Study on electrical ageing performance of XLPE insulating material under low frequency voltage
With the development and construction of offshore wind power,cross-linked polyethylene cables are gradually used in low-frequency power transmission.However,their insulation characteristics after ageing at low-frequency voltage are still unclear.So the insulation characteristics and ageing mechanism of cross-linked polyethylene after ageing at low frequency were studied in this paper.Firstly,cross-linked polyethylene samples were conducted accelerated ageing experiments at voltage frequencies of 20,35,50 Hz.Then,the physicochemical and electrical properties of the ageing samples were tested.Finally,the mechanism of voltage frequency on the electrical ageing of cross-linked polyethylene was investigated.The results show that with the decrease of the ageing voltage frequency,the crystallinity of cross-linked polyethylene decreases,the space charge accumulation and conductivity increase,and the AC electric strength decreases.The decrease of voltage frequency makes the ageing degree increase significantly.Combined with the infrared spectroscopy and crystallinity analysis,the decrease of voltage frequency makes the probability of charge into trap and forming hot electron be higher,the electroluminescence effect caused by electron-hole composite is stronger,which causes the increase of polymer molecular chain breakage and cleavage,and then its electric strength is reduced.
low frequency ageingsubmarine cablescross-linked polyethyleneinsulation degradation
万方数据
维普
