Research On Fast Switching Strategy Of The Main Fan In Mine Power System

In order to solve the problem of power supply interruption caused by power failure in coal mine,such as power failure,voltage fluctuation and short time interruption,the fan stop caused a safety accident,which threatens the safety of the person,and introduced the rapid switch of double power supply to the coal mine power supply system.Based on the standby power supply automatic device and the traditional fast switching device can not meet the current coal mine enterprises to power supply requirements,this paper proposed a and a half thyristor parallel in the mechanical switch of the semi-solid switching device.The device is better than standby automatic switching device,and has the flexible conversion control method,the movement speed is faster,and does not produce arc,and can take into account the conversion of the rapidity of conversion and reduce the purpose of transient impact.Based on the principle of the and a half power supply switching device,the fast switching control strategy is proposed,by controlling the thyristor conduction in the input process of the standby power supply,the two phase asymmetric transient and three-phase symmetric transient are changed,so as to realize a kind of fast voltage regulation effect,to eliminate the transient impact current;Based on the basic requirements of voltage sag detection,the detection voltage mutation algorithm and instantaneous voltage method are proposed.Simulation results show that the instantaneous voltage method is more accurate,and the detection is more stable.Speed up the fast switching speed of the power supply quick switch device,and switch the fan fan to standby power supply quickly after the fault is detected;Design hardware circuit,including voltage,current detection circuit,signal detection circuit,IGBT driving circuit and so on.And done the debugging of the software part.According to the operation characteristics of coal mine fan,analyzed the process and characteristics of residual pressure after power failure,studied and analyzed the control method of residual voltage switching,and built simulation model in MATLAB,the residual voltage and standby power phase difference.through comparing direct switching control method and tracking voltage change curve waveform,verify this paper is effective and feasible for the fast switching device control method.Finally,through building the experimental device,the experimental results show that the fast switching device with double power supply can switch successfully in the power switch,and achieves the experimental requirements effect.