The Studyand Exploitation Of Explosion-Proofac Motor Soft Starter Based On The PIC16F877

The AC motor plays an important role in the power system for the simple structure, the littlemaintenance, the inexpensive cost and the steady performance. Nevertheless, the rising currentalways seriously impacts the system of the electric power, which will be the six or seven timesthe current rating. With the increasing of the power, this impact will be more obvious. The ACmotor starter will make the rising of the AC motor steadfast. At the same time, it can also attainthe purpose, such as the no contacts and saving the electric power. So the research of AC motorstart control is an important task.Firstly, we will explain the significance and the perspective of the motor soft starter。Secondly, we will study the sloping rising and the invariable current rising, by use of the resultsof the experiments and the principle of the soft starter. We also explain the shocking of the motorwhen it rises. At last, the hardware circuits are designed, which are based on the mcu PIC16F877.The soft starter has many functions, such as liquid crystal displaying, protection, soft starting,communication, soft stopping, sloping voltage rising, steady current rising and so on. The softstarter has many characters with the using of the mcu PIC16F877 . The characters are as follows:the simple circuits; programming with the assembly and the c programming language; includingthe interface to the industry control network with the profibus bus.In the conclusion, the way of designing has been changed drastically, because of the using ofthe mcu PIC16F877. The convenient transplant, with the perfect functions, the simples and thecredibility, is our finally purpose.