Shielding hall of HV PD test

Shielding hall of HV PD test
Application:
HV test shielding room  (faraday cage) are Widely used in power cable, transformer, transformer switch, transformer substation and other High voltage levels of partial discharge test or impulse test.
For HV testing shielding room, as a HV test place, it should has good electromagnetic
shielding condition. And its electromagnetic compatibility always is of great importance.
Firstly, it should restrict electromagnetic wave into inside shielding room caused by
discharge when making HV test to weakening interfere to outside, especially on
electronic and communication system. Secondly, it should prevent outer
electromagnetic wave intruding into shielding room to cause measurement error of
partial discharge and wireless. Thirdly, it should reduces open circuit voltage and
closed current to restrain common-mode interference so that to avoid equipment
damage and to improve accuracy of impulse measurement.
For  GIS HV test shielding room, design area is 500 m2（Length 25m、Width 20m).
From provided information , we find that steel structure have been completed
already with one set of 20T crane indoor, crane supporting corbel also completed, the
height is 17.9m from ground to upper part of corbel. Main door height 13m,width 10m,
locates at downward of the west side, the door open direction towards to north .
According to ILJIN drawing, three side of structure column has already, but western
structure column still missing yet. however, as the main door will be located in this side,
the western side also should have steel structure , and this structure position still should
be unified considered with main door installation. We will be able to submit suggested
design diagram with position & size of this structure column for reference. in order to
save  construction cost, the construction engineering will be carried out by ILJIN
team.

Technical Specification 
 Shielding efficiency 0.15 MHz～1.6MHz≥60dB
 reverberation time ＜5S（at 400Hz 400Hz ）
 Background noise level (Ambient level)  ＜5Pc
 Grounding resistance  ：≤0.5Ω

Background noise can be promised to be not more than 5Pc if no-load equipment
without voltage. (this is what we should to ensure).
 Under equipment running condition ( applied voltage on equipment), user
should check on the whole testing system. such as whether power frequency
testing transformer meets with ambient requirements or not? whether if power
supply has been treated well or not? Whether surrounding other equipment are
placed too close to cause interference or not? And so on. To be honest, And it
seems not directly relevant to background noise level of shielding room .