Abstract: According to an embodiment of the invention, a system-connected inverter device that includes a three-level inverter, a voltage sensor, and a controller is provided. The three-level inverter includes multiple switching elements, is connected to an electric power system of alternating current and a direct current power supply, converts direct current power supplied from the direct current power supply from direct current power into alternating current power by an ON/OFF of the multiple switching elements, and supplies the alternating current power to the electric power system. The voltage sensor detects an alternating current voltage of the electric power system.

Abstract: An uninterruptible power supply device (60) does not have a wire connecting a bidirectional chopper (24) to a neutral point (NP). The bidirectional chopper (24) includes first and second capacitors (C11, C12), first to fourth transistors (Q11-Q14), and a normal mode reactor (50). In a discharging mode, a controller (63) causes the second and third transistors (Q12, Q13) to be complementarily turned on and controls the ON period of each of the second and third transistors (Q12, Q13) so that terminal-to-terminal voltages (V11, V12) of the first and second capacitors (C11, C12) are equal to each other.

Abstract: An electronic-device seal structure includes a base, a case which covers an upper surface of the base and has an opening at a surface thereof, and a pair of terminals attached to the base. A first clearance sealed with a sealing material is provided between the base and the case, and a second clearance is provided between the pair of terminals attached to an end surface of the base to face each other.

Abstract: A converter includes: a first transistor (Q1) connected between a first output terminal (T1) and an input terminal (T0); a second transistor (Q2) connected between the input terminal (T0) and a second output terminal (T2); first and second diodes (D1, D2) connected in anti-parallel to the first and second transistors (Q1, Q2), respectively; and a bidirectional switch that is connected between the input terminal (T0) and a third output terminal (T3) and that includes third and fourth transistors (Q3, Q4) and third and fourth diodes (D3, D4). The first and second diodes (D1, D2) and the third and fourth transistors (Q3, Q4) each are formed of a wide band gap semiconductor. The third and fourth diodes (D3, D4) and the first and second transistors (Q1, Q2) each are formed of a semiconductor other than the wide band gap semiconductor.

Abstract: In a nonaqueous electrolyte secondary battery which includes an electrode assembly that includes a positive electrode including a positive electrode current collector and a positive electrode mixture layer, a negative electrode including a negative electrode current collector and a negative electrode mixture layer, and a separator, the positive electrode mixture layer contains Ni in a proportion of not less than 85 mol % relative to the total molar amount of metal element(s) except lithium, and includes a lithium transition metal oxide bearing on the surface thereof an attached element belonging to Group VI of the periodic table. The negative electrode mixture layer includes a carbon material and a silicon compound. The surface pressure present on a plane in which the positive electrode and the negative electrode are opposed to each other through the separator is not less than 0.1 MPa/cm2.

Abstract: An uninterruptible power supply device (U1) includes a converter (40), an inverter (41), a bidirectional chopper (24), and a controller (53). The bidirectional chopper (24) includes first to fourth transistors (Q11-Q14), first to fourth diodes (D11-D14), and first and second, coils (51, 52). In a charging mode, the controller (53) causes the first and fourth transistors (Q11, Q14) to be complementarily turned on and controls the ON period of each of the first and fourth transistors (Q11, Q14) so as to cause respective detected values of first current and second current (11, 12) flowing through the first coil and the second coil (51, 52) to be equal to each other.

Abstract: An uninterruptible power supply system includes a plurality of uninterruptible power supply devices, and each uninterruptible power supply device includes a conversion circuit, an inversion circuit, a DC positive bus, a DC negative bus, and a capacitor. The uninterruptible power supply system includes a first fuse connected between DC positive buses of two uninterruptible power supply devices, and a second fuse connected between DC negative buses of the two uninterruptible power supply devices. DC voltages between the plurality of DC positive buses and between the plurality of DC negative buses can be made uniform and a cross current can be suppressed. Even when one uninterruptible power supply device fails and an overcurrent flows between the two DC positive buses and between the two DC negative buses, the failure range can be narrowly limited by the first and second fuses.

Abstract: An inverter includes: a first transistor (Q1) connected between a first input terminal (T1) and an output terminal (T4); a second transistor (Q2) connected between the output terminal (T4) and a second input terminal (T2); first and second diodes (D1, D2) connected in anti-parallel to the first and second transistors (Q1, Q2), respectively; and a bidirectional switch that is connected between a third input terminal (T3) and the output terminal (T4) and that includes third and fourth transistors (Q3, Q4) and third and fourth diodes (D3, D4). The first and second transistors (Q1, Q2) and the third and fourth diodes (D3, D4) are each formed of a wide band gap semiconductor. The third and fourth transistors (Q3, Q4) and the first and second diodes (D1, D2) are each formed of a semiconductor other than the wide band gap semiconductor.

Abstract: A converter includes a first diode (D1) having its anode and cathode connected to input terminal (T0) and a first output terminal (T1), respectively, a second diode (D2) having its anode and cathode connected to a second output terminal (T2) and an input terminal (T0), respectively, and a bidirectional switch connected between the input terminal (T0) and a third output terminal (T3). The bidirectional switch includes third to sixth diodes (D3 to D6) and a transistor (Q1). The first diode (D1), the second diode (D2), and the transistor (Q) are each formed of a wide-bandgap semiconductor, and the third to sixth diodes (D3 to D6) are each formed of a semiconductor other than wide-bandgap semiconductors.

Abstract: A converter includes a first diode (D1) having its anode and cathode connected to input terminal (T0) and a first output terminal (T1), respectively, a second diode (D2) having its anode and cathode connected to a second output terminal (T2) and an input terminal (T0), respectively, and a bidirectional switch connected between the input terminal (T0) and a third output terminal (T3). The bidirectional switch includes third to sixth diodes (D3 to D6) and a transistor (Q1). The first diode (D1), the second diode (D2), and the transistor (Q) are each formed of a wide-bandgap semiconductor, and the third to sixth diodes (D3 to D6) are each formed of a semiconductor other than wide-bandgap semiconductors.

Abstract: An uninterruptible power supply device (60) does not have a wire connecting a bidirectional chopper (24) to a neutral point (NP). The bidirectional chopper (24) includes first and second capacitors (C11, C12), first to fourth transistors (Q11-Q14), and a normal mode reactor (50). In a discharging mode, a controller (63) causes the second and third transistors (Q12, Q13) to be complementarily turned on and controls the ON period of each of the second and third transistors (Q12, Q13) so that terminal-to-terminal voltages (V11, V12) of the first and second capacitors (C11, C12) are equal to each other.

Abstract: An uninterruptible power supply device (U1) includes a converter (40), an inverter (41), a bidirectional chopper (24), and a controller (53). The bidirectional chopper (24) includes first to fourth transistors (Q11-Q14), first to fourth diodes (D11-D14), and first and second, coils (51, 52). In a charging mode, the controller (53) causes the first and fourth transistors (Q11, Q14) to be complementarily turned on and controls the ON period of each of the first and fourth transistors (Q11, Q14) so as to cause respective detected values of first current and second current (11, 12) flowing through the first coil and the second coil (51, 52) to be equal to each other.

Abstract: A power supply system includes an uninterruptable power-supply apparatus supplying power to a load, a switch connecting a bypass power supply to the load, and a switching circuit turning the switch on when the uninterruptable power-supply apparatus is stopped. In a case where the uninterruptable power-supply apparatus is stopped, the switching circuit turns the switch on when a phase of an output voltage of the bypass power supply is equal to a phase of an output voltage of the uninterruptable power-supply apparatus at a stopped timing.

Abstract: A reactor includes an annular iron core and four coils separately wound around the iron core. The four coils have first electrodes connected to output terminals of four choppers, respectively, and second electrodes each connected to a load. Therefore, the four choppers can be connected in parallel to the load by one reactor.

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 system includes a plurality of uninterruptible power supply devices, and each uninterruptible power supply device includes a conversion circuit, an inversion circuit, a DC positive bus, a DC negative bus, and a capacitor. The uninterruptible power supply system includes a first wiring connected between DC positive buses of two uninterruptible power supply devices, and a second wiring connected between DC negative buses of the two uninterruptible power supply devices. The operation of all uninterruptible power supply devices is stopped in response to an absolute value of a current flowing through a bundle of the first and second wirings exceeding an upper limit value.

Abstract: An uninterruptible power supply apparatus includes a cooler cooling a converter/chopper circuit and a cooler cooling a PWM inverter. The converter/chopper circuit and the cooler make up one integrated unit. Accordingly, a smaller apparatus can be achieved, compared with a conventional apparatus in which a cooler is provided for each of a converter and a chopper.

Abstract: A converter includes: a first transistor (Q1) connected between a first output terminal (T1) and an input terminal (T0); a second transistor (Q2) connected between the input terminal (T0) and a second output terminal (T2); first and second diodes (D1, D2) connected in anti-parallel to the first and second transistors (Q1, Q2), respectively; and a bidirectional switch that is connected between the input terminal (T0) and a third output terminal (T3) and that includes third and fourth transistors (Q3, Q4) and third and fourth diodes (D3, D4). The first and second diodes (D1, D2) and the third and fourth transistors (Q3, Q4) each are formed of a wide band gap semiconductor. The third and fourth diodes (D3, D4) and the first and second transistors (Q1, Q2) each are formed of a semiconductor other than the wide band gap semiconductor.

Abstract: An inverter includes: a first transistor (Q1) connected between a first input terminal (T1) and an output terminal (T4); a second transistor (Q2) connected between the output terminal (T4) and a second input terminal (T2); first and second diodes (D1, D2) connected in anti-parallel to the first and second transistors (Q1, Q2), respectively; and a bidirectional switch that is connected between a third input terminal (T3) and the output terminal (T4) and that includes third and fourth transistors (Q3, Q4) and third and fourth diodes (D3, D4). The first and second transistors (Q1, Q2) and the third and fourth diodes (D3, D4) are each formed of a wide band gap semiconductor. The third and fourth transistors (Q3, Q4) and the first and second diodes (D1, D2) are each formed of a semiconductor other than the wide band gap semiconductor.