Abstract: The air-conditioning apparatus includes a coolant circuit configured by sequentially connecting a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger; a motor that operates a compressor mechanism disposed inside the compressor; an inverter for driving the motor; and a control unit that controls the inverter. The control unit includes a liquefaction detecting unit that detects coolant liquefaction in the compressor; includes a first PWM signal generating unit that generates an inverter control signal for driving the motor; includes a second PWM signal generating unit that generates an inverter control signal for making the motor perform a preheating operation; and includes a switching unit that performs switching in such a way that the first PWM signal generating unit or the second PWM signal generating unit outputs the corresponding inverter control signal to the inverter.

Abstract: A converter circuit capable of being compact and light-weight and capable of reducing switching loss, a motor drive control apparatus, an air-conditioner, a refrigerator, and an induction heating cooker provided with the circuit. The converter circuit including: a step-up converter including a rectifier, a step-up reactor, a switching element, and a reverse current prevention element; a step-up converter having a step-up reactor, a switching element, and a reverse current prevention element and connected in parallel with the step-up converter; switching control unit that controls switching elements; and a smoothing capacitor that is provided at the output of the step-up converters. The switching control unit switches the current mode of the current flowing through the step-up reactors into any of a continuous mode, a critical mode, and a discontinuous mode based on a predetermined condition.

Abstract: In a pump, at least one of leg portions of a pilot hole component are extended by a specified distance compared to the other leg portions toward a side opposite to a surface where pilot holes are exposed, and the pilot holes formed in the some leg portions extend through the some leg portions between end planes of the some leg portions and are exposed in the other end plane of the molded stator, the other end plane located at the other end in the axial direction.

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: A converter circuit including a step-up converter including a rectifier, a step-up reactor, a switching element, and a reverse current prevention element; a step-up converter having a step-up reactor, a switching element, and a reverse current prevention element and connected in parallel with the step-up converter; a switching control unit that controls switching elements; and a smoothing capacitor that is provided at the output of the step-up converters. The switching control unit switches the current mode of the current flowing through the step-up reactors into any of a continuous mode, a critical mode, and a discontinuous mode based on a predetermined condition.

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: A mold motor includes a mold stator, a rotor, and a bracket. The mold stator includes a first bearing housing section formed of thermosetting resin, one bearing of the rotor fitting in one end in an axial direction of the first bearing housing section, an opening section formed at an end on the opposite side of the bearing housing section, and a bracket press-fitting section formed near the opening section and having a diameter larger than a stator inner diameter. The bracket includes a bracket resin section configuring a second bearing housing section in which the other bearing of the rotor fits and a bracket sheet metal section press-fit into the bracket press-fitting section of the mold stator. In the bracket, the bracket resin section and the bracket sheet metal section are integrally molded.

Abstract: A rotor resin assembly of a rotor of an electric motor includes a rotor magnet including a substantially cylindrical yoke molded from thermoplastic resin containing a soft magnetic material or ferrite and a resin magnet integrally formed in the outer circumference of the yoke, a position detection magnet arranged at one end in the axial direction of the rotor magnet, and a substantially doughnut-like rotor core arranged in the inner circumference of the rotor magnet and formed by laminating a predetermined number of electromagnetic steel plates. The rotor magnet, the position detection magnet, and the rotor core are integrally formed by resin. A shaft is inserted into an inner diameter section of the rotor core, and the rotor resin assembly is caulked by a jig to form a recess in the vicinity of the inner diameter sections of both end faces of the rotor core and assembled to the shaft.

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 air conditioner equipped with a compressor, an indoor heat exchanger and an outdoor heat exchanger includes: an inverter circuit that drives a motor of the compressor; an inverter-power detecting unit that detects power of the inverter circuit; a PWM-signal generating unit that inverter-current detecting unit generates PWM signals for controlling the inverter circuit; a voltage-command-value generating unit that outputs voltage command values to the PWM-signal generating unit; and an accumulation detecting unit that detects accumulation of a liquid refrigerant within the compressor and outputs a detection result to the voltage-command-value generating unit, wherein when accumulation of a liquid refrigerant within the compressor is detected, the voltage-command-value generating unit outputs the voltage command value so that power of the inverter circuit has a predetermined power value.

Abstract: In order to be able to comply itself to the environment-conscious design standard, a refrigerant heating method is obtained with high efficiency during standby and reduction of vibrations and noises of a bearing in a compressor.

Abstract: The air-conditioning apparatus includes a coolant circuit configured by sequentially connecting a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger; a motor that operates a compressor mechanism disposed inside the compressor; an inverter for driving the motor; and a control unit that controls the inverter. The control unit includes a liquefaction detecting unit that detects coolant liquefaction in the compressor; includes a first PWM signal generating unit that generates an inverter control signal for driving the motor; includes a second PWM signal generating unit that generates an inverter control signal for making the motor perform a preheating operation; and includes a switching unit that performs switching in such a way that the first PWM signal generating unit or the second PWM signal generating unit outputs the corresponding inverter control signal to the inverter.

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: A current detection device for detecting an electric current flowing through an inverter, an overcurrent level generation device for generating an abnormality judgment reference value, an overcurrent detection device for generating an interruption signal to the inverter on the basis of an output of the current detection device and the abnormality judgment reference value, and an adjusting apparatus for correcting the abnormality judgment reference value of the overcurrent level generation device on the basis of the output at a time when a constant electric current is applied to the current detection device are provided. The overcurrent level generating device is provided with one or a plurality of resistance value adjusting sections, and generates the abnormality judgment reference value in correspondence to a resistance value of the resistance value adjusting section.

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: 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: 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.