MgO/LDPE Space Charge Effects Of Nanometer Compound Materials And Dielectric Properties

Space charge effects is the main factor in restriction on power cable insulationdielectric strength. In DC high-voltage transmission, space charge accelerated theaging of insulating materials and shorten use time, which will be lead to breakdownof insulating materials finally. Dielectric constant、dielectric loss are essentialparameter of insulating materials. Consequently, scientifically accuratecharacterization to the charge trap spectrum distribution of dielectric material willhave very important scientific significance and practical value on improving andenhancing the properties and application level of dielectric material.The paper mainly studied space charge behavior of0%,0.5%,3%,5%MgO/LDPE polymer composite and dielectric properties through spectroscopyautomatic test、pulsed electro-acoustic method and photo stimulated discharge.First, this paper adopt spectroscopy automatic test system to test conductioncurrent、dielectric constant、electric volume resistivity of different proportions ofMgO/LDPE. Experimental result shows that a small amount of MgO mixed withLDPE increased volume resistivity and dielectric constant and declined conductioncurrent which have a significant impact on improving and enhancing insulatingproperty of polymers。Then, this paper that use0%,0.5%,3%,5%MgO/LDPE polymer compositeunder10kv/mm、30kv/mm、50kv/mm field intensity reach a conclusion ofdistribution of space charge through pulsed electro-acoustic method. The resultsshowed that a small amount of MgO mixed with LDPE effectively restrainproduction of space charge in the polarization process.Finally the PSD test device was used to measure PSD spectrum of purepolyethylene and polyethylene doped MgO0.5%,3%,5%. Research showsthat structural weakness and residual additives after preparation, which leadto deeper trap. Adding MgO can effectively restrain charge moving that injectedfrom electrode so as to improve internal electric field distortion.