Abstract: In the uninterruptible power supply, when the input switch is connected between the input terminal and the AC node of the converter and the fourth operation mode is selected, the input switch is turned off and the bypass switch is turned on, and the converter is controlled to convert the DC power of the battery into AC power and supply the AC power to the load via the bypass switch. Thus, even if the inverter is failed when the commercial AC power source is failed, it is possible to drive the load.

Abstract: An uninterruptible power supply device includes a bidirectional chopper that converts a first DC voltage supplied from a battery into a second DC voltage and supplies the second DC voltage to an inverter when a power failure of a commercial AC power supply occurs. The bidirectional chopper includes a capacitor that stabilizes the second DC voltage. The uninterruptible power supply device further includes: a current detector that detects an output current of the battery; and a control circuit that, based on a detection result by the current detector, calculates an estimated temperature increase value of the capacitor every time a predetermined time period elapses, and stops an operation of the bidirectional chopper when the calculated estimated temperature increase value is higher than an upper limit value.

Abstract: An uninterruptible power supply system includes: a group of electrical components that constitute the uninterruptible power supply system and are disposed in a first block of the housing; the other group of electrical components that constitute the uninterruptible power supply system and are disposed in a second block of the housing; and a partition structure disposed adjacent to an exhaust side of the second block to adjust an air flow flowing through the first block and the second block.

Abstract: A connection structure includes a circuit board, an insulating member, a housing, and a conductive wire. The insulating member includes a first portion and a second portion. The first portion is fixed to the circuit board. The second portion faces the first portion. The second portion is fixed to the housing. The housing includes a grounded contact. The conductive wire electrically connects the circuit board and the housing while being wound around the insulating member. A shortest distance along a surface of the housing from a position where the conductive wire and the housing are connected to the contact is shorter than a shortest distance along a surface of the housing from the second portion of the insulating member to the contact.

Abstract: An uninterruptible power supply device includes a bidirectional chopper that converts a first DC voltage supplied from a battery into a second DC voltage and supplies the second DC voltage to an inverter when a power failure of a commercial AC power supply occurs. The bidirectional chopper includes a capacitor that stabilizes the second DC voltage. The uninterruptible power supply device further includes: a current detector that detects an output current of the battery; and a control circuit that, based on a detection result by the current detector, calculates an estimated temperature increase value of the capacitor every time a predetermined time period elapses, and stops an operation of the bidirectional chopper when the calculated estimated temperature increase value is higher than an upper limit value.

Abstract: An electromagnetic contactor (15) is connected between an AC power supply (1) and a load (18), and is turned on during bypass power feeding. A control device (20) turns on a switch (14) and turns off the electromagnetic contactor (15) when an inverter (10) has a failure during inverter power feeding. The electromagnetic contactor (15) is turned on when a contact is closed by excitation of a coil according to a control signal from the control device (20). The electromagnetic contactor (15) has a manual switch that can close the contact by being pressed from outside. An uninterruptible power supply device (100) includes a pressing force applying mechanism (22, 26, 27) that applies a pressing force to the manual switch, and a control circuit (24, 28) that operates the pressing force applying mechanism when there occurs a failure that the electromagnetic contactor (15) cannot be turned on regardless of the control signal from the control device (20).

Abstract: A switch is connected between an AC power supply and a load. A controller detects an abnormality of the AC power supply by detecting an instantaneous value of a three-phase AC voltage supplied from the AC power supply, when the switch is on. Based on an instantaneous value of the three-phase AC voltage detected at a first time and a first threshold value preset for a peak value of the three-phase AC voltage, the controller estimates a second threshold value for an instantaneous value of the three-phase AC voltage at a second time having a prescribed time difference from the first time. The controller detects the abnormality of the AC power supply by comparing the estimated second threshold value with the instantaneous value of the three-phase AC voltage detected at the second time. The controller turns off the switch when the abnormality of the AC power supply is detected.

Abstract: In the uninterruptible power supply, when the input switch is connected between the input terminal and the AC node of the converter and the fourth operation mode is selected, the input switch is turned off and the bypass switch is turned on, and the converter is controlled to convert the DC power of the battery into AC power and supply the AC power to the load via the bypass switch. Thus, even if the inverter is failed when the commercial AC power source is failed, it is possible to drive the load.

Abstract: A controller (5) of an uninterruptible power supply apparatus includes: first to sixth comparator circuits (22a to 22f) respectively provided corresponding to first to sixth IGBTs (Q1 to Q6) and outputting, based on a comparison result of the magnitude of three-phase AC voltages, signals (A1 to A6) indicating that a corresponding IGBT is to be turned on; and a control unit (23) that, when a voltage between terminals (VD1 or VD2) of a first or second capacitor (C11 or C12) is higher than a target voltage (VDT), turns on and off each of the first to sixth IGBTs based on signals output from the first to sixth comparator circuits to decrease the voltage between terminals of the first or second capacitor.

Abstract: An uninterruptible power supply device includes: a converter that converts AC power supplied from an AC power supply into DC power and outputs the DC power to a first power supply node; a first bidirectional chopper that outputs DC power in a lead storage device to the first power supply node when the AC power supply has a power failure; a diode connected between the first power supply node and a second power supply node; a second bidirectional chopper that supplies and receives DC power between the second power supply node and a lithium ion battery; and a controller that controls the second bidirectional chopper to charge the lithium ion battery during regenerative operation of a load and to discharge the lithium ion battery during power running operation of the load.

Abstract: A switch is connected between an AC power supply and a load. A controller detects an abnormality of the AC power supply by detecting an instantaneous value of a three-phase AC voltage supplied from the AC power supply, when the switch is on. Based on an instantaneous value of the three-phase AC voltage detected at a first time and a first threshold value preset for a peak value of the three-phase AC voltage, the controller estimates a second threshold value for an instantaneous value of the three-phase AC voltage at a second time having a prescribed time difference from the first time. The controller detects the abnormality of the AC power supply by comparing the estimated second threshold value with the instantaneous value of the three-phase AC voltage detected at the second time. The controller turns off the switch when the abnormality of the AC power supply is detected.

Abstract: An AC switch (1) includes a first thyristor (T1), a second thyristor (T2), a third thyristor (T3), and a fourth thyristor (T4). The first thyristor (T1) has an anode connected to an AC power source (2), and a cathode connected to a load (3). The second thyristor (T2) is connected in antiparallel to the first thyristor (T1). The third thyristor (T3) has an anode connected to the AC power source (2), and a cathode connected to the load (3). The fourth thyristor (T4) is connected in antiparallel to the third thyristor (T3). A current detector (5) detects the AC current supplied from the AC power source (2) to the load (3). A controller (6) causes the first thyristor (T1) and the third thyristor (T3) to conduct alternately and causes the second thyristor (T2) and the fourth thyristor (T4) to conduct alternately, for each one-cycle period of the AC current, in accordance with the detection value from the current detector (5).

Abstract: An electromagnetic contactor (15) is connected between an AC power supply (1) and a load (18), and is turned on during bypass power feeding. A control device (20) turns on a switch (14) and turns off the electromagnetic contactor (15) when an inverter (10) has a failure during inverter power feeding. The electromagnetic contactor (15) is turned on when a contact is closed by excitation of a coil according to a control signal from the control device (20). The electromagnetic contactor (15) has a manual switch that can close the contact by being pressed from outside. An uninterruptible power supply device (100) includes a pressing force applying mechanism (22, 26, 27) that applies a pressing force to the manual switch, and a control circuit (24, 28) that operates the pressing force applying mechanism when there occurs a failure that the electromagnetic contactor (15) cannot be turned on regardless of the control signal from the control device (20).

Abstract: In a first power feeding mode, a controller supplies AC power output by an inverter to a load. In a second power feeding mode, the controller supplies AC power supplied from an AC power supply to the load. The controller switches an operation mode to the first power feeding mode when a voltage drop of the AC power supply is detected during the second power feeding mode. The controller, for a prescribed time period from detection of the voltage drop, causes a converter to perform reverse conversion to convert DC power output by a power storage device to AC power, and controls the reverse conversion in the converter such that an instantaneous value of an AC voltage output from the converter becomes equal to or higher than an instantaneous value of an AC voltage output from the inverter.

Abstract: An uninterruptible power supply device includes: a converter that converts AC power supplied from an AC power supply into DC power and outputs the DC power to a first power supply node; a first bidirectional chopper that outputs DC power in a lead storage device to the first power supply node when the AC power supply has a power failure; a diode connected between the first power supply node and a second power supply node; a second bidirectional chopper that supplies and receives DC power between the second power supply node and a lithium ion battery; and a controller that controls the second bidirectional chopper to charge the lithium ion battery during regenerative operation of a load and to discharge the lithium ion battery during power running operation of the load.

Abstract: A controller (5) of an uninterruptible power supply apparatus includes: first to sixth comparator circuits (22a to 22f) respectively provided corresponding to first to sixth IGBTs (Q1 to Q6) and outputting, based on a comparison result of the magnitude of three-phase AC voltages, signals (A1 to A6) indicating that a corresponding IGBT is to be turned on; and a control unit (23) that, when a voltage between terminals (VD1 or VD2) of a first or second capacitor (C11 or C12) is higher than a target voltage (VDT), turns on and off each of the first to sixth IGBTs based on signals output from the first to sixth comparator circuits to decrease the voltage between terminals of the first or second capacitor.

Abstract: In a first power feeding mode, a controller supplies AC power output by an inverter to a load. In a second power feeding mode, the controller supplies AC power supplied from an AC power supply to the load. The controller switches an operation mode to the first power feeding mode when a voltage drop of the AC power supply is detected during the second power feeding mode. The controller, for a prescribed time period from detection of the voltage drop, causes a converter to perform reverse conversion to convert DC power output by a power storage device to AC power, and controls the reverse conversion in the converter such that an instantaneous value of an AC voltage output from the converter becomes equal to or higher than an instantaneous value of an AC voltage output from the inverter.

Abstract: An AC switch (1) includes a first thyristor (T1), a second thyristor (T2), a third thyristor (T3), and a fourth thyristor (T4). The first thyristor (T1) has an anode connected to an AC power source (2), and a cathode connected to a load (3). The second thyristor (T2) is connected in antiparallel to the first thyristor (T1). The third thyristor (T3) has an anode connected to the AC power source (2), and a cathode connected to the load (3). The fourth thyristor (T4) is connected in antiparallel to the third thyristor (T3). A current detector (5) detects the AC current supplied from the AC power source (2) to the load (3). A controller (6) causes the first thyristor (T1) and the third thyristor (T3) to conduct alternately and causes the second thyristor (T2) and the fourth thyristor (T4) to conduct alternately, for each one-cycle period of the AC current, in accordance with the detection value from the current detector (5).