A switching operation is performed on a switching element of a power-factor improving unit that includes a reactor. An output voltage of the power-factor improving unit is set to a load voltage by switching on and off the switching element based on a result of comparison between an input current and an input-current reference signal of a power-supply voltage waveform. A zero cross of an alternate-current power supply is detected, and the switching operation is performed on the switching element a predetermined number of times based on a detection of the zero cross.

Power Supply Device

A switched reluctance motor includes: a stator including a cylindrical body, a plurality of salient poles coupled to an inner circumferential surface of the cylindrical body and provided with a winding coil, and an exterior member formed as a cylindrical shape by encompassing an assembly formed by coupling of the cylindrical body, the salient poles and the like; a rotor rotatably inserted inside the exterior member of the stator; a rotary shaft coupled to the rotor; and a phase indication magnet coupled to the rotor or the rotary shaft. Accordingly, an external structure of the motor is simplified, and the number of components and the number of assembling processes are remarkably reduced.

Switched reluctance motor

A power conversion device includes a power switching circuit that supplies AC voltages generated between switching elements operating as upper arms and switching elements operating as lower arms, and a control circuit that generates and supplies to the driver circuit signals for controlling the switching operation of the switching elements by a PWM method in a first operational region in which frequency of an AC power to be outputted is low, and that generates and supplies to the driver circuit signals for controlling the switching operation of the switching elements at timings based upon the phase of the AC power to be outputted in an operational region in which the frequency of the AC power to be outputted is higher than in the first operational region.

Power Conversion Device

A variable magnetic flux motor drive system includes: a variable magnetic flux motor having a variable magnet which is a low-coercive permanent magnet; an inverter that drives the variable magnetic flux motor 1; an inverter as a magnetization unit which supplies a magnetization current for controlling a magnetic flux of the variable magnet; and a boosting unit boosting an input DC voltage to a predetermined target value to output it to the inverter. The variable magnetic flux motor drive system makes it possible to achieve size reduction and high efficiency, while securing a voltage required for supplying a magnetization current when controlling the magnetic flux of the variable magnet.

Variable magnetic flux drive system

An electric power converter for a vehicle, including a semiconductor element from which a motor drive current is output, a drive circuit that drives the semiconductor element, a control circuit that controls the drive circuit, a capacitor that smooths a DC current to be input to the semiconductor element, a container housing the semiconductor element, the drive circuit, the control circuit and the capacitor, a refrigerant retained in a state of vapor-liquid two-phase equilibrium within the container, and a heat exchanger unit that condenses the refrigerant in a vapor phase to be a liquid phase and exchanges heat with outside, wherein the semiconductor element, the drive circuit, the control circuit and the capacitor are disposed in a positional arrangement that will leave the semiconductor element, the drive circuit, the control circuit and the capacitor immersed in the refrigerant as the electric power converter is installed in the vehicle, and the heat exchanger unit is disposed at a side of a wall of the container forming a vapor-phase space.

Electric Power Converter

PROBLEM TO BE SOLVED: To provide a hot water supply device capable of preventing breaking of a pump-loading circuit by improving accuracy in detecting a temperature of a power circuit, and increasing an output of a pump SOLUTION: This hot water supply device comprises a heat exchanger for exchanging heat between a refrigerant and the water, a tank for storing the water, and a pump for circulating the water, the pump comprises a pump portion comprising a second casing having a suction opening and a discharge opening of the water, and an impeller, a stator portion comprising an iron core formed by stacking electromagnetic steel plates, a winding wire inserted into the iron core, a circuit board 13 on which a driving circuit is mounted, and a first casing, and molded with a mold resin, and a rotor portion comprising a bearing approximately at its central portion, and provided with a wheel at an outer side of the bearing and a magnet portion at an outer side of the wheel, and the driving circuit is a circuit for driving a brushless DC motor composed of the stator portion and the rotor portion, and comprises the power circuit 32 and a temperature detecting circuit 40 detecting a temperature of the power circuit 32 COPYRIGHT: (C)2008,JPO&INPIT

Hot water supply device

PROBLEM TO BE SOLVED: To provide a synchronous motor driving device wherein rectangular wave excitation in which any excitation width between 120° and 180° inclusive is selectable and sine wave excitation can be accomplished by one piece of circuitry, and the excitation wave form can be changed in a very short time according to driving conditions (high-efficiency driving conditions, low-noise driving conditions) required for a synchronous motor to be driven. SOLUTION: The synchronous motor driving device is used to drive a synchronous motor through an inverter device. The driving device comprises: an output voltage vector computing means that determines the output voltage vector outputted by the inverter device according to a command value of rotational speed; a rectangular wave exciting means that outputs voltage in rectangular waveform with any excitation width between 120° and 180° inclusive according to the output voltage vector; a sine wave exciting means that outputs voltage by sine waveform excitation according to the output voltage vector; and an excitation waveform selecting means that selects an excitation method and an excitation width according to conditions required in driving the synchronous motor. COPYRIGHT: (C)2005,JPO&NCIPI

Synchronous motor driving device, control method for synchronous motor driving device, refrigerator-freezer, and air conditioner

PROBLEM TO BE SOLVED: To provide a motor drive control device that reduces harmonic current without increasing cost and the size of a circuit, and a compressor, an air blower, an air conditioner and a refrigerator or a freezer which use the motor drive control device.SOLUTION: A motor drive control device includes: a three-phase rectifier 2; a step-up converter unit 3; switching control means 10; a smoothing capacitor 7 that smooths output from the step-up converter unit 3; an inverter circuit 12 that converts output from the step-up converter unit 3 to AC voltage and supplies the AC voltage to a motor 15; inverter drive means 14 that drives the inverter circuit 12; a bus current detection part 8 that detects bus current; an output voltage detection part 9 that detects output voltage from the step-up converter unit 3; and an imbalance component detection part that detects imbalance of a three-phase AC power source, on the basis of output from the bus current detection part 8. The switching control means 10 determines on-duty of a switching element 5 and performs control such that input current from the three-phase AC power source becomes balanced.

Motor drive control device, compressor, air blower, air conditioner and refrigerator or freezer

PROBLEM TO BE SOLVED: To provide a motor drive controller for reducing a harmonic current without cost increase and enlargement of a circuit, and to provide a compressor, a blower, an air conditioner and a refrigerator or a freezer using the same. SOLUTION: The motor drive controller includes a three-phase rectifier 2, a voltage step-up converter 3 equipped with a reactor 4, a switching element 5 and a diode 6 and stepping up an output voltage of the three-phase rectifier 2, a switching control means 10 for controlling the switching element 5 of the voltage step-up converter 3, a smooth capacitor 7 for smoothening the output of the voltage step-up converter 3, an inverter circuit 12 for converting the output of the voltage step-up converter 3 to an AC voltage and supplying the converted AC voltage to a motor 15, and an inverter driving means 14 for driving the inverter circuit 12. The switching control means 10 controls the on-duty of a switching element 5 so that a power supply current is formed into a rectangular wave. COPYRIGHT: (C)2010,JPO&INPIT

Motor drive controller, compressor, blower, air conditioner and refrigerator or freezer

PROBLEM TO BE SOLVED: To provide a permanent magnet synchronous motor drive, reducing costs by suppressing a generated regenerative voltage without increasing the number of parts when a permanent magnet synchronous motor is rotated forcibly. SOLUTION: The permanent magnet synchronous motor drive is provided with: an inverter 40 which receives a DC voltage of DC power supply 10 and outputs voltage to a permanent magnet synchronous motor 30; a DC voltage detection means 90 for detecting the DC voltage inputted to the inverter 40; and an inverter control means 50 for controlling the voltage outputted from the inverter 40. The inverter control means 50 controls the inverter so as to perform at least opening or short-circuiting between the inverter 40 and the permanent magnet synchronous motor 30 based on the output at the time of regeneration detected by the DC voltage detection means 90. COPYRIGHT: (C)2010,JPO&INPIT

Yamada Tomoo

Papers

Hot water supply device

Synchronous motor driving device, control method for synchronous motor driving device, refrigerator-freezer, and air conditioner

Motor drive control device, compressor, air blower, air conditioner and refrigerator or freezer

Motor drive controller, compressor, blower, air conditioner and refrigerator or freezer

Permanent magnet synchronous motor drive, air conditioner, ventilating fan drive, washing machine, automobile, and vehicle