Wireless power transmission system for charging the inspection robot on power transmission lines

Abstract

In order to prolong continuous working time of the mobile robot to inspect on transmission lines, a robotic power management system is introduced in this paper based on the wireless power transmission technology. Magnetic resonance coupled WPT (wireless power transmission) unit is applied and its performance is analyzed in form of electrical circuit mode method. By modeling the output power of WPT unit, the relationship between coupled coefficient, angular frequency and amount of output power is given, and furthermore the energy consumption of each unit in power management system is quantified. Experiment results verified the validity of the circuit model of WPT and showed that the system could work conveniently in wireless way to provide power for the inspection robot. Keywords-wireless power transfer, coupled coefficient, Q-factor technologies recently due to its capability to transfers energy across large air gap with high efficiency. Although the coupled resonance based WPT need much more attention to design and test the drive circuit as its working frequency is usually up to several mega Hz, it's effective working distance which is up to several meters (decides by the material and the size of the resonance coil in application) is still really attractive for medium distance wireless power transmission applications. In this paper, the fundamental characteristics of a special magnetic resonance system for transmission line inspection robot have been examined. Equivalent circuit is given in order to give numerical analysis of the resonance system. In order to test the output power of the WPT unit, current in load coil is calculated, and the relationship between coupled coefficient, angular frequency and output power is given. Power transmission ratio is also given in chart which shows that amount of power loss of WPT accounts for few part of the total loss of the power management system and the ratio is acceptable. Equivalent circuit are also verified by experiment which shows that the proposed method is suitable for charging the inspection robot and the coupled resonance wireless power transmission system could also be applied in many other fields to avoid the trouble or obstacle of using electric cord. A wireless power transmission technique based robotic power management system is introduced: Section2 shows the general function charts of the power management system, and especially the wireless power transmission unit of the system. Section 3 details the circuit model of WPT for calculating the output power of this unit; Section 4 introduces the experiments results and proves that the WPT based power management system can efficiently transmit power wirelessly and the design in this paper has the function of prolonging continuous working period of the inspection robot.