Abstract: An electric power conversion device includes: a first electric power conversion circuit, a current detection circuit, an electric power conversion circuit of field coil excite use, a control circuit, and detector which detects an induced electromotive force generated in the motor generator. In a case where an over current, is detected by the first electric power conversion circuit, the control circuit turns off a switching of a phase of the first electric power conversion circuit from which an over current s detected and a switching of the electric power conversion circuit of field coil excite use. After the value of an induced electromotive force by the motor generator falls below a predetermined value, the control circuit controls to stop a supply of electric power of all phases by the first electric power conversion circuit.

Abstract: A solar cell has a P-type silicon substrate in which one main surface is a light-receiving surface and another main surface is a backside, a dielectric film on the backside, and an N-conductivity type layer in at least a part of the light-receiving surface of the P-type silicon substrate, wherein the P-type silicon substrate is a silicon substrate doped with gallium, and the backside of the P-type silicon substrate contains a diffused group III element. This provides a solar cell with excellent conversion efficiency provided with a gallium-doped substrate, and a method for manufacturing the same.

Abstract: A solar cell has a P-type silicon substrate in which one main surface is a light-receiving surface and another main surface is a backside, a dielectric film on the backside, and an N-conductivity type layer in at least a part of the light-receiving surface of the P-type silicon substrate. The P-type silicon substrate is a silicon substrate doped with gallium, and the backside of the P-type silicon substrate contains a diffused group III element.

Abstract: A method for screen printing, including: by using a screen printing apparatus provided with a screen printing plate having an opening part corresponding to a printing pattern, a scraper, and a squeegee, filling a paste supplied on an upper surface of the screen printing plate into the opening part of the screen printing plate by the scraper; and, after that, pushing out the paste to a predetermined position of an object to be printed from the opening part of the screen printing plate by the squeegee to screen-print the paste corresponding to the printing pattern on the object to be printed, wherein the humidity in the screen printing apparatus is adjusted during the screen printing. As a result, by controlling an amount of moisture in the paste on the screen printing plate, a screen printing method is capable of improving the printing property of the paste.

Abstract: An arc quenching device, which is highly reliable, small-sized, and inexpensive, includes: a semiconductor switch connected in parallel to a first switch which is mechanical; a constant voltage circuit configured to use a voltage which is generated between both contact points of the first switch to output a voltage which causes the semiconductor switch to turn on; and a second timer circuit configured to cause the semiconductor switch to turn off after a predetermined time has elapsed since the semiconductor switch turned on.

Abstract: An arc quenching device, which prevents a load device from displaying an unnecessary behavior during starting of a power supply, includes: a semiconductor switch connected in parallel to a first switch which is mechanical; a power supply circuit configured to use a voltage which is generated between both contact points of the first switch to output a voltage which causes the semiconductor switch to turn on; and a second switch configured to cause its open state to prevent the semiconductor switch from turning on.

Abstract: A photovoltaic generation system includes: a solar cell array formed with one or more solar cell modules; and a power conditioner, wherein each of the solar cell modules includes one or more solar cells, the photovoltaic generation system further has a first conductive wire connected to a conductor parts which is provided at each of the solar cell modules and which is insulated from the solar cells, and a constant voltage power supply whose one end is connected to the first conductive wire, and a potential is supplied to the conductor parts by the constant voltage power supply. As a result, the photovoltaic generation system which can suppress degradation of solar cell characteristics due to PID while suppressing increase in manufacturing cost of the solar cell module is provided.

Abstract: A solar cell having a P-type silicon substrate where one main surface is a light-receiving surface and another is a backside, a plurality of back surface electrodes formed on a part of the backside, an N-type layer in at least a part of the light-receiving surface, and contact areas in which the substrate contacts the electrodes. The P-type silicon substrate is a silicon substrate doped with gallium and has a resistivity of 2.5 ?·cm or less; and a back surface electrode pitch Prm [mm] of contact areas in which the P-type silicon substrate is in contact with the back surface electrodes and the resistivity Rsub [?·cm] of the substrate satisfy the relation represented by the following formula (1). log(Rsub)??log(Prm)+1.

Abstract: A solar cell has a P-type silicon substrate in which one main surface is a light-receiving surface and another main surface is a backside, a dielectric film on the backside, and an N-conductivity type layer in at least a part of the light-receiving surface of the P-type silicon substrate. The P-type silicon substrate is a silicon substrate doped with gallium, and the backside of the P-type silicon substrate contains a diffused group III element.

Abstract: Provided is a construction machine capable of suppressing deformation of a boom in a simple configuration and at low costs. The construction machine includes a pair of backstops having respective hydraulic cylinders; a supply device which supplies the hydraulic cylinders with hydraulic fluid; a deformation sensing device which senses deformation of the boom; and a control device which controls the supply device so as to make a thrust of the hydraulic cylinder of one backstop having a larger pressing force, out of the pair of backstops, be larger than a thrust of the hydraulic cylinder of the other backstop, the pressing force being applied due to the deformation of the boom.

Abstract: A solar cell includes a light-receiving surface electrode formed on a light-receiving surface, a back surface electrode formed on a backside, and a CZ silicon single crystal substrate doped with gallium. The CZ silicon single crystal substrate contains 12 ppm or more oxygen atoms. A spiral oxygen-induced defect is not observed in an EL (electroluminescence) image of the solar cell.

Abstract: The present invention is a method for manufacturing an FZ silicon single crystal for a solar cell, including the steps of: pulling a CZ silicon single crystal doped with gallium by a Czochralski method; and float-zone processing a raw material rod, with the raw material rod being the CZ silicon single crystal, at 1.6 atmospheric pressure or more to manufacture the FZ silicon single crystal. As a result, it is possible to provide a method for manufacturing an FZ silicon single crystal for a solar cell that can decrease the amount of gallium dopant evaporated during the float-zone processing, thereby preventing the silicon single crystal from increasing the resistance while decreasing oxygen, which is inevitably introduced into a CZ crystal, and preventing formation of a B-O pair, which causes a problem to the characteristics of a solar cell.

Abstract: Provided is a method for manufacturing a solar cell element that can increase the film thickness for collector electrodes formed in a screen printing process and reduce the resistance value of the same as well as contribute to improvements in conversion efficiency. When a collector electrode for a solar cell element is formed by screen printing of a conductive paste, that screen-printing process is repeated a plurality of times. At this time, the squeegee speed during the second or later screen printing is faster than the squeegee speed during the first screen printing. The second and later screen printing is superimposed on the collector electrode printed the first time; therefore, the faster the squeegee speed is, the better the plate release is for the paste and foundation. The amount of paste applied increases, and the film for the collector electrode that is formed becomes thicker.

Abstract: A solar cell is provided with: a semiconductor substrate having a light-receiving surface and a non-light-receiving surface; a PN junction section formed on the semiconductor substrate; a passivation layer formed on the light-receiving surface and/or the non-light-receiving surface; and power extraction electrodes formed on the light-receiving surface and the non-light-receiving surface. The solar cell is characterized in that the passivation layer includes an aluminum oxide film having a thickness of 40 nm or less. As a result of forming a aluminum oxide film having a predetermined thickness on the surface of the substrate, it is possible to achieve excellent passivation performance and excellent electrical contact between silicon and the electrode by merely firing the conductive paste, which is conventional technology. Furthermore, an annealing step, which has been necessary to achieve the passivation effects of the aluminum oxide film in the past, can be eliminated, thus dramatically reducing costs.

Abstract: An arc quenching device, which prevents a load device from displaying an unnecessary behavior during starting of a power supply, includes: a semiconductor switch connected in parallel to a first switch which is mechanical; a power supply circuit configured to use a voltage which is generated between both contact points of the first switch to output a voltage which causes the semiconductor switch to turn on; and a second switch configured to cause its open state to prevent the semiconductor switch from turning on.

Abstract: An arc quenching device, which is highly reliable, small-sized, and inexpensive, includes: a semiconductor switch connected in parallel to a first switch which is mechanical; a constant voltage circuit configured to use a voltage which is generated between both contact points of the first switch to output a voltage which causes the semiconductor switch to turn on; and a second timer circuit configured to cause the semiconductor switch to turn off after a predetermined time has elapsed since the semiconductor switch turned on.

Abstract: A method for manufacturing a solar cell having a P-type silicon substrate wherein one main surface is a light-receiving surface and another is a backside, a plurality of back surface electrodes formed on a part of the backside, an N-type layer in at least a part of the light-receiving surface, and contact areas in which the substrate contacts the electrodes; wherein the P-type silicon substrate is a silicon substrate doped with gallium and has a resistivity of 2.5 ?·cm or less; and a back surface electrode pitch Prm [mm] of contact areas in which the P-type silicon substrate is in contact with the back surface electrodes and the resistivity Rsub [?·cm] of the substrate satisfy the relation represented by the following formula (1). log(Rsub)??log(Prm)+1.

Abstract: A solar cell is provided with: a semiconductor substrate having a light-receiving surface and a non-light-receiving surface; a PN junction section formed on the semiconductor substrate; a passivation layer formed on the light-receiving surface and/or the non-light-receiving surface; and power extraction electrodes formed on the light-receiving surface and the non-light-receiving surface. The solar cell is characterized in that the passivation layer includes an aluminum oxide film having a thickness of 40 nm or less. As a result of forming a aluminum oxide film having a predetermined thickness on the surface of the substrate, it is possible to achieve excellent passivation performance and excellent electrical contact between silicon and the electrode by merely firing the conductive paste, which is conventional technology. Furthermore, an annealing step, which has been necessary to achieve the passivation effects of the aluminum oxide film in the past, can be eliminated, thus dramatically reducing costs.

Abstract: A solar cell includes: first and second conductivity type diffusion layers which are formed on a backside of a light-receiving surface of a substrate, first and second electrode portions, first and second electrode line portions, and first and a second electrode bus bar portions; a first insulator film which is formed to cover a side portion and a top of the second electrode portion in an intersection region of the second electrode portion and the first electrode bus bar portion, a second insulator film which is formed to cover a side portion and a top of the first electrode portion in an intersection region of the first electrode portion and the second electrode bus bar portion, wherein the second electrode portion is formed continuously in a line shape under the first insulator film, and the first electrode portion is formed continuously in a line shape under the second insulator film.