Research On Control Technology Of EPS Energy Storage Device Of Downhole Fan

In the tunneling face of high gas coal mine,gas is easy to gather on account of bad ventilation,in the event of slight spark will lead to a major explosion accident,which demands undermine local fan uninterruptedly working.In order to solve the problems of production interruption and casualties caused by bad ventilation in working face,it's necessary to improve the reliability and continuity of the power supply of main local ventilator.In this paper,a kind of energy storage device used as emergency power supply for ventilation system is designed to realize uninterrupted power supply and stable operation of local ventilator.Firstly,the power supply of ventilator in the tunneling face is analyzed in this paper.Aiming at the power supply interruptionat,the overall function of energy storage device with 2 working modes is designed,including capacity,two-stage PCS structure,the access to mine distribution and overall operation control strategy.To achieve the battery working in the ‘shallow charging and discharging' state,the capacity of energy storage battery pack capacity and number of monomer batteries are matched by means of optimal design method.In the EPS mode,the traditional droop curve is modified based on the characteristics of transmission line of coal mine distribution network,and a new droop control equation is obtained,which is used as the control method of AC/DC converter part in EPS mode.In order to verify the validity and applicability of the modified Droop control strategy,a system model is built in Matlab/Simulink for simulation experiments.The results show that the converter using the modified Droop control strategy has good output performance in EPS mode of energy storage device,able to realize seamless switching of power supply of main local ventilators'.In the standby charging mode,in order to avoid the problem harmful to battery such as overcharging,flexible switching control is adopted for the traditional three-stage charging process,which realizes the seamless smooth switching between charging modes.Compared with the charging process without flexible control by Matlab,simulation results show that the three-stage safe charging control strategy with flexible switching can improve the smoothness of switching at different charging stages,effectively avoiding the adverse effects of overcharging and current problems on battery capacity and life.In this paper,the overall design of the emergency energy storage device and the study of its two modes of control strategy provide a reference for the actual application of the device in underground working face fan power supply system,and have a certain application prospect.