Study Of Long Moter Leads And Driving On Inverter Based On Large Driving Power Belt Conveyor

Along with belt conveyer's power continuous increase,original CST drive or inverter drive type of belt-conveyer are unable to adapt to the requirements of development.In this paper,the long line transmission of variable frequency drive is used,and then the frequency conversion driving mode is choosed and the inverter is on the ground and then the electric motor is in coal mines.They are connected by long-term cable.But the use of long-term cable will generate overvoltage at the motor.The phenomenon of overvoltage will insulate the performance and reliability of motor.As a result,how to eliminate the phenomenon of over voltage of the motor isthe key point of this article.Based on the theory of transmission line,this paper studies the propagation characteristics of electromagnetic wave in the long line cable,and then establishes the circuit model of the MATLAB system of the long line transmission drive motor,and respectively changing the pulse rise time,impedance inverter and cable parameters.and then carrying on emulation.The waveform of the voltage value of the motor with the corresponding parameters is obtained.It can be seen,with the pulse rise time becoming longer,motor terminal voltage amplitude reduced;with the increase of the unit of inductance motor terminal,a voltage phenomenon has improved,oscillation frequency decreases;with the increase of the cable per unit length or unit capacitance,the voltage phenomenon of motor terminal is more serious,the time of cable oscillation increases,the frequency of cable oscillation decreases.In order to solve the problem of over voltage,two strategies are put forward in this paper,which are the filter and the use of multi pulse rectifier.This paper mainly studies the filter structure of two kinds of suppression motor terminal over-voltage,and then parameters design principle of the load end RC filter and the inverter terminal RLC filter are given.According to the principle of determining the parameters,circuit simulation is started after joining the RLC filter.And we can see indeed settle overvoltage and meet the requirements from the waveform.Finally,the harm of harmonic and the disadvantages are analyzed,and the multi pulse rectifier is proposed to solve the harmonic problem.The comparison between 6 pulse rectifier and 12 pulse rectifier is made,including the topology,theoretical formula and performance.