The Simulation And Analysis Of The Coupled Field In The Arc-Extinguishing Chamber Of High Voltage Self-blast SF₆ Circuit Breaker

In china, the electric power industry has been developed in the direction of the big unit, far distance, ultra high voltage, AC and DC adopted together since 1980s. Now, in this century, it is the time for the electric power industry to develop at a very fast speed, so the high voltage switch industries and the scientific researchers must do their best to develop the scientific research work. The self-blast SF₆ circuit breaker is the main studied product, so its key technique must be studied. The self-blast arc theory of the self-blast SF₆ circuit breaker is that the blocked arc effect used, in other words, the arc energy is used to make the SF₆ gas pressure in the compressed chamber rise and then has the arc blast when the arc current is zero. So the key problems of the self-blast SF₆ circuit breaker cover many subjects, such as electromagnetic field, heat, flow fluid field, mechanical field and so on. Focusing on it to have theory study will have realistic significance for increasing the design level of high voltage switch industry, especially for the ultra high voltage switcher theory improved.In this paper, at the background of the "The study of the 1100kV double breaks circuit breaker and its related technique" item which is cooperated by Pinggao group Co.Ltd. and us, aiming at the theory and character of the self-blast SF₆ circuit breaker, based on the basic equations of magneto-fluid mechanics, an idea is brought forward that is based on the domain decomposition method by using the parallel computation simulation technique to solve the model which is the arc model, gas flow field model and the electromagnetic field model coupled. An idea which is to use the lattice Boltzmann method to build the arc plasma field BGK equations is brought forward, and then the gas and the arc's interaction is studied deeply.On the condition of our currently available possessions, the parallel computation system based on the newly developed computer clusters technique is built independently, which is suitable for the coupled field solved. And the parallel computation performance of the computer cluster system is tested. The results show that the parallel computation system has good parallel computation efficiency. The theory and algorithm in the PHOENICS software is exploited and the parallel computation is made on the parallel computation system. It fulfills the distributed parallel computation of the coupled field based on the computer internet. It makes the results have precision and high computation efficiency.The domain decomposition method and the parallel technique is combined. The grid technique in the complex domain including the moving boundary technique which fits the circuit breaker breaking process is built. On the basis of the finite volume method, built the math model discrete equations, and the high precision discrete format with the delay-correction suitable for this computation is built on the basis of the QUICK format, the limiter is adopted in order to assure the format's finite character. The SIMPLE algorithm is used to solve the pressure and speed coupled equations, the iterative method and the compressed storagetechnique are made to solve the algebra equations. The coupled field problems of the electromagnetic field and gas field are dealt with. On the parallel computation system, the self-blast circuit breaker's breaking process at the different conditions such as no load and load condition are computed and simulated. The phenomenon of the energy flowing back to the compressed chamber is gotten and analyzed. The phenomena such as the pressure in the self-blast circuit breaker's compressed chamber, the gas flow field distribution, the gas and the arc's interaction and the arc parameters change and so on are analyzed too. The breaking process with no load of the self-blast circuit breaker is simulated;the breaking process with load of the self-blast circuit breaker in the different burning arc time is simulated too. The pressure in the heat-expansion chamber change, the flow field distribution change, the interaction between the gas and the arc and the arc parameters in the extinguishing arc chamber of the self-blast SF6 circuit breaker are analyzed.Based on the lattice Boltzmann method idea, the gas action is described by gas dynamic theory in micro-point and described by statistical mechanics in macro-point. The LB math model which can describe the two-dimension lattice Boltzmann flow and the heat transmission characteristic in the nozzle is built on the purpose of ignoring the gravitation and the electric field force. The model has many characters, such as good numerical stability, high-order accuracy, easy solution, dealing with the boundary conditions conveniently and so on. The theory of the extinguishing arc and the lattice Boltzmann method character are combined. By use of the Chapman-Enskog multi-scale analysis technique, the LB model can be recovered to the corresponding nozzle arc equations at macroscopic level. The theory model for the nozzle arc inner process mechanism is built, the mathematical computation and analysis by use of the computer is realized, and the aim of study of the inner arc process mechanism is fulfilled.The computation results in this paper are testified by the former test results and the maturity results. It is feasible that the idea based on the field decomposed method using the parallel computation technique to compute and simulate the math model which is the electric field, the gas flow field and the electromagnetic field coupled, it can be used as the theory guidance in the circuit breaker design and study process.