Abstract: A power conversion apparatus includes: matrix converter circuitry configured to perform bidirectional power conversion between a primary side and a secondary side; and control circuitry configured to: calculate a deterioration level based on a secondary side current of the matrix converter circuitry, a carrier frequency, and a primary-secondary frequency difference between a primary side frequency and a secondary side frequency of the matrix converter circuitry; and output a deterioration notification in response to determining that the deterioration level exceeds a predetermined level.

Abstract: A power conversion device 1 includes a matrix converter circuit 10 including a plurality of switching elements and being configured to perform bidirectional power conversion between alternating current power on a primary side and alternating current power on a secondary side, a power conversion control unit 114 configured to switch on and off the plurality of switching elements in unison with a carrier wave to cause an alternating current on the secondary side to follow a control command, and a carrier wave changing unit 116 configured to change, based on a nearness level between a frequency on the primary side and a frequency on the secondary side, a frequency of the carrier wave.

Abstract: The power conversion device may include: power conversion circuitry configured to perform a power conversion for outputting a driving power to an induction motor; and control circuitry. The control circuitry may be configured to: receive a master command phase from a master power conversion device; generate a voltage command having a command phase in a rotating coordinate system based on a torque target value, wherein a rotating magnetic field for driving a rotor of the induction motor is generated to rotate with the rotating coordinate system; calculate a rotation phase of the rotating coordinate system based on a command phase difference between the master command phase and the command phase to reduce the command phase difference; and control the power conversion circuitry to output the driving power to the induction motor, in synchronization with the master power conversion device, based on the rotation phase and the voltage command.

Abstract: A power conversion apparatus includes: matrix converter circuitry configured to perform bidirectional power conversion between a primary side and a secondary side; and control circuitry configured to: calculate a deterioration level based on a secondary side current of the matrix converter circuitry, a carrier frequency, and a primary-secondary frequency difference between a primary side frequency and a secondary side frequency of the matrix converter circuitry; and output a deterioration notification in response to determining that the deterioration level exceeds a predetermined level.

Abstract: A power conversion device includes a power conversion circuitry configured to convert DC power into AC power by switching on/off a plurality of switching elements to switch each of a plurality of phase voltages to a voltage level selected from one of three levels including a first voltage, a second voltage higher than the first voltage, and a third voltage higher than the second voltage. A control circuitry is configured to control the plurality of switching elements so as to convert DC power into AC power without producing a combination of the first voltage and the third voltage between any two phases of the plurality of phase voltages.

Abstract: A power conversion device includes a power conversion circuitry configured to convert DC power into AC power by switching on/off a plurality of switching elements to switch each of a plurality of phase voltages to a voltage level selected from one of three levels including a first voltage, a second voltage higher than the first voltage, and a third voltage higher than the second voltage. A control circuitry is configured to control the plurality of switching elements so as to convert DC power into AC power without producing a combination of the first voltage and the third voltage between any two phases of the plurality of phase voltages.

Abstract: A fluid mixer of the present invention has an element (1) and a chassis (2) that accommodates the element therein and that is engaged with at least both ends of the element, the element having: a first-flow-path forming section (13) at an end of which a fluid inlet (3) is formed and in which a first flow path (4) is formed; and a body section (12) at an end of which a fluid outlet (8) is formed, in which a second flow path (5) is formed, and on an outer circumferential surface of which a plurality of communicating holes (11) are formed so as to allow the second flow path to communicate with the outside.

Abstract: A matrix converter includes a power converter circuit connectable on one side thereof with an alternating-current supply via a high- frequency filter and connectable on another side thereof with an alternating-current motor; a snubber circuit connected with a one-side line for connecting the high-frequency filter and the power converter circuit; a discharge switch discharging a charge accumulated in the snubber circuit depending on a voltage of the snubber circuit; and a control circuit configured to execute controlling the power converter circuit on the basis of a carrier frequency in test such that a test voltage is applied to the alternating-current motor, changing the carrier frequency in test on the basis of an operation state of the discharge switch, and determining constants of the alternating-current motor on the basis of a response state of the alternating-current motor at the time when the test voltage is applied.

Abstract: A matrix converter includes a power converter circuit connectable on one side thereof with an alternating-current supply via a high-frequency filter and connectable on another side thereof with an alternating-current motor; a snubber circuit connected with a one-side line for connecting the high-frequency filter and the power converter circuit; a discharge switch discharging a charge accumulated in the snubber circuit depending on a voltage of the snubber circuit; and a control circuit configured to execute controlling the power converter circuit on the basis of a carrier frequency in test such that a test voltage is applied to the alternating-current motor, changing the carrier frequency in test on the basis of an operation state of the discharge switch, and determining constants of the alternating-current motor on the basis of a response state of the alternating-current motor at the time when the test voltage is applied.

Abstract: A fluid mixer of the present invention has an element (1) and a chassis (2) that accommodates the element therein and that is engaged with at least both ends of the element, the element having: a first-flow-path forming section (13) at an end of which a fluid inlet (3) is formed and in which a first flow path (4) is formed; and a body section (12) at an end of which a fluid outlet (8) is formed, in which a second flow path (5) is formed, and on an outer circumferential surface of which a plurality of communicating holes (11) are formed so as to allow the second flow path to communicate with the outside.

Abstract: The present invention pertains to an ultraviolet sterilization device comprising: a transfer pipe (2) having an inlet port (4) and an outlet port (5); and an ultraviolet light source (3) that causes ultraviolet rays to be incident to the transfer pipe. Fluid to be treated that is inside the transfer pipe is sterilized by the ultraviolet rays irradiated from the ultraviolet light source. At least the inner peripheral surface of the transfer pipe is formed from a material having a smaller refractive index than the refractive index of the fluid to be treated that flows through the transfer pipe. The ultraviolet rays irradiated on the fluid to be treated are irradiated so as to be completely reflected by the inner peripheral surface of the transfer pipe.

Abstract: The present invention pertains to an ultraviolet sterilization device (1) for irradiating with ultraviolet light a fluid flowing through a flow passage (6) having an inlet opening (4) and an outlet opening (5), and sterilizing the fluid. The ultraviolet sterilization device is equipped with a light guide (2) formed to tubular shape, and having a flow passage inside, as well as having a light scattering means (8) on the outside peripheral surface, and an ultraviolet light source (3) arranged on the outside surface of the light guide, for irradiating the light guide with ultraviolet light. Ultraviolet light from the ultraviolet light source irradiating the light guide is scattered by the light scattering means, and irradiates the flow passage through the inside peripheral surface of the light guide.

Abstract: A fluid mixer which can mix fluid while making the distribution of concentration or distribution of temperature of the fluid in the direction of flow uniform without any unevenness and which is both compact and easy to install piping for is provided. This fluid mixer has a fluid inlet, a first flow path connected to the fluid inlet, a spiral flow path connected to the first flow path, a plurality of branch flow paths branched from the spiral flow path, a second flow path to which the plurality of branch flow paths are connected, and a fluid outlet connected to the second flow path, the plurality of branch flow paths branching from different positions of the spiral flow path and being connected with the second flow path at different positions of the second flow path.

Abstract: A spiral type fluid mixer which enables mixing by a distribution of concentration or distribution of temperature in a flow direction of the fluid made uniform without unevenness and which is compact and enables easy piping work is provided. This spiral type fluid mixer is provided with a fluid inlet, a first flow path which is connected to the fluid inlet, a first spiral flow path which is connected to the first flow path, a plurality of branch flow paths which are branched from the first spiral flow path, a second spiral flow path to which the plurality of branch flow paths are connected, a second flow path which is connected to the second spiral flow path, and a fluid outlet which is connected to the second flow path, the plurality of branch flow path being branched from different positions of the first spiral flow path and being connected with the second spiral flow path at different positions of the second spiral flow path.

Abstract: A fluid mixer includes a main flow path comprised of a first flow path and a second flow path, spiral flow paths formed around the second flow path in shapes substantially concentric with the second flow path and offset in position from each other in a circumferential direction, the spiral flow paths having first ends communicated with the first flow path, branch flow paths branched from a plurality of locations of the second flow path in a flow direction, the branch flow paths being communicated with the spiral flow paths at a plurality of locations of the spiral flow paths in the flow direction, a fluid inlet at an open end of either of the first flow path and the second flow path, and a fluid outlet at an open end of the other of the first flow path and the second flow path.

Abstract: An in-line-type fluid mixer is provided, which includes a first channel-forming part defining a first inlet channel from a first inlet portion to a first passage portion; a second channel-forming part defining a second inlet channel from a second inlet portion to a second passage portion; a third channel-forming part defining an outlet channel having a sectional area that increases from a narrower portion through a flaring portion to an outlet portion, and being communicated with the first inlet channel and the second inlet channel, respectively, at an end of the narrow portion; and a whirling stream-generating part for generating a whirling stream in at least one of the first inlet channel and the second inlet channel.

Abstract: A fluid mixer includes a main flow path comprised of a first flow path and a second flow path, spiral flow paths formed around the second flow path in shapes substantially concentric with the second flow path and offset in position from each other in a circumferential direction, the spiral flow paths having first ends communicated with the first flow path, branch flow paths branched from a plurality of locations of the second flow path in a flow direction, the branch flow paths being communicated with the spiral flow paths at a plurality of locations of the spiral flow paths in the flow direction, a fluid inlet at an open end of either of the first flow path and the second flow path, and a fluid outlet at an open end of the other of the first flow path and the second flow path.

Abstract: An in-line-type fluid mixer is provided, which includes a first channel-forming part defining a first inlet channel from a first inlet portion to a first passage portion; a second channel-forming part defining a second inlet channel from a second inlet portion to a second passage portion; a third channel-forming part defining an outlet channel having a sectional area that increases from a narrower portion through a flaring portion to an outlet portion, and being communicated with the first inlet channel and the second inlet channel, respectively, at an end of the narrow portion; and a whirling stream-generating part for generating a whirling stream in at least one of the first inlet channel and the second inlet channel.

Abstract: A valve includes a valve body (1, 2), a tube (3) made of an elastomer extending through the inside of the valve body, and a roller (23) and a pressing surface (14) disposed facing each other across the tube (3). The roller (23) can be brought close to the pressing surface (14) to collapse the tube (3) between the roller (23) and pressing surface (14) and close the flow passage in the tube (3), and the roller (23) can be moved along the tube (3) to make a collapsed position where the tube (3) is collapsed by the roller (23) and the pressing surface (14) move along the flow passage axis of the tube (3) while maintaining the flow passage in the closed state.

Abstract: A manifold valve having two valves, which enables operation of one valve while disables operation of the other valve, is compact, and facilitates installation in and detachment from a pipeline, that is, a manifold valve provided with a main passageway, a branch passageway split off from the main passageway, a main passageway valve opening and closing the main passageway, and a branch valve opening and closing the branch passageway, the main passageway, the branch passageway, the main passageway valve, and the branch valve being integrally formed, wherein the main passageway valve and the branch valve are each a manual valve having a valve element, a stem connected to the valve element, and an operating lever connected to the stem, the operating lever pivoting in an axial direction of the stem to open and close the passageway, the main passageway valve and the branch valve each converting pivoting motion of the operating lever to linear motion of the valve element and pressing the valve element against and sep