Research On The Control Method Of Unpowered Downhill And Energy Recovery For High Voltage Transmission Line Inspection Robot

Inspection robot can automatically check the power line segments across the mountains, rivers, and lakes and primeval forests and so on, thus, to free the inspection workers from heavy labor and realize the automation of power system inspection. With more and more perfect inspection and obstacle-crossing function, and higher autonomous ability of inspection robot, the issue of energy consumption has become the main factor that restricts long distance and large scope of inspection of inspection robot. Therefore, currently saving and recycling energy has become the key content of studying high-voltage inspection robot, and an important method to improve the inspection ability of robot, which is definitely in accordance with the great requirements of intelligent operation and maintenance of power grid.The research content of this dissertation roots in the National 863 Plan "(ultra) high voltage multi split transmission line autonomous inspection robot and its application(2006AA04Z202)", and other projects "Demonstration of key technology and engineering application of transmission line inspection robot in high voltage multi tower crossing forest region" founded by Baishan (Jilin province) electric power company. Taking advantage of the structural characteristics of the high voltage transmission line, this dissertation puts forward the use of gravity to drive the robot to go downhill, and use the method of dynamic braking and regenerative braking to control the downhill speed of robot without power and recycle regenerative braking energy. The key research content and innovative points of this dissertationare as follows:First, the dissertation puts forward unpowered downhill operation scheme according to the structural characteristics of the high voltage transmission line; designs unpowered downhill decision strategy and uses dynamic braking to control the downhill speed without power based on the circuit model; controls the downhill speed without power under the dynamic environment in real time by the use of various domain of discourse fuzzy control method.Second, the dissertation proposes unpowered downhill energy recovery method based on regenerative braking. This dissertation adopts hybrid power system scheme with lithium battery and super capacitor in parallel to avoid the damage to lithium battery caused by high current charging and discharging in the process of unpowered downhill; proposes energy distribution control strategy of composite power supplied in different section of line segments and recycle regenerative braking energy with unpowered downhill based on the SOC of lithium battery and super capacitor.Third, the dissertation comes up with an unpowered downhill speed-controlling and energy recovery method under the double fusion feedback braking and dynamic braking. This dissertation adopts the scheme combined with front wheel feedback braking and the rear wheel dynamic braking, with the force analysis of the robot in the process of downhill; solves the range of speed of front wheel DC motor energy feedback based on the double wheel motion feature of robot's constant downhill speed, and adopts the PWM wave duty cycle correction method based on RBF neural network to realize the constant downhill speed of unpowered robot. On the basis of this, the dissertationfurther puts forward the control strategy of the regenerative braking torque distribution for maximum recycle of regenerative braking energy.Fourth, the dissertation presents an optimal control method of unpowered downhill speed and regenerative energy according to the temperature change characteristics and the difference of front and rear wheel of walking motor. This dissertation finds out the energy control system duty cycle and the allocation factor of regenerative braking energy based on the relationship between rated current and torque under different temprature in motor armature winding.Experiments results show that this optimization method can effectively reduce the temperature difference between the front and rear wheel motor in the long distance operation process, reducing the security risks of rising motor temprature.Through the experimental study on the simulation and real transmission lines, the correctness and validity of the proposed speed control and energy recovery method has been verified, which lays the theoretical foundation for the realization of long distance, large scope of inspection for the high-voltage inspection robot.