Design On The Electric Motor Protector Based On The MCU

AC motor is the most widely used power equipment .It takes an important part in the national economic .As the AC motor is usually used in harsh environment ,the protection of the AC motor has become a concernment . All kinds of microcontroller, digital signal processor and other embedded processor are widely used in the area of motor protection with the rapid development of the micro-electronics ,computer technology, .The realization of the protection device for electric motor based on microcontroller is accepted by most of the engineers and it's also the theme of this paper . We have developed a motor protection which can be used in all kinds of bad environment .The main content of this paper are described as follows:1. Taking the induction motor for an example the paper analyses the elementary principle of the motor work, the fault character and the protection theory in detail.2. The paper puts forward a protection project for the motor. Short circuit protection, stall protection, out of balance protection, open circuit protection, over voltage protection, low voltage protection, electric leakage protection and overheat protection is configured in the device.3. The motor protection unit is designed with the STC12C5410 MCU .The LCD display and other peripheral equipment are added to make up the motor protection system .Consequently this kind of protection device take on powerful logic analysis function and process function .It can provide high quality protection function .The trouble memories and trouble analysis function is the other perfect function. Considering that the protection device has to work in the extremely bad environment special design is done in the EMC.4. In the design of the software system, the protection device take advantage use of the programming feather of the STC12C5410 MCU and the source on chip, adopts modularized programming idea, subdivides large task into small function models and then realizes the protection function in the use of sub-function and interrupt process function.