Research Of PLC And Inverter Control Belt Conveyor Driven Multi-motor

Along with the rapid development of society, demand of energy source increasescontinually.Although China is a big agriculture country，it’s still far from enough to meetthe society demands. So the exploitation of the mine must continue to rise with theincreasing demands for society. However a mine want to improve coal products,transportsystems must beimproved. At present most of the coal transportation system using beltconveyor.As its large volume,low cost, and easy to maintain, so it is populor in mine.Dynamic models of belt conveyors have been created in the Paper，the effects ofvarious starting Plans on the starting charaeteristics of belt conveyors have been analyzed，and the best starting acceleration curve of belt conveyors has been identified. Besides，themethod to adjust the Power balance has been found out after a analysis of ideal and actualdistribution of the driven power of each motor. On the basis of the analysis of operationprinciple and characteristics of the belt conveyor, This paper gives a rather detailedanalysis of control system.At present the drive system of large-scale belt conveyoradopted Controlled Start Transmission. With the development of high powersemiconductor devices, frequency control drive systems are widely used. Firstly, thispaper briefly expounds the general theories of variable-frequency regulating speedtechnology,PLC. And then，A three motor drive system was designed according to thefeatures of a belt conveyor. Because of the belt conveyor is a kind of the constant torquecontrol system，and the high requirements of control，so we choose the SIMOVERT MVserious Voltage Vector Control Inverter as the key controller of the system. The startingcharacteristics and the ratio of the three motorits performance was simulated by using thevector control and the technique of SVPWM of the software of MATLAB. The powerbalance of the three motor adopt the master-slave control method. We set up amain-motor,the rest of motors are auxiliary. On the basis of the simulation experiments,this paper has selected a belt conveyor, we select the6SE80-1AA01converter and S7-300PLC, according to the drive motor of the belt conveyor and the demand of control.This paper adopt PROFIBUS to communicated between PLC and frequencyconversion,and the data will be send to the host computer.The experimental results have showed that variable frequency soft-driving systemcan meet the requirements of driving force output changes during the starting proeess forlarge belt conveyors，extend the start-up time and greatly reduce the starting tension ofthe conveyor belts.Meanwhile，the use of variable frequency driving system can reducethe strength of the conveyor thereby reducing the cost of equipment investment.Moreover，variable frequency drive also has the advantages of low maintenanee and energy saving.