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US 11,056,907 B2Granted
Uninterruptible power supply device
AssigneeToshiba Mitsubishi-Electric Industrial Systems Corporation
InventorMasaru Toyoda
Life of this patent
Estimating the term…
Abstract
In an uninterruptible power supply device for supplying DC power to a load, a control device is configured such that, when the load is performing power running operation, the control device turns on a second switch to supply DC power from a diode rectifier to the load, turns off a first switch, and controls a converter to suppress a harmonic current contained in an AC current flowing from an AC power supply to the diode rectifier, and when the load is performing regenerative operation, the control device turns off the second switch, turns on the first switch, and controls the converter to convert regenerative power generated by the load into AC power.
Claims18
An uninterruptible power supply device for supplying DC power to a load, comprising:
- a DC bus connected to the load;
- a converter connected between an AC power supply and the DC bus;
- a diode rectifier connected between the AC power supply and the DC bus, in parallel to the converter;
- a DC/DC converter configured to perform DC voltage conversion between the DC bus and a power storage device for storing DC power;
- a first switch electrically connected between the converter and the DC bus;
- a second switch electrically connected between the diode rectifier and the DC bus;
- and
- a control device configured to control the converter, the DC/DC converter, and the first and second switches,
- the control device being configured to
- when the load is performing a power running operation, turn on the second switch to supply DC power from the diode rectifier to the load, turn off the first switch, and control the converter to suppress a harmonic current contained in an AC current flowing from the AC power supply to the diode rectifier, and
- when the load is performing a regenerative operation, turn off the second switch, turn on the first switch, and control the converter to convert regenerative power generated by the load into AC power,
- wherein the uninterruptible power supply device further comprises:
- a voltage detector configured to detect a voltage of the DC bus, wherein the control device is configured to determine, based on a detection value of the voltage detector, whether the load is performing the power running operation or the regenerative operation and wherein the control device includes:
- a first controller configured to generate a first control signal for outputting a compensation current from the converter, the compensation current having a phase opposite to that of the harmonic current,
- a second controller configured to generate a second control signal for matching the voltage of the DC bus to a reference voltage, and
- a third controller configured to turn on/off the first and second switches, and to switch between the first and second control signals and output selectively one of the first and second control signals to the converter, based on a result of determining whether the load is performing the power running operation or the regenerative operation.
13 more elements
An uninterruptible power supply device for supplying DC power to a load, comprising:
- a DC bus connected to the load;
- a converter connected between an AC power supply and the DC bus;
- a diode rectifier connected between the AC power supply and the DC bus, in parallel to the converter;
- a DC/DC converter configured to perform DC voltage conversion between the DC bus and a power storage device for storing DC power;
- a first switch electrically connected between the converter and the DC bus;
- a second switch electrically connected between the diode rectifier and the DC bus;
- and
- a control device configured to control the converter, the DC/DC converter, and the first and second switches,
- the control device being configured to
- when the load is performing power running operation, turn on the second switch to supply DC power from the diode rectifier to the load, turn off the first switch, and control the converter to suppress a harmonic current contained in an AC current flowing from the AC power supply to the diode rectifier, and
- when the load is performing regenerative operation, turn off the second switch, turn on the first switch, and control the converter to convert regenerative power generated by the load into AC power,
- wherein the first switch includes a semiconductor switch configured to allow a current to flow from the DC bus to the converter, in an ON state, and
- wherein the first switch further includes a mechanical switch connected in parallel to the semiconductor switch.
10 more elements
An uninterruptible power supply device for supplying DC power to a load, comprising:
- a DC bus connected to the load;
- a converter connected between an AC power supply and the DC bus;
- a diode rectifier connected between the AC power supply and the DC bus, in parallel to the converter;
- a DC/DC converter configured to perform DC voltage conversion between the DC bus and a power storage device for storing DC power;
- a first switch electrically connected between the converter and the DC bus;
- a second switch electrically connected between the diode rectifier and the DC bus;
- and
- a control device configured to control the converter, the DC/DC converter, and the first and second switches,
- the control device being configured to
- when the load is performing power running operation, turn on the second switch to supply DC power from the diode rectifier to the load, turn off the first switch, and control the converter to suppress a harmonic current contained in an AC current flowing from the AC power supply to the diode rectifier, and
- when the load is performing regenerative operation, turn off the second switch, turn on the first switch, and control the converter to convert regenerative power generated by the load into AC power,
- wherein the first switch has a semiconductor switch having two semiconductor elements connected in anti-parallel with each other, and a mechanical switch connected in parallel to the semiconductor switch.
9 more elements
An uninterruptible power supply device for supplying DC power to a load, comprising:
- a DC bus connected to the load;
- a converter connected between an AC power supply and the DC bus;
- a diode rectifier connected between the AC power supply and the DC bus, in parallel to the converter;
- a DC/DC converter configured to perform DC voltage conversion between the DC bus and a power storage device for storing DC power;
- a first switch electrically connected between the converter and the DC bus;
- a second switch electrically connected between the diode rectifier and the DC bus;
- and
- a control device configured to control the converter, the DC/DC converter, and the first and second switches,
- the control device being configured to
- when the load is performing power running operation, turn on the second switch to supply DC power from the diode rectifier to the load, turn off the first switch, and control the converter to suppress a harmonic current contained in an AC current flowing from the AC power supply to the diode rectifier, and
- when the load is performing regenerative operation, turn off the second switch, turn on the first switch, and control the converter to convert regenerative power generated by the load into AC power,
- wherein the first switch is a mechanical switch.
9 more elements
Dependencies are inferred from the claim text.