Abstract This design adopts the digital electronic protected mode for electric machines (i.e. protected mode based on single chip control), which uses the low-cost single chip to replace expensive parts of PLC. Moreover, this mode has obvious advantages on software and hardware as compared to both relay-control protected mode and analog electron-control protected mode. The design content includes design for both host frame and slave frame. In this design, on the ground of the application of integrated circuit and relative knowledge on single chip control, the powerful single chip is used to fulfill the circuit design for hardware of intelligent protector and the program for motor protection needs to be compiled to achieve the protect function under various conditions such as over-pressure, under-pressure and overload. The key point of this thesis is to introduce the communication mode between host computer and slave computer, the software design for each modules of host computer as well as the anti-interference capability of the single chip.
