Design Of Cable Automatic Retraction And Extension Control System Based On Thermoelectric Coupling

Copper-core XLPE insulated overhead cable(hereinafter referred to as JKYJ overhead cable)is an important equipment to ensure power system transmission and data communication,and its normal operation plays an important role in social and economic development.However,with the change of the load current and operating environment temperature of the overhead cable,the axial thermal deformation of the overhead cable will occur,which will affect the thermal stability of the overhead cable during operation,which will cause great harm to the safe and stable operation of the overhead cable.In this paper,the influence of ambient temperature and load current on the thermodynamic characteristics of overhead cables is comprehensively considered,the finite element analysis based on thermoelectric coupling is carried out on the temperature field and thermal expansion of overhead cables,the influence law of cable temperature on thermal expansion coefficient is obtained,the key control parameters of the automatic retraction system are calculated,the cable automatic retraction device is designed,and the program compilation and prototype test of the automatic retracting and discharging control system are completed.Through the finite element simulation software Ansys,the temperature field distribution and thermal expansion effect of JKYJ overhead cable in non-energized state and power-on state were analyzed respectively,and the expansion change of JKYJ overhead cable under different working conditions was obtained.Then,when the cable load is 300 A,400A and 500 A,the dynamic characteristics of thermal expansion at an ambient temperature(-10℃～20℃)are simulated and analyzed.The above obtained result data are compared and analyzed,and the average thermal expansion coefficient of JKYJ overhead cable under different temperature sections is obtained,which is used as the main parameter basis for the cable automatic retraction control system under thermoelectric coupling.On the basis of finite element analysis,the cable automatic retracting device is designed,and its data acquisition,controller and actuator are selected by hardware and a test prototype is built,and the control process of the control system is designed,and the software programming and human-computer interaction interface configuration of the control system are completed,so that the cable automatic retracting and discharging control system can realize the function of adaptive retracting and discharging control of the cable according to the current load current and environmental temperature changes.It effectively reduces the risk of accidents caused by the collapse of JKYJ overhead cables and mechanical fixtures under the influence of thermal expansion.Finally,the automatic control process and retracting length of the prototype are tested in the laboratory,and the experiments show that the automatic retracting and retracting control system can adaptively retract and play the overhead cable according to the change of ambient temperature and load current,and the average error of the retracting length during the retracting and retracting process does not exceed 1%.The research work in this paper provides a theoretical basis for the study of the thermal expansion change law of JKYJ overhead cable under the influence of ambient temperature and load current coupling,and the designed cable automatic retraction control system based on thermoelectric coupling reduces the harm of thermal expansion effect to overhead cables,effectively improves the reliability of long-term stable operation of transmission network,and has certain engineering practical significance.