Operation Safety Analysis and Protection of Hot-line Working Robot in Strong Electric Field

Robotic operation can ensure the safety of the operators and reliability of operation while improving the economic benefits of substation. However, because of the compact structure of the intelligent substations, the operating space is small. Further, as the main material of hot-line working robots is metal, which greatly changes the strength and distribution of the electric field around its working position when entering the working position and in the process of operation. In serious cases, interphases or phase to ground air breakdown occurs. Hence the working space of hot-line working robots is limited not only by the narrow space between devices in the substation but also by the electrical safety clearance of phase to phase and phase to ground. Therefore, it is necessary to find a safe working space (“SWS”) for the robot which should not be too small for the robot to accomplish the task effectively. The purpose of this paper is to provide: (i) a design reference for hot-line working robots which can not only guarantee the electrical safety distance but also minimize the effect to the electric field and (ii) a method to find the SWS of the robot in which the robot can accomplish the task effectively with the example of the hot-line working robot for isolated circuit breaker (“DCBot”). We analyze the influence of different installation positions and postures of the manipulators on the electric field in this paper and present a calculation method of the SWS of the manipulator in a very non-uniform electric field caused by the intervention of manipulators, which is significant to the research on hot-line working robots. The SWS has been tested in simulated and energized experimental system, and the experiment results show that the robot can work safely and efficiently.