Abstract: An inverter circuit includes a DC-AC inverter, a sampling circuit, a voltage-current conversion circuit, an isolation circuit and an electronic starter switch. The sampling circuit includes a first and a second diode connected in parallel and opposite in polarity. A forward voltage drop at the first diode blocks the conductance of a first transistor of the voltage-current conversion circuit when there is no load, and a forward voltage drop at the second diode turns on the first transistor when there is a load. The connection of the first and second diodes to a second AC output terminal of the DC-AC inverter nearly has no impact on the AC output of the inverter circuit. These enable the inverter circuit to have low power consumption when there is no load and to be immediately activated upon connection of a load, thereby achieving detection of a load smaller than 0.1 W.

Abstract: An LLC resonant power regulator system includes a transformer having a primary inductor and a secondary inductor and an input resonant tank including an input resonant capacitor, an input leakage inductor, and the primary inductor connected in series. The system also includes an input stage having a plurality of switches that are controlled in response to a respective plurality of switching signals sweeping frequency to supply an input resonant current to the input resonant tank. Each of the respective plurality of switching signals can have a fixed duty cycle and a sweeping frequency. The system further includes an output resonant tank that includes an output resonant capacitor, an output leakage inductor, and the secondary inductor connected in series. The output resonant tank can be configured to generate an oscillating output resonant current at an output.

Abstract: The invention relates an inverter that may be set up as part of a power generation system for the connection of a number of substrings, which, using DC switches, can be connected to each other in series into a string and with the inverter. The inverter includes a bridge circuit to transform the power generated by the string comprising series-connected substrings into a grid-compatible AC voltage and to feed the power into a grid. The inverter also includes a ground fault detector arranged on the AC side of the bridge circuit for ground fault monitoring of the string. A controller connected to the ground fault detector controls the DC switches so that in case of a ground fault, a complete decoupling of the connection of the string from the bridge circuit and a separation of the string into potential-free substrings is performed. A method of operating such a power generation system is also described.

Abstract: A resonant conversion system is provided, in which a resonant converter receives an input voltage to generate an output voltage, and a buck converter provides the input voltage of the resonant converter, and controls the input voltage to perform an over-current protection process.

Abstract: The present invention is directed to a reactor 1 including a combined product 10 made up of a coil member 2 and a magnetic core 3, and a case 4 storing the combined product 10. The case 4 is formed by a combination of a side wall portion 41 surrounding the combined product 10 and a bottom plate portion 40 being a member separate from the side wall portion 41. Between the bottom plate portion 40 of the case 4 and the coil member 2 (coils 2a and 2b), an insulating sheet 42 is interposed. In order to fabricate the reactor 1, the insulating sheet 42 is disposed on the bottom plate portion 40, and the combined product 10 is disposed on the insulating sheet 42. Then, the side wall portion 41 is disposed from above the combined product 10, and the side wall portion 41 and the bottom plate portion 40 are engaged with each other.

Abstract: Embodiments of the invention relate to a power system for converting direct current (“DC”) power on a DC bus into alternating current (“AC”) power with a regulated voltage output and for feeding the AC power to an electrical system which may include a power utility or an electric grid, for example. A power conversion control system is used for controlling the power conversion and for maintaining the DC bus voltage (“DC voltage”) at a certain level.

Abstract: There is described a method for measuring an alternating current which is generated using inverters and is fed into an AC power system, wherein a zero crossing signal of the AC power system is predefined, and wherein, triggered by the zero crossing signal, the measured alternating current is periodically adjusted in such a manner that an adjustment value which is assigned to the zero crossing signal is predefined, a measured value which is assigned to the zero crossing signal being adapted to said adjustment value. This method makes it possible for the measurement signal detected by a measuring circuit to be periodically adjusted using an adjustment value even during operation.

Abstract: A circuit includes first and second electronic switches, first and second excitation circuits, and first and second inductors. The first and second electronic switches are electrically coupled in series. The first and second excitation circuits are used for respectively controlling the first and second electronic switches to be turned on and turned off and are configured to synchronously switch the first and second electronic switches. The first inductor is electrically coupled between the first excitation circuit and the first electronic switch, for transmitting the switch control signal of the first excitation circuit to the first electronic switch. The second inductor is electrically coupled between the second excitation circuit and the second electronic switch, for transmitting the switch control signal of the second excitation circuit to the second electronic switch.

Abstract: An inverter with soft switching is used for a high step-up ratio and a high conversion efficiency. The inverter includes an isolation voltage-quadrupling DC converter and an AC selecting switch. The isolation voltage-quadrupling DC converter includes an active clamping circuit. By a front-stage converter circuit, a continuous half-sine-wave current is generated. By a rear-stage AC selecting switch, the half-sine-wave current is turned into a sine-wave current. Thus, electricity may be supplied to an AC load or the grid. The circuit is protected by isolating the low-voltage side from the high-voltage side. The conversion efficiency is high. The leakage inductance is low. The switch stress is low. The inverter is durable and reliable. Hence, the inverter is suitable for use in a photovoltaic system to increase the total conversion efficiency.

Abstract: There is provided an inverter including: an inverter unit including at least one inverter arm having a plurality of switches, and switching the input power according to control to output an alternating current power; at least one driving unit including at least one high voltage gate driving unit having a plurality high voltage gate drivers connected to one another in series between an input terminal of an instruction signal instructing a switching control of an inverter unit and an output terminal of a control signal controlling switching of the inverter unit to control switching driving of a high side switch and including at least one low voltage gate driver to control switching driving of a low side switch; and at least one bootstrap unit charging/discharging and dividing a voltage generated at the time of switching the plurality of switches according to switching control of the driving unit.

Abstract: In some aspects of the invention, a number of semiconductor switches through which output current passes can be reduced between a direct current power source side, which is an input, and an alternating current output, thus achieving loss reduction, and enabling higher efficiency, price reduction, and miniaturization of a device. In some aspects, a direct current power source, formed of a series connection circuit of single power sources, which has three mutually different voltage levels including zero can be provided with first, second, third, and fourth arm pairs, each configured by connecting two arms formed of semiconductor switches in series, an alternating current switch configured by combining semiconductor switches. As such, a plurality of voltage levels can be to be selected from and output by an on and off control of these switch elements.

Abstract: An output circuit providing isolation between inputs and the output employs first and second opto-couplers for isolation. Pulse activation of the first opto-coupler turns on an output transistor and pulse activation of the second opto-coupler turns off the output transistor. An input stage of the output circuit is and light emitting devices of the first and second opto-couplers are powered by a first power source and an output stage of the output circuit is powered from an external power source. Power consumption by the input stage of output circuit occurs only during pulse activation of the first and second opto-couplers.

Abstract: A power converter is presented. The power converter includes at least one leg, the at least one leg includes a first string, where the first string includes a plurality of controllable semiconductor switches, a first connecting node, and a second connecting node, and where the first string is operatively coupled across a first bus and a second bus. Furthermore, the at least one leg includes a second string operatively coupled to the first string via the first connecting node and the second connecting node, where the second string includes a plurality of switching units. A method for power conversion is also presented.

Abstract: The invention relates to a method for operating an inverter (1), in particular a pulse-controlled inverter, comprising multiple phase systems (2, 3, 4), each of which has an outer conductor (7, 8, 9) and at least one semiconductor component (12, 13), and a temperature monitoring device (15) that has multiple temperature sensors (16, 17, 18) which sense the temperature of at least one part of at least one of the phase systems (2, 3, 4). In said method, a temperature gradient is determined from each of the sensed temperatures, the difference of the determined temperature gradients from each other is ascertained, and if the difference exceeds at least one threshold value, a fault of a cooling device of the inverter (1) is identified. The invention further relates to an inverter (1).

Abstract: An inverter and an active power filter system have been disclosed in the invention, so that the application range of the inverter under the occasions of different capacitor requirement can be widened, the cost can be decreased, and the efficiency can be improved. The technical scheme is: an auxiliary capacitor module can be added on the traditional inverter structure and connected in parallel selectively with the capacitor in the inverter. In a system without connecting an external auxiliary capacitor module, the value of capacitance can be designed to be smaller to satisfy the application under normal occasions. If the device operates under the occasions having large harmonic current or having large neutral line current, the ripple current on the capacitor will be larger so that large capacitance will be required to satisfy the life requirement, therefore, the problem can be solved by a method of installing an auxiliary capacitor module.

Abstract: The method can be used for the regulation of power in an alternating current electrical network (ACNW; ACNW1, ACNW2), using a conversion system (PCS) having at least two terminals (1,2; 1,2,3; 1,2,3,N) for connection to the network, wherein each of said terminals has a corresponding electrical potential. Each of the potentials of these terminals has an upper and a lower envelope, the difference between which, or envelope voltage (VEP,EN), is a variable positive continuous quantity having a maximum value (VEA) called the envelope amplitude.

Abstract: A power conversion system includes a filter unit, a DC/DC converter, a DC link, an inverter, a control unit, and a traction motor. The DC/DC converter is used for boosting DC voltage of a DC source and electrically coupled to the DC source through the filter unit. The DC/DC converter includes multiple SiC MOSFETs configured in a synchronous rectification mode by channel reverse conduction control. The inverter is used for converting the boosted DC voltage from the converter to multi-phase AC voltage through the DC link. The control unit is used for providing PWM commands to the converter and the inverter, to convert the DC voltage to AC voltage configured to drive an AC driven device.

Abstract: A method for operating an electronically controlled inverter and an inverter are provided. The inverter includes semiconductor switches, inductors and a first capacitor. The semiconductor switches of the inverter are controlled by a microcontroller alternately as elements of a buck converter and as elements of an inverting Cuk converter with a continuous connection of a neutral conductor at the output to a positive pole at the input side.

Abstract: There is disclosed a power supply stage, comprising: generating means for generating a power supply voltage from a high efficiency variable voltage supply in dependence on a reference signal; adjusting means for receiving the generated power supply voltage, and adapted to provide an adjusted selected power supply voltage tracking the reference signal in dependence thereon.

Abstract: A method of controlling a photovoltaic system includes providing a photovoltaic device having a variable DC voltage output and a variable DC current output. The photovoltaic device has a combination of a voltage output level and a current output level corresponding to a maximum power point. A DC power supply is connected in a parallel and/or series combination with the photovoltaic device. A DC load is connected in series to the combination of the DC power supply and the photovoltaic device such that the load is powered by the combination. A characteristic of the DC power supply is adjusted such that the voltage output and the current output of the photovoltaic device substantially match the voltage output level and the current output level corresponding to the maximum power point or other desired power point.

Abstract: A voltage booster system for use, for example, in an electric vehicle places a switched capacitor voltage converter between a high voltage battery and the vehicle's electrical load, typically a traction power inverter for driving the vehicle's electric motor. The battery input to the converter is pulsed to couple a charging voltage to the converter while the converter is disconnected from the load. The converter is then coupled to the load during the period that the pulse input is disconnected.

Abstract: A power conversion apparatus includes: a line breaker that is connected in series to a direct-current power supply; a first capacitor that is connected in parallel to the direct-current power supply through the line breaker; a discharge circuit that includes a resistor and a first switching circuit connected in series and is connected in parallel to the first capacitor; a power converter for driving a synchronous machine; a second capacitor that is connected in parallel to a direct-current side of the power converter; a second switching circuit that is connected in series between the first capacitor and the second capacitor; and a control circuit for controlling the discharge circuit. The control circuit controls the discharge circuit on the basis of the voltage of the first capacitor and the voltage of the second capacitor.

Abstract: A household Grid-Connected inverter applied to a solar power generation system with maximum power tracking function includes a solar power module; a MPPT power converter connected to the solar power module; and a DC/AC filter connected to the MPPT power converter. The DC/AC filter can be connected to the household grid in parallel. The solar power module is used to convert and output the solar energy in form of DC voltage. The MPPT power converter converts the DC into a high-frequency current with envelope of the same phase as the household grid, and also maximizes the output power. The DC/AC filter is used to output to the current which has the same phase as the household power and of the wave current form. Thereby, a simplified structure which can increase the device expanding flexibility and provide maximum output performance for solar power generation is achieved with lower cost.

Abstract: A multiple inverter and an active power filter system are disclosed in the invention, said multiple inverter can decrease the volume and harmonics, increase the efficiency and decrease the cost, and can be applied to various occasions. The technical scheme is: the filter assembly in the multiple inverter is installed at the output inductor of the multiple inverter for filtering the harmonics.

Abstract: The present invention provides an apparatus for controlling a multiphase multilevel voltage source inverter. The apparatus includes a signal-generating unit and a converter. The signal-generating unit responds to an input signal to produce a switching strategy control signal and a duration timing control signal corresponding to the switching strategy control signal. The converting unit responds to the switching strategy control signal and the duration timing control signal to produce a switching signal. The voltage source inverter responds to the switching signal to generate a multiphase-and-multilevel AC voltage output.

Abstract: A system for optimizing switching dead-time includes a power converter that includes a half-bridge circuit comprising a first switch coupled in series with a second switch, first and second state detection circuits respectively coupled to the first and second switches and configured to respectively detect an activation state of the first and second switches. First and second switch control circuits coupled respectively to the first and second switches are configured to respectively toggle the first and second switches between an activate state and a deactivated state. The first switch control circuit includes a first input configured to receive an activation signal from the second state detection circuit indicative of the activation state of the second switch, and the second switch control circuit includes a first input configured to receive an activation signal from the first state detection circuit indicative of the activation state of the first switch.

Abstract: There is provided a power supply unit supplying a standby power by sharing a switch of a main converter. The power supply unit includes: a main converter, and a standby converter. The main converter controls a current flowing in a primary side winding of a main transformer and supplies a main power through a secondary side winding of the main transformer. The standby converter controls a current flowing in a primary side winding of a standby transformer and supplies a standby power through a secondary side winding of the standby transformer, and a portion of a plurality of switches of the main converter is included in switches of the standby converter.

Abstract: The present invention relates to a near zero current-ripple inversion circuit including top and bottom cells, a transformer (T1) comprising primary windings (P1, P2) and a secondary winding (S1), and at least one middle cell connected in series between the top and bottom cells. The top cell comprises two capacitors (C1, C2) and a switch (Q1) each connecting to the middle cell, and an inductor (Lr1) and the primary winding (P1) connected in series between the capacitor (C1) and switch (Q1), wherein the switch (Q1) is connected to the capacitors (C1, C2) respectively. The bottom cell comprises a capacitor (C3) and a switch (Q2) each connecting to the middle cell, and an inductor (Lr2) and the primary winding (P2) connected in series between the capacitor (C3) and switch (Q2), wherein the primary winding (P2) is connected to the middle cell, and the capacitor (C3) and switch (Q2) are connected.

Abstract: Power switching circuitry has a heat absorbing structure, and a heat conductive substrate having power switching components on a first surface and a second surface adjacent to the heat absorbing structure. Electrically conductive members, comprising first and second members, are on the first surface and extend along a first axis orthogonal to the heat conductive substrate. The second portion is more remote from the heat conductive substrate, and has a smaller cross-sectional area than, the first portion to define a shoulder region orthogonal to the first axis. A circuit board is located on the shoulder regions, with the second portions extending through the circuit board. An urging mechanism urges the circuit board against the shoulder regions, whereby the electrically conductive members provide a current path between the heat conductive substrate and the circuit board, and urge the heat conductive substrate into thermal contact with the heat absorbing structure.

Abstract: A photovoltaic inverter includes an input circuit, a decoupling circuit and an output circuit. The input circuit has a DC input port, an input capacitor, a magnetizing inductor, a first unidirectional element and a first switch. The magnetizing inductor forms first and second connection nodes. The decoupling circuit has a second unidirectional element, a second switch, a third switch, a third unidirectional element and a decoupling capacitor. The second unidirectional element and the second switch are connected in series at a first node. The third switch and the third unidirectional element are connected in series at a second node. The output circuit has a transformer, a fourth unidirectional element, a fourth switch, an output capacitor, a fifth switch, a fifth unidirectional element, an output inductor and an AC output port. The transformer includes an input port and first and second output ports. A control method of the inverter is disclosed.

Abstract: An AC photovoltaic module includes a DC photovoltaic module for converting solar energy to DC electrical power, and an inverter for converting DC electrical power to AC electrical power, the inverter being adapted for connection to a frame portion of the module and being sized and configured, and provided with arrangements of electrical components thereof, to dispense heat from the inverter, whereby to prolong operational life and reliability of the inverter.

Abstract: The disclosure relates to a method for transferring batteries to a discharged state, a battery system, an inverter, a system for generating an AC voltage, a charging current source and a motor vehicle. The battery system includes a controllable inverter having parallel current branches and having series-connected power switches that are switchable by external control of the controllable inverter. The battery system further includes a controllable charging and disconnecting device having an interrupted current path and having a charging current source between the battery and the controllable inverter.

Abstract: A method for balancing a voltage of an inverter determines an expected voltage of a capacitor based on a voltage of the capacitor at a start of a switching cycle and determines a duty cycle minimizing a value of an objective function representing a difference between the expected voltage of the capacitor and a desired voltage of the capacitor. A switching sequence controlling the inverter is selected based on the duty cycle.

Abstract: A reactor 1A includes a single coil 2 formed by spirally winding a wire 2w and a magnetic core 3 that is disposed inside and outside the coil 2 and forms a closed magnetic circuit. The magnetic core 3 includes an inner core portion 31 disposed inside the coil 2 and an outer core portion 32 disposed so as to cover the outer periphery of the coil 2. The outer core portion 32 is formed of a composite material containing a magnetic powder and a resin. In a section of this composite material, the maximum bubble diameter is 300 ?m or less. In the reactor 1A, the outer core portion 32 has a maximum bubble diameter of 300 ?m or less and, as a result, the loss is low and magnetic characteristics are less likely to be decreased.

Abstract: A portable electronic device has a battery to provide power to operate the device, a connector including a power supply pin to be coupled to an external power supply, and a power manager having a battery charger circuit that draws power through the power supply pin to charge the battery. The power manager has a current limit feedback control loop that limits the drawn current in accordance with a predetermined output current rating of the external power supply. The power manager automatically changes the behavior of its control loop to stabilize operation of the coupled external power supply. Other embodiments are also described and claimed.

Abstract: A circuit switching element is provided that switches a step-up/step-down bidirectional chopper circuit, arranged between a DC bus and a power storage element, to a first chopper circuit or to a second chopper circuit, whose step-up and step-down characteristics are in a complementary relation. The first and second chopper circuits are used together at a time of charge and discharge. Accordingly, an AC motor drive device having mounted therein a power storage system is obtained, in which the power storage system can perform charge and discharge to and from the power storage element, regardless of a bus voltage and can increase energy use efficiency.

Abstract: A semiconductor device includes: a case with an opening formed thereat; a semiconductor element housed inside the case; a first conductor plate housed inside the case and positioned at one surface side of the semiconductor element; a second conductor plate housed inside the case and positioned at another surface side of the semiconductor element; a positive bus bar electrically connected to the first conductor plate, through which DC power is supplied; a negative bus bar electrically connected to the second conductor plate, through which DC power is supplied; a first resin member that closes off the opening at the case; and a second resin member that seals the semiconductor element, the first conductor plate and the second conductor plate and is constituted of a material other than a material constituting the first resin member.

Abstract: A two-level two-terminal modular multilevel converter subsystem. The subsystem includes a first capacitor and a second capacitor. The modular multilevel converter subsystem is configured to selectively place the first capacitor in series with the second capacitor. The modular multilevel converter subsystem is also configured to selectively place the first capacitor in parallel with the second capacitor relative to first and second output terminals of the modular multilevel converter subsystem.

Abstract: An apparatus and method for controlling the delivery of a pre-determined amount of power from a DC source to an AC grid includes an inverter and an inverter controller. The inverter includes an input converter, an energy storage capacitor, and an output converter. The inverter controller includes an input converter controller and an output converter controller. The input converter controller includes feedforward controller configured to perform a calculation to determine a value for the duty cycle for the input converter such that: (1) the input converter delivers the pre-determined amount of power and (2) the magnitude of a ripple signal reflected into the input source is attenuated toward zero. The input converter controller may also include a quadrature corrector configured to determine the effectiveness of the calculation in attenuating the ripple and to adaptively alter the calculation to improve the effectiveness.

Abstract: A system for using an IGBT module, electrically rated for use in a traction inverter used with a powered system, in an auxiliary inverter used with the powered system which requires a different electrically rated IGBT module than the traction inverter, the system including an IGBT module, including plurality of IGBTs as part of the IGBT module, electrically rated for use with a traction inverter, and a plurality of gate drives each configured to singularly connect to a respective one of the plurality of IGBTs within the IGBT module. All three phases of three-phase electrical power of the auxiliary inverter are associated with the IGBT module.

Abstract: A current resonance power supply includes a transformer having a primary winding and a secondary winding, two switching elements connected to one end of the primary winding of the transformer and arranged in series, a resonance capacitor connected to the other end of the primary winding, and a voltage detection unit connected between the one end of the primary winding and the two switching elements and configured to detect that AC voltage input to a primary side of the transformer becomes lower, wherein operations of the switching elements are controlled based on a detection result of the voltage detection unit.

Abstract: Technology leading to a size reduction in a power conversion apparatus comprising a cooling function and technology relating to enhancing productivity and enhancing reliability necessary for commercial production are provided. Series circuits comprising an upper arm and lower arm of an inverter circuit are built in a single semiconductor module 500. The semiconductor module has cooling metal on two sides. An upper arm semiconductor chip and lower arm semiconductor chip are wedged between the cooling metals. The semiconductor module is inserted inside a channel case main unit 214. A DC positive electrode terminal 532, a DC negative electrode terminal 572, and an alternating current terminal 582 of a semiconductor chip are disposed in the semiconductor module. The DC terminals 532 and 572 are electrically connected with a terminal of a capacitor module. The alternating current terminal 582 is electrically connected with a motor generator via an AC connector.

Abstract: An inverter device includes a substrate, upper arm elements, lower arm elements, positive and negative input electrodes, and an output electrode. The upper arm elements serve as an upper switching element and are arranged along a first direction. The lower arm elements serve as a lower arm switching element and are arranged along the first direction. At least one of bus bars of the positive and negative input electrodes and the output electrode extends parallel to the first direction. At least one of the bus bars of the positive and negative input electrodes and the output electrode has a length in the longitudinal direction that is greater than a width between two ends of the upper arm elements and the lower arm elements in the first direction.

Abstract: A power converter includes a dc input having first and second terminals. A main converter is coupled to the first terminal of the dc input. A standby circuit coupled to the second terminal of the dc input and the main converter. The main converter is coupled to control a transfer of energy from the dc input through the standby circuit to a main output of the main converter during a normal operating condition of the power supply. The standby circuit is coupled to decouple the main converter from the second terminal of the dc input during a standby operating condition of the power converter. A standby converter is coupled to the first and second terminals of the dc input to control a transfer of energy from the dc input to a standby output of the standby converter during the standby operating condition of the power converter.

Abstract: The multi-phase inverter modulating method provides for calculating a duty cycle vector (D) calculated as a function of electric parameters defining a rotating vector (Vo) representative of an output electric quantity required from the inverter, is multiplied for a stored modulation matrix to obtain a plurality of duty cycle signals for a plurality of electronic switches of said inverter.

Abstract: A switching power converter has a power converter connected between a DC power source and a load and having a power switch, a current detector detecting a load current, and a PWM controller outputting a first frequency to control the switching frequency of the power switch and outputting an adjustable second frequency to adjust the switching frequency of the power switch according to the load current and a condition of judgment. The condition of judgment serves to determine if the load is a heavy or light load. In the case of light load, the second frequency is reduced to lower the switching loss of the power switch. In the case of heavy load, the second frequency is raised to reduce the ripple of the load current. Accordingly, the conversion efficiency of the switching power converter can be enhanced.

Abstract: A power supply apparatus for LED is provided. The power supply apparatus for LED includes a detector, a voltage dropper, and a control switch. The detector detects whether an LED is connected to the power supply apparatus. The voltage dropper drops a voltage applied to the LED. The control switch is connected to the voltage dropper in parallel, and changes a path of a power applied to the LED according to the detected result of the detector. Accordingly, the power supply apparatus for LED compensates for a low impedance of an LED to an impedance equal to or higher than a predetermined impedance at a time when connection of the LED is detected, thereby inhibiting an overcurrent from flowing in the LED.

Abstract: A switching power supply apparatus includes a low-side switching control unit and a high-side switching control unit. The low-side switching control unit includes a low-side turn-off circuit that turns off a low-side switching element behind a delay time when reversal of the polarity of a winding voltage of a transformer is detected during a period in which a drive voltage signal is supplied to the low-side switching element. The high-side switching control unit includes a high-side turn-on delay circuit that delays a time from the time when the polarity of the winding voltage of the transformer is reversed to a time when a high-side switching element is turned on. The delay time of the low-side turn-off delay circuit is set so as to be shorter than the delay time of the high-side turn-on delay circuit.

Abstract: 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 2?/3 from one phase to another, the sine waves having the same peak value.

Abstract: A power converter of the present invention is configured to convert DC power generated by a power generator (1) into AC power. The power converter includes: a boost converter circuit (3) configured to boost an output voltage of the power generator (1); an inverter circuit (5) configured to convert an output voltage of the boost converter circuit (3) into AC power and to interconnect the AC power with a power system (2); a buck converter circuit (8) configured to perform power conversion of output power of the boost converter circuit (3) and to supply resultant power to an internal load (60); and a controller (9). The controller (9) is configured to control the output voltage of the boost converter circuit (3) to be lower than or equal to a second voltage value which is less than the maximum value of AC voltage of the power system (2), in a case of supplying output power of the power generator (1) to the internal load (60) via the boost converter circuit (3) and the buck converter circuit (8).