摘要
聚丙烯(polypropylene,PP)具有工作温度高、绝缘性能优良和可回收再利用的优点,已成为热塑性电缆绝缘材料研发的热点。模塑接头采用与电缆本体相同的材料作为接头绝缘,不仅可以解决预制式接头可活动界面的问题,还有助于实现整个PP电缆线路体系的绿色可回收性。首先完成了10kVPP电缆模塑接头的制作,并对PP电缆及模塑接头绝缘切片的晶体结构、电气性能和力学性能进行了研究。结果表明:与电缆绝缘切片试样相比,PP模塑接头绝缘切片试样的结晶度较高、微晶尺寸较大、熔融温度较高;电气性能上,其体积电阻率较高、介质损耗角正切值较小、工频击穿场强较高;力学性能上,其断裂伸长率较小、弹性模量较大。这可能是由于电缆与模塑接头工艺不同所致,电缆采用水冷方式进行冷却,PP在快速降温过程中形成小尺寸球晶,而模塑接头在室温下自然冷却,PP分子链充分折叠排列形成大尺寸晶体。晶体结构的不同导致了电缆绝缘与模塑接头绝缘电气性能和力学性能的差异,但二者之间仍具有较好的一致性,验证了模塑接头应用于PP电缆的可行性,并为高压PP电缆和模塑接头的进一步研发提供参考。
Polypropylene has become a hotspot in the research and development of thermoplastic cable insulation materials due to its advantages of high working temperature,excellent insulation performances and recyclability.The molded joint employs the same insulation material as the cable body as joint insulation,which can not only find a solution of the movable interface of the prefabricated joint,but also help to realize the recyclability of the whole PP cable line system.Firstly,a 10 kV PP cable molded joint is manufactured,and the crystal structure,electrical performances and mechanical properties performances of PP cable insulation and molded joint insulation slices are studied.The results show that the PP molded joint insulation sample has higher crystallinity,larger microcrystal size,and higher melting temperature compared with the cable insulation slices.For electrical performances,the molded joint insulation has higher volume resistivity,smaller tangent of dielectric loss angle,and higher power frequency breakdown field strength.For mechanical performances,the elongation at break of the molded joint insulation is smaller and the elastic modulus is larger.This may be due to the different processing methods of the cable and the molded joint.The cable is cooled by water cooling,and small spherulites are formed in the rapid cooling process.While the molded joint is cooled naturally at room temperature,and the PP molecular chains are fully folded and arranged to form large crystals.The different crystalline structures of PP cable and molded joint insulation lead to the differences of electrical and mechanical performances.However,the performances of cable insulation layer and molded joint insulation layer are still consistent.The results verify the feasibility of the application of the molded joint in PP cable,and provide references for the further research and development of high voltage PP cable and molded joint.
作者
展云鹏
刘唱
徐曼
侯帅
惠宝军
朱闻博
傅明利
ZHAN Yunpeng;LIU Chang;XU Man;HOU Shuai;HUI Baojun;ZHU Wenbo;FU Mingli(Department of Electrical Engineering,Xi’an Jiaotong University,Xi’an 710049,China;Electric Power Research Institute,CSG,Guangzhou 510663,China)
出处
《南方电网技术》
CSCD
北大核心
2024年第6期20-28,共9页
Southern Power System Technology
基金
国家自然科学基金资助项目(52107028)
中国南方电网有限责任公司科技项目(SEPRI-K216003)。
关键词
聚丙烯电缆
模塑接头
晶体结构
电气性能
polypropylene cable
molded joint
crystal structure
electrical performances
