Research On Underground Mine Leakage Protection Based On Fault Eigenvalue

Coal mine underground environment is dangerous and bad,easy to accumulate coal dust and gas,coal mine underground once leakage of electricity,is likely to cause electric shock,lead to fire,coal dust and gas explosion and other malignant accidents.Due to the complex mechanism of leakage process,weak leakage signal and easy interference,the existing leakage protection methods have some shortcomings,so the mine power grid leakage fault identification has not been well solved.Firstly,the characteristics of underground low-voltage power supply system are explained,and the existing leakage protection principle and its advantages and disadvantages are analyzed.Using the circuit model of mine low-voltage network and its equivalent model of single-phase leakage,the mathematical expressions of various characteristic quantities of leakage when single-phase leakage occurs are obtained.Through the mathematical expression of each characteristic quantity of leakage,it can be found that the main factors affecting the leakage process are: insulation resistance to the ground,capacitance to the ground,leakage resistance,the initial phase Angle of the power supply and the position of the leakage point,etc.Then,according to the single-phase leakage model of mine low-voltage power grid,the mathematical model of underground power grid insulation parameter identification based on the least square algorithm is established,and the principle of fault eigenvalue discrimination based on the least square method is explained.By simulating different leakage fault factors,the zero sequence voltage and zero sequence current signals collected are solved by the least square parameter method,and the ground insulation impedance and capacitance sequences of each branch are obtained,so as to identify the fault lines and fault lines.Compared with the original steady-state leakage protection method,the feasibility and efficiency of the method based on fault characteristic value are demonstrated.Finally,the hardware and software of the selective leakage protection device based on the scheme are designed.Figure [38] table [11] reference [60]...