When a certain part of the utility grid, with substantial number of interconnected PVs, gets cut off from the grid islanding phenomenon may occur. There are two ways to suppress the islanding phenomenon, one of them is performed on the utility side, the other one on the PV side. On the utility side the reactor insertion method and the capacitor insertion method are advocated. The islanding phenomenon suppression characteristics of these two methods are compared in tests. Further, it is proved that the process, leading to the suppression of islanding phenomena, can be described in general power supply theory.
We are in the process of developing and commissioning a scanning photoelectron microscopy (SPEM) at the X 1A beamline of the National Synchrotron Light Source (NSLS). It is desigend to make use of the Soft X-ray Undulator (SXU) at the NSLS. This high brightness source illuminates a Fresnel zone plate, which forms a focused probe, < 0.2 pm in size, on the specimen surface. A grating monochromator selects the photon energy in the 400-800 eV range with an energy resolution of better than 1 eV. The expected flux in the focus is in the 5 x 107-109 photons/s range. A single pass Cylindrical Mirror Analyzer (CMA) is used to record photoemission spectra, or to form an image within a fixed electron energy bandwidth as the specimen is mechanically scanned.As a first test, a 1000 mesh Au grid was successfully imaged with a resolution of about 1 p n and the CMA tuned to the Au 4fphotoelectron peak. Once it is commissioned, a program is planned which will utilize the microscope to study beam sensitive systems, such as thin oxide/sub-oxide films of alumina and silica, and ultimately various adsorbates on these films.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.