There is provided a high frequency AC inverter comprising a DC-DC circuit, an output power circuit and a load circuit and a controller, the load circuit comprising a load circuit detector configured to detect the electrical parameters of the load circuit. The output power circuit comprises a DC to AC driver having a variable frequency output, a HFAC driver circuit comprising a resonant network and a transformer coupled to the HFAC driver circuit and the load circuit. The controller is configured to control the output frequency of the DC to AC driver and the output of the DC to DC circuit in response to the detected electrical parameters of the load circuit.

A power converter system is described. The power converter system includes a power converter comprising at least one converter unit, each converter unit comprising a plurality of semiconductor devices, each semiconductor device including at least a controllable semiconductor switch. A local controller is associated with at least one converter unit and adapted to receive CD and MD from a main controller. In response to a detected fault condition of the power converter system, the local controller is adapted to use at least one of the one or more locally-stored values to determine an operating state of the power converter system, and to use the determined operating state to select a fault operating procedure to control each associated converter unit according to the selected fault operating procedure without using any CD from the main controller.

A power converter system is described. The power converter system includes a power converter comprising at least one converter unit, each converter unit comprising a plurality of semiconductor devices, each semiconductor device including at least a controllable semiconductor switch. A local controller is associated with at least one converter unit and adapted to receive CD and MD from a main controller. In response to a detected fault condition of the power converter system, the local controller is adapted to use at least one of the one or more locally-stored values to determine an operating state of the power converter system, and to use the determined operating state to select a fault operating procedure to control each associated converter unit according to the selected fault operating procedure without using any CD from the main controller.

An energy storage device and a method thereof for supplying power are provided. Control a power conversion circuit to lower an AC output voltage during a preset period to a preset voltage, control the power conversion circuit to change from outputting the preset voltage to outputting a surge voltage, so that the power conversion circuit enters a surge generation period, and determine whether to turn off the energy storage device according to whether an output terminal of the power conversion circuit generating a surge current during the surge generation period.

An energy storage device and a method thereof for supplying power are provided. Control a power conversion circuit to lower an AC output voltage during a preset period to a preset voltage, control the power conversion circuit to change from outputting the preset voltage to outputting a surge voltage, so that the power conversion circuit enters a surge generation period, and determine whether to turn off the energy storage device according to whether an output terminal of the power conversion circuit generating a surge current during the surge generation period.

A load abnormality detecting circuit for an inverter to detect abnormality of a load during an operation of the inverter which has a switching element and a phase synchronizing loop controlling an output frequency to be a resonance frequency of the load, the load abnormality detecting circuit includes a phase shift detection part that detects a phase shift between an output voltage and an output current which are applied from the inverter to the load and sends an abnormal load signal based on the detected phase shift. The switching element including a self-arc-extinguishing element and a reflux diode connected in reversely parallel to the self-arc-extinguishing element. The phase shift detection part detects advance and delay of a phase of the output current with respect to the output voltage.

Provided is a SIMBO buck-boost inverting converter including: a power stage for receiving an input voltage to generate first and positive output voltages and a negative output voltage, the power stage including a plurality of switches and an inductor; a control circuit for generating a plurality of control voltages based on the first and the second positive output voltages, the negative output voltage and a current of the inductor; an energy generation and distribution circuit for generating a plurality of duty cycles based on the control voltages; and a logic control and gate driving circuit for generating a plurality of switch control signals for controlling the switches of the power stage based on the duty cycles; wherein the control circuit and the energy generation and distribution circuit feedback-control and adjust the duty cycles to adjust a balance between an input energy and an output energy.

Provided is a SIMBO buck-boost inverting converter including: a power stage for receiving an input voltage to generate first and positive output voltages and a negative output voltage, the power stage including a plurality of switches and an inductor; a control circuit for generating a plurality of control voltages based on the first and the second positive output voltages, the negative output voltage and a current of the inductor; an energy generation and distribution circuit for generating a plurality of duty cycles based on the control voltages; and a logic control and gate driving circuit for generating a plurality of switch control signals for controlling the switches of the power stage based on the duty cycles; wherein the control circuit and the energy generation and distribution circuit feedback-control and adjust the duty cycles to adjust a balance between an input energy and an output energy.

A converter system includes a rectifier, a DC link stage and an inverter connected in series. A control unit includes a slow reference frame angle determination unit that generates a slow reference frame angle θ.sub.r,slow representing an angle that is slowly following a grid phase deviation, and a fast Phase Locked Loop generating a fast reference frame angle θ.sub.r,fast representing an angle that is fast following a grid phase deviation. The control unit uses the slow reference frame angle θ.sub.r,slow and the fast reference frame angle θ.sub.r,fast to control the rectifier output current, and the fast reference frame angle θ.sub.r,fast to control the inverter output voltage and to synchronize the inverter output voltage with the grid voltage.

An adapter device, including an AC connection including first AC contact and second AC contact; a DC connection including first DC contact and second DC contact; a first bridge branch including first switching device and second switching device, the first switching device and second switching device connected in series at a first bridge point, the first bridge point connected to first AC contact; a second bridge branch including third switching device and fourth switching device, third switching device and fourth switching device connected in series at a second bridge point, the second bridge point connected to second AC contact; and mode-setting device configured to predetermine a direction of power flow between AC connection and/or DC connection, first bridge branch and second bridge branch connected in parallel to the first DC contact and second DC contact, and different types of switching devices used as switching devices of a bridge branch.