Abstract: A power integrated circuit includes, in part, a multitude of controllers, a multitude of pulse-width generators, a multitude of output stages and a configuration matrix. Each controller is adapted to be responsive to a feedback signal and a reference signal to generate a control signal carrying pulse width information. Each control signal causes a difference between an associated output voltage feedback signal and the reference signal to be less than a predefined value. Each pulse-width generator is associated with and responsive to a different one of the controllers to generate a pulse-width modulated signal in response. The configuration matrix selectively couples the plurality of pulse-width generators to the output stages.

Abstract: A grid tie system includes a plurality of solar panels, a plurality of inverters, wherein each of the inverters is in electrical communication with at least one of the solar panels to convert a direct current to an alternating current, wherein each of the inverters has an active state and an inactive state and at least one of the inverters includes a tracking component to track a maximum power point of at least one of the solar panels, and a controller in communication with at least one of the inverters for selectively toggling the at least one of the inverters between the active state and the inactive state.

Abstract: A power converter circuit includes a synchronization circuit that is configured to generate at least one synchronization signal. A series circuit includes a number of converter units configured to output an output current. At least one of the converter units includes a transformer and is configured to generate an output current such that a frequency or a phase of the generated output current is dependent on the synchronization signal.

Abstract: Some embodiments of the invention provide a method for balancing the power output to each phase of a set of micro-inverters. The method of some embodiments is performed by a gateway, which receives output messages from a plurality of micro-inverters. The gateway identifies the phase of each micro-inverter and calculates the output of the plurality of micro-inverters to each power line of a multi-phase system. The gateway then sends control signals to the micro-inverters to control the output of each micro-inverter to maintain a balanced aggregate power output to each phase of the power grid.

Abstract: A circuit, having a plurality of regulated, parallel, voltage sources, an a.c.-d.c. converter circuit and a regulating unit, and a method for controlling it. The regulated voltage sources include an unregulated voltage source of a temporally variable output d.c. voltage, a step-up converter and an associated regulating device, where the step-up converter is a three-point step-up converter. The regulating unit measures the intermediate circuit voltage of the a.c.-d.c. converter circuit and is connected with the regulating devices. In the method for control, the regulating unit determines the voltage in the intermediate circuit of the a.c.-d.c. converter circuit and from this determines, as a function of the maximally and minimally permissible intermediate circuit voltage, a set-point value for the output voltage of the regulated voltage sources. This set-point value is transmitted to the regulating devices, from which the regulating devices determine the control conditions for the step-up converter.

Abstract: A multiple-output DC-DC converter has a first and a second DC-DC sub-converter, each DC-DC subconverter may be a buck, boost, or buck-boost converter having a primary energy-storage inductor. Each DC-DC subconverter drives a separate output of the multiple-output converter and typically has a separate feedback control circuit for controlling output voltage and/or current. The converter has a common timing circuit to maintain a phase offset between the first and DC-DC subconverters. The primary energy storage inductors of the first and second DC-DC converter are magnetically coupled to raise an effective ripple frequency of the converter and simplify output filtering.

Abstract: A photovoltaic (PV) power generation system comprising an array of PV cell modules arranged in strings connected via secondary stage power efficiency optimizers to a central inverter is provided. In at least one of the strings, sunlight receiver assemblies (including the PV cells) of the PV cell modules are provided each with a corresponding primary stage or integrated power efficiency optimizer to adjust the output voltage and current of the PV cell. The PV cell modules can, but need not include optical concentrators.

Abstract: The invention relates to a wind power plant (4) which consists of a nacelle (12) arranged on a tower (14), a rotor (28), a generator (16), a power converter (20) on the generator side, a power converter (22) on the network side and a transformer (26), the two power converters (20, 22) being electrically connected to each other on the DC voltage side, and the power converter (22) on the network side being connected on the AC voltage side to a feeding point (8) of a destination network (6) by means of the transformer (26). Every phase module (74) of the power converter (22) on the network side has an upper and lower valve branch (T1, T3, T5; T2, T4, T6) having at least two bipolar subsystems (76) that are connected in series and the power converter (20) on the generator side and the power converter (22) on the network side are interconnected on the DC side by means of a DC cable (72).

Abstract: A power system and a control method thereof are disclosed. The power system comprises: providing a plurality of power sources; electrically connecting a plurality of converters between the power sources and at least one load, wherein the converters are electrically connected to the power sources respectively in a one-to-one manner; and positive feed-forward controlling each of the converters by using a positive feed-forward control circuit electrically connected to one of the power sources in a one-to-one manner, for the use to protect the input voltage source from over-current drawing by reducing the input current of the converter when the source voltage drops, regardless constant output-voltage.

Abstract: A plurality of generators can be connected in parallel to a common electrical bus. Each generator has a controller that regulates the voltage and frequency of the electricity being produced. Before a given generator connects to the electrical bus, its controller senses whether electricity is present on the bus and if not, the connection is made. Otherwise, the controller synchronizes the electricity being produced to the electricity is present on the bus before the connection occurs. The controller in each generator may also implement a load sharing function which ensures that the plurality of generators equitably share in providing the total amount of power demanded by the loads. The load sharing can be accomplished by controlling the generators to operate a substantially identical percentages of their individual maximum power generation capacity.

Abstract: A power supply system includes a power source and a power extending board detachably connected between the power source and an electronic device. The power source includes at least two outputs. The power extending board includes at least two first transmitting terminals and a second transmitting terminal connected to the two first transmitting terminals. Each of the two outputs transmits a first driving voltage from the power source to the second transmitting terminal via a corresponding first transmitting terminal. The first driving voltages from the power source are identical to each other. The second transmitting terminal transmits a second driving voltage to the electronic device. The second driving voltage is identical to each of the first driving voltages.

Abstract: A power converter circuit includes a synchronization circuit configured to generate at least one synchronization signal. A series circuit includes a number of converter units configured to output an overall output current. At least one of the converter units generates an output current such that at least one of a frequency and a phase of the generated output current is dependent on the synchronization signal.

Abstract: A method and apparatus for generating AC power. In one embodiment, the apparatus comprises a DC/AC inversion stage capable of generating at least one of a single-phase output power, a two-phase output power, or a three-phase output power; and a conversion control module, coupled to the DC/AC inversion stage, for driving the DC/AC inversion stage to selectively generate the single-phase output power, the two-phase output power, or the three-phase output power based on an input power to the DC/AC inversion stage.

Abstract: Described is a method and apparatus for per-panel photovoltaic energy extraction with integrated converters. Also described are switched-capacitor (SC) converters have been evaluated for many applications because of the possibility for on-chip integration; applications to solar arrays are no exception. Also described is a comprehensive system-level look at solar installations, finding possibilities for optimization at and between all levels of operation in an array. Specifically, novel concepts include new arrangements and options for applying switched-capacitor circuits at 3 levels: for the panel and sub-panel level, as part of the overall control strategy, and for ensuring stable and robust interface to the grid with the possibility of eliminating or reducing the use of electrolytic capacitors.

Abstract: A bulk power assembly includes a bulk power distribution (BPD) subassembly and a bulk power controller and hub (BPCH) subassembly coupled to the BPD subassembly. The BPD assembly is configured to provide bulk DC power from both AC input power and DC input power. The BPD subassembly is configured to distribute the DC bulk power. The BPCH subassembly is configured to monitor and control the BPD assembly.

Abstract: A universal power supply system allows each board mounted DC power module or each AC/DC power supply device therein having identical dimensions and appearance to further have a specification setting circuit. When the board mounted DC power module or the AC/DC power supply device is plugged in a backboard module, the specification setting terminal outputs a specification identification signal to a monitoring circuit of the backboard module. As built in with a specification mapping table, the monitoring circuit can compare the specification identification signal to find a model number corresponding to the signal, and automatically sets a critical current value or critical power value of each board mounted DC power module for over-current protection or over-power protection. Accordingly, the universal power supply system can be adapted to different board mounted DC power modules or AC/DC power supply devices without redesigning the backboard module.

Abstract: A power supply adapted for supplying electrical power to a load (108), the power supply comprising: at least one powered full bridge circuit (100), wherein the powered full bridge circuit is adapted for being powered by a direct current voltage supply (106), wherein the full bridge circuit (100) comprises a first output connection (104a), and a first switching means (102a-102d) for controlling the application of electrical power to the output connection, at least one floating full bridge circuit (110), wherein each floating full bridge circuit comprises a capacitor (116) adapted for powering the floating full bridge circuit (110), wherein each floating full bridge circuit comprises a second output connection (114b), a second switching means (112a-112d) for controlling the application of electrical power to the output connection, a stack of bridge circuits (100, 110) comprising the at least one powered full bridge circuit and the at least one floating full bridge circuit, wherein the second output convection (

Abstract: A power generation system including photovoltaic modules for generating DC power and power converters coupled to the photovoltaic modules for converting the DC power to AC power is provided. The power generation system also includes a central controller that executes the steps of determining a real time AC power generation capacity of the power converters, determining a difference between a required AC power generation capacity and the real time AC power generation capacity, identifying a real time AC voltage of each of the power converters, identifying a reserve AC current capacity of each of the power converters based on the real time AC voltage and an AC current rating of each of the power converters and using the reserve AC current capacity to generate reserve power for reducing the difference between the required AC power generation capacity and the real time AC power generation capacity.

Abstract: A distributed power system including multiple (DC) batteries each DC battery with positive and negative poles. Multiple power converters are coupled respectively to the DC batteries. Each power converter includes a first terminal, a second terminal, a third terminal and a fourth terminal. The first terminal is adapted for coupling to the positive pole. The second terminal is adapted for coupling to the negative pole. The power converter includes: (i) a control loop adapted for setting the voltage between or current through the first and second terminals, and (ii) a power conversion portion adapted to selectively either: convert power from said first and second terminals to said third and fourth terminals to discharge the battery connected thereto, or to convert power from the third and fourth terminals to the first and second terminals to charge the battery connected thereto.

Abstract: According to one embodiment, a system configured to provide dynamic power management for a plurality of energy cells comprises an array of energy cells for providing a primary current path to a load, and a respective power stage for each energy cell. The power stages are configured to transfer power to and from each respective energy cell. The system further comprises a temporary energy storage node enabling energy transfer from a first plurality of energy cells comprised by the array of energy cells to a second plurality of energy cells comprised by the array of energy cells. In one embodiment, the system further comprises a feedback system for maintaining the temporary energy storage node at a constant average power.

Abstract: A system may include a power module that includes a group of power supplies, particular ones of the group of power supplies being operable at a group of voltages ranging from a first voltage to a second voltage. The system may further include a controller coupled to the particular ones of the group of power supplies, the controller being to ramp up an output voltage, associated with the group of power supplies, from the first voltage to the second voltage in a group of discrete steps; where ramping up the output voltage by a particular one of the group of discrete steps is performed while a load is receiving power from the group of power supplies; and where ramping up the output voltage by a particular one of the group of discrete steps prevents over-current protection on the group of power supplies from being activated.

Abstract: A method for controlling power flow within a multi-terminal DC power transmission system including two or more converter stations and the corresponding multi-terminal DC power transmission system are provided. The method includes the steps of: controlling the power flow to a steady state reference operating point for operating points within a control dead band defined for each respective converter station, and controlling the power flow by means of droop control in at least one of the converter stations upon detection of exceeding of an end point of one or more of the control dead bands.

Abstract: A power converter is disclosed including a switching converter having a switching node, a first quasi-resonant multiplier stage having a resonant input coupled to the switching node, and a second quasi-resonant multiplier stage having a resonant input coupled to the switching node. In another embodiment, a power converter includes a switching converter having a switching node, a first quasi-resonant multiplier stage having a boost input coupled to the switching node, and a first clamp coupled to the first multiplier stage.

Abstract: In one example, a method of operating a photovoltaic (PV) system substantially at a maximum power point is described. The PV system includes a PV module and an inverter coupled to the PV module. The method includes controlling an output of the inverter as a function of a trans-conductance of the PV module over time.

Abstract: Systems and methods for referencing a photovoltaic array are disclosed. An exemplary method includes converting DC power with an inverter from a photovoltaic array to AC power at a line frequency and placing the entire photovoltaic array above ground potential or below ground potential. The AC power is transformed with a transformer and an integrity-check signal is generated to vary a voltage of the photovoltaic array to perform an integrity check. A star point of the transformer is pinned to ground at the line frequency so the integrity-check signal is applied to the DC-side of the inverter and a limited level of fault current is allowed to flow from ground to the star point of the transformer to facilitate a detection of ground faults.

Abstract: A renewable energy, utility-size electric power system is provided with a high voltage, renewable energy harvesting network connected by a direct current link to a centralized grid synchronized multiphase regulated current source inverter system. The harvesting network includes distributed renewable energy power optimizers and transmitters that control delivery of renewable energy to the grid synchronized multiphase regulated current source inverter system. A visual immersion monitoring and control system can be provided for a three dimensional, visually oriented, virtual reality display, and command and control environment.

Abstract: The invention provides a solar photovoltaic three-phase micro-inverter system comprising a plurality of three-phase micro-inverters. Every three of the three-phase micro-inverters form a group and are coupled to a three-phase AC power grid. Each of the three-phase micro-inverters comprises 3 single-phase inverter circuits, each of the single-phase inverter circuits comprises 2 conversion circuits, and each of the conversion circuits corresponds to one phase of the three-phase AC power grid. AC outputs of the same conversion circuits of the three micro-inverters in one group are coupled to three-phase live wires of the three-phase AC power grid respectively. Accordingly, the invention provides a method for improving conversion efficiency of the solar photovoltaic three-phase micro-inverter system.

Abstract: A device for supplying power to a load, requiring both a pre-determined supply of electrical power and high power for short durations of the operating cycle of the load, where the operating cycle is repeated. The power supply device includes a connection to an electrical grid, an AC voltage transformation circuit, a voltage rectification means and a plurality of DC/DC converters mounted in series to terminals of the load. Each of the DC/DC converters has a storage capacitor mounted in parallel to it and at least one of the DC/DC converters is supplied directly by the voltage rectification means. At least another one of the DC/DC converters is not supplied directly by the voltage rectification means. The power supply device may compensate for losses in the power supply device and load, and may substantially continually and uniformly balance voltages at terminals of the storage capacitors.

Abstract: A multi-source power converter is proposed to permit bidirectional DC to AC conversion from n (n?2 and n?N) DC voltage sources to an AC load with a reduced number of switches, and DC to DC conversion. Both single and three phases AC load are considered. The proposed topology consists in a single stage of conversion, and therefore a high efficiency can be expected for the system. Any type of DC sources can be used in the system (fuel-cell, battery, ultra-capacitor, photo-voltaic cells, DC bus, DC to DC or AC to DC converter, etc.). The AC load can be either single or three phases (single-phase AC grid/microgrid, three-phase electric machines, induction machine, synchronous machine, etc.). There is no requirement for the n DC voltage source values; they can be equal or different and they can be used individually or together by the converter to generate the AC output. If different DC voltage values are used, the converter can be controlled to generate a multi-level AC voltage.

Abstract: A solar module device with the master circuit generates the timing signal to synchronize each of the synchronized half wave rectified DC waveform generated by each of the slave circuits to a grid AC signal or a reference AC signal to allow the DC-AC power conversion of a plurality of solar cell groups provided in a module in an on-grid application and an off-grid application.

Abstract: A system for providing power from a direct current (DC) source to the power grid. The system includes a first inverter with an input and an output. The input is adapted to connect to the DC source. A first switch disposed between the output and the power grid. A second inverter with a DC terminal and an AC terminal, the AC terminal is adapted to connect in parallel with the output of the first inverter. A battery adapted to connect to the DC terminal of the second inverter. A second switch connected between the DC terminal of the second inverter and the input of the first inverter. The second switch also operatively connects the DC source to the battery. The system may further include a charging circuit adapted to be disposed between the input and the DC terminal and a load adapted to connect to the output.

Abstract: A staggered parallel three-level DC/DC converter and an AC/DC converter includes: at least one input power supply, N-phase three-level DC/DC circuits, N resonant inductors, N resonant capacitors, N transformers, N rectifier circuits, a first inductor, and an output circuit; one end of an i th resonant inductor is connected to an i th-phase three-level DC/DC circuit, the other end of the i th resonant inductor is connected to an excitation inductor of an i th transformer; one end of an i th resonant capacitor is connected to the i th-phase three-level DC/DC circuit, and the other end of the i th resonant capacitor is connected to the excitation inductor of the i th transformer; or one end of the first inductor is connected to the input power supply, and the other end of the first inductor is connected to the N-phase three-level DC/DC circuit; where N is an integer and is greater than or equal to 2, and i is an integer and 1?i?N.

Abstract: A solar power plant is disclosed for converting solar energy into electric energy, and having a plurality of solar cell units, each solar cell unit containing a first cell pole and a second cell pole. The cell poles can cooperate for feeding electric energy produced by the solar cell unit as direct current out of the solar cell unit. A direct-current converter can include a plurality of direct-current input poles and two direct-current output poles, each direct-current input pole being connected to at least one cell pole. The direct-current converter can convert input direct currents entered via the direct-current input poles, and having input voltages, into an output direct current having an output voltage, and feed the output direct current via the direct-current output poles out of the direct-current converter.

Abstract: A system includes at least one generator coupled to an island grid, at least one energy storage unit and at least one converter coupled to the at least one energy storage unit and configured to be coupled to the island grid. The system further includes a control circuit configured to cause the at least one converter to transfer power between the at least one energy storage unit and the grid responsive to a change in a load on the island grid to maintain operation of the at least one generator at a predetermined operating point. The at least one generator may include a control system configured to match generator output to the load and the control circuit may be configured to maintain the control system of the at least one generator within a predetermined dynamic response capability limit responsive to the change in the load.

Abstract: Methods and systems for controlling power conversion systems. In one aspect, a power management system includes a first power conversion system coupled to a first energy source and a second power conversion system coupled to a second energy source, and a control system. The control system causes, while the first power conversion system is operating in an active mode and the second power conversion system is operating in a standby mode, the second power conversion system to exit the standby mode, the second power conversion system providing a reactive power flow upon exiting the standby mode. The control system causes the first power conversion system to provide a compensatory reactive power flow to compensate for at least a portion of the reactive power flow from the second power conversion system.

Abstract: Various systems and method for distributing electrical power are provided. In one embodiment, a system includes a first inverter coupled to an electrical bus, a second inverter coupled to the electrical bus, a filter including a first inductor and a second inductor, and a transfer switch circuit coupled between the first inverter and the second inverter and a load. The transfer switch circuit is configured to transfer power from the first inverter through the first inductor to the load and transfer power from the second inverter through the second inductor to the load in a first mode of operation. The transfer switch circuit is further configured to transfer power from the first inverter through the first inductor and through the second inductor to the load in a second mode of operation.

Abstract: A sub-sea power delivery system includes a plurality of modular power converter building blocks on each of the power source side and the sub-sea load side that are stacked and interconnected to meet site expansion requirements and electrical load topologies. The power delivery system comprises a system DC transmission link/bus, wherein the system DC link is configured to carry HVDC or MVDC power from an onshore utility or topside power source to multiple sub-sea load modules. The stacked modular power converter topology on the sub-sea side of the sub-sea power delivery system is symmetrical with the stacked modular power converter topology on the on-shore/top-side of the sub-sea power delivery system.

Abstract: A system includes a boost converter configured to amplify input voltage received from one or more power sources into output voltage. The system also includes a current sensor configured to sense a current of the input voltage for example, by induction. The system further includes a controller configured to adjust an amplification of the boost converter in response to the current sensed by the current sensor. When utilized in each of a plurality of power source modules coupled to a common load, the power source modules adjust the amplifications of their boost converters towards equalization of their output voltages and their currents in response to sensed currents of the input voltages changing through demand of the common load. Associated systems and methods are also disclosed.

Abstract: A power generation system includes at least one generator that generates a medium voltage direct current that has a positive DC voltage output and a negative DC voltage output. The system also provides a medium voltage DC (MVDC) cable system with a positive pole cable and a negative pole cable, wherein the positive pole cable is connected to the positive DC voltage output and the negative pole cable is connected to the negative DC voltage output. A substation is connected to the MVDC cable system and includes at least one DC/DC step-up converter to step-up the medium voltage direct current to a high voltage direct current.

Abstract: The present invention is directed towards a serially connected micro-inverter (SCMI) system comprising a plurality of power sources for producing DC power, a plurality of micro-inverters, where each micro-inverter is coupled to at least one power source of the plurality of power sources, for converting the DC power into AC power, an AC bus for coupling the plurality of micro-inverters in series to form a string and for coupling the AC power an AC line; and a controller, coupled to the string, for measuring an output signal of one or more strings of series coupled micro-inverters, comparing the measured output signal to a desired signal for the string; and adjusting a phase angle of an output from each micro-inverter in the one or more strings until a difference between the measured output signal and the desired signal is less than a predetermined threshold value.

Abstract: A smart card includes an internal voltage generator, a clock generator, and an internal circuit. The internal voltage generator generates a first internal voltage and a second internal voltage based on an input voltage received through an antenna. A level of the second internal voltage is lower than a level of the first internal voltage. The clock generator receives the first internal voltage and the second internal voltage to generate a clock signal. A frequency of the clock signal is changed according to the level of the first internal voltage. The internal circuit operates based on the clock signal and the second internal voltage.

Abstract: A capacitor bank includes a laminated bus bar having a high potential conductive layer and a low potential conductive layer disposed in close proximity at opposing surfaces of an intervening insulation layer. The bank also includes a plurality of bus capacitors electrically connected to the laminated bus bar. The laminated bus bar and the bus capacitors having a combined inductance sufficiently low such that the bus capacitors are electrically connected effectively in parallel with the laminated bus bar.

Abstract: A power generation control device is electrically connected to a photovoltaic panel for controlling an output voltage of the photovoltaic panel. The power generation control device includes a scanning unit, configured to perform a scanning process in which the output voltage of the photovoltaic panel is sequentially changed in a predetermined voltage range. The predetermined voltage range is changed in accordance with the photovoltaic panel.

Abstract: An electronic device for optimizing the output power of a solar cell, the electronic device having: a variable resistor coupled in series between the solar cell and a load, a control unit that is configured to control the variable resistor, a sensor for measuring an output voltage and a sensor for measuring the output current of the solar cell, wherein the control unit is configured to vary the resistance of the series resistor over time such that the first order derivative of the output voltage over time has a constant value, to monitor the second order derivative of the output current over time simultaneously, to detect whether the second order derivative of the output current over time exceeds a predetermined threshold value and to identify the corresponding values of the output voltage and current as a maximum power point (MPP) of the solar cell.

Abstract: Method and apparatus for generating power. In one embodiment the method comprises determining a value of a DC parameter pertaining to a DC power source providing DC power to an inverter; comparing the value to a threshold; and operating the inverter to generate positive power or negative power based on a result of comparing the value to the threshold.

Abstract: A solar array power generation system includes a solar array electrically connected to a control system. The solar array has a plurality of solar modules, each module having at least one DC/DC converter for converting the raw panel output to an optimized high voltage, low current output. In a further embodiment, each DC/DC converter requires a signal to enable power output of the solar modules.

Abstract: A photovoltaic system includes a photovoltaic array and a DC/AC inverter. The photovoltaic array includes an output, a plurality of photovoltaic strings each including a plurality of photovoltaic modules electrically connected in series to form an output having a first direct current voltage, and a plurality of DC/DC converters each including a first maximum power point tracking mechanism for a corresponding one of the photovoltaic strings, an input of the output of the corresponding one of the photovoltaic strings, and an output having a second direct current voltage. Each output of the DC/DC converters is electrically connected in parallel or series to form the output of the photovoltaic array having a direct current voltage. The DC/AC inverter includes a second maximum power point tracking mechanism for the photovoltaic array, an input of the output of the photovoltaic array, and an output having an alternating current voltage.

Abstract: Power inverters are controlled in response to reactive power support commands received from a power grid such that at least one power inverter provides reactive power to the power grid. The reactive power provided is based on each power inverter's reactive power capacity only while the total power capacity of each power inverter providing the reactive power is not exhausted in generating real power.

Abstract: A power distribution system. The power distribution system may comprise a plurality of renewable energy sources and plurality of converters to increase fault tolerance in the event of a component failure and to minimize output power degradation. Each converter may be comprised of a plurality of input ports, wherein each input port receives controlled amount of energy from the plurality of renewable energy sources. Each input port may also be disconnected in the event of component or device failure. Each of the converters is preferably configured to have additional power capacity to offset any reduced output capacity by a faulty converter, and preferably, the performance of each converter is monitored by the system to maintain its performance. The power distribution system may be monitored by a third party to maintain the energy output levels and to facilitate the power distribution system's restoration to normal functioning.

Abstract: A method of converting a direct voltage generated by a decentralized power supply system into three-phase alternating voltage by means of a plurality of single-phase inverters (WR1-WR3), said alternating voltage being provided for supplying an electric mains, is intended to avoid inadmissible load unbalances using single-phase inverters. This is achieved in that, upon failure of one inverter (WR1-WR3), an asymmetrical power supply distribution is reduced by limiting the output of the other inverters. The method makes it possible to simplify three-phase voltage monitoring.