Mitsubishi Electric Corporation

Shota Kamiya

Kazunori Hatakeyama

Kenta Yuasa

Shinsaku Kusube

Shinya Matsushita

Yosuke Shinomoto

Tsutomu Makino

Norikazu Ito

Shoji Isoda

Keisuke Uemura

Takashi Yamakawa

A heat pump device includes a compressor including a motor, a heat exchanger, an inverter, and an inverter control unit. The inverter control unit generates a drive signal for the inverter. When the compressor is heated, the inverter control unit applies, to the motor, a high-frequency voltage with which the motor cannot be rotationally driven; estimates a magnetic pole position indicating a stop position of a rotor of the motor; determines an amplitude and a phase of a voltage command based on an estimation result of the magnetic pole position and a necessary amount of heat, and generates a drive signal.

Heat pump device, air conditioner, and freezer

A direct-current power supply device includes a switching unit constituted by a first switching element and a second switching element and a control unit that controls the operations of the first witching element and the second switching element. The switching unit has a first mode in which on-duty is a first value and a second mode in which the on-duty is a second value larger than the first value. When transitioning the switching unit from the first mode to the second mode, the control unit controls the switching unit such that the time until the on-duty reaches the second value is equal to or longer than a fixed time and controls, after the on-duty reaches the second value, an operation cycle of the switching unit to extend the operation cycle.

Direct-current power supply device, motor driving device, air conditioner, and refrigerator

To provide a DC power-supply device that can suppress voltage unbalance of a plurality of capacitors serially connected between both terminals of a load, achieve stable drive of the load and long life of the capacitors, and contribute to high reliability, in a configuration in which an alternating current is converted into a direct current and is supplied to a load, and a refrigeration-cycle application device including the DC power-supply device. The DC power-supply device includes a rectifier circuit, a reactor connected to an input or an output side of the rectifier circuit, a first capacitor and a second capacitor serially connected between output terminals to a load, a charging unit that selectively charges one or both of the first capacitor and the second capacitor, and further includes a control unit that controls the charging unit so that voltage unbalance between the first capacitor and the second capacitor is suppressed.

DC power-supply device and refrigeration-cycle application device including the same

A first reactor is provided on the input side of a rectifying circuit that rectifies AC power (on the side of an AC power supply), and on the output side of the rectifying circuit (on the side of a load), first and second capacitors that are connected in series to each other, and first and second switching elements that switch between charging and not charging of the first and second capacitors, respectively, are provided, a second capacitor group in Y-connection, provided with three capacitors, each of which is connected to each phase-terminal of the first reactor on the side of the rectifying circuit, is connected to the midpoint of the first and second switching elements, and the output voltage to the load is boosted, while the on-duty of the first switching element and the on-duty of the second switching element are controlled to be equal to each other.

DC power-supply device, motor drive device including the same, and refrigeration-cycle application device including the motor drive device

A heat pump device includes: a compressor including a compression mechanism compressing a refrigerant and a motor driving the compression mechanism; an inverter unit applying a voltage for driving the motor; an inverter control unit generating a driving signal for driving the inverter unit; and temperature sensors detecting temperatures of the compressor, wherein the inverter control unit includes a normal operation mode in which a refrigerant is compressed by performing a normal operation of the compressor and a heating operation mode in which a heating operation of the compressor is performed by applying, to the motor, a high-frequency voltage, and in the heating operation mode, the inverter control unit determines an amplitude and a phase of a voltage command for generating the high-frequency voltage on a basis of a temperatures detected by the temperature sensors and a necessary amount of heat specified in advance.

A DC power-supply device that suppresses an excessive inrush current, can prevent breakage of elements and burnout of circuits, and converts alternating current from a three-phase AC power supply into direct current to supply it to a load, includes a rectifier circuit having a reactor connected to input or output side thereof and rectifying the alternating current from the three-phase AC power supply; first and second capacitors and connected in series between output terminals to the load; a charging unit selectively charges one or both of the first and second capacitors; and a control unit controlling the charging unit. When charging of the first and second capacitors is started, the control unit reduces the on-duty ratio, and then, until the on-duty ratio during a normal operation is reached, the control unit executes control such that the on-duty ratio is gradually increased as a predetermined time period is passed.

DC power-supply device and refrigeration cycle device

A heat pump device capable of efficiently and reliably preventing a liquid refrigerant from stagnating in a compressor an air conditioner, a heat pump water heater, a refrigerator, and a freezing machine including the heat pump device. The configuration is such that, when the compressor is under operation standby, a high-frequency voltage synchronizing with a carrier signal is supplied to the compressor motor to carry out the locked energization of the compressor motor. From respective inter-phase voltages, respective phase voltages, or respective phase currents of the compressor motor for a plurality of high-frequency energization cycles, the detection values for one high-frequency energization cycle are restored. A power value calculated using the restored detection values for one high-frequency energization cycle is controlled to coincide with a heating power command necessary for discharging the liquid refrigerant stagnated in the compressor to the outside of the compressor.

Heat pump device, and air conditioner, heat pump water heater, refrigerator, and freezing machine including heat pump device

A heat pump device includes: a compressor that compresses a refrigerant; a motor that drives the compressor; a wiring switching unit that switches a wiring structure of the motor; an inverter that applies a desired voltage to the motor; and an inverter control unit that generates a PWM signal for driving the inverter, that includes, as an operation mode, a heating operation mode in which a heating operation is performed on the compressor and a normal operation mode in which a refrigerant is compressed by performing a normal operation on the compressor, and that controls a switching operation of the wiring switching unit in accordance with an operation mode.

Heat pump device, heat pump system, air conditioner, and freezer

A heat pump device includes a compressor including a compression mechanism that compresses a refrigerant and a motor that drives the compression mechanism, an inverter that applies a voltage for driving the motor, a converter that applies a voltage to the inverter, an inverter control unit that generates a driving signal for driving the inverter, and a converter control unit that generates a driving signal for driving the converter. The inverter control unit includes a heating-operation-mode control unit that controls a driving-signal generating unit such that the driving-signal generating unit outputs, as inverter driving signals, PWM signals for heating the compressor without rotationally driving the motor by feeding a high-frequency current that the motor cannot follow in a heating operation mode.

Heat pump device, air conditioner, and freezer that efficiently heats refrigerant on standby

A DC power-supply device that suppresses an increase of a harmonic current and deterioration of a power factor without causing any imbalance among respective phase currents, in a configuration in which a three-phase alternating current is converted into a direct current and supplied to a load. The DC power-supply device includes a rectifier circuit, a reactor connected to an input side or an output side of the rectifier circuit, a first capacitor and a second capacitor serially connected between output terminals to a load, and a charging unit. During a cycle combining a charging period and a non-charging period of a pair of the first capacitor and the second capacitor, the charging unit is controlled so that a charging frequency becomes 3n times (n is a natural number) the frequency of the three-phase alternating current.

A direct-current power supply device includes a rectifier connected to a power supply, a charge storage unit configured by a first capacitor and a second capacitor connected in series, a switching unit configured by a first switching elementand a second switching element connected in series and backflow preventing elements that suppress a backflow of electric charges from the charge storage unit, a reactor, a control unit that controls operations of the first switching element and the second switching element, and a direct-current-voltage detecting unit that detects a first both-end voltage, which is a voltage across the first capacitor, and a second both-end voltage, which is a voltage across the second capacitor. The control unit detects, on the basis of a voltage difference between the first both-end voltage and the second both-end voltage, a short-circuit failure of one of the first switching element and the second switching element.

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Tokyo, Japan

Shota Kamiya