Experimental study on characteristics of RF interference generated by valves and shielding effectiveness of valve hall of HVDC converter station

Periodic turn-on and turn-off of valves in valve hall of HVDC converter station generates radio frequency interference, which may badly affects persons and equipments close to the hall. In China, no systemic research has been presently made on the characteristics of RF interference and the shielding of the valve hall to reduce the interference level. Measurement and analysis of RF interference and actual shielding effectiveness of valve hall had been made in four typical HVDC converter stations for the first time internally. Data indicate that RF interference in valve hall reduces rapidly as increase in frequency, and there is no obvious relationship between RF interference and carrying power of valves. Results also illuminate that the actual shielding effectiveness of valve hall is not more than 20dB.All the measurement data and analysis results will give farther help to design of shielding of valve hall in plusmn500kV HVDC converter stations.