Abstract: A voltage converter, including an input adapted to couple to a voltage source and a transformer including a primary coil and a secondary coil. Primary side circuitry, including a first switching circuit, is coupled to the primary coil. A second switching circuit is coupled between a first terminal and a second terminal of the secondary coil, and configured to selectively close to short circuit the first terminal to the second terminal.

Abstract: A medium-voltage grid-connected photovoltaic inverter system includes: a photovoltaic inverter, a medium-voltage transformer, a medium-voltage switch, and an inverter grid-connected controller. A direct current input terminal of the photovoltaic inverter is connected to a direct current bus. A low-voltage side of the medium-voltage transformer is connected to an alternating current output terminal of the photovoltaic inverter. An input terminal of the medium-voltage switch is connected to a high-voltage side of the medium-voltage transformer, and an output terminal of the medium-voltage switch is configured to be connected to a medium-voltage grid. A current sensor is integrated in the medium-voltage switch to detect a grid-connected current of the photovoltaic inverter system and output a current detection signal.

Abstract: A power supply system, a converter, and a circulating current suppression method of the converter. The power supply system includes at least two converters that are coupled between a direct current power supply and an alternating current grid. Each converter obtains target output reactive power when an output current of the converter starts to increase from an initial current, obtains a reactive power compensation parameter based on the three-phase output voltages. Further, each converter obtains compensated output reactive power of the converter based on the reactive power compensation parameter and adjusts actual output reactive power of the converter based on the target output reactive power and the compensated output reactive power, so that an absolute value of a difference between common-mode output voltages of any two of the at least two adjusted converters is less than a difference threshold.

Abstract: In order to protect an inverter from prohibited switching states, a monitor including monitoring inputs and monitoring outputs is provided. The monitoring inputs are connected to the control outputs in order to receive the switching patterns, and the monitoring outputs are connected to the power switches. The monitor is designed to compare a transition from a first switching pattern to a second switching pattern with a number of prohibited transitions and/or with a number of permitted transitions and block the second switching pattern in the event of a match with one of the prohibited transitions and/or in the event of a deviation from the number of permitted transitions and to output the second switching pattern to the power switches via the monitoring outputs in the event of a deviation from the number of prohibited transitions and/or in the event of a match with one of the permitted transitions.

Abstract: A medium-voltage grid-connected photovoltaic inverter system includes: a photovoltaic inverter, a medium-voltage transformer, a medium-voltage switch, and an inverter grid-connected controller. A direct current input terminal of the photovoltaic inverter is connected to a direct current bus. A low-voltage side of the medium-voltage transformer is connected to an alternating current output terminal of the photovoltaic inverter. An input terminal of the medium-voltage switch is connected to a high-voltage side of the medium-voltage transformer, and an output terminal of the medium-voltage switch is connected to a medium-voltage grid. A voltage sensor is integrated in the medium-voltage switch to detect a line voltage at the high-voltage side of the medium-voltage transformer and a line voltage at a side of the medium-voltage grid and generate a grid-connected voltage detection signal.

Abstract: Provided is a power source system including: a storage battery; a control unit operating by being supplied with power from the storage battery and monitoring the storage battery; a first switch configured as a latch type switch disposed on a first electrical path between the storage battery and the control unit; and a second switch configured as a latch type switch disposed on a second electrical path between the storage battery and an electrical equipment as an object to which the storage battery supplies power. The first switch and the second switch are connected in parallel to the control unit; current is supplied to the control unit from the storage battery; and the control unit includes a switch control unit configured to stop a current supply to the control unit from the storage battery.

Abstract: A control device includes: a prediction unit configured to predict the harmonic current at each of prediction points comprised in a predetermined prediction target period after current time, based on control information of the motor in at least a next carrier cycle of the inverter, and a command value determination unit configured to output, to the active filter unit, a current command value for generating a compensation current having a polarity opposite to a polarity of a harmonic current at a prediction point, at a timing corresponding to the prediction point comprised in the next carrier cycle in the prediction target period, based on a prediction result of the prediction unit. Each of the prediction points is provided at a predetermined time interval since start time of the prediction target period. The time interval is longer as the next carrier cycle is longer.

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 electric power conversion system comprising: an alternating current (AC) source comprising a plurality of AC terminals for conducting AC power; a voltage source electrically coupled to the AC terminals; and a controller operably coupled to the voltage source, the controller being configured to: operate the voltage source to apply a fault reducing voltage at the AC terminals that reduces an AC line-to-line fault current (If).

Abstract: Provided is a method for controlling an electrical installation, in particular a wind power installation or a wind farm. The method includes determining a specific location within an electrical supply network to which the electrical installation is electrically connected via the electrical supply network, determining an electrical variable which maps an electrical distance between the electrical installation and the specific location and ascertaining a potential reactive power of the electrical installation for the specific location depending on the electrical variable which maps an electrical distance between the electrical installation and the specific location.

Abstract: A power converter for a power system performs power control of a power system by using a first control value derived based on a first stabilization command value for causing a voltage on a first DC bus to be within a first range and a first control command value different from the first stabilization command value. A power converter for a solar cell performs power control of a solar cell by using a second control value derived based on a second stabilization command value for causing a voltage on a second DC bus to be within a second range and a second control command value different from the second stabilization command value. The first range is narrower than the second range.

Abstract: A voltage converter for direct current includes a power converter circuit having a transformer, a switch converter bridge on a primary-side of the transformer, and a full-bridge rectifier on a secondary side of the transformer. The full-bridge rectifier has first and second rectifier branches. A capacitor is asymmetrically connected to the second rectifier branch.

Abstract: A power conversion device includes a host device to control each submodule, and a plurality of repeating devices to relay communication between the host device and each submodule. The host device includes a command information generator to generate command information including an arm command, and a communication controller provided for each arm. Each of a plurality of communication controllers extracts, from the command information, an arm command associated with the communication controller, and transmits a communication frame including the extracted arm command to a repeating device that is connected to each submodule included in the arm associated with the communication controller.

Abstract: A power system for connecting a power source, an energy storage unit and a grid includes a power inverter, an energy storage power converter and a controller. The power inverter is electrically coupled to the power source through a DC bus and converts DC power from the DC bus to AC power output to the grid. The power converter is electrically coupled between the DC bus and the energy storage unit and stores power in the energy storage unit and discharges power from the energy storage unit. The controller controls the power converter to store excess power from the power source that cannot be output to the grid in the energy storage unit, and control the energy storage power converter to discharge power stored in the energy storage unit to the power inverter to output to the grid.

Abstract: A load management system for managing loads in a power distribution grid. The load management system includes a control unit and at least two current transformers, which are each connected to the control unit by a signal cable. A first current transformer of the at least two current transformers is arranged in the power distribution grid such that the first current transformer is suitable for measuring a current level that is dominant in a grid connecting line of the power distribution grid, which grid connecting line is connected to a power supply company. A second current transformer of the at least two current transformers is arranged in the power distribution grid such that the second current transformer is suitable for measuring the current level that is dominant in a power line of the power distribution grid, which power line feeds at least one charging station of the power distribution grid.

Abstract: This application provides a photovoltaic system and a maximum power point tracking control method for a photovoltaic system. The photovoltaic system includes an MPPT controller and a power converter, and the MPPT controller is connected to the power converter. The MPPT controller is configured to: be connected to a photovoltaic array, and track a global maximum power point MPP of the photovoltaic array. The MPPT controller may be further configured to obtain, when there is a periodic shade for the photovoltaic array, a multi-peak search start moment of global MPPT of the photovoltaic array based on a status of tracking the global MPP of the photovoltaic array in a target time period, so that when the multi-peak search start moment in each MPPT period arrives, the global MPPT of the photovoltaic array is started, to output a working point of the global MPP of the photovoltaic array to the power converter.

Abstract: Systems, apparatuses, and methods for overcoming the disadvantages of current air transportation systems that might be used for regional travel by providing a more cost effective and convenient regional air transport system. In some embodiments, the inventive air transport system, operational methods, and associated aircraft include a highly efficient plug-in series hybrid-electric powertrain (specifically optimized for aircraft operating in regional ranges), a forward compatible, range-optimized aircraft design, enabling an earlier impact of electric-based air travel services as the overall transportation system and associated technologies are developed, and platforms for the semi-automated optimization and control of the powertrain, and for the semi-automated optimization of determining the flight path for a regional distance hybrid-electric aircraft flight.

Abstract: An apparatus including direct-current (DC)-alternating-current (AC) inverter circuitry, first and second circuits, and output circuitry. The DC-AC inverter circuitry inverts a DC input signal corresponding to an input voltage to an AC signal. The first circuit and second circuits respectively include inductive isolation circuits driven in response to power from the at least one AC signal, and rectifier circuits that responds to the inductive isolation circuits by outputting first and second rectified signals, where at least one of the first and second rectifier circuits characterized as being limited by a voltage breakdown rating. The output circuitry provides a DC output voltage signal and to cascade a plurality of signals, including the first and second rectified signals, to provide a voltage source that is dependent on the first and second rectified signals and greater than voltage breakdown rating.

Abstract: An integrated renewable energy source (RES) and energy storage system (ESS) facility configured to supply power to an AC electrical grid includes energy storage system capacity and inverter capacity that are larger than a point of grid interconnect (POGI) limit for the facility, enabling high capacity factors and production profiles that match a desired load. At least one first DC-AC power inverter is associated with RES, and at least one second AC-DC power inverter is associated with the ESS. AC-DC conversion is used when charging the ESS with RES AC electric power, and DC-AC conversion utility is used when discharging ESS AC electric power to the electric grid. Aggregate DC-AC inverter utility exceeds the facility POGI limit, and excess RES AC electric power may be diverted to the second inverter(s).

Abstract: Various enhancements to grid-interactive inverters in accordance with embodiments of the invention are disclosed. One embodiment includes input terminals configured to receive a direct current, output terminals configured to provide an alternating output current to the utility grid, a controller, an output current sensor, and a DC-AC inverter stage comprising a plurality of switches controlled by control signals generated by the controller. In addition, the controller is configured to: generate control signals that cause the switches in the DC-AC inverter stage to switch a direct current in a bidirectional manner; measure the alternating output current; perform frequency decomposition of the output current; and generate control signals that cause the switches in the DC-AC inverter stage to switch current in a way that the magnitude of a plurality of unwanted current components is subtracted from the resulting output current.

Abstract: Methods, circuits, and devices for power conversion are disclosed. In some embodiments, the device comprises a circuit comprising a first, second, and third leg. Each leg may comprise two switches. The first leg is switched at a first frequency to generate a first signal, and the second leg is switched at a second frequency lower than the first frequency to generate a second signal. The third leg is switched by a neutral leg control signal to generate a third signal. The circuit generates an output power signal (e.g., a split-phase power signal) based on the first signal, second signal, and the third signal.

Abstract: A standby generator includes a standby housing defining a cavity and an internal combustion engine. The engine includes an engine block including a cylinder comprising a piston, an engine housing at least partially covering the engine block, and a crankshaft configured to rotate about a vertical crankshaft axis in response to movement by the piston. The standby generator also includes an alternator configured to generate alternating current electrical power, a controller comprising a rectifier configured to convert the alternating current to a direct current and an inverter configured to convert the direct current to a clean alternating current electrical power, and a transfer switch configured to receive the clean alternating current electrical power from the controller and at least one of grid, solar, or battery power, and configured to supply power to an electrical load. The internal combustion engine, the alternator, and the controller are positioned within the cavity.

Abstract: A method for maintaining reliability of a distributed power system including a power converter having input terminals and output terminals. Input power is received at the input terminals. The input power is converted to an output power at the output terminals. A temperature is measured in or in the environment of the power converter. The power conversion of the input power to the output power may be controlled to maximize the input power by setting at the input terminals the input voltage or the input current according to predetermined criteria. One of the predetermined criteria is configured to reduce the input power based on the temperature signal responsive to the temperature. The adjustment of input power reduces the input voltage and/or input current thereby lowering the temperature of the power converter.

Abstract: A high voltage power system is disclosed. In some embodiments, the high voltage power system includes a high voltage pulsing power supply; a transformer electrically coupled with the high voltage pulsing power supply; an output electrically coupled with the transformer and configured to output high voltage pulses with an amplitude greater than 1 kV and a frequency greater than 1 kHz; and a bias compensation circuit arranged in parallel with the output. In some embodiments, the bias compensation circuit can include a blocking diode; and a DC power supply arranged in series with the blocking diode.

Abstract: A distributed energy management system includes a photovoltaic (PV) source, and a plurality of controllable loads in communication with the PV source. The plurality of controllable loads include a first controllable load including a first interactive plug associated with a first connected state timer and a first disconnected state timer, and a second controllable load including a second interactive plug associated with a second connected state timer and a second disconnected state timer. The PV source is configured to determine a maximum PV power, determine a difference between the maximum PV power and a current PV power, responsive to determining that the difference is less than or equal to a threshold power, set the reference AC voltage as a first voltage, and responsive to determining that the difference is greater than the threshold power, set the reference AC voltage as a second voltage greater than the first voltage.

Abstract: A method for controlling a fault of a three phase four wire interlinking converter system according to one embodiment of the present disclosure comprises obtaining a first d-q-o coordinate plane based on an internal phase angle of output voltage produced from each phase of an inverter; converting the first d-q-o coordinate plane to a second d-q-o coordinate plane based on the o-axis configured differently from the first d-q-o coordinate plane; obtaining an output voltage vector for determining a fault location by performing d-q transform on the second d-q-o coordinate plane; determining occurrence of a fault and an area related to the fault based on the output voltage vector; and in the occurrence of the fault, allocating a zero voltage vector to the area related to the fault.

Abstract: The present invention relates to a system and a method for controlling a relay using a flip-flop, in which a flip-flop controlling a relay by receiving a signal of a control unit in a battery management system of a vehicle and supply flip-flop operation power to the flip-flop through a monitoring circuit connected to a battery of the vehicle when operation power of the battery management system of the vehicle is interrupted to maintain a closing state of a relay controlling driving power of the vehicle and to conserve power of the vehicle for a predetermined time.

Abstract: Systems and methods for supplying power at a medium voltage from an uninterruptible power supply (UPS) to a load without using a transformer are disclosed. The UPS includes an energy storage device, a single stage DC-DC converter or a two-stage DC-DC converter, and a multi-level inverter, each of which are electrically coupled to a common negative bus. The DC-DC converter may include two stages in a unidirectional or bidirectional configuration. One stage of the DC-DC converter uses a flying capacitor topology. The voltages across the capacitors of the flying capacitor topology are balanced and switching losses are minimized by fixed duty cycle operation. The DC-DC converter generates a high DC voltage from a low or high voltage energy storage device such as batteries and/or ultra-capacitors. The multi-level, neutral point, diode-clamped inverter converts the high DC voltage into a medium AC voltage using a space vector pulse width modulation (SVPWM) technique.

Abstract: Provided in the present invention are a microgrid control system and a microgrid, the microgrid control system comprising: a grid-connected switch, an energy router, a first controller and a second controller; the first controller controls the grid-connected switch and sends a first control instruction; the second controller receives the first control instruction and responds to the first control instruction for controlling the energy router.

Abstract: Distributed grid network intelligence enables intelligent local energy storage backup control. A consumer node includes a local energy storage system. A distributed control node for the consumer node monitors local power demand and local energy generation. The control node calculates an interface operation for accessing energy from the local energy storage or charging the local energy storage, based on the local power demand and the local energy generation. The control node triggers a local power converter to execute the interface operation with the local energy storage.

Abstract: A motor drive comprises a rectifier circuit portion arranged to receive an externally supplied AC voltage and to generate a DC bus voltage. An inverter circuit portion is arranged to receive the DC bus voltage (VDC_Bus) and to generate an AC output voltage (Vout) for supply to an external load. A DC bus portion is connected between the rectifier and the inverter. An inductor (L1) is connected in series along a bus conductor between the rectifier and inverter, and a DC link capacitor (C1) is connected in parallel between the bus conductors. A voltage across the DC link capacitor (C1) is input to a tuneable notch filter arranged to supply a filtered signal. A controller varies the resonant frequency of the notch filter to a plurality of values across an operational range and modulates a supply current provided by the inverter with a probe current signal at the resonant frequency.

Abstract: A method for controlling a fault of a three phase four wire interlinking converter system according to one embodiment of the present disclosure comprises obtaining a first d-q-o coordinate plane based on an internal phase angle of output voltage produced from each phase of an inverter; converting the first d-q-o coordinate plane to a second d-q-o coordinate plane based on the o-axis configured differently from the first d-q-o coordinate plane; obtaining an output voltage vector for determining a fault location by performing d-q transform on the second d-q-o coordinate plane; determining occurrence of a fault and an area related to the fault based on the output voltage vector; and in the occurrence of the fault, allocating a zero voltage vector to the area related to the fault.

Abstract: A method for optimizing the energy supply from a variable electrical energy source in an electrical facility, operating in a self-consumption mode, connected to an electrical energy distribution network. A control device is configured to control an electrical energy inverter in an electrical facility and to an electrical facility including a control device for controlling an electrical energy inverter.

Abstract: An online monitoring system for measuring the on-state voltage drop of power semiconductor devices comprises a voltage withstanding circuit and a voltage clamping circuit, one terminal of the voltage withstanding circuit is connected to one terminal of the voltage clamping circuit, and the other terminals of the voltage withstanding circuit and the voltage clamping circuit are randomly connected to two terminals of the power semiconductor device under test (DUT) respectively. The two terminals of the voltage clamping circuit are output terminals of the online monitoring system. A clamping voltage of the voltage clamping circuit is higher than the on-state voltage drop of the DUT. When the DUT is off, the output voltage of the system is fixed to the clamping voltage, and when it is on, the output voltage is not clamped. The system has simplified structure and enables convenient, accurate and low-cost measurement of on-state voltage drop.

Abstract: A multi-path converter and a control method thereof are disclosed. The multi-path converter includes a current transfer path using a capacitor and a current transfer path using an inductor such that a current is output to an output end (load) through a plurality of parallel paths, thereby reducing a total RMS current flowing through the inductor, and a control method therefor.

Abstract: A power conversion device of an embodiment includes a power conversion unit, a first capacitor, a gate circuit, a bypass circuit, and a discharging circuit. The power conversion unit includes a plurality of switching elements each having a gate and generates alternating current (AC) power from direct current (DC) power supplied to a provided DC input terminal. The first capacitor is provided on a DC input side of the power conversion unit. The gate circuit includes a drive circuit configured to output a gate drive signal to be supplied to gates of one or more switching elements among the plurality of switching elements and a second capacitor configured to smooth a power supply voltage of power to be supplied to the drive circuit. The bypass circuit causes the second capacitor to be charged with a part of power stored in the first capacitor at the time of power supply loss of a control system circuit and enables the gate drive signal to be maintained in a negative bias by power stored in the second capacitor.

Abstract: A monitoring device for monitoring leakage currents at active conductors has a differential current measurement device, a signal generation device and a control device, which differential current measurement device is designed to record a first signal (I_DIFF) characterizing the differential current of the active conductors and to feed the first signal to the control device. The signal generation device is designed to generate at least one second signal (V_GRID) and to feed the second signal to the control device, which at least one second signal (V_GRID) includes information about the phase angle of a signal occurring at one of the active conductors. The control device is designed to generate a third signal (I_LC_RES) on the basis of the first signal (I_DIFF) and of the at least one second signal (V_GRID), which third signal characterizes the resistive leakage current.

Abstract: A method for controlling a variable speed drive comprising Ni low-voltage power cells connected in series for each phase among multiple phases, i being a phase index. The method comprises repeating P iterations comprising: activating at least one cell of one or more phases and deactivating the other power cells of the variable speed drive, wherein the at least one activated cell is selected on the basis of predefined activation controls depending on an iteration index; and receiving at least one output voltage of the variable speed drive across the terminals of the electrical device for at least one phase. The method further comprises, at the end of the P iterations, determining, from the measured output voltages, values of rectified voltage at the output of respective rectification stages of the power cells, and storing the rectified voltages obtained, which are respectively associated with the power cells.

Abstract: A multiphase interleaved forward power converter includes an inductor and first and second subconverter comprising respective transformers. The converter also includes first and second drives configured to respectively operate the first and second subconverters with cycling periods comprising a conduction period, a reset period, and an idle period. The first and second drives are also configured to phase shift the cycling periods in each subconverter such that the conduction period of the subconverter is at least partially complementary to the idle period of the other subconverter. The second drive also clamps a voltage across a winding of the transformer of the first subconverter to substantially prevent a first resonance voltage from propagating in the first subconverter during the idle period of the first subconverter.

Abstract: A converter assembly including a source connection system comprising a primary source connection, and at least one secondary source connection; a load connection system; a primary source converter including a primary rectifier connected electrically to the primary source connection, and having a boost topology, and a DC link connected electrically between the primary rectifier and the load connection system, the DC link including DC link capacitance; a secondary source converter, which is a direct-current converter having a boost topology, connected electrically between the at least one secondary source connection and the DC link; and a pre-charge converter adapted for pre-charging the DC link capacitance. The pre-charge converter includes a pre-charge direct-current converter having a step down topology.

Abstract: A method of operating a power generator having a first electrical output electrically connected to a utility grid and a second electrical output electrically connected to a load includes detecting if the first electrical output of the power generator is electrically disconnected from the utility grid, and electrically connecting at least a neutral line of the first electrical output to ground in response to detecting that the first output is electrically disconnected from the utility grid.

Abstract: Disclosed herewith is a voltage coordinated control method for an AC/DC distribution system, including steps of: acquiring an actual voltage and an actual current at a DC-side of a converter of the system to obtain a first DC voltage and a first DC current; generating a present reference current signal for the converter according to a voltage-current droop control model, and generating a first control signal to control an output state of the converter; and acquiring an actual voltage at a DC-side of an energy storage adapter in the system to obtain a second DC voltage, generating a present reference power signal for the adapter according to a voltage-power droop control model, and generating a second control signal to control an output state of the adapter.

Abstract: The present invention relates to a functional device (10) powered by a constant current driver (12). The device (10) comprises constant current driver (12), electrical energy storage unit (14), functional unit (16), and control unit (18). The device (10) is controlled by the control unit (18) such that the constant current driver (12) provides a constant current to the functional unit (16) and the storage unit (14) in dependence of a pulse width modulated voltage signal. Current is provided to the storage unit (14) for charging the storage unit (14) during at least part of off periods of the pulse width modulated voltage signal. During on periods of the pulse width modulated voltage signal, current is provided to the functional unit (16) and no current is provided to the storage unit (14). This allows providing the device with a constant current driver with less idle periods and lower current supply.

Abstract: The invention relates to a power system with an electric circuit connected between a power grid and a power source. The electric circuit includes a main power converter having main input terminals connected to the power source 16 by a DC link and output terminals. The main power converter is controlled by a controller. The electric circuit includes a main transformer having a primary winding 8a and a secondary winding, the primary winding being connected to the output terminals of the main power converter. Main switchgear is connected between the secondary winding of the main transformer and the power grid. An auxiliary transformer has a primary winding connected to the power grid in parallel with the main switchgear and a secondary winding connected to the controller. A pre-charge circuit is connected between the auxiliary transformer and the DC link.

Abstract: A power supply current control device including: a current limit value calculation unit configured to calculate a current limit value on a basis of a difference between a power supply voltage and a predetermined set voltage, a power supply current, and a resistance model representing a resistance component of the power supply circuit; a power supply current limit unit configured to limit a magnitude of the power supply current on a basis of the current limit value; a change rate limit value calculation unit configured to calculate a change rate limit value on a basis of the difference and a change speed of the power supply voltage; and a power supply current change rate limit unit configured to limit a change rate of the power supply current on a basis of the change rate limit value.

Abstract: A power converter circuit includes a monitoring module that monitors a DC power source, the monitoring module comprising a microcontroller. The power converter circuit also includes a temperature sensor providing temperature data to the microcontroller. In response to an indication from the temperature data of a failure or a problem, the microcontroller changes a parameter of the power converter circuit.

Abstract: A phase-shifted full bridge (PSFB) switching converter includes a transistor full-bridge having first and second half-bridges. Each half-bridge includes a high-side transistor and a low-side transistor. A controller circuit is configured to generate a drive signal for each transistor. The (first/third and second/fourth) drive signals for the transistors of each half-bridge are periodic with a cycle period, pulse-width modulated and have a temporal offset to each other that equals half of the cycle period. The drive signals for the half-bridges are phase shifted-with respect to one another. The controller circuit also is configured to generate the first drive signal so that the first high-side transistor is switched off when the third drive signal indicates to switch on the second high-side transistor, and to generate the second drive signal so that the first low-side transistor is switched off when the fourth drive signal indicates to switch on the second low-side transistor.

Abstract: An electrical power generating system for providing auxiliary or backup power to a load bus. The system may be used indoors, and generally includes a fuel cell unit comprising a first DC output, an electrical storage unit comprising a DC input coupled to the first DC output of the fuel cell, the electrical storage unit further comprising a second DC output. An inverter coupled to the second DC output receives power, the inverter comprising a first AC output. The system includes a contactor connected between the first AC output and an AC load bus. The AC load bus comprises an AC voltage, and a controller comprising inputs is adapted to sense a phase, a frequency, and a magnitude of the first AC output and the AC voltage and close the contactor when they substantially match.

Abstract: The application discloses an arrangement of switches for a voltage source converter cell, the voltage source converter cell having two AC terminals, wherein the arrangement of switches forms a number of parallel series circuits (branches, current paths), wherein the switches in each of the series circuits paths are being controlled by external signals to alter a conductivity status of the switches between an “ON”-state and an “OFF”-state. The external signals are generated by one or more control units, and the two AC terminals are each connected to subsets of the series circuits of the switches. The control units comprises failure detection means, the failure detection means being adapted to determine a defective switch in the series circuits by predetermined conditions.

Abstract: A power conversion device includes a power converter connected to an electrical storage device that stores DC power, and having a function to convert the DC power stored in the electrical storage device into AC power, and also having a function to output the AC power to one or both of a customer load and a power system; a detection unit that detects voltage and current at a first point on a power line that connects the power converter with the power system; and a control unit that generates a drive command for controlling the power converter based on the voltage and the current detected by the detection unit. The customer load is connected to a second point, on the power line, between the power converter and the first point. The power converter operates on the basis of the drive command generated by the control unit.