The Research Of Reactive Power Compensation Capacitor's Fault Mechanism

In China, the power grid is moving into the country interconnection, a large scale AC/DC hybrid transmission system. It has the characteristics, such as large capacity, long distance, ultra-voltage and multi-area interconnection. The interconnected power grid has the flexible scheduling and economic operation, but it needs higher reliability of the electric facilities. In modern power transmission system, the reactive power compensation equipment is closely linked to the running stability, low-cost and voltage support of the power grid. As the mainly equipment of reactive power compensation, high-voltage power capacitors are widely using in power grids. The damage times of power capacitor is very large and the damage cannot be repaired, even more, some capacitors are happen explosion and cause serious accidents. So the safety and economy of power system have potential threat, and the safety of operators and maintainer are also threaten. The power capacitor damage is affected by power grid operation and on-site environment factors. Since the complex combination and changes of many factors, it is difficult to study the mechanism of power capacitors and fault diagnosis. Therefore, it has the theoretical and practical significance to study the damage mechanism and fault diagnosis of power capacitors.The work completed in the dissertation includes:(1) As it is difficult to determine the primary factor of the influence power capacitor damage, Has counted the capacitor breakdown data which Dongguan Power supply bureau one year institute records, Carries on the statistical analysis from the multiple perspectives, obtains the related rule, provides the direction for the deep research power capacitor breakdown mechanism.(2) Conducts the analytical study in view of the influence power capacitor movement reliable temperature factor, proposed the influence capacitor operating temperature's factor, and has established the capacitor heat transfer process mathematical model. Has carried on the sector analysis based on the model to the effective radiating surface, obtains the corresponding conclusion.(3)Proposed that power capacitor's incipient failure very has the possibility is creates by the quality flaw, introduced simply power capacitor's four kind of typical breakdowns, and have established the part electric field simulation model through the finite element simulation software, has analyzed the different flaw to the part electric field distributed influence, has provided the reference to the capacitor plant's design and the examination, put forward the purchase proposal for the power transformation department.