Research On The Key Technologies Of Soft-starter In Mid-voltage Asynchronous Motor

Asynchronous motors are widely used in the industrial and transportation area because of the reliable operation and the simple structure. It has been the most widely used in our country, and the load of electricity of asynchronous motor is more than half of the total. But it will give impulsion to the electric when it's started directly no taking any measures, especially for the pumps.In China, soft starter based on thyristor at low range (such as 380V) has won extensive application. However, in mid-voltage range (3-10kV),because the technical reason, the mid-voltage soft-starter still rely on imports.Mid-voltage soft starter and low-voltage soft starter's basic principle is the same, and in mid-voltage soft starter, due to current single thyristor of changeover ability is not enough, so want to use multiple thyristor series split pressure. But every thyristor performance parameters are not completely consistent, such in motor starting, the voltage balance of existing series problem may burn out these pipes, or even destroy all devices. the paper research and design mid-voltage soft start-up devices with using thyristor series.First detailed analysis of asynchronous motor is introduced, and the traditional starting process of soft starter defects and insufficiency, then drew thyristor soft starter, and introduce the concept of thyristor soft starter to the principle and its advantages and application, and detailed analysis of the thyristor soft starter way of working, then based on the soft start given several ways in MATLAB/SIMULINK simulation model and simulation results. And using intelligent control algorithm of the simulation results are optimized.Then the paper do some of design to the mid-voltage soft starter for software and hardware, in basis of with the basis of principle and simulation of soft starter thyristor, in hardware design is the main circuit and control circuit design, and detailed gives thyristor series design methods, give diagram. In software, introduces the development environment and the main control method, and gives part of the software flow chart.Finally, the article presented simple summary and prospect to this study.