Study Of High Voltage Motor Soft Starter Based On Series Of Thyrisors

In recent years thyristor motor soft starter fast becomes a mainstream product in the market for its good performance, high efficiency and reliable. But in domestic market, the soft starter is mainly medium and low voltage, for the high-voltage motor soft starter the research is still relatively little. In this thesis, high-voltage motor soft starter for the engineering background and the series thyristor as the main object of study, we make the voltage level to improve by the series thyristor, ultimately realize the high-voltage motor soft starter.Firstly, the thesis starts from the switching characteristics of thyristor, through mathematical analysis, related research has been done about the turn-on of and turn-off characteristics of the thyristor. Meanwhile, establish a mathematical model and simulation model of the reverse recovery characteristics of the thyristor, understand the fundamental principles of the turn-off of the thyristor. The selection of the thyris-tor and the series has laid a theoretical foundation.Secondly, thyristor series on issues is in-depth studied, including the choice of its parameters before the thyristor series, the problem of voltage unbalance and the voltage balance circuit design of the thyristor series, then through the establishment of simulation model, analysis the practical problems of the thyristor series by the si-mulation.Thirdly, some experiments have been done about the series of thyristors. Before the experiment, select the parameters of thyristor, the external device parameters and design the experimental circuit. By the experimental, the series thyristors can be seen at the same turn-on and turn-off.Finally, starting from the high-voltage motor soft starter, the series of thyristor trigger and high-voltage measurement issues are researched. On this basis, established the model of the high-voltage motor soft starter, by analyzing the simulation results, we can get the advantages of the high-voltage soft starter at the aspect of motor start.