Research On Structure Design And Application Of Fast Repulsion Mechanism

In our country, the development of power system, especially the planning of ultra-high voltage based strong smart grid, is making higher demands of preferable speediness, controllability and intellectualization on switching operation, and traditional operating mechanisms are outdated to meet these requirements. Because it has simple structure, rapid action, and good power electronic controllability, a new kind of fast repulsion mechanism is performming significant advantages in preferable speediness, controllability and intellectualization. However, it is lack of systematic research in structure design and application so far.In this dissertation, the energy conservation method, the time and displacement method and the finite element method are analyzed. Compared with the previous two methods, the finite element method is more effective in calculating dynamic problems of electromagnetic field.Structure design is essential to its dynamic performance. the super energy storage capacitor is identified as operation power supply, and its parameter is calculated. The bistable disk spring is adopted for retaining force in opening and closing position, and the dynamic retaining force curve is calculated, which is also compared with permanent magnetic retaining mechanism. Using The finite element analysis software of ANSOFT. the effect of main structure parameters on dynamic performances are modified and analyzed, which provides a theoretical basis for the structure optimization.Vacuum circuit breaker's switch on and off oscillation are seriously threatened. Under the principle and structural characteristics, a new type of excitation circuit is designed, which has simple structure, and also could solve switch on and off oscillation problems bothly.For the example of swich off. the optimal delay time of time delayer is concluded through simulation under the optimal structure parameters.The fast switch based on fast repulsion mechanisn applying to fault current limiter has broad application prospects. Series reactor is installed to limit the oscillating discharge from the energy storage capacitor during switching operation. Reactor is seried into capacitor branch and fast swtich respectively, and simulation results show that the fist case is more effective to limit the fault current in case that the closing time of the fast switch must be short enough.