The Design Of Mine Feeder Switch Protection System Based On DSP

The mine environment is complex,dark and humid,and the gas concentrati,on is high.When the power supply grid and electrical equipment are operated in this environment,it is easy to cause short-circuit,leakage,and lack of safety hazards.If these hidden dangers cannot be detected and eliminated in time,equipment damage or even personnel will be caused.casualties.At present,the "three major protection" products for mine power supply safety have a single function,low fault detection and measurement accuracy,poor protection sensitivity,and lack of functions such as early warning,human-machine exchange,communication and host computer communication.Based on this,this paper analyzes the various fault characteristics of underground power supply equipment and power grid operation,,and designs a smart feeder switch protection system integrating monitoring,protection and communication.According to the characteristics of leakage and phase loss,an additional DC protection method is proposed.For short-circuit and overload fault characteristics,phase-sensitive protection and identification current amplitude protection method are adopted.For over-voltage and under-voltage characteristics,voltage amplitude protection measures are adopted..Based on the proposed protection principle,the signal acquisition and protection circuit is designed.The microprocessor DSP performs full-wave Fourier processing on the grid signals of the supplied and used equipment,and obtains grid parameters such as voltage,current,power factor,active and reactive power through calculation.According to the calculation result,it is judged whether there are faults such as leakage,phase loss,short circuit,overload,overvoltage and undervoltage.When a fault occurs,the system can judge the fault type and control the feedswitch to automatically open,and the system can automatically remember the trip moment.The current,voltage and insulation resistance values are communicated to the host computer via the RS-485 bus for remote monitoring.The test shows that the mine feed protection system has high detection precision,reliable protection and stable performance,and can be used in mines with voltage levels of 660?1140V or higher.It realizes real-time monitoring and protection of mine power grid operation status and power equipment,and provides reliable guarantee for safe and stable operation of power grid.