Mitsubishi Electric Corporation

Ryota Kondo

Satoshi Murakami

Masaki Yamada

Takaaki Takahara

Yusuke Higaki

Naohisa Uehara

Matahiko Ikeda

Hiroyasu Iwabuki

Takashi Kaneyama

Yuta Komatsu

Kazutoshi Awane

Hiroto Mizutani

Mai Uenaka

Yoshiaki Ishiguro

Hidehiko Kinoshita

Akira Nakagawa

Shingo Kato

Yoshihiro Takeshima

Hajime Toyoda

Akinu Nakabayashi

Nobuhiro Kihara

Masaru Kobayashi

Takuya Nakanishi

Yuya Tanaka

Hiroyuki Higashino

Tomokazu Sakashita

Hirokazu Nakabayashi

Kei Hayase

Ryosuke Kobayashi

Yuuya Tanaka

Naoki Moritake

Yutaka Kuboyama

Mai Nakada

Yohei Tan

Tomoyuki Taniguchi

Kazuhiro Fujioka

Shoji Morita

Hiroki Kurahashi

A feedback control unit includes a controller which calculates a duty ratio for switching elements on the basis of a command value and a detection value of electrical information. A continuous/discontinuous current mode distinguishment unit includes a duty ratio increase/decrease distinguishment unit which performs distinguishment between increase and decrease in the duty ratio, and an output voltage detection value increase/decrease distinguishment unit which performs distinguishment between increase and decrease in a detection value of a voltage of second terminals. If the duty ratio has decreased and the detection value of the voltage has increased, or if the duty ratio has increased and the detection value of the voltage has decreased, the continuous/discontinuous current mode distinguishment unit determines that an operation mode is a discontinuous current mode, and feeds back a result of the determination to the feedback control unit.

Device for controlling power conversion circuit

To provide a controller for power conversion circuit which can maintain the detection value of second voltage at the target value of second voltage without depending on feedback control, when the first voltage is varied. A controller for power conversion circuit changes a control value by feedback control so that the detection value of second voltage approaches a target value of second voltage; calculates a control value for control, by correcting the control value based on the detection value of first voltage so as to correct, in feedforward manner, a change of the control value due to a change of the first voltage if correction of the control value is not performed; and controls on/off the switching device based on the control value for control.

Power conversion circuit controller with feedforward correction

A setting unit sets a duty ratio of a PWM signal based on a target voltage value, and outputs the duty ratio to a voltage conversion circuit. An estimated value calculation unit cyclically calculates an estimated duty ratio value based on the detected input voltage value and the detected output voltage value. An abnormality detection unit cyclically calculates, as a difference value, a difference between an updated estimated value and a comparison reference value, and detects abnormality of a voltage detection unit based on a change in calculated difference value. The updated estimated value is a newly calculated estimated duty ratio value. The comparison reference value is a value based on the estimated duty ratio value calculated in a cycle prior to a cycle in which the updated estimated value is calculated.

Power conversion device

A power conversion device and a motor system according to the present disclosure comprises an inverter circuit which is connected to a motor, a switch circuit, and a control circuit. The power conversion device and the motor system are characterized in that the inverter circuit and the switch circuit are capable of two-level operation and three-level operation, and the control circuit switches between the two-level operation and the three-level operation on the basis of the motor torque command and the rotational speed command. As a result, it is possible to reduce the total loss in the power conversion device and the motor.

Power conversion device and motor system

An inverter is provided for driving a motor. A first capacitor, and a second capacitor including capacitors connected in series, are connected in parallel to a DC power supply. A switch circuit having switching elements is connected between the inverter and the second capacitor. A control circuit is provided for controlling the inverter and the switch circuit. The control circuit performs control to switch the switch circuit so as to supply current from the second capacitor to the inverter during 3-level operation, and supply current from both of the first capacitor and the second capacitor to the inverter during 2-level operation.

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.

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 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 parallel power supply device includes a plurality of DC/DC converters connected in parallel, and each DC/DC converter includes: first and second switching circuits with a transformer therebetween; first and second reactors; and a control circuit. The control circuit generates a duty cycle so that a deviation between voltage of a load and target voltage becomes 0. Correction is performed such that, when the magnitude of the duty cycle is smaller than a set value Vth, the magnitude is fixed at 0, and otherwise, the magnitude is decreased by the set value Vth. Then, the phase shift amounts for drive signals for the first and second switching circuits are determined, and the first and second switching circuits are subjected to phase shift control.

Parallel power supply device

A DC/DC converter enabling a step-up operation and a step-down operation in a bidirectional power transmission, and capable of adjusting transmission power amount with a good response. A DC/DC converter decreases a first phase shift amount and increases a second phase shift amount, as a first transmission power amount increases, when a first transmission power amount is larger than a first reference point.

DC/DC converter

A gate drive circuit including a drive-on element that applies an on-state voltage to a gate of a drive target semiconductor element and a drive-off element that applies an off-state voltage to the gate is such that a recovery switch, a reactor, and a capacitor are connected in series between output terminals of the gate drive circuit as a recovery circuit that can recover a charge accumulated in input capacitance of the drive target semiconductor element when turning on, and the drive-on element, the drive-off element, and the recovery switch are controlled by a control circuit, whereby power consumption of the gate drive circuit is reduced.

Gate drive circuit, that supplies power to a gate of a semiconductor switching element, and carries out a driving on and off of the gate

A temperature estimation device calculates a first estimation temperature of a reactor on the basis of a reference estimation temperature to which a first lag period is provided and outputs from a temperature change amount calculation unit to which a second lag period is provided, predicts a second temperature change amount of the reactor over a predetermined period on the basis of the first estimation temperature, and then predicts a second estimation temperature of the reactor.

Temperature estimation device and electric device

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.

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Chiyoda-ku, Japan

Ryota Kondo