Design On Integrated Low-voltage Feeder Protection System Based On C8051F040

The low voltage feed switch integrated protection system is the key part ofpower distribution in coal mine, its performance determines the electric safety andefficiency in underground mine. Along with the raising of the automatic andintelligent level of coal mine industry, the Continuity, Reliability and Safety ofpower supply are becoming more of a concern. So, study on the low voltage feedswitch integrated protection system has great theoretical and practical value.Based on the status of current feed switch protector，we design a kind of lowvoltage feed switch integrated protection system, which use C8051F040as controlcore and include many kinds of protection functions, such as monitoring, protecting,warning and control circuit in this thesis. First of all, the basic requirements andproblem on current of feeder switch protector were introduced, and proposed that itis necessary to design a low voltage feed switch integrated protection system of highperformance. Secondly, it analyzed the fault of power distribution in coal miningand the protection method of those fault, and then, it gave the design proposal of thewhole system, including hardware and software. In the end, we proved that thesystem obtained the expected effect by the experiment of the circuit and system.In the design of the system,we proposed the method of range switch in currentdetection to improve the measuring accuracy and range; according to the inversetime lag principle, we proposed the method of by-stage protection to make sure thespecial of the time lag in the protection of overload; we proposed the method ofearly-warning and inquiry of fault to help the maintenance workers to find problemand improve the work efficiency; and proposed the method of multiple algorithmselection in leakage protection to improve the accuracy and rapidity; addedanti-interference measures in the key circuit to improve the stability of the system.