摘要:
A wind power generation system includes an excessive current consumption device, an AC input of which is connected between a generator rotor and an excitation converter on a system failure to detect a DC voltage ascent of the excitation converter and operate a shunt circuit on the system failure.
摘要:
A group III nitride semiconductor light emitting device including an LED structure formed on top of a single crystal, base layer (103) formed on top of a substrate (101) including a principal plane (10) having a flat surface (11) configured from a (0001) C plane, and a plurality of convex portions (12) including a surface (12c) non-parallel to the C plane having a width (d1) of 0.05 to 1.5 μm and height (H) of 0.05 to 1 μm, the base layer is formed by causing a group III nitride semiconductor to grow epitaxially so as to cover the flat surface and convex portions, and the width (d1) of the convex portions and top portion thickness (H2) of the base layer at the positions of the top portions (12e) of the convex portions satisfy: H2=kd1 (wherein 0.5
摘要:
The present invention is a method for producing a group III nitride semiconductor layer in which a single crystal group III nitride semiconductor layer (103) is formed on a substrate (101), the method including: a substrate processing step of forming, on the (0001) C-plane of the substrate (101), a plurality of convex parts (12) of surfaces (12c) not parallel to the C-plane, to thereby form, on the substrate, an upper surface (10) that is composed of the convex parts (12) and a flat surface (11) of the C-plane; and an epitaxial step of epitaxially growing the group III nitride semiconductor layer (103) on the upper surface (10), to thereby embed the convex parts (12) in the group III nitride semiconductor layer (103).
摘要:
A semiconductor electric power converter in accordance with the present invention comprises an arm consisting of an IGBT, a capacitor connected between a collector and a gate of said IGBT, and a gate circuit connected to the gate of said IGBT for controlling the switching operation of said IGBT, wherein a plurality of said arms connected in series are connected in parallel and each midpoint of said arms connected in of series is connected to a load. Thereby the impedance between the gate terminal of the IGBT and the gate circuit is decreased when the gate voltage is higher than the gate voltage command value or the impedance between the gate and the emitter of the IGBT is decreased when the collector voltage is high so that an electric charge stored in the gate is rapidly discharged.
摘要:
A CVT control system comprises a controller. The controller determines the desired engine speed as a first function of operator power demand and vehicle speed during a predetermined period involving a momenet when a control element moves off from one of the maximum and minimum reduction ratio command positions, and determines the desired engine speed as a second function of the operator power demand and the vehicle speed during the subsequent period to the predetermined period.
摘要:
Provided is a group-III nitride semiconductor light-emitting device which has a high level of crystallinity and superior internal quantum efficiency and which is capable of enabling acquisition of high level light emission output, and a manufacturing method thereof, and a lamp. An AlN seed layer composed of a group-III nitride based compound is laminated on a substrate 11, and on this AlN seed layer, there are sequentially laminated each layer of an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer respectively composed of a group-III nitride semiconductor, wherein the full width at half-maximum of the X-ray rocking curve of the (0002) plane of the p-type semiconductor layer 16 is 60 arcsec or less, and the full width at half-maximum of the X-ray rocking curve of the (10-10) plane is 250 arcsec or less.
摘要:
In a wind power generation system, an energy consuming unit is connected to a DC part of a generator-side converter. A shunt circuit is connected between the generator-side converter and a rotor of an AC-excited power generator. In the event of system failure, the switching operation of the converter is stopped, the shunt circuit is put into operation, and the energy consuming unit is put into operation so that DC voltage (voltage of the DC part) is maintained within a prescribed range.
摘要:
In a wind power generation system, an AC input of a unit for coping with system faults is connected to an excitation converter and a DC port of the unit for coping with system faults is connected to a DC port of a converter through resistors. A plurality of energy consumptive circuits each constructed of a resistor and switching units are provided for the DC port of the unit for coping with system faults.
摘要:
To shorten a startup interval to reach a synchronizing condition, a phase difference and an amplitude difference between the grid voltage and the stator voltage of one phase of a winding are obtained. The difference in amplitude is decreased prior to or in parallel to synchronizing the stator voltage with the grid voltage. The calculated compensation phase compensation value is used as an initial value for synchronizing at the next synchronizing operation.
摘要:
An object of the present invention is to provide a Group III nitride semiconductor element which comprises a thick AlGaN layer exhibiting high crystallinity and containing no cracks, and which does not include a thick GaN layer (which generally serves as a light-absorbing layer in an ultraviolet LED). The inventive Group III nitride semiconductor element comprises a substrate; a first nitride semiconductor layer composed of AlN which is provided on the substrate; a second nitride semiconductor layer composed of Alx1Ga1-x1N (0≦x1≦0.1) which is provided on the first nitride semiconductor layer; and a third nitride semiconductor layer composed of Alx2Ga1-x2N (0
摘要翻译:本发明的目的是提供一种III族氮化物半导体元件,其包括具有高结晶度且不含裂纹的厚AlGaN层,并且不包括厚的GaN层(其通常用作光吸收层 紫外线LED)。 本发明的III族氮化物半导体元件包括基底; 由AlN构成的第一氮化物半导体层,其设置在基板上; 由设置在第一氮化物半导体层上的由Al x 1 Ga 1-x1 N(0 <= x1 <= 0.1)组成的第二氮化物半导体层; 以及由在第二氮化物上提供的Al x2 Ga 1-x2 N(0