Research On Mechanical Fault Vibration Detecting Technology Of GIS

As the national economy of China developing rapidly, the electricity demanding has being increased. The voltage level of the power system required rising, so the reliability of power quality needs continue to strengthen, in this situation, SF6 gas-insulated switch gear(abbreviated GIS) with the advantages of small size, easy maintenance, long maintenance cycle, strong adaptability and reliability has been recognized and widely using in power system, becomes one of the important equipment in the power grid. With a large number of GIS using, the failure rate increases, so the fault detection and diagnosis of GIS would be more and more attention. But in early power system the study of fault detection for GIS focused on its discharge failure, then in the actually operation of GIS, in addition to the discharge fault, mechanical fault is the main reason leading to the accident. Long-term vibration of GIS maybe caused the bolts loose, a gas leak, and the insulated accident. At the same time, insulators and insulation column will be different degree of damage, which affects the robustness of the housing ground, when could cause a massive power fault, causing irreparable great loss to the power grid. Therefore, to enhance the research on mechanical fault vibration detecting of GIS can ensure the power system security and stability. Under this background this paper will conduct in-depth research to the mechanical fault vibration detection and diagnosis of GIS.Firstly, this paper briefly describes the internal composition of GIS, classification and description of the main features, and describes different types of mechanical failure principle, such as the electromagnetic force, electric power, magnetostrictive, switch operating mechanism, contact poor contact, breaker failure and so on, in based on this, continue the theory analysis and numerical calculation to the normal and abnormal sound vibration signal generation of GIS. And proposed GIS conductor and housing natural frequency calculation method to guide the subsequent experiments.Secondly, in the laboratory establish a GIS platform, construct two fault types tests of Isolating switch contact badly and the ground screw loose, then summed up vibration signals under normal and fault of GIS to study the vibration signal characteristic, analyzed the causes and characteristics of the performance of different types of faults generated spectral distribution and characteristics of GIS,clear when the fault vibration signal, and summarize a GIS repository of mechanical fault abnormal sound vibration signal detection provides for a base of on-site detection and judgmentFinally, according to GIS theory analysis and vibration analysis with vibration signals of GIS, this paper designs a mechanical fault vibration detection system. The system can display time-domain waveform and spectrum distribution of real-time, then may signal acquisition, data analysis, processing and other functions. To some extent promote the development of GIS mechanical problems for the study of GIS mechanical fault vibration detecting problems of the future provides a theoretical basis.