Panasonic Intellectual Property Management Co., Ltd.

Kenji Hanamura

Shun Kazama

Hiroyuki Fujii

Hajime Hida

Wataru Horio

Shogo Hirota

Fumito Kusama

Fumiiki Yoneda

Tomoki Ito

Masayuki Nakahara

Takashi Shirakawa

Kota Maeba

Akihiro Kikuchi

Kazunori Kidera

For power transfer from a first DC part to a second DC part in a dual active bridge (DAB) converter by stepping down a voltage, a first bridge circuit includes a period in which the first DC part and a primary winding of an insulated transformer conduct and a period in which ends of a primary winding of the insulated transformer are short-circuited in the first bridge circuit. A second bridge circuit includes a rectification period. A control circuit variably controls a phase difference between a first leg a the second leg, variably controls a simultaneous off period of a fifth switching element and a sixth switching element, and variably controls a simultaneous off period of a seventh switching element and an eighth switching element.

Power conversion device

For power transfer from a first DC part to a second DC part in a dual active bridge (DAB) converter by stepping up a voltage, the second bridge circuit includes a period in which a secondary winding of an insulated transformer and the second DC part conduct and a period in which ends of the secondary winding of the insulated transformer are short-circuited in the second bridge circuit. A control circuit fixes a phase difference between a first leg a the second leg, variably controls a simultaneous off period of a fifth switching element and a sixth switching element, and variably controls a simultaneous off period of a seventh switching element and an eighth switching element.

An electric power tool includes an electric motor (AC motor), an impact mechanism, an impact detecting unit, and a measuring unit. The impact mechanism performs an impact operation that generates impacting force by receiving motive power from the electric motor. The impact detecting unit determines whether or not the impact operation is being performed. The measuring unit measures at least one of a d-axis current or a q-axis current, each of which is supplied to the electric motor. The impact detecting unit determines, based on at least one of a measured value (current measured value) of the d-axis current or a measured value (current measured value) of the q-axis current, whether or not the impact operation is being performed. The measured values (current measured values) of the d-axis current and the q-axis current have been obtained by the measuring unit.

Electric power tool

An electric tool includes an AC motor (an electric motor) and a control unit. The AC motor includes a permanent magnet and a coil. The control unit is configured to perform control on operation of the AC motor. The control performed by the control unit includes field weakening control. In the field weakening control, the control unit causes a flux-weakening current to flow through the coil. The flux-weakening current is a current that generates, in the coil, a magnetic flux that weakens a magnetic flux of the permanent magnet.

Electric tool

An inverter circuit includes a plurality of flying capacitors and converts a DC voltage supplied from a DC power supply into an AC voltage. A filter circuit approximates a waveform of an output voltage of the inverter circuit to a sinusoidal wave. An excess current protection circuit supplies a block signal for turning off a plurality of switching elements to the driving circuit when an excess current is detected. When at least one of an abnormal voltage in any of the plurality of flying capacitors and an abrupt change in an output voltage of the power converter occurs, voltages other than a positive voltage of the DC power supply, a negative voltage of the DC power supply, and a zero voltage are restricted from being output from the inverter circuit.

A power converterincludes: flying capacitor circuitsandconnected in series so as to be in parallel with a DC power supply; flying capacitor circuitsandconnected in series so as to be in parallel with the DC power supply; switching elements Sand Sconnected in series between output terminals of the flying capacitor circuitsand; switching elements Sand Sconnected in series between output terminals of the flying capacitor circuitsand; a first output end OUTprovided at a midpoint between the switching elements Sand S; and a second output end OUTprovided at a midpoint between the switching elements Sand S, wherein a node between the flying capacitor circuitsandand a node between the flying capacitor circuitsandare connected to a midpoint of a DC power supply voltage.

Power converter

In a power converter including: a first DC-DC converter, an inverter, and a control circuit, a second DC-DC converter that controls an input and an output of a power storage unit is connectable to a DC bus. The control circuit deactivates a reverse power flow suppression function for suppressing a reverse power flow from the inverter to a power system when the second DC-DC converter is not connected to the DC bus and activates the reverse power flow suppression function when the second DC-DC converter is connected to the DC bus.

Power converter, power conversion system

The converter circuit includes an inverter. The converter circuit receives DC power from a DC power supply (such as a solar cell or a storage battery unit), has the DC power converted into AC power by at least the inverter, and outputs the AC power to a load or a power grid. When acquiring information that two or more types of power curtailment causes have arisen, a control circuit makes the converter circuit limit power output to a maximum degree of power curtailment out of two or more degrees of power curtailment according to specifics of the two or more types of power curtailment causes.

Power conversion system, method for controlling converter circuit, and program

In a power converter, a DC bus is supplied with a DC power from a voltage conversion circuit for regulating a voltage of a power output from a DC power supply, a voltage of the DC power being regulated by the voltage conversion circuit. An inverter converts a DC power on the DC bus into an AC power and supplies the AC power as converted to a power system. A controller controls the inverter. When it is necessary to suppress an output, the controller suppresses the AC power supplied by the inverter to increase a voltage on the DC bus.

Power conversion apparatus, power conversion system, and method for controlling power conversion apparatus

A drive device according to one aspect of the disclosure includes a control terminal connector, a switch circuit, a current limit circuit, and a clamp switch on a circuit board. The clamp switch is located in a second quadrant or a fourth quadrant of four quadrants, where the four quadrants are partitioned by two mutually orthogonal virtual lines with the current limit circuit set as an origin and the four quadrants consist of a first quadrant including an area where the control terminal connector is located, the second quadrant, a third quadrant, and the fourth quadrant, in clockwise order.

Electric device including a switch circuit, a current limit circuit and a clamp swith, for driving a power switch

A driving apparatus of the present disclosure includes a coil including a second terminal connected to a control terminal of a switching element, a charging switch connected between a first potential line and a first terminal of the coil, a clamp switch connected between the first potential line and the control terminal of the switching element, a charging diode connected between a second potential line and the first terminal of the coil, and a control circuit that outputs a charging control signal for turning on the charging switch and for turning off the charging switch before a potential of the control terminal of the switching element reaches the first potential and a clamp control signal for turning on the clamp switch after the charging switch is turned on.

Driving apparatus and electric power converter

A driving apparatus includes a first potential line that applies a first potential, a second potential line that applies a second potential, a coil including a first terminal and a second second terminal that is connected to a control terminal of a switching element, a charging switch connected between the first potential line and the first terminal of the coil, a clamp switch provided between the first potential line and the second terminal of the coil, a reverse-flow blocking diode connected in series with the clamp switch between the first potential line and the second terminal of the coil, and a control circuit that controls the charging switch and the clamp switch.

Growing community of inventors

Osaka, Japan

Kenji Hanamura