Abstract: An object of the present invention is to efficiently heat a refrigerant retained in a compressor. An inverter control unit generates six drive signals corresponding to the respective switching elements of the inverter, and outputs the generated drive signals to the corresponding switching elements of the inverter to cause the inverter to generate a high-frequency AC voltage. Particularly, the inverter control unit generates a drive signal having a switching pattern A for turning on all the three switching elements on a positive voltage side or a negative voltage side of the inverter, and subsequent thereto, generates a drive signal having a switching pattern B for turning on two switching elements of the three switching elements and turning off one switching element thereof.

Abstract: A rectifier connected with an AC source through a reactor, a plurality of capacitors connected in series between output terminals of the rectifier, first switching means connected between one input terminal of the rectifier and a connection point of a plurality of capacitors, second switching means connected between the other input terminal of the rectifier and the connection point of a plurality of capacitors, and a plurality of diodes connected with the plurality of capacitors in inverse-parallel are provided.

Abstract: An AC-DC converter is provided which suppresses a harmonic current and improves power factor at low cost. Such an AC-DC converter includes a rectifier connected to an AC power supply via a reactor, capacitors connected in series across the output terminals of the rectifier, a first bidirectional switch having one end connected to one input terminal of the rectifier and the other end connected to a connecting point of capacitors, a second bidirectional switch having one end connected to the other input terminal of the rectifier and the other end connected to the other end of the first bidirectional switch, and a control circuit for actuating the first and second bidirectional switches during a half cycle of the AC power supply so as to control a voltage inputted to the rectifier to a desired output voltage.

Abstract: A power converter includes step-up means for varying a voltage applied by a power supply to a predetermined voltage, commutating means for performing a commutation operation for allowing a current flowing through the step-up means to flow through a second path, smoothing means for smoothing a voltage related to outputs of the step-up means and the commutating means to produce power and supplying the power to a load side, and control means for performing control related to voltage varying, such as stepping up, by the step-up means and controlling the commutation operation of the commutating means on the basis of at least one of a voltage and a current related to the step-up means.

Abstract: An inverter device, a motor driving device, a refrigerating air conditioner, and a power generation system, which can reduce the recovery loss thereof, are obtained. A plurality of arms that can conduct and block current are provided. At least one of the plurality of arms includes: a plurality of switching elements each having a parasitic diode and being connected in series with each other; and a reverse current diode connected in parallel with the plurality of switching elements.

Abstract: Provided is an alternating-current direct-current converter capable of controlling a harmonic current and improving a power factor at reduced costs.

Abstract: To obtain a converter circuit capable of being made to be small and light-weighted and reducing switching loss, a motor drive control apparatus, an air-conditioner, a refrigerator, and an induction heating cooker provided with the circuit. There are provided: a step-up converter 3a including a rectifier 2, a step-up reactor 4a, a switching element 5a, and a reverse current prevention element 6a; a step-up converter 3b having a step-up reactor 4b, a switching element 5b, and a reverse current prevention element 6b and connected in parallel with the step-up converter 3a; switching control means 7 that controls switching elements 5a and 5b; and a smoothing capacitor that is provided at the output of the step-up converters 3a and 3b. The switching control means 7 switches the current mode of the current flowing through the step-up reactors 4a and 4b into any of a continuous mode, a critical mode, and a discontinuous mode based on a predetermined condition.

Abstract: A rectifier connected with an AC source through a reactor, a plurality of capacitors connected in series between output terminals of the rectifier, first switching means connected between one input terminal of the rectifier and a connection point of a plurality of capacitors, second switching means connected between the other input terminal of the rectifier and the connection point of a plurality of capacitors, and a plurality of diodes connected with the plurality of capacitors in inverse-parallel are provided.

Abstract: An AC-DC converter is provided which suppresses a harmonic current and improves power factor at low cost. Such an AC-DC converter includes a rectifier connected to an AC power supply via a reactor, capacitors connected in series across the output terminals of the rectifier, a first bidirectional switch having one end connected to one input terminal of the rectifier and the other end connected to a connecting point of capacitors, a second bidirectional switch having one end connected to the other input terminal of the rectifier and the other end connected to the other end of the first bidirectional switch, and a control circuit for actuating the first and second bidirectional switches during a half cycle of the AC power supply so as to control a voltage inputted to the rectifier to a desired output voltage.

Abstract: An energy saving service includes: a service contract conclusion step in which a service contract is concluded with a customer who has purchased or will purchase a product with a permanent magnet motor; a driving device provision step in which a driving device which can drive a permanent magnet motor with any specifications is provided on the basis of the service contract; and a product upgrade step in which the driving device drives the permanent magnet motor so as to improve the performance of the product with the permanent magnet motor, thereby upgrading the product with the permanent magnet motor.

Abstract: One of the purpose is to obtain a motor drive circuit and an outdoor unit for an air conditioner using the same, which can flexibly support change of a model at a low price and in a small lot without using unnecessary materials, wherein a stress in a soldering part due to self-heating is low, a solder reliability is high, and design constraints are small, while maintaining a low-noise and low-loss power wiring due to lowering inductance.

Abstract: An apparatus for generating a three-phase pulse-width-modulation signal for a three-phase voltage inverter employing a semiconductor switching element includes a generating unit that generates the three-phase pulse-width-modulation signal based on at least one combination of three basic voltage vectors and at least a zero vector.

Abstract: One of the purpose is to obtain a motor drive circuit and an outdoor unit for an air conditioner using the same, which can flexibly support change of a model at a low price and in a small lot without using unnecessary materials, wherein a stress in a soldering part due to self-heating is low, a solder reliability is high, and design constraints are small, while maintaining a low-noise and low-loss power wiring due to lowering inductance.

Abstract: An apparatus for generating a three-phase pulse-width-modulation signal for a three-phase voltage inverter employing a semiconductor switching element includes a generating unit that generates the three-phase pulse-width-modulation signal based on at least one combination of three basic voltage vectors and at least a zero vector.

Abstract: An energy saving service includes: a service contract conclusion step in which a service contract is concluded with a customer who has purchased or will purchase a product with a permanent magnet motor; a driving device provision step in which a driving device which can drive a permanent magnet motor with any specifications is provided on the basis of the service contract; and a product upgrade step in which the driving device drives the permanent magnet motor so as to improve the performance of the product with the permanent magnet motor, thereby upgrading the product with the permanent magnet motor.