| Overhead ground wire is an important protection facility for high-voltage transmission lines,and one of the most basic and effective lightning protection measures for lines.The ground wire is mostly in bad line conditions and weather conditions.Due to factors such as lightning strike,line vibration,device wear,etc.,the outer layer may be broken or scattered,which will reduce the electrical and mechanical properties of the overhead ground wire and affect the safe operation of the transmission line below.It will even cause the line to flash over and discharge,resulting in a large-scale power outage.Therefore,it is necessary to perform regular maintenance on the overhead ground wire,and repair the ground wire with broken strands in time to prevent larger problems.However,at present,manual repair is still carried out by manual on-line operation.This method requires the staff to be in a high-altitude line environment with risks of mechanical strength for a long time.If there is a live operation,they need to wear protective clothing,which greatly limits the operation of the staff.Not only is the work inefficient,but there are also great security risks.With the reform of the power system and the improvement of the degree of marketization of power operations,the traditional manual breaking and repairing operation methods have been unable to meet the needs of high-reliability transmission of modern power systems.In this paper,a robot for repairing broken strands of overhead ground wire is designed to replace the manual repairing task of overhead ground wire.Taking this as the research object,the main work is carried out in the following aspects.The operation process of manually repairing the broken strand overhead ground wire is analyzed,and according to the tasks of each stage and the actual line of the overhead ground wire,the three-dimensional mechanical structure of the robot body for the broken strand repairing overhead ground wire is designed.The repairing robot mainly includes: a walking mechanism,which is used to drive the robot to move on the line.Wire-stripping mechanism for handling scattered ground wires.The pre-twisted wire winding mechanism is reinforced by winding a certain length of pre-twisted wire.The three major mechanisms correspond to reaching the broken strand position in the manual repair process,restoring the broken wire into the groove,and strengthening the treatment.The kinematics of the repairing robot for broken strands of the overhead ground wire is analyzed,and the equivalent kinematics model of the repairing robot is established,and the simulation model is built by using the robot toolbox in MATLAB,and the parameter changes of each joint during movement are observed.In order to observe the action state of the repairing robot more intuitively,a co-simulation model of Solid Works-MATLAB was established to verify the rationality of the motion of the mechanism in the designed model,which provided help for subsequent control.In order to improve the stability of the repair robot during operation,a single-motor global fast terminal sliding-mode controller is designed,and the load torque observer is used for feedforward compensation,which reduces the disturbance of uncertain disturbance to the joint motors.According to the special control requirements of the pre-twisted wire winding mechanism,under the structure of cross-coupling synchronous control,the synchronous compensation controller is used to realize the respective synchronous actions of the two groups of winding discs and the lateral moving device.A real robot for repairing broken strands of an overhead ground wire was processed and assembled,and the selection of components and the design of the control system hardware were completed.After testing the basic functions of each mechanism,the control system was integrated with the repairing robot body,and a simulated circuit was built to test the repairing task,which verified the functional integrity and feasibility of the repairing robot. |
