A power supply control device according to one or more embodiments may be provided to: control a power conversion device that has a configuration in which a resonant circuit is provided on an output side of a matrix converter including switching circuits having snubber elements, and that performs AC-AC conversion of output from a multi-phase AC power supply. The power supply control device performs control such that: the output current, which has a phase difference caused by the resonant circuit, is negative during a period in which an absolute value of a positive-going output voltage that is output from the power conversion device increases while the output current is positive during a period in which the absolute value of a negative-going output voltage increases; and a polarity of the output current does not change within a period in which the snubber element is discharged.

A matrix converter includes a plurality of first bidirectional switches electrically connected to each of input phases of an AC power supply and each of output phases of a load, respectively, and a plurality of second bidirectional switches electrically connected to each of the input phases and each of the output phases, respectively. The first bidirectional switch and the second bidirectional switch are electrically connected in parallel to one of the input phases and one of the output phases.

A matrix converter system and control method includes a matrix converter, a generator, a plurality of output capacitors, and a controller. The matrix converter includes a plurality of switches and is connected between a multiphase input and a multiphase output. The plurality of output capacitors are connected between the multiphase output and ground. The generator is connected to the multiphase input and includes internal inductances. The controller is configured to control the plurality of switches to control active current and reactive current from the generator based on the internal inductances of the generator. The active and reactive currents are controlled to charge the plurality of output capacitors. The matrix converter operates in a current control mode and is able to boost output voltage above the input voltage level.

A matrix converter system and control method includes a matrix converter, a generator, a plurality of output capacitors, and a controller. The matrix converter includes a plurality of switches and is connected between a multiphase input and a multiphase output. The plurality of output capacitors are connected between the multiphase output and ground. The generator is connected to the multiphase input and includes internal inductances. The controller is configured to control the plurality of switches to control active current and reactive current from the generator based on the internal inductances of the generator. The active and reactive currents are controlled to charge the plurality of output capacitors. The matrix converter operates in a current control mode and is able to boost output voltage above the input voltage level.

A matrix converter system and control method includes a matrix converter, a generator, a plurality of output capacitors, and a controller. The matrix converter includes a plurality of switches and is connected between a multiphase input and a multiphase output. The plurality of output capacitors are connected between the multiphase output and ground. The generator is connected to the multiphase input and includes internal inductances. The controller is configured to control the plurality of switches to control active current and reactive current from the generator based on the internal inductances of the generator. The active and reactive currents are controlled to charge the plurality of output capacitors. The matrix converter operates in a current control mode and is able to boost output voltage above the input voltage level.

A method for controlling a modular multilevel converter to reduce the lower order harmonics generated by the converter is provided. The method may also reduce the overall switching loss of the converter by switching the switches close to fundamental switching frequencies while still reducing the lower order harmonics that are generated.

There is disclosed a power conversion apparatus 3 for converting polyphase ac power directly to ac power. A conversion circuit includes first switching devices 311, 313, 315 and second switching devices 312, 314, 316 connected, respectively, with the phases R, S, T of the polyphase ac power, and configured to enable electrical switching operation in both directions. There are provided input lines R, S, T connected with input terminals of the switching devices and output lines P, N connected with output terminals of the switching devices. The output terminals of the first switching devices and the output terminals of the second switching devices are, respectively, arranged in a row. The first switching devices and second switching devices are arranged side by side with respect to a direction of the rows. The output lines are disposed below the input lines in an up and down direction.

A variety of AC current sources provide a controlled amount of AC output current even as a particular load may at times approach zero resistance. These AC current sources can be plugged into conventional power outlets, e.g. 60 Hz (USA) and 50 Hz (European). The AC current sources can tolerate a near-short or full-short circuit load for a brief time, without disabling itself or tripping any safety-interrupt. This is achieved by an architecture that achieves the peculiar electrical requirements needed for specific chemical reforming processes, such as vaporization of an ionic fluid. One purpose of the AC current sources is to reform a customized proton-rich ionic fluid.