长距离330 kV电缆护套交叉互联接地方式研究及回流缆优化布置方法  

Research on Cross-connection Grounding Modes of Long-distance 330 kV Cable Sheath and Layout Optimization of Return Cable

作　　者：张军强 董卓元 盛飞 姚新宇 李晓婷 高永亮 李江涛[2] 刘书瀚 孙义 ZHANG Junqiang;DONG Zhuoyuan;SHENG Fei;YAO Xinyu;LI Xiaoting;GAO Yongliang;LI Jiangtao;LIU Shuhan;SUN Yi(State Grid Shaanxi Electric Power Company Economic and Technological Research Institute,Xi’an 710075,China;School of Electrical Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]国网陕西省电力公司经济技术研究院,西安710075 [2]西安交通大学电气工程学院,西安710049

出　　处：《高压电器》2020年第2期189-196,共8页High Voltage Apparatus

摘　　要：随着电压等级的升高和电缆的增长,为了实现330 kV电缆线路设计的合理化、规范化,给出护套保护器等装置的选型依据,文中研究了长距离330 kV电缆的两种护套交叉互联方式。首先根据已有的330 kV电缆参数和隧道敷设方式,使用电磁暂态分析软件EMTP-ATP进行仿真建模,对正常运行时线路各点护套感应电压进行分析,得出其分布规律和两种不同护套接地方式的感应电压特征。其次,探讨了系统发生单相短路接地故障时,故障线路和非故障线路的护套故障感应电压波形特点以及分布规律,将两种接地方式下的感应电压数据进行了对比,并探讨了电缆线路的增长对分布规律和感应电压值的影响。最后,针对单端经保护接地方式提出回流缆布置方法,并研究了增设回流缆和采取回流缆换位对系统的影响。根据仿真研究可得,护套两端直接接地方式在稳态以及暂态故障时感应电压值相对较低,且有较高的经济性,可以作为330 kV电缆护套的首选接地方式。若采用单端接地方式,增设回流缆可以减小故障时电缆护套感应电压,采用回流缆换位可以减小稳态运行时的环流大小。To design long-distance 330 kV cable line rationally and standardly and provide selection basis of the devices such as cable sheath protector,two cross-connection modes of the 330 kV cable sheath are studied.Firstly,according to the existing 330 kV cable parameters and laying method of cable in tunnel,the electromagnetic transient analysis software EMTP-ATP is used for simulation modeling,and the sheath’s induced voltage of each point of the line in normal operation is analyzed to obtain the voltage’s distribution laws and characteristics for two sheath grounding modes.Secondly,in the case that a single-phase short-circuit grounding fault occurs in the system,the features and distribution laws of the sheath’s induced voltage waveforms of the faulty line and normal line are discussed.The induced voltage data under the two grounding modes are compared,and the effects of the line length on the distribution law and the value of the induced voltage are analyzed.Thirdly,a return cable layout method is proposed for the single-end protected grounding mode,and the influences of the additional return cable and the return cable relocation on the system are investigate.It is concluded that the direct grounding mode at both ends of the sheath has relatively low induced voltage in steady state and transient fault state,and has high economical efficiency,so it can be taken as the preferred grounding mode for the 330 kV cable sheath.For the single-end grounding mode,the addition of return cable can reduce the induced voltage of the cable sheath when fault occurs,and return cable relocation can reduce the circulating current during steady-state operation.

关 键 词：长距离330 KV电缆 感应电压 交叉互联 回流缆 

分 类 号：TM75[电气工程—电力系统及自动化]