Abstract: The present uninterruptible power supply apparatus includes a converter (5) configured to convert AC power into DC power; an inverter (10) configured to convert DC power into AC power and supply the converted AC power to a load (24); and a control device (18) configured to control the converter (5) and the inverter (10). The control device (18) is configured to execute a mode selected from a sinusoidal wave output mode and a waveform distortion generation mode. In the sinusoidal wave output mode, an AC voltage (VO) with a sinusoidal waveform and with no waveform distortion is supplied to the load (24). In the waveform distortion generation mode, an AC voltage (VO) with waveform distortion within an allowable range for the load (24) is supplied to the load (24).

Abstract: A control device controls an uninterruptible power supply device such that a transition is made to an inverter power supply mode when a power source abnormality detecting unit detects a power failure of an AC power source in a case where a commercial power supply mode is selected. The power source abnormality detecting unit computes an estimated value of the maximum value of AC input voltage, based on detected values of the instantaneous value and the phase of AC input voltage supplied to an input terminal. The power source abnormality detecting unit is configured to store temporal transition of the maximum value when the AC power source undergoes a simulated power failure and determine a power failure of the AC power source, based on comparison between temporal transition of the estimated value of the maximum value and the stored temporal transition of the maximum value during power failure.

Abstract: An uninterruptible power supply apparatus includes a converter (5) configured to convert AC power into DC power, and an inverter (10) configured to convert DC power into AC power and supply the converted power to a load (24). The load (24) is configured to receive an AC voltage within a range of allowable input voltage to consume constant AC power. The uninterruptible power supply apparatus has maximum efficiency ? when a ratio of load capacity to rated capacity of the uninterruptible power supply apparatus is a predetermined value ?. The uninterruptible power supply apparatus further includes a control device (18) configured to control an output voltage of the inverter (10) within the range of allowable input voltage so as to increase the efficiency ?, when the ratio of the load capacity to the rated capacity is different from the predetermined value ?.

Abstract: An uninterruptible power supply device includes: an inverter configured to convert AC power from an AC power supply into DC power and output the DC power to a DC bus; a converter configured to convert the DC power received from the DC bus into AC power and supply the AC power to a load; a bidirectional chopper configured to transmit and receive DC power between the DC bus and a storage battery; a bidirectional chopper configured to transmit and receive DC power between the DC bus and a lithium ion battery; a controller configured to cause the storage battery to be charged during normal operation, and to be discharged during power failure; and a controller configured to cause the lithium ion battery to be charged when the load is performing a regenerative operation, and to be discharged when the load is performing a power running operation.

Abstract: An uninterruptible power supply is configured to receive, together with a first load, AC power supplied from an AC power source. The uninterruptible power supply includes: a converter configured to convert AC power from the AC power source into DC power; an inverter configured to convert DC power generated by the converter or DC power in a battery into AC power to supply the converted power to a second load; a controller configured to control reactive power generated at the converter to compensate at least a part of reactive power generated at the first load; and a limiter configured to limit reactive power generated at the converter to upper limit power or lower. The upper limit power is set to a value according to the difference between the rated capacity of the uninterruptible power supply and AC power supplied to the second load.

Abstract: An uninterruptible power supply system, including: a plurality of uninterruptible power supply devices which are connected in parallel with respect to a load, and switch between power supplies supplying power to the load depending on states of the power supplies; a control unit controlling an operation of switching between the power supplies by the uninterruptible power supply devices; a storage battery connected to the plurality of uninterruptible power supply devices in common; a converter converting AC power; a contactor switching between the DC power converted by the converter and DC power input from the storage battery; and an inverter inverting the DC power and supplying the power to the load. The control unit deactivates the inverter which does not contribute to supplying a power amount required for the load, of a plurality of inverters.

Abstract: An uninterruptible power supply device includes a switch, a power converter, and another power converter. The switch includes a first electrode that receives AC power from an AC power supply and a second electrode connected to a load via an AC bus, and is turned on during a normal operation and turned off during a power failure. The power converter converts DC power from a DC power supply into AC power and outputs it to the AC bus during a power failure. The other power converter converts the AC power received from the AC bus into DC power and stores it in a lithium-ion battery when the load is performing regeneration running, and converts the DC power of the lithium-ion battery into AC power and supplies it to the AC bus when the load is performing power running.

Abstract: An uninterruptible power supply includes: a converter (4) configured to convert alternating-current power supplied from an alternating-current power supply (51) into direct-current power; an inverter (7) configured to convert the direct-current power generated by the converter or direct-current power of a storage battery (52) into alternating-current power and supply the alternating-current power to a load (53, 54); and a control circuit (14) configured to control the inverter. When activating the inverter, the control circuit gradually increases a voltage value (V) of an output voltage (VO) and a frequency (F) of the output voltage (VO) while maintaining a ratio of the voltage value (V) and the frequency (F) at a fixed value (F).

Abstract: A control device controls an uninterruptible power supply device such that a transition is made to an inverter power supply mode when a power source abnormality detecting unit detects a power failure of an AC power source in a case where a commercial power supply mode is selected. The power source abnormality detecting unit computes an estimated value of the maximum value of AC input voltage, based on detected values of the instantaneous value and the phase of AC input voltage supplied to an input terminal. The power source abnormality detecting unit is configured to store temporal transition of the maximum value when the AC power source undergoes a simulated power failure and determine a power failure of the AC power source, based on comparison between temporal transition of the estimated value of the maximum value and the stored temporal transition of the maximum value during power failure.

Abstract: An uninterruptible power supply system includes a regular uninterruptible power supply device configured to supply AC power to a load, and an auxiliary power conversion device configured to supply AC power to the load when the regular uninterruptible power supply device has a failure. The auxiliary power conversion device includes a converter and an inverter. When a DC voltage generated by the converter is higher than a lower limit voltage, the auxiliary power conversion device outputs an AC voltage having a sinusoidal wave and falling within an acceptable input voltage range of the load. When the DC voltage is lower than the lower limit voltage, the auxiliary power conversion device outputs an AC voltage having waveform distortion within an acceptable range for the load and falling within the acceptable input voltage range of the load.

Abstract: A power conversion system includes: an output terminal connected to a load; a switch configured to be turned on in a first case that an AC voltage from the AC power supply is normal, and to be turned off in a second case that the AC voltage from the AC power supply is abnormal; a power converter configured to convert the AC power from the AC power supply into DC power and store the DC power in a storage battery in the first case, and to convert the DC power in the storage battery into AC power and output the AC power to the output terminal in the second case; and a line-commutated inverter configured to operate in synchronization with an AC voltage appearing at the output terminal, and convert the DC power supplied from a fuel cell into AC power and output the AC power to the output terminal.

Abstract: An uninterruptible power supply is configured to receive, together with a first load, AC power supplied from an AC power source. The uninterruptible power supply includes: a converter configured to convert AC power from the AC power source into DC power; an inverter configured to convert DC power generated by the converter or DC power in a battery into AC power to supply the converted power to a second load; a controller configured to control reactive power generated at the converter to compensate at least a part of reactive power generated at the first load; and a limiter configured to limit reactive power generated at the converter to upper limit power or lower. The upper limit power is set to a value according to the difference between the rated capacity of the uninterruptible power supply and AC power supplied to the second load.

Abstract: An uninterruptible power source includes an eco-mode for supplying power from an AC power source to a load via a contactor. In the eco-mode, when a degree of voltage drop of the AC power source reaches 5%, a switching controller turns on a thyristor switch and then turns off a contactor. When the degree of voltage drop of the AC power source reaches 10%, a power conversion controller is configured to cause an inverter to invert DC power of a battery into AC power, and control the inversion in the inverter to synchronize the AC voltage output from the inverter to the AC voltage supplied from the AC power source. When the inversion in the inverter is performed after turning off contactor, the switching controller is configured to turn off the thyristor switch.

Abstract: When power failure of an AC power source occurs during an eco-mode in which AC power is supplied via a bypass switch, an uninterruptible power source is configured to change over to inverter power supply in which AC power is supplied from an inverter. When turning off the bypass switch during power failure, a power conversion controller is configured to (i) control the converter to invert the DC power output by the battery into AC power and output the AC power to a node, and (ii) control the inverter to invert the DC power output by the battery into AC power and output the AC power to an output terminal. The power conversion controller controls the converter and the inverter such that phase and magnitude of an AC voltage output to the node become equal to phase and magnitude of an AC voltage output to output terminal.

Abstract: An uninterruptible power supply device includes N UPS modules connected in parallel with one another between an AC power supply and a load, a current detector configured to detect a load current, and a controller configured to select n UPS modules, and an auxiliary UPS module, based on a result of detection by the current detector. Each of the n UPS modules is configured to supply, to the load, a shared current which is 1/n of the load current. The auxiliary UPS module is configured to output, to the load, a counter voltage having a value in accordance with output voltages of the n UPS modules, and thereby to stand by in a state where no current flows between the auxiliary UPS module and the n UPS modules and between the auxiliary UPS module and the load.

Abstract: An uninterruptible power supply apparatus includes a converter (5) configured to convert AC power into DC power, and an inverter (10) configured to convert DC power into AC power and supply the converted power to a load (24). The load (24) is configured to receive an AC voltage within a range of allowable input voltage to consume constant AC power. The uninterruptible power supply apparatus has maximum efficiency ? when a ratio of load capacity to rated capacity of the uninterruptible power supply apparatus is a predetermined value ?. The uninterruptible power supply apparatus further includes a control device (18) configured to control an output voltage of the inverter (10) within the range of allowable input voltage so as to increase the efficiency ?, when the ratio of the load capacity to the rated capacity is different from the predetermined value ?.

Abstract: The present uninterruptible power supply apparatus includes a converter (5) configured to convert AC power into DC power; an inverter (10) configured to convert DC power into AC power and supply the converted AC power to a load (24); and a control device (18) configured to control the converter (5) and the inverter (10). The control device (18) is configured to execute a mode selected from a sinusoidal wave output mode and a waveform distortion generation mode. In the sinusoidal wave output mode, an AC voltage (VO) with a sinusoidal waveform and with no waveform distortion is supplied to the load (24). In the waveform distortion generation mode, an AC voltage (VO) with waveform distortion within an allowable range for the load (24) is supplied to the load (24).

Abstract: An uninterruptible power supply apparatus supplies AC power from any one of a first inverter of a first power conversion device and a second inverter of a second power conversion device to a load, and when this inverter has a malfunction, the uninterruptible power supply apparatus supplies the AC power from the other inverter to the load. When a DC voltage provided to the second inverter is higher than a lower limit voltage, the second power conversion device outputs an AC voltage having a sinusoidal waveform and falling within an acceptable input voltage range of the load, and when the DC voltage is lower than the lower limit voltage, the second power conversion device outputs an AC voltage having waveform distortion within a range acceptable to the load and falling within the acceptable input voltage range of the load.

Abstract: Provided is an uninterruptible power supply apparatus that can properly adjust the capacity of cooling a heat radiation source. A housing for housing an uninterruptible power module is provided with a cooling fan for cooling the internal space of the housing. The housing is further formed with an opening. The opening formed in one housing and the opening formed in an adjacent housing for housing another uninterruptible power module are configured to face each other. Furthermore, each uninterruptible power module includes a fan control circuit for controlling the cooling fan. The fan control circuit controls the actuation and suspension of the cooling fan on the basis of a total load of the plurality of uninterruptible power modules.

Abstract: When power failure of an AC power source occurs during an eco-mode in which AC power is supplied via a bypass switch, an uninterruptible power source is configured to change over to inverter power supply in which AC power is supplied from an inverter. When turning off the bypass switch during power failure, a power conversion controller is configured to (i) control the converter to invert the DC power output by the battery into AC power and output the AC power to a node, and (ii) control the inverter to invert the DC power output by the battery into AC power and output the AC power to an output terminal. The power conversion controller controls the converter and the inverter such that phase and magnitude of an AC voltage output to the node become equal to phase and magnitude of an AC voltage output to output terminal.