A Research Of Testing And Evaluating Method In Ship Grid Pulse Interference Grading And Counting

The ship grid interference pulse appears when the high power electrical equipment in theship grid starts or stops. It can change the current in the grid unexpectedly and disturb otherequipment. With the strong randomness, and without the obvious regularity and repeatability ofthe amplitude, the wave shape and the epoch, the interference pulse becomes the most potentialmenace to the proper and safe functioning of the digital system.Until now, the method of controlling interference pulse is to carry through pulsecharacteristic test by equipment and system in EMC standard. Such as Using digital oscillographto test, to obtain data, to analyze and to choose solve method. However, because of the theparticularity of interference pulse and the limitation of standard, common quantify method can’treflex the level of interference pulse, and common testing method can’t offer required data ingrid environment. Application in real project lacks pertinence, so over-design or lack-design arepossible. The critical problem is how to describe interference pulse quantificationally and toobtain required data effectively.This research is based on the theory of Probability&Stat. and Numerical Analysis. Basedon the particularity analysis of the ship grid interference pulse, this research established themathematic model for evaluating the ship grid interference pulse. Aimed at the requirement forthe testing data in the evaluating model, this research analyzed critical technology for relatedtesting equipment. Besides, this research designed the test project for the equipment in the labtesting and in real ship grid testing. Its propose is to realize the ship global EMC, to objectivelyevaluate the interference pulse, and to adopt targeted measure.Firstly, based on the basic principle of interference pulse and according to the characteristic,component factor and the coupling path, this research analyzed the difference between shipinterference pulse and normal interference pulse. The emphasis is putting forward therandomness of the ship grid interference pulse, and suggesting evaluating and analyzing it byprobability theory. Secondly, based on Probability&Stat. and Numerical Analysis, this research establishedthree models, which respectively was based on risk index, normal distribution and numeral curvefitting. In the three models, the evaluation methods aim at a specific amplitude point and aamplitude range has been stated specifically.Lastly, according to the requirement of the testing data in the evaluation model, the criticaltechnology of the testing proto for obtaining relative data was researched, including filtering,attenuation and classification&counting. And this research designed the testing project for thelab testing and real ship testing.