AC motor drive system
AssigneeMitsubishi Electric Corporation
InventorsKazuyoshi Watabu, Akiko Tabuchi, Tetsuya Okuda, Yoshinori Kanda
Life of this patent
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Abstract
When regenerative power from an AC motor via an inverter exceeds a predetermined power threshold, a charging/discharging control unit, which outputs a control signal for controlling the inverter on the basis of a DC bus voltage value and a charging/discharging current value, causes a power storage device to be charged such that the DC bus voltage value becomes a voltage threshold corresponding to the power threshold and causes a charging current at a start time of charging to the power storage device to start from a charging current value that is based on a DC bus voltage value.
Claims6
An AC motor drive system comprising:
- a converter that supplies DC power;
- an inverter that converts the DC power into AC power;
- a DC bus that connects the converter and the inverter;
- an AC motor driven by the AC power;
- a DC-voltage-value detecting unit that detects a DC bus voltage value on an output side of the converter;
- a power storage device that is charged with the DC power from the DC bus and discharges the charged DC power to the DC bus;
- a charging/discharging circuit connected to the DC bus in parallel with the inverter and connected between the DC bus and the power storage device, the charging/discharging circuit causing the power storage device to be charged and discharge;
- a charging/discharging-current-value detecting unit that detects a charging/discharging current value of the power storage device;
- and
- a charging/discharging control unit that outputs a control signal for controlling the inverter on a basis of the DC bus voltage value and the charging/discharging current value, wherein
- when regenerative power from the AC motor via the inverter exceeds a predetermined power threshold, the charging/discharging control unit causes the power storage device to be charged such that the DC bus voltage value becomes a voltage threshold corresponding to the power threshold and causes a charging current at a start time of charging to the power storage device to start from a charging current value that is based on a DC bus voltage value of the DC bus.
An AC motor drive system comprising:
- a converter that converts an AC current into DC power;
- an inverter that converts the DC power into AC power that is different from AC power input to the converter;
- a DC bus that connects the converter and the inverter;
- an AC motor driven by the AC power that is an output of the inverter;
- a DC-voltage-value detecting unit that detects a DC bus voltage value on an output side of the converter;
- a power storage device that is charged with the DC power from the DC bus and discharges the charged DC power to the DC bus;
- a charging/discharging circuit connected to the DC bus in parallel with the inverter and connected between the DC bus and the power storage device, the charging/discharging circuit causing the power storage device to be charged and discharge;
- a charging/discharging-current-value detecting unit that detects a charging/discharging current value of the power storage device;
- an AC-voltage-value detecting unit that detects an AC voltage value on an input side of the converter;
- and
- a charging/discharging control unit that outputs a control signal for controlling the inverter on a basis of the DC bus voltage value, the charging/discharging current value, and the AC voltage value, wherein
- when regenerative power from the AC motor via the inverter exceeds a predetermined power threshold, the charging/discharging control unit causes the power storage device to be charged such that the DC bus voltage value becomes a voltage threshold corresponding to the power threshold and the AC voltage value and causes a charging current at a start time of charging to the power storage device to start from a charging current value that is based on the DC bus voltage value and the AC voltage value.
Dependencies are inferred from the claim text.