Medium Voltage Cold Shrinkable Cable Accessories Design And CAE System Development

With the development of China’s power grid,power cables are more widely used in power systems.Compared with overhead lines,power cables are easier to install,and operation and maintenance are more straightforward and become mainstream in new urban transmission systems.The safe and stable operation of power cables is an essential part of ensuring the reliability of power supply in the entire region.Since the length of cross-linked polyethylene(XLPE)cables are generally less than 1000 m,cable accessories are essential for active connection between cables.Due to the existence of composite interface and electric field stress concentration inside the cable joint,it becomes the weakest link of the transmission line and a typical part where will cause the problem in operation.At the same time,due to improper installation and the environment,cable accessories are prone to form weak points of insulation and cause insulation breakdown.According to statistics,the cable body and accessory failures in the past ten years show that cable joint quality failure rate accounts for 63%,while 73% of joint failures originate from interface discharge,and cable joint intermediate joint quality problems are more and more attention.This paper aims to use the finite element simulation technology to optimize the design of the intermediate joint of the medium-voltage cold-shrinkable cable accessory according to the cable accessory design requirements,and simulate the electric field condition of the accessory working condition.This paper firstly takes the intermediate joint of the medium-voltage cold-shrinkable cable accessory as an example,starting from the analysis and design of the cable accessory structure,based on the material performance and dimension design principle of the cable accessory,proposes the cable accessory design scheme,which lays the foundation for the finite element simulation.Then,using the finite element simulation method,the influence of the shielding tube on the internal electric field of the accessory under different lengths and the stress cone is simulated and simulated;and the influence of the shape of the shielding tube port on the field strength is changed,according to the above two simulation results.Optimized design scheme,combined with test,pre-and post-optimization of cable accessories,partial discharge and withstand voltage test,indicating the effectiveness of the optimization scheme.Finally,the development design VB calls the ANSYS Maxwell finite element simulation design system.This paper proposes a VB/CAE cable accessory design software based on the VB language to meet the design requirements of modern products.Mainly utilizes the file transfer and execution functions between VB and ANSYS Maxwell.Through VB as a development tool,a user interface for parameter input was designed,and ANSYS Maxwell was secondary developed.The software can automatically complete the drawing function and the electric field simulation calculation function.Finally,the software is used to verify the design of the accessory to prove the feasibility of the software design.The paper starts with theoretical analysis,simulation experiments and experimental verification.The software system can provide a reference for the design of intermediate joints for future cable accessories.