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US 2026/0269737 A1Published application
Power converter, controller, and control method
AssigneeFuji Electric Co., Ltd.
InventorOsamu HIKONE
Life of this patent
Estimating the term…
Abstract
A power converter selectively uses a cell balance mode and a cell imbalance mode, the cell balance mode is a mode in which each of a plurality of single-phase AC output units superimposes only outputs of a number of power conversion cells corresponding to a minimum number of the numbers of available power conversion cells to output single phase AC, and the cell imbalance mode is a mode in which each of the plurality of single-phase AC output units superimposes outputs of all available power conversion cells to output the single-phase AC such that phase differences between line-to-line voltages of adjacent phases among phases are all equivalent.
Claims7
A power converter comprising:
- a controller;
- and
- a plurality of single-phase AC output units for respective phases, each of the plurality of single-phase AC output units being configured to output single-phase AC and including a predetermined number of power conversion cells,
- wherein the predetermined number is two or more,
- wherein each of the power conversion cells is configured to:
- convert power supplied from an external power supply into single-phase AC of a predetermined voltage and frequency, and
- output the single-phase AC,
- wherein output units of the predetermined number of the power conversion cells are connected in series to enable outputs of the predetermined number of the power conversion cells to be superimposed to output the single-phase AC,
- wherein each power conversion cell of the predetermined number of the power conversion cells includes a short circuit configured to short-circuit an output unit of the power conversion cell,
- wherein a short circuit unit corresponding to a portion of the predetermined number of the power conversion cells is configured to be short-circuited such that outputs of remaining power conversion cells are superimposed to output the single-phase AC,
- wherein, for each of the plurality of single-phase AC output units, the controller is configured to drive each of all or a portion of the predetermined number of the power conversion cells based on a comparison between a voltage command value and triangular waves having a same frequency and a same phase with shifted voltage levels, and to superimpose outputs of all or the portion of the predetermined number of the power conversion cells to change stepwise, and
- wherein, when numbers of available power conversion cells for the plurality of single-phase AC output units are not all a same number, the controller is configured to selectively use:
- a first control state in which each of the plurality of single-phase AC output units superimposes only outputs of a number of the power conversion cells corresponding to a minimum number of the numbers of available power conversion cells to output the single-phase AC, and
- a second control state in which each of the plurality of single-phase AC output units superimposes outputs of all available power conversion cells to output the single-phase AC such that phase differences between line-to-line voltages of adjacent phases among the phases are all equivalent.
11 more elements
A controller configured to control a power converter including:
- a plurality of single-phase AC output units for respective phases, each of the plurality of single-phase AC output units being configured to output single-phase AC and including a predetermined number of power conversion cells,
- wherein the predetermined number is two or more,
- wherein each of the power conversion cells is configured to:
- convert power supplied from an external power supply into single-phase AC of a predetermined voltage and frequency, and
- output the single-phase AC,
- wherein output units of the predetermined number of the power conversion cells are connected in series to enable outputs of the predetermined number of the power conversion cells to be superimposed to output the single-phase AC,
- wherein each power conversion cell of the predetermined number of the power conversion cells includes a short circuit configured to short-circuit an output unit of the power conversion cell, and
- wherein, for each of the plurality of single-phase AC output units, the controller is configured to drive each of all or a portion of the predetermined number of the power conversion cells based on a comparison between a voltage command value and triangular waves having a same frequency and a same phase with shifted voltage levels, and to superimpose outputs of all or the portion of the predetermined number of the power conversion cells to change stepwise, the controller comprising:
- circuitry configured to,
- for each of the plurality of single-phase AC output units, drive each of all or a portion of the predetermined number of the power conversion cells based on a comparison between a voltage command value and triangular waves having a same frequency and a same phase with shifted voltage levels, and to superimpose outputs of all or the portion of the predetermined number of the power conversion cells to change stepwise, and
- selectively use, when numbers of available power conversion cells for the plurality of single-phase AC output units are not all a same number,
- a first control state in which each of the plurality of single-phase AC output units superimposes only outputs of a number of the power conversion cells corresponding to a minimum number of the numbers of available power conversion cells to output the single-phase AC, and
- a second control state in which each of the plurality of single-phase AC output units superimposes outputs of all available power conversion cells to output the single-phase AC such that phase differences between line-to-line voltages of adjacent phases among the phases are all equivalent.
10 more elements
A control method for a power converter including:
- a plurality of single-phase AC output units for respective phases, each of the plurality of single-phase AC output units being configured to output single-phase AC and including a predetermined number of power conversion cells,
- wherein the predetermined number is two or more,
- wherein each of the power conversion cells is configured to:
- convert power supplied from an external power supply into single-phase AC of a predetermined voltage and frequency, and
- output the single-phase AC,
- wherein output units of the predetermined number of the power conversion cells are connected in series to enable outputs of the predetermined number of the power conversion cells to be superimposed to output the single-phase AC,
- wherein each power conversion cell of the predetermined number of the power conversion cells includes a short circuit configured to short-circuit an output unit of the power conversion cell, and
- wherein, for each of the plurality of single-phase AC output units, the controller is configured to drive each of all or a portion of the predetermined number of the power conversion cells based on a comparison between a voltage command value and triangular waves having a same frequency and a same phase with shifted voltage levels, and to superimpose outputs of all or the portion of the predetermined number of the power conversion cells to change stepwise, the control method comprising:
- for each of the plurality of single-phase AC output units,
- driving each of all or a portion of the predetermined number of the power conversion cells based on a comparison between a voltage command value and triangular waves having a same frequency and a same phase with shifted voltage levels, and to superimpose outputs of all or the portion of the predetermined number of the power conversion cells to change stepwise;
- and
- selectively using, when numbers of available power conversion cells for the plurality of single-phase AC output units are not all a same number,
- a first control state in which each of the plurality of single-phase AC output units superimposes only outputs of a number of the power conversion cells corresponding to a minimum number of the numbers of available power conversion cells to output the single-phase AC, and
- a second control state in which each of the plurality of single-phase AC output units superimposes outputs of all available power conversion cells to output the single-phase AC such that phase differences between line-to-line voltages of adjacent phases among the phases are all equivalent.
11 more elements
Dependencies are inferred from the claim text.