110kV电力电缆护层电压仿真与补偿研究

Study on simulation and compensation of 110kV power cable sheath voltage

针对城市施工改造引起的高压电缆不对称敷设,从而导致电缆末端护层感应电压过大的问题,提出一种基于电感补偿的电缆护层感应电压补偿方法。首先对单回路与双回路敷设的电缆护层感应电压进行理论推导,得出在对称及非对称敷设条件下各相护层感应电压值;然后介绍电感补偿法的原理,并通过PSCAD/EMTDC软件对单、双回路电缆护层感应电压进行仿真分析,对比补偿前后的护层感应电压,证明了电感补偿技术的可行性;最后制作样机对南京两地区已敷电缆进行现场测试以验证仿真数据的合理性,经过比较发现二者有较好的吻合性。研究结果表明,补偿效果与补偿线圈匝数成正比关系;在不产生过补偿的情况下,气隙长度越短,补偿效果越好。

Aiming at the problem that the cable is laid asymmetrically due to urban construction,which leads to excessive induced voltage of cable sheath,an inductive voltage compensation method for cable sheath based on inductance compensation is proposed.First,the induced voltage of cable sheath of single circuit and double circuits is theoretically deduced,and the induced voltage value of each phase sheath under symmetrical and asymmetric laying conditions is obtained.Then the principle of inductance compensation method is introduced,and the sheath voltage of single and double circuit cables is simulated and analyzed through PSCAD/EMTDC software.The sheath induced voltage before and after compensation is compared,and the feasibility of inductance compensation technology is verified.Finally,a prototype is made to test the cable laid in Nanjing and other regions on the spot to verify the correctness of the simulation data.Through comparison,it is found that there is a good coincidence effect.The study results show that the compensation effect is proportional to the number of compensation turns,and the shorter the air gap length is,the higher the compensation effect will be without overcompensation.