A vehicle driving device includes a permanent magnet motor, an inverter that drives the permanent magnet motor, a DC-to-DC converter that is a buck-boost converter and connected to the inverter, and a driving battery that is connected to the DC-to-DC converter. The DC-to-DC converter outputs, to the inverter, (i) a voltage inputted to the DC-to-DC converter of a positive electrode of the driving battery as-is and (ii) a voltage inputted to the DC-to-DC converter of a negative electrode of the driving battery after increasing the voltage in a negative direction.

A motor driving device includes an acquisition unit configured to acquire multiple pieces of data in data acquisition periods having different lengths; a selection unit configured to select a piece of data from among the multiple pieces of data, based on timing at which a switching circuit switches switching devices; and a control unit configured to control the switching circuit based on the selected data.

A motor driving device includes an acquisition unit configured to acquire multiple pieces of data in data acquisition periods having different lengths; a selection unit configured to select a piece of data from among the multiple pieces of data, based on timing at which a switching circuit switches switching devices; and a control unit configured to control the switching circuit based on the selected data.

A power supply system includes a first saturable reactor electrically connected to a first AC phase input, to a second AC phase input, and to a third AC phase input. The first saturable reactor is electrically connected to a first DC output. A second saturable reactor is electrically connected in parallel with the first saturable reactor to the first AC phase input, to the second AC phase input, and to the third AC phase input. The second saturable reactor is electrically connected to a second DC output. A reactor controller can be operatively connected to the first saturable reactor and to the second saturable reactor to regulate DC output voltage to the first and second DC outputs.

A power supply system includes a first saturable reactor electrically connected to a first AC phase input, to a second AC phase input, and to a third AC phase input. The first saturable reactor is electrically connected to a first DC output. A second saturable reactor is electrically connected in parallel with the first saturable reactor to the first AC phase input, to the second AC phase input, and to the third AC phase input. The second saturable reactor is electrically connected to a second DC output. A reactor controller can be operatively connected to the first saturable reactor and to the second saturable reactor to regulate DC output voltage to the first and second DC outputs.

A power conversion system for a wind turbine generator, comprising a machine-side converter having an AC voltage input from a generator and a DC voltage output to a DC link, wherein the machine-side converter is a modular multi-level converter comprising one or more converter legs corresponding to a respective one or more electrical phases of the generator, each of the converter legs comprising a plurality of converter cells, the system further comprising: a converter control module which provides the machine-side converter with a gate signal, and an electrical frequency estimation module configured to estimate the mean electrical frequency of the generator; wherein the gate signal has at least one mean switching frequency corresponding to at least one electrical phase of the generator; wherein the converter control module is configured to modulate the mean switching frequency of the gate signal in dependence on the mean electrical frequency of the generator.

A power conversion system for a wind turbine generator, comprising a machine-side converter having an AC voltage input from a generator and a DC voltage output to a DC link, wherein the machine-side converter is a modular multi-level converter comprising one or more converter legs corresponding to a respective one or more electrical phases of the generator, each of the converter legs comprising a plurality of converter cells, the system further comprising: a converter control module which provides the machine-side converter with a gate signal, and an electrical frequency estimation module configured to estimate the mean electrical frequency of the generator; wherein the gate signal has at least one mean switching frequency corresponding to at least one electrical phase of the generator; wherein the converter control module is configured to modulate the mean switching frequency of the gate signal in dependence on the mean electrical frequency of the generator.

A vehicle driving device includes a permanent magnet motor, an inverter that drives the permanent magnet motor, a DC-to-DC converter that is a buck-boost converter and connected to the inverter, and a driving battery that is connected to the DC-to-DC converter. The DC-to-DC converter outputs, to the inverter, (i) a voltage inputted to the DC-to-DC converter of a positive electrode of the driving battery as-is and (ii) a voltage inputted to the DC-to-DC converter of a negative electrode of the driving battery after increasing the voltage in a negative direction.

A vehicle driving device includes a permanent magnet motor, an inverter that drives the permanent magnet motor, a DC-to-DC converter that is a buck-boost converter and connected to the inverter, and a driving battery that is connected to the DC-to-DC converter. The DC-to-DC converter outputs, to the inverter, (i) a voltage inputted to the DC-to-DC converter of a positive electrode of the driving battery as-is and (ii) a voltage inputted to the DC-to-DC converter of a negative electrode of the driving battery after increasing the voltage in a negative direction.

A motor drive system includes: a flywheel; a servomotor for buffer which includes a plurality of independent windings and allows the flywheel to rotate; a plurality of inverters for buffer respectively connected to the windings; a plurality of converters respectively connected to the DC links; inverters for drive which perform power conversion between a DC power in the DC links and an AC power which is a drive power or a regenerative power of the servomotor for drive; and a motor control unit for buffer configured to control driving of the servomotor for buffer by controlling power conversion of the respective inverters for buffer respectively connected to the windings.