a power switch, a first inductor, a first capacitor, a second capacitor, and a rectifying switch. The power isolating and converting unit comprises windings for isolation an input stage connected to a power source from an output stage connected to a load. The power switch, the first inductor, and the first capacitor are arranged at the input stage, and the second capacitor and the rectifying switch are arranged at the output stage. The ripple-filtering inductor, which may be arranged at the input or output stage, and the first inductor divide the power supplied from the power source, thus the voltage drop of the first inductor is reduced for smoothing the ripple voltage at the output stage.

Abstract: A reactor includes an annular iron core and four coils separately wound around the iron core. The four coils have first electrodes connected to output terminals of four choppers, respectively, and second electrodes each connected to a load. Therefore, the four choppers can be connected in parallel to the load by one reactor.

Abstract: The present disclosure relates to a multi-level inverter capable of performing a bypass operation without adding any separate module. The multi-level inverter includes a first capacitor and a second capacitor coupled in series to each other, a plurality switches for generating a multi-level output voltage by using a voltage charged in the first capacitor and the second capacitor and a plurality of diodes respectively coupled in parallel to the plurality of switches, a first output terminal and a second output terminal for outputting the output voltage, and a controller for switching a state of each of the plurality of switches to an on or off state according to one of predetermined bypass modes, thereby interrupting the output of the output voltage through the first output terminal and the second output terminal.

Abstract: A high-voltage measurement divider for an X-ray tube is provided. The high-voltage measurement divider includes a ground connection, a high-voltage connection, a measuring tap, and divider modules of substantial identical design apart from the circuitry. Each of the divider modules has a first connection, a second connection, a resistor board, and at least one flat potential electrode. The divider modules are connected at corresponding connections in series between the ground connection and the high-voltage connection. At least one division stage is formed by each of the divider modules, and a first division stage is formed between the measuring tap and the ground connection.

Abstract: A power converter for converting DC power to DC power includes an inverter stage having two or more switched inverters configured to receive DC power from a source and produce a switched AC output power signal. A transformation stage is coupled to receive the switched output power signal from the inverter stage, shape the output power signal, and produce a shaped power signal. A rectifier stage having two or more switched inverters coupled to receive the shaped power signal and convert the shaped power signal to a DC output power signal is included. A controller circuit is coupled to operate the power converter in a variable frequency multiplier mode where at least one of the switched inverters is switched at a frequency or duty cycle that results in an output signal having a frequency that is a harmonic of the fundamental frequency being generated by the power converter.

Abstract: Power converters, e.g., AC/DC and DC/DC, typically have unique circuitry for a proper graceful start-up and to develop correct operating voltage biases. Typically this unique circuitry is incorporated in a primary-side controller. This primary-side controller could also be the primary means of control of the power converter once started. However, a secondary-side controller is typically needed for more exact output voltage regulation, duplicating circuitry already present in the primary-side controller. Complication is typically added by linear communication between the two controllers across an isolation barrier. A simplified primary-side start-up controller is envisioned providing minimal circuitry to power up a converter until a secondary-side controller activates and takes control by sending discrete PWM commands across the isolation barrier instead of a linear signal. The start-up controller can provide voltage and current protection if the secondary-side controller fails.

Abstract: A semiconductor device of an embodiment includes a first electrode, a second electrode facing the first electrode, an alternating-current electrode, a first switching element provided between the first electrode and the alternating-current electrode, and a second switching element provided between the second electrode and the alternating-current electrode. The first switching element and the second switching element are electrically connected in series between the first electrode and the second electrode, and the alternating-current electrode is electrically connected between the first switching element and the second switching element.

Abstract: The present topology for controlled power switch module is concerned with a module where the parasitic inductance of the emitter of the top power switch is optimized to allow the injection of a sample of the overvoltage across this parasitic inductance in the gate drive circuit of the top power switch as a feedback to slow down the slope of the falling gate voltage during an overvoltage that is above a predetermined value.

Abstract: The invention relates to a method for controlling an inverter and to an inverter a DC/DC stage, which comprises at least one main switch (S2) and a discharge circuit, and with a DC/AC stage. The discharge circuit is formed by a series connection of a bidirectional switching element, which comprises two switches (SA1, SA2), and an inductivity. A device is provided for controlling the switches (SA1, SA2) and is designed such that one switch (SA1, SA2) is activated in an alternating manner and the switch-on time of the switch is determined by the controlling device prior to a switch-off time of the main switch (S2).

Abstract: One embodiment pertains to a method including transitioning a logic state of at least one enable signal. A first power transistor begins to turn off. A parameter level of the input of the first power transistor is directly sensed. A second power transistor is turned off when the parameter level is less than a threshold level.

Abstract: An inverter comprises a first boost apparatus having an input coupled to a positive dc bus, a second boost apparatus having an input coupled to a negative dc bus, a first switch coupled to an input of an L-C filter and the first boost apparatus, a second switch coupled to the input of the L-C filter and the second boost apparatus, a third switch coupled between the positive dc bus and the first switch, wherein a common node of the first switch and the third switch is directly connected to an output of the first boost apparatus, a fourth switch coupled between the negative dc bus and the second switch, wherein a common node of the fourth switch and the second switch is directly connected to an output of the second boost apparatus and an isolation switch coupled between the input of the L-C filter and ground.

Abstract: A five-level converting device includes an AC terminal, a bus capacitor module having a positive terminal, a negative terminal and a neutral terminal, a first switch module and a second switch module. The first switch module includes a bidirectional switching circuit, and the bidirectional switching circuit includes two first switching units reversely connected in series. The second switch module includes two second switching units, two third switching units, two fourth switching units, and two fifth switching units. The two second switching units are cascaded and connected to the two fourth switching units in parallel. The third, the fourth and the fifth switching units are cascaded and are connected to the bus capacitor module in parallel. Two different connection points of the first switch module are connected to the third switching units and fifth switching units through two flying capacitor modules respectively.

Abstract: A technique for detecting a valley timing at lower cost is described. A drive circuit comprises a peak voltage holder, a valley voltage holder, a center voltage generator, a monitor, and a detector. The peak voltage holder holds a peak voltage of an oscillating signal that is based on a voltage at a terminal of an inductor coupled to a switching element. The valley voltage holder holds a valley voltage of the oscillating signal. The center voltage generator generates a center voltage based on the peak voltage and the valley voltage. The monitor monitors the present value of the voltage at the terminal. The detector detects, as a valley timing, a timing at which a predetermined delay time has elapsed from a timing at which the monitored present value of the voltage at the terminal has fallen below the center voltage.

Abstract: In a DC/DC converter that performs zero-voltage switching, capacitors are connected respectively in parallel to first and second MOSFETs that are included in an inverter unit in the primary-side of a transformer, and an inductor is connected to an AC output line. In a range of a current being more than a predetermined value, a control circuit controls the inverter unit using a PWM control with a fixed dead time, and in a light load range where the current is equal to or less than the predetermined value, the control unit changes the control to a PFM control and decreases a frequency so that the dead time becomes longer as the current decreases, to thereby keep a duty ratio without change.

Abstract: A DC-DC converter is operated in a boost mode by operating a plurality of low-voltage side switches with a first fixed duty cycle (greater than 0.5), with cutting off a plurality of the first high-voltage side switches and a plurality of the second high-voltage side switches, with conducting a plurality of the first diodes of the first high-voltage side switches and a plurality of the second diodes of the second high-voltage side switches, and with alternatively conducting and cutting off a bidirectional switch. In a buck mode, the low-voltage side switches are cut off and a plurality of diodes of the low-voltage side switches are conducted. Furthermore, the first high-voltage side switches are complemented and are operated with a second fixed duty cycle (less than 0.5) while the second high-voltage side switches are conducted and cut off alternatively and the bidirectional switch is switched on and off.

Abstract: A power source device includes a transformer, a first switching element and a second switching element, a resonance capacitor, and a switch. One end of the second switching element is connected with one end portion of a primary winding. The other end of the second switching element is connected with one end portion of the resonance capacitor. The primary winding and the resonance capacitor are resonated with each other by alternately operating the first and second switching elements to supply electric power to a load connected with a secondary winding of the transformer. The primary winding includes a first primary winding and a second primary winding. Depending on the load, the switch connects or disconnects between the first primary winding and the resonance capacitor, or connects or disconnects between the second primary winding and said resonance capacitor.

Abstract: A switching power supply unit includes input terminals, output terminals, first to third primary windings and first to third secondary windings, a switching circuit, a rectifying smoothing circuit, and a driver. In the switching circuit, first and second switching devices, third and fourth switching devices, and first and second capacitors, coupled in series to one another, are disposed in parallel between the input terminals. In the rectifying smoothing circuit, first to third arms, each having two of rectifying devices disposed in series, are disposed in parallel between the output terminals, the first secondary winding is coupled between the first and the second arms to form an H-bridge coupling, the second and the third secondary windings are coupled between the second and the third arms to form an H-bridge coupling, and a choke coil is disposed between the first to the third arms and an output capacitor.

Abstract: According to an embodiment there is provided a multilevel power supply comprising two power sources that share a common node, a switching arrangement, a charge storage device and an output terminal. The two power sources are configured to provide a first potential V1, a second potential V2 and a third potential V3, wherein V1>V2>V3. The switching arrangement is configured to charge the charge storage device between potentials V1 and V3 in a first switching state and to connect the charge storage device between potential V2 and the output in a second switching state.

Abstract: A power converter, includes a first terminal and a second terminal which are connected to a direct current; a third terminal connected to an alternating current; N multi-level bridge arms connected in parallel to the first terminal and the second terminal, where the N multi-level bridge arms work in a parallel-interleaved manner, each multi-level bridge arm of the N multi-level bridge arms includes an alternating current node, and multiple time-varying levels are generated at the alternating current node, where the multiple levels are more than two levels; and a coupling inductor, including N windings coupled by one common magnetic core, where one end of each winding of the N windings is connected to an alternating current node of one multi-level bridge arm of the N multi-level bridge arms, and the other end of each winding of the N windings is connected to the third terminal.

Abstract: Provided is a power converter capable of reliably turning OFF a switching element before turn-OFF of a diode even with a fluctuation in rpm so as not to generate a backflow of a current. The power converter includes a diode ON-interval monitoring unit (18) configured to measure a change rate of a diode ON detection interval signal. When a diode ON detection interval change rate signal (S20) exhibits a decrease on a negative side and is smaller than a predetermined value (an absolute value thereof exceeds a predetermined value), an OFF-timing of the switching element is advanced by a predetermined value or larger, to thereby reliably turn OFF the switching element before the turn-OFF of the diode even with the fluctuation in rpm.

Abstract: A switched-mode power regulator circuit has four solid-state switches connected in series and a capacitor and an inductor that regulate power delivered to a load. The solid-state switches are operated such that a voltage at the load is regulated by repetitively (1) prefluxing the inductor then charging the capacitor causing an increased current to flow in the inductor and (2) prefluxing the inductor then discharging the capacitor causing increased current to flow in the inductor. The inductor prefluxing steps enable the circuit to provide increased output voltage and/or increased output current.

Abstract: In one embodiment, a power apparatus includes a buck converter including a first capacitor, a first inductor and a first switch for connection with a direct current power supply, wherein when the first switch is closed and the buck converter is connected to the direct current power supply, the first capacitor and the first inductor are connected in series to the direct current power supply, a full-bridge inverter including at least four switches including the first switch, a second, third and fourth switch so that the first switch is shared by the inventor and buck converter, the inverter being operative to convert direct current to alternating current by alternating (a) closing the first and fourth switch with the second and third switch open, and (b) closing the second and third switch with the first and fourth switch open, and a transformer to step down an output of the inverter.

Abstract: A converter comprises an input stage coupled to a power source, wherein the input stage comprises a plurality of power switches, a first resonant tank coupled to the input stage, wherein the first resonant tank is of a first Q value, a second resonant tank coupled to the input stage, wherein the second resonant tank is of a second Q value, a transformer coupled to the input stage through the first resonant tank and the second resonant tank and an output stage coupled to the transformer.

Abstract: An NPC converter is controlled by estimating current flow during the short vector periods of a space vector modulation drive signal. The current estimation is used to close a first order inner current regulator loop that steers current to either the upper capacitor or the lower capacitor of a DC link. An outer voltage regulator measures the voltage imbalance across the capacitors and drives the inner current loop. By managing the associated duty cycle of each vector a bias current is formed that balances the capacitor voltages.

Abstract: Provided is a vehicle which enables a highly-efficient DC-DC converter and a highly-efficient power supply to a load, regardless of a power supply amount of to the load. When the power supply amount to a load R1 is a predetermined value or more, a control means 5 implements a first mode for making the switching elements S1 to S4 driven, and when the power supply amount of to the load R1 is the predetermined value or less, the control means 5 implements a second mode, for making the switching elements S3 and S4 stopped in an OFF state, and making only the switching elements S1 and S2 driven.

Abstract: In a power converter which performs power conversion between plural-phase AC and DC, variation in voltage of the DC capacitor in each converter cell is detected, and when the variation exceeds a predetermined value, a DC voltage command value as a control target value in a DC voltage control unit which controls DC voltage between DC buses is corrected by being increased or decreased. Thus, when AC grid failure occurs, the capacitor voltage of each converter cell is maintained and the operation continuity is improved.

Abstract: The present invention discloses a stereoscopic DC-DC converter for power transfer between two DC grids, the converter comprises a first converter, a second converter and a third converter, a positive terminal of the first converter is connected to a positive terminal of a second DC grid, a negative terminal of the first converter is connected to a positive terminal of the second converter, a negative terminal of the second converter is connected to a positive terminal of the third converter, a negative terminal of the third converter is connected to a negative terminal of the second DC grid, in the meantime, a positive terminal of the second converter is also connected to a positive terminal of a first DC grid, and the negative terminal of the second converter is also connected to a negative terminal of the first DC grid.