A method and system for testing sound insulation of substation main noise equipment sound insulation cover

Abstract

The invention discloses a testing method and system for the sound insulation factor of a sound insulation cover used for main noise equipment in a transformer station. The method comprises the following steps: respectively setting at least one measuring point on the surface of the main noise equipment in the sound insulation cover and on the external surface of the sound insulation cover, and arranging one vibration acceleration sensor at the position of each measuring point; respectively acquiring a first vibration acceleration signal of the surface of the main noise equipment and a second vibration acceleration signal of the external surface of the sound insulation cover via the vibration acceleration sensors, and respectively converting the first vibration acceleration signal and the second vibration acceleration signal into a first charge signal and a second charge signal; reconstructing sound fields in and out of the sound insulation cover by using a data acquisition and analysis system based on the Green's function method; and calculating the average sound power level of the internal and external sound power levels of the sound insulation cover so as to obtain the sound insulation factor, reconstructing sound fields in and out of the sound insulation cover by using the Green's function method, and then testing the sound insulation factor of the sound insulation cover by using the data acquisition and analysis system. The testing method and system provided by the invention improve testing efficiency.

Description

technical field [0001] The present invention relates to the technical field of noise testing of power system equipment, and more specifically, to a method and system for testing the sound insulation of a sound insulation cover for main noise equipment in a substation. Background technique [0002] At present, for the test and evaluation of the sound insulation of the sound insulation enclosure (box-in) of the main noise equipment in the substation, the sound intensity method or the sound pressure method is mainly used to test the sound transmission loss of the sound insulation enclosure before leaving the factory, that is, the internal sound source passes through the insulation box. After the sound cover, the attenuation of sound energy, the evaluation index is the incident sound power level L Wi and the transmitted sound power level L at the outlet Wt The difference can be expressed in TL as: [0003] TL (dB) = 10lgW i / W p = L Wi -L Wt ; [0004] It is also possible...

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Problems solved by technology

[0006] However, there are certain defects in the two methods, resulting in low test accuracy.

The traditional sound intensity method to test the transmission loss of the sound insulation enclosure uses a sound intensity meter to scan the surface of the equipment, which is affected by many factors, such as the scanning speed of the tester, the scanning surface area, and the scanning angle, etc. will affect the test accuracy; the traditional The sound pressure method is greatly affected by environmental factors when testing sound pressure, especially the background noise, because there are many sound sources in the UHV substation and their locations are scattered, and most of them belong to the audible noise excited by power frequency voltage and current , the frequency components are strongly correlated with

At the test site, it is difficult to distinguish the contribution of sound power independently excited by coherent sound sources that are relatively close to each other. The acoustic environment is extremely complex, and it is difficult to accurately measure the internal and external sound pressure of the sound insulation enclosure of a single noise source equipment, which will reduce the test accuracy.

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