Abstract: A water purification device, a flushing control method for a water purification device, and a water purification system. The water purification device includes an ultrafiltration composite filter element and an opening/closing unit. The ultrafiltration composite filter element is provided with a plurality of filter elements connected in parallel. The opening/closing unit communicates with the water inlets of the plurality of filter elements. The opening/closing unit, when in a water-producing state, is configured to introduce raw water into the filter elements from the water inlets. The opening/closing unit, when in a flushing state, is further configured to introduce the raw water into the filter element(s) from the water inlet(s) of one or more filter elements; and the other one or more filter elements are flushed with the purified water, and then waste water is discharged by the water inlet(s) of the other one or more filter elements or a drainage outlet.

Abstract: A testing device for propagation characteristic of electromagnetic wave in gas insulated switchgear includes an ultrahigh frequency signal generator, a GIS testing chamber, an emitting antenna and a receiving antenna which are provided inside the GIS testing chamber. A detachable disc insulator is provided between the emitting antenna and the receiving antenna. Both terminals of a GIS testing chamber are sealed by polyurethane wave-absorbing sponge; the ultrahigh frequency signal generator is connected with the emitting antenna, and the receiving antenna is connected with a oscilloscope. A guide rod which is fixed by the disc insulator is provided in the GIS testing chamber. The present invention is capable of achieving testing propagation characteristic of partial discharge ultrahigh frequency electromagnetic wave signal of a gas insulated switchgear in a laboratory, so as to master attenuation characteristics of the partial discharge ultrahigh frequency electromagnetic wave signal.

Abstract: A testing device for propagation characteristic of electromagnetic wave in gas insulated switchgear includes an ultrahigh frequency signal generator, a GIS testing chamber, an emitting antenna and a receiving antenna which are provided inside the GIS testing chamber. A detachable disc insulator is provided between the emitting antenna and the receiving antenna. Both terminals of a GIS testing chamber are sealed by polyurethane wave-absorbing sponge; the ultrahigh frequency signal generator is connected with the emitting antenna, and the receiving antenna is connected with a oscilloscope. A guide rod which is fixed by the disc insulator is provided in the GIS testing chamber.

Abstract: A method for recognizing a transformer partial discharge pattern based on a singular value decomposition (SVD) algorithm includes a training model and a classification recognizing process, comprising: firstly setting up an experimental environment having artificial defects, collecting at least one datum sample, and calculating statistical feature parameters of each datum sample to form a datum sample matrix; performing singular value decomposition on the datum sample matrix and determining an order of an optimal retention matrix by judging whether a feature of a retention matrix is clear, so as to obtain a type feature description matrix and a class-center description vector group after dimensionality reduction; preprocessing samples to be recognized to obtain a sample vector, and performing linear transformation on the sample vector utilizing a type space description matrix.