Research on Fault Detection Technology of Primary and Secondary Circuit of Switchgear

Abstract

AbstractAt present, the primary and secondary equipment integration has been realized in 10 kV switching station and ring main unit, and the functions of telesignalling, telemetering and telecontrol have been realized by assembling Data Transfer Unit (DTU). However, in actual operation and maintenance, if an equipment fault occurs, it is necessary to first determine whether it is a primary or secondary equipment failure, and then send corresponding maintenance personnel to the site. In addition, this maintenance mode also needs to be powered off. The existing primary equipment does not have a circuit breaker test position. If the test is required, the whole section of bus must be powered off. Due to the important user and reliability requirements, the power off is almost difficult to implement. If the fault identification cannot be solved at one time, the power off times need to be increased, which affects the reliability of power supply. The primary equipment is electrified, and the secondary equipment has few test methods, low safety factor and more equipment operation with faults, which is not conducive to the healthy development of distribution network (M. Adams, Effectiveness of different design solutions to control internal faults in MV switchgear, IEE Colloquium on Risk Reduction: Internal Faults in T&D Switchgear (Digest No: 1997/295), pp. 5/1–5/6, 1997). In order to solve the above problems, this paper proposes a ring network unit fault detection device that can distinguish between primary and secondary circuit failures without power failure. On the basis of the traditional fault diagnosis method, a low-voltage live detection method with high safety and easy operation is added.