A power supply circuit for powering components of a facility are disclosed. The power supply circuit may include a power transformer, a power input terminal, a power output terminal, a bridge, a relay, and a control circuit. The relay is connected between the power input terminal and the power output terminal. A primary side of the power transformer is coupled between the relay and the power output terminal. The bridge is coupled to the secondary side of the power transformer. In a normal power mode, the control circuit closes the relay and operates the bridge as a rectifier. In an emergency power mode, the control circuit opens the relay and operates the bridge as a pulse width modulator. In this manner, the bridge and the power transformer can be used both to charge a battery during normal operation and generate emergency AC power from the battery.

In an MMC-based power conversion device, a control device generates, for each leg circuit, a first voltage command value not based on circulating current circulating between a plurality of leg circuits and a second voltage command value based on the circulating current. A plurality of individual controllers are provided respectively corresponding to a plurality of converter cells and generate a gate control signal for controlling turning on and off of a switching element of the corresponding converter cell, based on the first voltage command value and the second voltage command value. When generating the gate control signal using pulse width modulation, each individual controller modulates a carrier signal in accordance with the second voltage command value such that the pulse width of the gate control signal changes in accordance with the second voltage command value.

In an MMC-based power conversion device, a control device generates, for each leg circuit, a first voltage command value not based on circulating current circulating between a plurality of leg circuits and a second voltage command value based on the circulating current. A plurality of individual controllers are provided respectively corresponding to a plurality of converter cells and generate a gate control signal for controlling turning on and off of a switching element of the corresponding converter cell, based on the first voltage command value and the second voltage command value. When generating the gate control signal using pulse width modulation, each individual controller modulates a carrier signal in accordance with the second voltage command value such that the pulse width of the gate control signal changes in accordance with the second voltage command value.

A power module having electrical connection parts, preferably made of metal, each having a main plate, the main plates extending in one and the same main plane so as to be substantially coplanar. At least one of the electrical connection parts includes at least one electrical connector projecting from its main plate. At least one transistor is electrically connected between two upper faces of respectively two of the main plates, and an electrically insulating overmolding, for example made of resin, covers each transistor and at least one portion of the upper faces of the main plates.

A buck-assisted split-source inverter including a DC link having two voltage rails, at least two pairs of series connected switches, a first connection point and a second connection point for receiving voltage terminals of a fuel cell, one of the two voltage rails forming the first connection point, a switch component and an inductor connected in series having a first end formed of a terminal of the switch component and a second end formed of a terminal of the inductor, the first end forming the second connection point for receiving a voltage terminal of a fuel cell. The inverter further including at least two first diodes, a second diode having first and second terminals, wherein the switch component is adapted to be controlled conductive when any one of the lower switches connected to voltage rail forming the first connection point is controlled conductive.

A control circuit is applied to a system provided with a rotary electric machine, a power converter electrically connected to a winding of the rotary electric machine, a power source, a cutoff switch provided on an electrical path that connects the power source and the power converter, and a storage unit. The control circuit is provided with a failure determination unit that determines whether a failure occurs in the system and a regeneration prevention unit that prevents a power regeneration, where a current flows from a rotary electric machine side towards a storage unit side, from occurring. In the case where the failure determination unit determines that a failure occurs in the system, the cutoff switch is turned OFF after the regeneration prevention unit prevents an occurrence of the power regeneration.

A frequency converter adapted to be connected to another frequency converter via a direct current bus is provided. The frequency converter comprises: a positive bus interface adapted to be interconnected with a positive bus interface of the other frequency converter; an external bleeder resistor interface adapted to be interconnected with an external bleeder resistor interface of the other frequency converter; and a first control logic which controls a parallel connection, between the frequency converter and the other frequency converter and realized by a direct current bus, to be turned on or off. A corresponding frequency converter assembly, a control method, and a computer readable storage medium are also provided.

A four-level rectifier may include an output, a first capacitor, a second capacitor, a third capacitor, and three phases. The first, second, and third capacitors may be connected in series. The output may be connected between the first capacitor and the third capacitor. Each of the three phases may include an input, a first diode, a second diode, a first switch, a second switch, and a third switch. The first diode may be connected between the input and the first capacitor. The second diode may be connected between the input and the third capacitor. The first switch may be connected between the input and the second switch and the third switch. The second switch may be connected to the first capacitor and to the second capacitor. The third switch may be connected to the second capacitor and to the third capacitor.

A four-level rectifier may include an output, a first capacitor, a second capacitor, a third capacitor, and three phases. The first, second, and third capacitors may be connected in series. The output may be connected between the first capacitor and the third capacitor. Each of the three phases may include an input, a first diode, a second diode, a first switch, a second switch, and a third switch. The first diode may be connected between the input and the first capacitor. The second diode may be connected between the input and the third capacitor. The first switch may be connected between the input and the second switch and the third switch. The second switch may be connected to the first capacitor and to the second capacitor. The third switch may be connected to the second capacitor and to the third capacitor.

A microgrid system includes first and second DC power sources electrically connected to respective first and second DC electrical power busses, a first uninterruptable power module electrically connected to the first DC electrical power bus and configured to be connected to an alternating current (AC) load, a second uninterruptable power module electrically connected to the second DC electrical power bus and configured to be connected to the AC load, a first bi-directional AC/DC inverter having a DC end and an AC end, where the first DC electrical power bus is connected to the DC end of the first bi-directional AC/DC inverter, a second bi-directional AC/DC inverter having DC and AC ends, where the second DC electrical power bus is connected to the DC end of the second bi-directional AC/DC inverter, and an AC electrical power bus electrically connected to the first and second bi-directional AC/DC inverters at their AC ends.