Abstract: A solar inverter system includes a first inverter, a second inverter, and a controller. The first inverter has a first input terminal, and a first output terminal. The first input terminal is coupled to a solar panel. The second inverter has a second input terminal, and a second output terminal. The second input terminal is coupled to the solar panel. The first output terminal and the second output terminal are parallel with a utility grid. The controller is coupled to the first inverter and the second inverter for controlling the first inverter and the second inverter to output total output power in turn, or controlling the first inverter and the second inverter to output the total output power simultaneously.

Abstract: Various methods and apparatus are described for an integrated remotely controlled photovoltaic system having a number of components. A central backend server management system is configured to facilitate management of two or more solar arrays at a remote site from a client device connected over a public wide area network (WAN). An integrated electronics housing contains multiple circuits, including power generation inverter circuits and solar array motion control circuits for one or more PhotoVoltaic (PV) solar arrays at the remote site. The multiple circuits cohesively exist in the integrated electronics housing and actually perform better because of the interconnectivity. The communication circuitry within the integrated electronics housing is configured to establish secure communications over the WAN with the central backend server management system. The integrated electronics housing acts as the local system control point for the first solar array.

Abstract: A motor driving control apparatus includes a motor driving unit which drives a motor and a driving control unit which supplies to the motor driving unit a command value for the motor driving unit to drive the motor. A power characteristic acquiring unit acquires a power characteristic of an AC power supply that supplies power to the motor. A control parameter determining unit determines based on a voltage characteristic of the AC power supply whether, during driving of the motor, the voltage of the AC power supply drops to a level that adversely affects the driving of the motor, and if positive, the control parameter determining unit sets a control parameter so that the voltage of the AC power supply does not drop below that level and supplies the control parameter to the driving control unit in order for the driving control unit to determine the command value.

Abstract: A reactive energy compensator is provided. The compensator is connected to an alternating electrical network including M phase(s), M being an integer greater than or equal to 1. The compensator includes M connection terminals, N banks of capacitor(s) capable of providing reactive energy, N being an integer greater than or equal to 2, N two-way voltage inverters, connected to each other in parallel and each connected to a unique capacitor bank, each inverter being able to convert a direct current into an alternating current including M phase(s) in one direction and the alternating current into direct current in the other direction, each inverter including first and second input terminals and M output terminal(s), the input terminals being connected to the corresponding capacitor bank, each output terminal corresponding to a phase of the alternating current and being connected to a corresponding connection terminal, and a device for balancing the voltage of the N capacitor banks.

Abstract: Provided is a switching control method of a transformer coupled booster to suppress an increase in energizing current in a transformer of the transformer coupled booster and downsize the transformer coupled booster. A primary coil current that flows through a primary coil of the transformer, and a secondary coil current that flows through a secondary coil of the transformer are detected. The current difference between the detected primary coil current and the detected secondary coil current is calculated. Based on the calculated current difference, the cycle of ON/OFF periods of four arms provided on the transformer coupled booster is maintained at a constant level. Control is carried out so that the ratio of the first arm's ON period to the OFF period is always equal to the ratio of the third arm's ON period to the OFF period.

Abstract: A method of operating a DC-AC inverter to produce AC power having alternating positive and negative half cycles is disclosed. The inverter includes an input connected to a DC power source, an output, a first buck converter coupled between the input and the output and a second buck converter coupled between the input and output. The method includes alternately operating the first buck converter and the second buck converter to alternately produce the positive and negative half cycles at the output.

Abstract: A reactive energy compensator that can be electrically connected to an AC electrical network, including at least one input direct voltage bus, at least one voltage inverter including switches and first and second capacitors having first and second voltages at their terminals, control means for the switches, including computation means capable of generating a target control current, means for combining the target control current and the output current from the inverter, means for transmitting a control signal capable of driving the switches, and correction means for the control signals of the switches, the correction means being capable of adding a balancing current to the target control current, the balancing current being able to correct the target control current so as to reduce the difference between the values of the first and second voltages, the target control current being increased for an even harmonic of the network frequency.

Abstract: An apparatus and method for controlling the delivery of power from a DC source to an AC grid includes an inverter configured to deliver power from the unipolar input source to the AC grid and an inverter controller. The inverter includes an input converter, an active filter, and an output converter. The inverter controller includes an input converter controller, an active filter controller and an output converter controller. The input converter controller is configured to control a current delivered by the input converter to a galvanically isolated unipolar bus of the inverter. The output converter is configured to control the output converter to deliver power to the AC grid. Additionally, the active filter controller is configured to control the active filter to supply substantially all the power that is deliver by the output controller to the AC grid at a grid frequency.

Abstract: An A/D conversion apparatus includes an N-stage pulse circulating circuit including N (N is a natural number, N?3) inverting circuits connected in a ring shape, the inverting circuits delaying an input pulse signal by a delay time corresponding to an amplitude of a separately input analog input signal, and outputting inverted pulse signals obtained by inverting the pulse signal, a counter unit that counts a number of circulations by which the pulse signal has circulated in the pulse circulating circuit within a predetermined time based on the inverted pulse signal output from one of the N inverting circuits, and a switching unit that switches an output destination of the inverted pulse signal, which is output from an inverting circuit of an Mth (M is an odd natural number, 1?M?N?1) stage of the pulse circulating circuit, according to a change in an operation environment.

Abstract: A multiple dc sources bi-directional energy converter includes a plurality of direct current (DC) power sources; one alternating current (AC) power source; at least one stacked alternating current (AC) phase, each stacked alternating current (AC) phase having at least two or more full bridge converters, each respectively coupled to one of the direct current power sources, each full bridge converter having an inductor electrically coupled thereto; and a local controller coupled to each full bridge converter controlling the firing sequence of the switching devices in said full bridge converter to generate an approximately nearly sinusoidal voltage waveform when operated as a voltage source inverter in one direction or generate an approximately nearly constant direct current (DC) output when operated as a full-wave active rectifier in the opposite direction.

Abstract: A stacked voltage source inverter having separate DC sources is described herein. This inverter is applicable to low or medium voltage, low to medium power applications such as photovoltaic utility interface systems, battery storage application such as peak shaving with renewables, motor drive applications and for electric vehicle drive systems. The stacked inverter consists of at least one phase wherein each phase has a plurality of low voltage full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with fast switching and small low pass AC output filter. A system controller controls operating parameters for each inverter. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

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 present invention provides an electric circuit wherein a multi-phase bridge is connected in series with a plurality of single-phase bridges. The multi-phase bridge is composed of a plurality of 3-level diode clamped legs, while the single-phase bridges each is composed of two 3-level diode clamped legs. The present invention also provides control strategy for synthesizing multi-level voltage waveforms from output voltages of the multi-phase bridge and the plurality of single-phase bridges.

Abstract: A power converter enhances conversion efficiency from DC power to AC power. A first chopper circuit chops DC voltage from a photovoltaic panel at a system frequency producing a first square-wave whose voltage level changes positively. A second chopper circuit chops the first square-wave at a frequency double the system frequency producing a second square-wave whose voltage level changes negatively and adds the first square-wave and the second square-wave to produce a third square-wave that changes positively and negatively in a sine-wave manner. A third chopper circuit charges and discharges by chopping the third square-wave at a third frequency fixed by timing according to a difference between the third square-wave and a sine-wave voltage. PWM control is performed on the charge and discharge outputs such that the difference is corrected, producing a sine-wave voltage that continuously changes positively and negatively. A spike noise of an output voltage is suppressed.

Abstract: The present invention relates to a method for feeding an unbalanced, three-phase current into a three-phase AC voltage system, comprising the steps of: producing a positive phase-sequence system for the current to be fed in, producing a negative phase-sequence system for the current to be fed in, superimposing the positive phase-sequence system and the negative phase-sequence system to form the current to be fed in and feeding the current composed in this manner into the three-phase AC voltage system.

Abstract: The invention relates to an inverter system (1) with several inverters (2), each of which having at least one control unit (6), with at least one line (7) each being provided between the inverters (2) for data exchange, as well as to an inverter (2), and to a method of operating several inverters (2) in such an inverter system (1). To achieve a high transmission safety, and a high data-transmission rate, it is provided that each inverter (2) has a communication device (8) which is connected to a control unit (6) of the inverter (2) and to the data lines (7) of two neighboring inverters (2), and which has a switching device (13), the switching device (13) being configured to switch the data lines (7) between a ring system and between a bus system logically based on this ring system.

Abstract: A semiconductor arrangement includes a circuit carrier, bonding wire and at least N half bridge circuits. The circuit carrier includes a first metallization layer, a second metallization layer, an intermediate metallization layer arranged between the first metallization layer and the second metallization layer, a first insulation layer arranged between the intermediate metallization layer and the second metallization layer, and a second insulation layer arranged between the first metallization layer and the intermediate metallization layer. Each half bridge circuit includes a controllable first semiconductor switch and a controllable second semiconductor switch. The first semiconductor switch and the second semiconductor switch of each half bridge circuit are arranged on that side of the first metallization layer of the circuit carrier facing away from the second insulation layer. The bonding wire is directly bonded to the intermediate metallization layer of the circuit carrier at a first bonding location.

Abstract: Photovoltaic (PV) array emulators and methods are described. In one example, a method for use in testing a PV inverter includes coupling a first PV inverter to an alternating current (AC) power source. A second PV inverter is coupled to receive an output of the first PV inverter. The first PV inverter is operated to emulate a PV array and provide a DC power output to the second PV inverter.

Abstract: A power generator includes one or more full bridge inverter modules coupled to a semiconductor opening switch (SOS) through an inductive resonant branch. Each module includes a plurality of switches that are switched in a fashion causing the one or more full bridge inverter modules to drive the semiconductor opening switch SOS through the resonant circuit to generate pulses to a load connected in parallel with the SOS.

Abstract: A method and an arrangement are disclosed for balancing load between parallel connected inverter modules, which inverter modules are arranged to supply a common load. The method can include providing similar switching instructions for parallel connected inverter modules, determining on the basis of phase currents of each parallel inverter module a first time period for each output phase of each inverter module for correcting current imbalance by advancing or delaying turn-on or turn-off time instants of switch components of the inverter modules, and advancing or delaying the turn-on or turn-off time instants of the switching instructions based on the first time period.

Abstract: A power management system comprising a processor is provided. The power management system obtains maximum operating capacities of the power converters over time while in the curtailed mode and uses at least some of the maximum operating capacities for determining and commanding an adjusted operating capacity of at least one of the power converters to maintain a substantially constant level of output power.

Abstract: A control system for parallel connected inverter legs energized by a power source and configured for servicing a load is disclosed. The invention facilitates the number of running inverter legs to adaptively react to changes in the load by dynamically switching various inverter legs “on” or “off” in response to variations in load demand, while continuing magnetization of an output transformer connected with an “off” inverter leg via a back-feed from another output transformer of an “on” inverter leg, greatly improving the dynamic response to load changes. This design enables a fast reaction to load changes with “off” inverter legs transitioning to on-line operation instantaneously.

Abstract: A Voltage Source Converter of M2LC-type has a series connection of switching cells (7), in which each switching cell has on one hand at least two semiconductor assemblies connected in series and having each a semiconductor device of turn-off type and a free-wheeling diode connected in parallel therewith and on the other at least one energy storing capacitor (20). The series connection of switching cells has one first end (61) connected to a direct voltage pole (5) on high voltage potential and an opposite end (62) connected to a phase output (10) of the converter. An arrangement (70) is configured to connect the phase output (10) to another said pole (6) on neutral voltage potential on a direct voltage side of the converter and to deliver voltage pulses to said phase output being both positive and negative with respect to said neutral potential.

Abstract: The invention relates to converters (inverters, pulse or frequency converters) and to driving “magnetically active” operating means. According to one embodiment, a circuit arrangement for feeding the operating means 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). A second branch (z1) of another frequency converter (WR2) is adapted for and operable at a second switching frequency of more than 5 kHz for outputting a supplementary alternating current generated at said switching frequency to the same winding (L1). In the at least one winding (L1), the two alternating currents (iA(t); iB(t)) of the two branches (Z1, z1) are superimposed to form a sum current.

Abstract: An energy storage system and a controlling method of the energy storage system are provided. The energy storage system reduces power consumption and increases inverter efficiency by providing a plurality of inverters in parallel and selectively driving ones of the inverters according to a power requirement of the load. The energy storage system supplies an alternating current (AC) power to a load. The energy storage system includes: a battery for supplying a direct current (DC) power; a plurality of inverters for connecting in parallel between the battery and the load to convert the DC power to the AC power; and a controller for selectively driving the inverters in accordance with a power requirement of the load.

Abstract: Multilevel DC to AC power converter has three DC inputs (IN1, IN2, IN3) for receiving, respectively, three DC voltages (V1,V2,V3), wherein V1>V2>V3, one AC output (OUT1) for delivering an AC voltage (Va), a set of at least six switching means (T1,T2,T3,T4,T5,T6) arranged in a symmetric pyramidal fashion, and switch control means for controlling an ON/OFF state of each of the six switching means. The switch control means is configured such that the top two switching means (T5,T6) are switched ON and OFF in a complementary fashion and, exclusively, at a fundamental frequency (Fa) of the AC voltage to be delivered at the AC output (OUT1), whereas at least some of the other four switching means (T1,T2,T3,T4) are switched ON and OFF at higher frequencies. The top two switching means (T5,T6) are hence subject to lower switching losses, thereby increasing the overall efficiency of the converter.

Abstract: A method of providing reactive power support is proposed. The method includes detecting at least one of a plurality of network parameters in a distributed solar power generation system. The generation system includes a plurality of photovoltaic modules coupled to a grid via inverters. The method further includes sensing a state of the photovoltaic modules coupled to the distributed solar power generation system and determining a reactive power measure based upon the sensed state and the detected network parameters. The reactive power measure is used to generate a reactive power command. The reactive power command is further used to compensate reactive power in the distributed solar power generation system.

Abstract: A device for converting a DC voltage into an AC voltage and vice versa comprises a control system to control the voltage conversion and at least one phase leg (1) with a first (Uvp1) voltage source connected in series between a first DC terminal (4) and a first AC terminal (6) and with a second (Uvn1) voltage source connected in series between the first AC terminal (6) and a second DC terminal (5). Each of the voltage sources comprises at least a first and a second submodule (15) in series-connection, where each submodule (15) comprises at least two power electronic switches (16) connected in parallel with at least one capacitor (17).

Abstract: Techniques include systems and methods of synchronizing multiple parallel inverters in a power converter system. In one embodiment, control circuitry is connected to a power layer interface circuitry at each of the parallel inverters, via an optical fiber interface. The system is synchronized by transmitting a synchronizing pulse to each of the inverters. Depending on the operational mode of the system, different data exchanges may occur in response to the pulse. In an off mode, power up and power down data may be exchanged between the control circuitry and the inverters. In an initiating mode, identification data may be transmitted from the inverters to the control circuitry. In an active mode, control data may be sent from the control circuitry to the inverters. In some embodiments, the inverters also transmit feedback data and/or acknowledgement signals to the control circuitry.

Abstract: A system includes a low switching frequency power converter configured to be coupled to a solar cell, wherein the low switching frequency power converter is configured to generate alternating current (AC) power based on low voltage direct current (DC) power transmitted from the solar cell and transmit the converted AC power. The system also include a multi-pulse transformer configured to receive the converted AC power and generate transformed power based on the converted AC power, wherein the transformed power comprises power at a voltage level that differs from the a voltage level of the converted AC power.

Abstract: A power converter apparatus is provided with a lead-in board in which alternating-current power received from power converting units is connected in parallel, and a connection base including frames for installing the power converting units therein. The frames are provided with connection sections for connecting the main, circuits of the power converting units. The lead-in board is provided with breakers for cut off alternating-current power from the power converting units.

Abstract: A control device that controls an electric motor drive device. The control device is configured with a first voltage control section that derives a modulation rate representing a ratio of an effective value of the voltage command values to the DC voltage and a voltage command phase. A second voltage control section generates a control signal for controlling the DC/AC conversion section on the basis of the modulation rate, the voltage command phase, and a magnetic pole position representing a rotational angle of a rotator of the AC electric motor. A computation cycle of the first voltage control section is set to be longer than a computation cycle of the second voltage control section.

Abstract: A high voltage inverter is provided which includes a plurality of k-level flying capacitor H bridge modules, k being greater than 2, each having a positive dc terminal, a negative dc terminal, and two ac terminals, a connecting unit for connecting said ac terminals of said plurality of k-level flying capacitor H bridge modules in series to form a cascading set of modules, and a dc source connected to an ac source and having a transformer, a rectifier rectifying an output voltage of said transformer, and a capacitor connected between the positive and negative dc terminals.

Abstract: A power converter arrangement configured to convert a direct voltage into an alternating voltage to be supplied to a grid includes a photovoltaic generator configured to generate the direct voltage, a voltage intermediate circuit, a main power converter connected in series with a bypass switch, a maximum power point controller configured to set a maximum power point voltage, and at least one voltage-limited additional circuit configured to be active during a start-up phase of the photovoltaic generator. The at least one voltage-limited additional circuit and the main power converter are configured as a voltage divider in parallel with the photovoltaic generator. The at least one voltage-limited additional circuit is configured as a capacitive voltage divider having a first capacitor and an intermediate circuit capacitor connected in series.

Abstract: When a commercial power supply E operates normally, converter sections PFC1, PFC2 connected in parallel to each other can operate to approximate the input current from the commercial power supply E to the waveform and phase of the input voltage to correct a power factor while supplying stabilized output voltages Vo1, Vo2 to a load. When the voltage of the commercial power supply E drops, the smoothing capacitor Co1 operates as an input power supply to power the converter section PFC2, which allows the smoothing capacitor Co2 to supply the stabilized output voltage Vo2 to the load.

Abstract: A power supply circuit for receiving an input voltage to drive a plurality of loads is disclosed. The power supply circuit comprises a plurality of switch circuits, a plurality of power conversion circuits and a phase delay circuit. The plurality of switch circuits are connected with the plurality of loads, respectively. The plurality of power conversion circuits are connected with the plurality of loads and the plurality of switch circuits, respectively, for converting the input voltage into a plurality of driving voltages and transmitting the plurality of driving voltages to the plurality of loads, respectively, when the plurality of switch circuits are conducted.

Abstract: A power converter includes at least two power conversion sections operating in parallel. The power converter receives a variable input power and generates an AC output voltage. When the power source is generating enough power to supply a DC voltage to the power converter greater than or equal to the peak magnitude of the desired AC voltage output, each power conversion section operates in parallel, converting the DC voltage to the desired AC voltage output. When the power generated by the variable power source results in a DC voltage having a magnitude less than the peak magnitude of the desired AC voltage output, the power conversion sections operate in series. One power conversion section operates as a boost converter to boost the DC voltage level to a suitable level for the second power conversion section, which generates the desired AC output voltage.

Abstract: An interleaved flyback converter device with leakage energy recycling includes: two flyback converters and an input power. Each flyback converter includes a capacitor, a switch, two diodes, and a transformer. The input power is connected to the capacitors of the two flyback converters respectively. By using the capacitors as input voltage, the two flyback converters are provided with lower voltage rating. The diodes are used to recycle leakage energy directly, and to clamp voltage on power components. Therefore, in addition to enhancing efficiency via recycling leakage energy, the two flyback converters have lower switching losses due to lower switching voltage.

Abstract: To realize power supply to each gate drive circuit without using an individual dedicated power supply for each gate drive circuit. A power conversion apparatus includes an individual drive unit that does not require a dedicated power supply, and includes gate drivers connected to switches and interface circuits and a power converter gate drive configured with a common power supply for supplying power to the gate drive unit. Power is supplied from main circuits or a number of common power supplies fewer than that of the number of the switches through one or more power supply terminals included in the interface circuit. Also, the signal can be transmitted by isolation from a signal source to the gate drivers.

Abstract: A multi-output buck converting apparatus with a controllable energy-releasing function includes a main buck converter and at least one auxiliary buck converter to provide multi-output voltages. The multi-output buck converting apparatus further includes an energy releasing unit and an abnormal voltage signal generating unit. The abnormal voltage signal generating unit generates a control signal to control a switch device of the energy releasing unit when the multi-output buck converting apparatus shuts down. Therefore, the energy, which is stored in the auxiliary buck converter, can be released through the energy releasing unit so as to avoid returning the energy to the main buck converter and rebounding a main output voltage.

Abstract: An arrangement for supplying electric power to a load through a filter bus includes at least two Voltage Source Converters connected in parallel to the filter bus through an inductor each and configured to share the load. Each converter is associated with a control unit configured to regulate the voltage (vf) of the filter bus while maintaining dynamic control of the current from the converter. This control unit involves production of two perpendicularly-intersecting filter bus voltage vectors (vfx, vfy) from the filter bus voltage and the control unit involves production of a current vector (ikx, iky) for each filter bus vector. The control unit also involves multiplying of each current vector with a droop coefficient common to all the current vectors. The result of this multiplication is sent to means for subtracting this result from the respective filter bus voltage reference vector (v*fx, v*fy).

Abstract: A DC to AC converter includes a first switch, a second switch, a first half bridge inverter, and a second half bridge inverter. The first switch includes a first terminal and a second terminal. The second switch includes a first terminal and a second terminal. A portion between the first terminal of the first switch and the first terminal of the second switch is operable to receive a direct current power source. The first half bridge inverter includes a first terminal, a second terminal, and an output terminal. The second half bridge inverter includes a first terminal, a second terminal, and an output terminal. A portion between the output terminal of the first half bridge inverter and the output terminal of the second half bridge inverter is operable to output an alternative current.

Abstract: The present invention aims to provide a power converter with an arm including switching devices connected in parallel, realizing long lifespans of switching devices. An inverter includes an upper and a lower arm, and gate drive circuits each driving the corresponding arm according to a gate control signal Gup_s indicating ON/OFF periods. Each arm includes switching devices connected in parallel. Each gate drive circuit includes: a switching gate control circuit 230u bringing a switching device 210u into conduction at the beginning of the ON period and bringing the same out of conduction within the ON period; and a conduction gate control circuit 231u bringing switching devices 211u and 212u within a period from when the switching device 210u is brought into conduction until the same is brought out of conduction, wherein the switching device 210u has a lower parasitic capacitance than the switching devices 211u and the 212u.

Abstract: A plurality of power supply circuits Z1? are provided according to a load capacity. The power supply circuits Z1? have sides connected in parallel on the side of a direct current input Vi and have sides connected in series on the sides of alternating current outputs Ao. A rectifying circuit DC1 is connected via a resonance circuit Z2 across a combined output of the serially connected sides of the power supply circuits Z1? on the sides of the alternating current outputs Ao. Switching frequencies are simultaneously controlled by a single control signal outputted from a control circuit S1 based on a direct current output voltage detected from the rectifying circuit DC1 through a detection resistor R5.

Abstract: In one embodiment, each of a plurality of sites may produce surplus power. All or a fraction of the surplus power may be supplied to the power grid according to an agreement between the user of a site and an electric utility. A computer of the utility is in communication with a computer at each of a plurality of sites having a local power source. Terms of power provision that include an amount of power to be provided during a specified time of day is communicated between a site and the utility.

Abstract: A high voltage AC/DC or DC/AC power conversion system including a voltage source converter with at least two series-connected converter valve bridges, at least two reactors, where each of the reactors is connected to one of the AC phase terminals of the at least two bridges and at least one transformer connected to an AC supply voltage. In order to block a DC voltage from the at least one transformer, one of at least two capacitors is connected in series with each of the at least two reactors and is connected between the corresponding reactor and the at least one transformer.

Abstract: A power electronics and control architecture for powering an AC load from a multi-source power system through a single conversion stage is disclosed. A controllable DC-to-AC inverter accepts a DC output voltage range from a DC power source at a DC input, and outputs an adjustable AC at an AC output. A sensor measures an output power of the DC power source to obtain a measured output power, and a processor sets a power level at the DC input based on the measured output power. The processor sets the power level to control the output power of the DC power source, and synchronizes the adjustable AC to a common AC output of the multi-source power system.

Abstract: The present invention relates to a control device and a control method of a high voltage inverter capable of automatically and accurately setting up neutral point information at a master controller and a plurality of cell controllers of the high voltage inverter, wherein a master controller determines information of neutral point set up to itself and performs a communication with the cell controllers each disposed at each of a plurality of U phase unit cells, a plurality of V phase unit cells and a plurality of W phase unit cells to determine the neutral point information preset on the cell controllers and to detect a cell controller set up with neutral point information different from that of the master controller, and to correct the neutral point information of the detected relevant cell controller using the neutral point information set up in the master controller, thereby operating the high voltage inverter.

Abstract: A distributed power system wherein a plurality of power converters are connected in parallel and share the power conversion load according to a prescribed function, but each power converter autonomously determines its share of power conversion. Each power converter operates according to its own power conversion formula/function, such that overall the parallel-connected converters share the power conversion load in a predetermined manner.

Abstract: An area electric power system includes a number of direct current power sources, and a number of inverters operatively associated with the number of direct current power sources. Each of the number of inverters is structured to provide real power and controlled reactive power injection to detect islanding. An output is powered by the number of inverters. A number of electrical switching apparatus are structured to electrically connect the number of inverters to and electrically disconnect the number of inverters from a utility grid. A number of devices are structured to detect islanding with respect to the utility grid responsive to a number of changes of alternating current frequency or voltage of the output.