Patent application number | Description | Published |
20080252145 | DC/DC POWER CONVERSION DEVICE - 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 same driving cycle and are out of phase with each other. | 10-16-2008 |
20090015071 | POWER CONVERSION APPARATUS - 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. | 01-15-2009 |
20090116268 | POWER CONVERTING APPARATUS - A converter controllable in regenerative running mode, which is a power converting apparatus capable of suppressing harmonics without increasing the size of a reactor, and reducing power loss and electromagnetic noise. A power converter is configured by directly connecting AC sides of single-phase sub-converters having a DC voltage lower than a DC voltage of a 3-phase main converter to AC input lines of individual phases thereof in series. The main converter is driven by one gate pulse per half recurring cycle and a voltage produced by each sub-converter at AC terminals thereof is controlled to match a difference between an AC power supply voltage and a voltage produced by the main converter at AC terminals thereof, whereby phase voltages of the power converter are generated as the sums of phase voltages of the individual converters. | 05-07-2009 |
20090261793 | DC/DC POWER CONVERTING APPARATUS - Three or more circuits, in which series-connected low-voltage and high-voltage side switches including MOSFETs including parasitic diodes are connected across positive and negative terminals of each of smoothing capacitors, are connected in series. One of elementary series circuits, each including a capacitor and an inductor, is disposed between any adjacent two of the circuits with the elementary series circuits set to have the same period of resonance. The MOSFETs of rectifier circuits are brought into an ON state simultaneously with the MOSFETs of a driving inverter circuit and brought into an OFF state earlier than the MOSFETs of the driving inverter circuit by a period of time not exceeding a time period equal to (period of resonance)/2. A resonance phenomenon of the capacitor and the inductor is used and conduction loss in the rectifier circuits is reduced in DC/DC power conversion performed through charging and discharging operation of the capacitor. | 10-22-2009 |
20100014335 | THREE-PHASE POWER CONVERTING APPARATUS - A three-phase inverter circuit ( | 01-21-2010 |
20100019753 | DC/DC POWER CONVERTING APPARATUS - Three or more circuits including a driving inverter circuit and rectifier circuits are connected in series, each of the circuits including a high-voltage side MOSFET and a low-voltage side MOSFET connected in series as well as a smoothing capacitor having positive and negative terminals between which the MOSFETs are connected. LC series circuits, each including a capacitor and an inductor, are disposed individually between one specific circuit and the other circuits with periods of resonance of the LC series circuits made equal to one another. In performing DC/DC power conversion through charging and discharging operation of the capacitors, a resonance phenomenon of the LC series circuits is used to improve conversion efficiency and achieve a reduction in size of the apparatus structure. | 01-28-2010 |
20100052598 | POWER REGENERATIVE CONVERTER - There are provided a smoothing capacitor ( | 03-04-2010 |
20100073082 | RECTIFIER - Provided is a highly efficient rectifier which can readily replace a two-terminal diode and whose conduction loss is reduced from that of the two-terminal diode. | 03-25-2010 |
20100177540 | POWER CONVERSION APPARATUS - 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. | 07-15-2010 |
20110089765 | POWER CONVERTING APPARATUS - A power converting apparatus includes a first inverter circuit including a high-voltage first DC voltage source and operated at a low frequency using Si IGBTs having a high withstand voltage exceeding 1000 V and a second inverter circuit including a low-voltage capacitor operated by high-frequency PWM using SiC MOSFETs having a low withstand voltage, wherein an AC side of the first inverter circuit is connected in series to an AC side of the second inverter circuit. The power converting apparatus outputs AC power having a prescribed voltage waveform obtained from the sum of voltages generated by the first and second inverter circuits. | 04-21-2011 |
20110114604 | ELECTRIC DISCHARGE MACHINING APPARATUS, ELECTRIC DISCHARGE MACHINING METHOD, AND SEMICONDUCTOR SUBSTRATE MANUFACTURING METHOD - An electric discharge machining apparatus includes: electrodes the total quantity of which is equal to N; an alternating-current power source; and capacitors the total quantity of which is equal to N. The alternating-current power source applies an alternating voltage commonly to the electrodes. One end of each of the capacitors is connected to a corresponding one of the electrodes, whereas the other ends of the capacitors are commonly connected to the alternating-current power source. | 05-19-2011 |
20110121661 | POWER CONVERSION DEVICE - In a power conversion device which performs DC/DC conversion, an inverter circuit ( | 05-26-2011 |
20110128763 | POWER CONVERTING APPARATUS - A power converting apparatus is provided with three sets of half-bridge inverters ( | 06-02-2011 |
20110181250 | POWER SUPPLY APPARATUS - A power supply apparatus includes: an AC generator including an AC generating section, and a rectifier for rectifying an AC voltage generated in the AC generating section, and outputting a DC voltage; and a DC/DC converter for converting the output voltage of the rectifier into a DC voltage having a different voltage value, wherein the output voltage of the rectifier is set to be larger than the output voltage of the DC/DC converter in accordance with the rotation speed of the AC generating section and the amount of power supply to an electrical load connected to the DC/DC converter, and is stepped down and outputted by using the DC/DC converter. The power supply apparatus is capable of increasing an output power efficiently. | 07-28-2011 |
20110211381 | POWER CONVERTING APPARATUS - A neutral point clamped three-phase three-level inverter is connected to a first DC power supply and single-phase inverters are connected in series with AC output lines of individual phases of the three-phase three-level inverter such that sums of output voltages of the three-phase three-level inverter and output voltages of the respective single-phase inverters are output to a load through a smoothing filter. An output control unit controls the three-phase three-level inverter so that the individual phases of the three-phase three-level inverter output primary voltage pulses at a rate of one pulse per half cycle and controls the individual single-phase inverters by PWM, so that output voltages to the individual phases of the load form sine waves of which phases are offset by 2π/3 from one phase to another, the sine waves having the same peak value. | 09-01-2011 |
20110215648 | UNINTERRUPTED POWER SUPPLY UNIT - An uninterrupted power supply unit is provided with a straightforward switch connected between a power source and a load to supply or interrupt a power to a system. The combination of the outputs from two kinds of single phase inverters enables compensating for a variation in the system voltage in the normal condition and to supply a predetermined voltage to the load after decreasing in the system voltage and opening of a straight forward switch. | 09-08-2011 |
20110215651 | POWER CONVERSION APPARATUS - In a power conversion apparatus that converts AC power to DC power, an inverter circuit including one or more single-phase inverters connected in series with each other is connected in series at the subsequent stage of a rectification of an AC input. At the subsequent stage of the inverter circuit, a smoothing capacitor connected via a rectification diode, and a short-circuiting switch for bypassing the smoothing capacitor are provided. The short-circuiting switch is subjected to ON/OFF control by PWM control such that a voltage of the DC voltage supply of the inverter circuit follows a target voltage. The inverter circuit is subjected to output control such that a DC voltage of the smoothing capacitor follows a target voltage and an input power factor is improved. | 09-08-2011 |
20110273916 | POWER CONVERTING APPARATUS - A power converting apparatus includes a first inverter ( | 11-10-2011 |
20110280049 | POWER CONVERTING APPARATUS - A power converting apparatus is configured with single-phase sub-converters ( | 11-17-2011 |
20120014139 | POWER CONVERTING APPARATUS - In a power converting apparatus which converts AC power into DC power, an inverter circuit including at least one series-connected single-phase inverter is connected in a downstream of a stage in which an AC input is rectified in series therewith. In the downstream stage of the inverter circuit, there are provided a smoothing capacitor connected via a rectifier diode and a short-circuiting switch for bypassing the smoothing capacitor. The short-circuiting switch is set to an ON state only in each of short-circuiting phase ranges of which midpoint matches each of zero-crossing phases and an output of the inverter circuit is controlled by using a current command so that a DC voltage of the smoothing capacitor follows a target voltage and an input power factor is improved. | 01-19-2012 |
20120092915 | POWER CONVERSION APPARATUS - A power conversion apparatus including: a three-level inverter including bridge circuits each including a first semiconductor switching device and a second semiconductor switching device connected in series, the bridge circuits being connected to a positive terminal and a negative terminal of a DC power supply, and switch circuits having bidirectional characteristics and connected to respective AC output terminals of the bridge circuits which are the connection points between the first semiconductor switching devices and the second semiconductor switching devices, and to an intermediate potential point of the DC power supply; and single-phase inverters each including a plurality of semiconductor switching devices and respectively connected in series to the AC output terminals of the bridge circuits. The sum of an output voltage of the three-level inverter and output voltages of the single-phase inverters is supplied to a load. | 04-19-2012 |
20120099353 | POWER CONVERTING APPARATUS - A power converting apparatus includes a main inverter having a high-voltage DC power supply that operates at a low frequency employing SiC MOSFETs having a high withstand voltage exceeding 600 V and a sub-inverter having a low-voltage capacitor that operates through high-frequency PWM employing Si MOSFETs having a low withstand voltage. With AC sides of the main inverter and the sub-inverter connected in series, the power converting apparatus outputs AC power having a prescribed voltage waveform by adding voltages individually generated by the main inverter and the sub-inverter. Specifically, the SiC MOSFETs are used only in the main inverter of which devices are required to have a high withstand voltage and the Si MOSFETs are used in the sub-inverter of which devices may have a relatively low withstand voltage, whereby conduction loss is reduced with an inexpensive circuit configuration. | 04-26-2012 |
20120120694 | POWER CONDITIONER FOR PHOTOVOLTAIC POWER GENERATION - Power generated by a solar battery of thin-film type is stepped up to a predetermined DC voltage by a step-up chopper circuit, and the predetermined DC voltage is converted into three-phase AC power by an inverter circuit, and the three-phase AC power is supplied to an AC power supply system via an output DC voltage circuit. The solar battery is not grounded, and a negative electrode thereof has a floating capacitance between the negative electrode and the ground. The AC power supply system is configured by three-phase star-connection, and the neutral point is grounded. The output DC voltage circuit includes three batteries, and the batteries are provided, for the respective phases, between the AC power supply system and a sine wave filter connected to the AC output side of the inverter circuit. Therefore, it is possible to prevent acceleration of the deterioration of the solar battery. | 05-17-2012 |