Mitsubishi Electric Corporation

Takaaki Takahara

Ryota Kondo

Satoshi Murakami

Masaki Yamada

Hiroyasu Iwabuki

Naohisa Uehara

Hiroto Mizutani

Hajime Toyoda

Koichi Arisawa

Keisuke Uemura

Hidehiko Kinoshita

Haruka Matsuo

Koyo Matsuzaki

Kenji Takahashi

Takuya Nakanishi

Hiroyuki Higashino

Yusuke Higaki

Tomokazu Sakashita

Tomohiro Kutsuki

Masaru Shinozaki

Yuta Komatsu

Yoshikazu Yaji

Kei Hayase

Yuuya Tanaka

Ryuji Momose

Yasunori Otsuka

This disclosure provides an outdoor unit for an air-conditioning apparatus with improved reliability. The outdoor unit () includes a housing whose inside is divided into a fan chamber () and a machine chamber (). A compressor and a reactor that are heat-generating components are provided in a lower area of the machine chamber (). An electric board () including a printed circuit board () and an electric component (), and an electric component box () constituted by an inner box () and an outer box () and accommodating the electric board are provided above the heat-generating components. A lower face of the inner box (first thermal insulation plate) and a lower face of the outer box (second thermal insulation plate) constitute a double thermal insulation plate ().

Outdoor unit for air-conditioning apparatus

A power conversion device includes a rectification unit that rectifies first alternating current (AC) power supplied from a commercial power supply, a capacitor connected to an output end of the rectification unit, an inverter that converts power output from the rectification unit and from the capacitor into second AC power, and outputs the second AC power to a load including a motor, which inverter is connected to both ends of the capacitor, and a control unit that controls operation of the inverter to output the second AC power from the inverter to the load to reduce current flowing to the capacitor, which second AC power includes a pulsation that depends on a pulsation of power flowing from the rectification unit to the capacitor. No discharge circuit and no overvoltage protection circuit are provided for the capacitor.

Power conversion device, motor drive unit, and refrigeration cycle apparatus

A power converter includes a converter, a smoothing capacitor, an inverter, and a single calculator. The converter includes a switching element and rectifies a power supply voltage applied from an alternating-current power supply. The smoothing capacitor smooths a rectified voltage output from the converter into a direct-current voltage including a ripple. The inverter converts the direct-current voltage smoothed by the smoothing capacitor into an alternating-current voltage for a motor. The calculator performs control such that a first physical quantity representing an operation state of the converter is equal to a second physical quantity representing an operation state of the inverter.

Power converter, motor driver, and refrigeration cycle applied equipment

Provided is a power conversion device that can suppress interference between control of input current from an AC power supply and voltage control for a DC capacitor to perform both the controls with high accuracy, and can reduce the capacitance and size of the DC capacitor. A power conversion circuit includes a rectification bridge circuit, a leg circuit having upper and lower legs connected in series, a DC capacitor, a smoothing capacitor, and a reactor. A control circuit performs PWM control of the leg circuit by generating a duty cycle so as to control a voltage of the DC capacitor while controlling an input current from an AC power supply, in a control cycle. When the duty cycle is generated, a sum of duty cycles is made constant in one cycle for each leg.

Power conversion device that can suppress interference between control of input current from an AC power supply and voltage control for a DC capacitor

A period from when switching elements S, Sat first diagonal positions in a full-bridge inverter are turned off at the same time to when switching elements S, Sat second diagonal positions are turned on at the same time, is defined as T, and a period from when the switching elements S, Sat the second diagonal positions are turned off at the same time to when the switching elements S, Sat the first diagonal positions are turned on at the same time, is defined as T. With a total length of Tand Tset to be constant, the lengths of Tand Tare controlled to be changed every switching cycle.

Power conversion device

An output terminal of a contact type charger connected to an AC power supplyand being for boosting or stepping down an input voltage, and an output terminal of a non-contact type charger for receiving power in a non-contact manner are connected to an input terminal of a DC/DC converter via an integrated bus, a DC link capacitor is connected between an AC/DC converter and an isolated DC/DC converter included in the contact type charger, an integrated capacitor is connected to the integrated bus, and a control circuit adjusts a DC voltage of the DC link capacitor or the integrated capacitor such that at least one of power losses or a total power loss of the contact type charger, the non-contact type charger, and the DC/DC converter is reduced.

Power conversion device having a configuration for simultaneous wired and wireless charging

A power conversion device includes: a main body including a substrate to which a power conversion unit and a coil are provided; and a first heat dissipation portion which holds the substrate and dissipates heat of the substrate, wherein the substrate is formed by one sheet, the coil is formed integrally with the substrate, the first heat dissipation portion is fixed to a substrate first surface of the substrate, a heat dissipation second surface of the first heat dissipation portion has a coil cooling portion opposed to and abutting on a part where the coil is formed, of the substrate.

Power converter

A DC capacitor and a leg are connected in parallel to a high-voltage-side power line and a low-voltage-side power line. The leg includes a plurality of semiconductor switching elements connected in series between the power lines with an output end, connected to a load, between the plurality of semiconductor switching elements. An attenuator for attenuating a resonance is connected to a main circuit loop formed of the DC capacitor, the high-voltage-side power line, the low-voltage-side power line, a semiconductor switching element in ON state, and a drain-source parasitic capacitance of a semiconductor switching element in OFF state.

A control circuit performs at least pulse width modulation control on a first leg and selects to perform pulse width modulation control and pulse frequency modulation control, to perform pulse width modulation control and phase shift modulation control, or to perform pulse width modulation control, pulse frequency modulation control, and phase shift modulation control on a second leg, based on comparison of a voltage conversion ratio between DC voltage of a DC capacitor and output voltage to a load with at least one threshold.

Power conversion apparatus

A power conversion device including: a reactor formed such that a DC winding and a plurality of coupled windings are wound around one magnetic body, one end of the DC winding is connected to a voltage source, one end of each of the plurality of coupled windings is connected to another end of the DC winding, another end of each of the plurality of coupled windings is connected to each intermediate connection point between a plurality of upper and lower arms composed of switching elements, and magnetic fluxes generated by currents flowing through the DC winding and the coupled windings merge with each other in the same direction; and a control device for controlling the switching elements, wherein the upper arms or the lower arms are controlled by in-phase driving or interleave driving on the basis of the duty of switching operation.

Power conversion device with in-phase and interleave driving based on determination of duty ratio

A power conversion device includes an input detector for detecting input parameters of the DC input to the inverter; an output detector for detecting output parameters of the DC output from the power converter device; a duty calculator for calculating a duty for the switching elements of the inverter; a frequency search range calculator for determining an upper limit and a lower limit of a frequency search range for determining the drive frequency after the operating condition is changed, using at least one parameter of the input parameters, the output parameters, and a duty parameter; and a frequency search processor for determining the drive frequency by searching the frequency search range.

Power conversion device with high power conversion efficiency

A full-bridge inverter is configured with a parallel connection of a first leg and a second leg, and controlled in a dual-leg resonant mode in which a positive-side switching element of the first leg and a negative-side switching element of the second leg are turned on/off at the same time and a negative-side switching element of the first leg and a positive-side switching element of the second leg are turned on/off at the same time, and controlled in a single-leg resonant mode in which the positive-side switching element of the first leg and the negative-side switching element of the second leg, and the negative-side switching element of the first leg and the positive-side switching element of the second leg are turned on/off shiftedly in time by a phase shift amount.

Power conversion device with operation in dual-leg resonant mode or single-leg resonant mode

This power conversion device includes: a rectification circuit; an inverter circuit having a full-bridge configuration, and having a DC capacitor, and first and second legs each of which has two switching elements connected in series to each other; a transformer; and a control circuit for controlling operation of the inverter circuit, wherein the control circuit controls an ON period for the first leg, thereby controlling increase/decrease in current flowing through a first rectification circuit from an AC input, and controls an ON period for the second leg and a phase shift amount between the ON period for the first leg and the ON period for the second leg, thereby controlling voltage of the DC capacitor to be constant. Thus, it becomes possible to achieve high-power-factor control and output power control at the same time by a single stage of full-bridge inverter circuit.

Power convertor

A transformer is composed of three or more windings magnetically coupled. An AC/DC converter () for converting AC power of an AC power supply (), a capacitor (), and a switching circuit () are connected to one winding (), and a switching circuit () or () for power conversion of a DC power supply is connected to at least one of the other windings. Voltage of the capacitor () or the AC power supply () is detected. On the basis of the detected value thereof, the operation state of each switching circuit (), (), () is determined by an operation state determination circuit (). On the basis of a result of the determination, the power supply is switched among the AC power supply () and the DC power supplies () and () by an output switch circuit ().

Power conversion device which detects power shortage and switches to a power supply that is capable of supplying power

A power conversion device includes a reactor, a single-phase inverter, and a single-phase converter which are connected in series to each other between an AC power supply and a smoothing capacitor, and performs power conversion between AC voltage of the AC power supply and DC voltage of the smoothing capacitor. The power conversion device includes a control unit which controls switch elements of the single-phase inverter and switch elements of the single-phase converter so that charging operation and discharging operation of the DC capacitor are performed in one switching cycle of the single-phase inverter and the charging amount and the discharging amount thereof are equal to each other.

Growing community of inventors

Chiyoda-ku, Japan

Takaaki Takahara