Abstract: A control device generates a voltage command value for controlling a current flowing between a three-phase AC power supply and a power converter such that a full voltage representative value representing voltage values of all power storage devices agrees with a DC voltage command value. The control device generates a zero-phase voltage command value for controlling a circulating current flowing in a delta connection such that the voltage values of the power storage devices are balanced among first to third arms. The control device combines the voltage command value and the zero-phase current command value to generate an output voltage command value for controlling an output voltage of each unit converter. The control device removes a control amount of the full voltage representative value from a computation of the zero-phase voltage command value to cause output current control and circulating current control not to interfere with each other.

Abstract: An endoscope system includes: an endoscope including an insertion portion whose front end is inserted inside a subject; a heater disposed at the front end and configured to heat a predetermined member disposed at the front end; a plurality of thermometers disposed near the predetermined member at the front end and configured to detect temperatures at the front end; a power source configured to supply electrical power to the heater; determination circuitry configured to determine whether or not highest temperature, from among the temperatures detected by the plurality of thermometers, is equal to or higher than a first threshold value; and a power controller configured to control, based on determination result of the determination circuitry, the electrical power supplied by the power source to the heater.

Abstract: A stereo image pickup unit includes: first and second image pickup apparatuses including first and second image pickup devices and first and second mount boards, the image pickup apparatuses being formed in a same shape each other; and a holding frame for holding the first and second image pickup devices, the first and second mount boards including non-mounting surfaces perpendicular to rear surfaces of the first and second image pickup devices and projecting toward an outer side of projection surfaces of the first and second image pickup devices, the holding frame holding the first and second image pickup apparatuses such that the non-mounting surfaces are opposed to each other on a parallax direction inner side.

Abstract: A power conversion device includes a plurality of leg circuits and a control device. The plurality of leg circuits correspond to respective phases of an AC circuit and connected in parallel between common first and second DC terminals. Each leg circuit includes a plurality of chopper cells each including an energy storage and cascaded to one another and at least one inductance connected in series to the plurality of chopper cells. The control device controls an operation of only at least one chopper cell included in each leg circuit based on a circulating current which circulates through the leg circuits.

Abstract: A lens includes a cover part and a light-shielding part. The cover part includes a lens part, a connection part, and a plurality of flange parts, formed with a thermosetting first resin and continuous to one another. The light-shielding part covers lateral end surfaces and an upper surface of each of the flange parts and outer lateral sides of the connection part and formed with a thermosetting second resin having a greater light-absorptance or a greater light-reflectance than the thermosetting first resin.

Abstract: A lens includes a cover part and a light-shielding part. The cover part includes a lens part, a connection part extending downward from lateral sides of the lens part, and one or more flange parts each extending outward from a lower-end portion of the connection part. The lens part and the connection part define a recess having an opening facing downward. The flange parts extend outward from a periphery of the opening of the recess. The lens part, the flange parts, and the connection part are formed of a thermosetting first resin and continuous to one another. The light-shielding part covers outer lateral surface of the connection part and is formed of a thermosetting second resin having a greater light-absorptance or a greater light-reflectance than the thermosetting first resin. The flange parts have a greater thickness than the connection part.

Abstract: A lens includes a cover part and a light-shielding part. The cover part includes a lens part, a connection part, and a flange part which are formed of a thermosetting first resin and continuous to one another. The light-shielding part covers an outer lateral side of the connection part and is formed of a second resin having a greater light-absorptance or a greater light-reflectance than the first resin.

Abstract: A DC transmission system transmits AC power generated by a generator to an AC distribution grid and a DC distribution grid using DC power. The DC transmission system includes an AC/DC converter, a DC/DC converter, and a DC/AC converter. The AC/DC converter outputs DC power by converting AC power from the generator. The DC/DC converter boosts a first voltage of the DC power outputted from the AC/DC converter, into a second voltage. The DC/AC converter outputs, to the AC distribution grid, AC power by converting the DC power outputted from the DC/DC converter. When the second voltage changes, the DC/DC converter controls the first voltage in response to the change in the second voltage.

Abstract: Each of a plurality of specified chopper cells which are some of a plurality of chopper cells included in each leg circuit in a power conversion device is configured as a full bridge. A control device controls operations of first and second switching elements of each specified chopper cell based on a circulating current which circulates through each leg circuit. The control device controls operations of third and fourth switching elements of each specified chopper cell based on a voltage of a capacitor of the specified chopper cell.

Abstract: A DC power transmission system interconnects a plurality of AC systems via a DC line. A plurality of power conversion devices are connected between the plurality of AC systems and the DC line. One of the plurality of power conversion devices controls the voltage on the DC line, while the remaining power conversion device controls a current input and output to and from the DC line. In a restart which resumes power conversion from a stopped state for controlling a DC current on the DC line, the power conversion device performing current control monitors the voltage on the DC line and starts a restart operation without transmitting or receiving information to or from the other power conversion device.

Abstract: Since a power converter including a modular multilevel converter uses a large number of cells each combining a plurality of switching elements and a DC capacitor, there is a problem of conduction loss due to the switching elements. The conduction loss is reduced by connecting a bypass circuit between terminals of each of the cells, controlling to open and close the switching element, and controlling to short-circuit the bypass circuit connected to the cell controlled to output zero voltage.

Abstract: When short-circuit between DC lines is detected, a control device of a power conversion device performs protection control to turn off semiconductor switching elements in a power converter, and when elimination of the short-circuit between the DC lines is detected, the control device performs restart control of the power converter by giving a voltage command value for causing negative-polarity current in flowing through a diode in an upper arm of a second series body of a second converter cell to flow to a phase arm 4, to each converter cell in first and second arms.

Abstract: When short-circuit between DC lines is detected, a control device of a power conversion device performs protection control to turn off semiconductor switching elements in a power converter, and when elimination of the short-circuit between the DC lines is detected, the control device performs restart control of the power converter by giving a voltage command value for causing negative-polarity current in flowing through a diode in an upper arm of a second series body of a second converter cell to flow to a phase arm 4, to each converter cell in first and second arms.

Abstract: A stereo image pickup unit includes: first and second image pickup apparatuses including first and second image pickup devices and first and second mount boards, the image pickup apparatuses being formed in a same shape each other; and a holding frame for holding the first and second image pickup devices, the first and second mount boards including non-mounting surfaces perpendicular to rear surfaces of the first and second image pickup devices and projecting toward an outer side of projection surfaces of the first and second image pickup devices, the holding frame holding the first and second image pickup apparatuses such that the non-mounting surfaces are opposed to each other on a parallax direction inner side.

Abstract: The present invention is provided with a power converter and a control device for controlling the power converter, wherein each of the positive arm and the negative arm is comprised one converter cell or a plurality of converter cells connected in series, each converter cell being comprised: a series unit in which a plurality of switching elements are connected in series to each other; and a DC capacitor connected in parallel to the series unit, and the control device includes a DC voltage command value calculation unit which calculates a voltage command value for outputting, during a DC short circuit fault, AC voltage similar to that in a steady state to the AC terminal of the power converter, and for outputting, to the DC terminal of the power converter, DC voltage that allows the protection relay in the DC line to operate.

Abstract: An endoscope includes: a first lens located at a distal-most position, a part of the first lens being exposed outside; a movable lens barrel configured to be able to move, and configured to hold a movable lens disposed on a proximal end side with respect to the first lens; an actuator unit including a coil that drives the movable lens barrel and generates heat by receiving a supply of electric power; and a control section that outputs first electric power to the coil when holding the movable lens barrel at a predetermined position, and outputs second electric power larger than the first electric power to the coil when conducting heat generated from the coil to the first lens at the predetermined position.

Abstract: A power conversion device which is connected between an electric generation grid and a demand area grid and performs power conversion includes: a power converter which is connected to an electric generation grid and which converts AC power received from the electric generation grid to DC power and transmits the DC power via DC bus; and a control device for controlling the power converter. The control device includes a detection unit for detecting DC current of the DC bus, and a protection control unit for performing protection control for suppressing an amount of power received from the electric generation grid, on the basis of variation in the DC current, thereby continuing operation in the case of disturbance in the demand area grid.

Abstract: In a control device of a power conversion device, an AC control portion generates a first voltage command value representing an AC voltage component to be output from a plurality of chopper cells of each leg circuit. A DC control portion generates a second voltage command value representing a DC voltage component to be output from the plurality of chopper cells of each leg circuit. A circulating current control portion generates a third voltage command value to be output from the plurality of chopper cells of each leg circuit in order to suppress a circulating current. The circulating current control portion performs a non-linear operation with the first, second, and third voltage command values. The plurality of chopper cells of each leg circuit operate in accordance with a result of the non-linear operation.

Abstract: Each of a plurality of specified chopper cells which are some of a plurality of chopper cells included in each leg circuit in a power conversion device is configured as a full bridge. A control device controls operations of first and second switching elements of each specified chopper cell based on a circulating current which circulates through each leg circuit. The control device controls operations of third and fourth switching elements of each specified chopper cell based on a voltage of a capacitor of the specified chopper cell.

Abstract: A power conversion device includes a plurality of leg circuits and a control device. The plurality of leg circuits correspond to respective phases of an AC circuit and connected in parallel between common first and second DC terminals. Each leg circuit includes a plurality of chopper cells each including an energy storage and cascaded to one another and at least one inductance connected in series to the plurality of chopper cells. The control device controls an operation of only at least one chopper cell included in each leg circuit based on a circulating current which circulates through the leg circuits.