Research On Post Insulator Defects Detection Device

In recent years, China’s electric power industry has developed rapidly, and installed capacity of generators has increased year by year. Insulators, as a crucial part of power transmission and transformation equipment, are closely attached to the development of this industry. Insulators are devices that can tolerate electric pressure and mechanical stress between conductors with different electric potentials, or between the conductor and the grounding potential component. Insulators should be invalid due to changes in the environment and conditions of power load or the breakdown of insulators will lead to the fault of the whole line.Thus, to seek for a nondestructive online testing of insulators with convenience, security and lower cost is necessary. In 1980s, the vibrating sonic testing as been adopted by Russian scientists to shortcomings of insulators of porcelain posts in the power system. As a simple, accurate testing approach, this testing is promising in testing insulating equipments as well as in industrial manufacture.The specific content of this paper is follows:Firstly, the author introduces the types, present application of insulators and causes of their shortcomings, as well as testing of common shortcomings with their merits and demerits. According the analysis, the vibrating sonic testing is brought in and will be analyzed in details. The main research content of this paper is based on that.In the following section, there is a theoretical introduction of the vibrating sonic testing from simple harmonic motion and Fourier decomposition with fundamentals of vibration. Vibrators with single degree of freedom are exemplified to illustrate the impact of frequency on object rigidity; this section also introduces the collection and handling of vibrating signals; calculation results of simulated model of post insulators from the literature references pave theoretical grounding and offers judgment for following testing.From the overall design plan, there is an introduction of design principles and plans of each module, including power supply, driving of vibrating oscillators, signal reception and circuit design of CPU components. All modules are tested and jointly adjusted to guarantee their normal function.The author builds a model of a whole copper post for simulation to obtain vibration modes in the beginning phases and test them via devices to collect frequency spectrum of the copper post Then the simulated results are compared with testing results; an artificial destructive experiment is adopted on steel post and another simulated test is conducted to generate frequency spectrum compared with that before the cutting. The author will analyzes them based on related theories.A field test will finally be conducted in a transformer plant concerning post insulators of 110kV bus. Test results will be uploaded to a computer in groups for analysis and testing criteria; while the author analyzes testing results of some special insulators as a reference to the generating of standard.