Research On Leakage Protection In Coal Mines Based On Information Fusion

With the continuous advancement of the construction of smart mines and the increasing load of the mine power grid in our country,the safety of the coal mine power grid has become increasingly prominent.Leakage protection is an important safety measure underground.The power supply grid of coal mines in my country adopts the operation mode that the neutral point is not grounded or the arc suppression coil is grounded.When a single-phase ground fault occurs,the current is small due to the small capacitance to the ground.At the same time,the direction of the zero-sequence current is uncertain,which makes it difficult to judge the faulty circuit,which can easily cause the switch to malfunction or refuse to operate.Research on protection methods is of great significance to ensure the safety of coal mine power supply.At present,there are many methods for line selection.The commonly used methods are steady-state analysis,transient analysis and signal injection,but these three methods are not satisfactory.Therefore,the application of integrated intelligent line selection has become the current mainstream research trend.Based on the analysis of zero-sequence fifth harmonic current,energy amplitude method,zero-sequence reactive power,and active power method to determine the line,when a single-phase grounding fault occurs in a small current grounding system,there are applications Complementary information is used for data fusion according to the selection of the system.This paper proposes fuzzy theory to fuse various complementary information to meet the requirements of route selection,clarify the definition and calculation method of the membership function of the fault measure and the weight criterion coefficient.The fuzzy information is fused for simulation,so that the line selection is accurate.Based on fuzzy decision information fusion analysis,bus technology and communication technology,this paper develops a protection device with STM32 as the main chip.Through the establishment of an underground power grid simulation leakage experiment platform in the laboratory,three branches were set up,and different grounding points and different grounding methods were set respectively,and multiple verifications were carried out.The experimental data is obtained,which proves that the error rate is lower than that of the single line selection method.It can be seen from the experimental results that when a leakage fault occurs on the line,the device quickly and accurately distinguishes the faulty line and takes effective measures to the line.The selectivity,sensitivity and reliability of the leakage protection device are significantly improved.