| The hoisting system of the main shaft undertakes the hoisting task of the raw coal in the mine,which is the key technology of the mine and the key link of restricting the production and operation of the mine.The advanced electric control system of the hoist has always been an important symbol of weighing the modernization of the production of the coal mine.With the development of science and technology,the synchronous motor frequency control technology has been widely used in the mine.Today,with the energy shortage,energy saving and consumption reduction have been recognized by the whole society.Frequency control has become a powerful means of energy saving and consumption reduction in modern industrial production.Based on the organic combination of power electronic technology,network technology,computer technology and modern control theory,frequency conversion and speed regulation technology has the advantages of wide speed regulation range,high precision,fast response,high power factor,convenient operation and remarkable energy saving.In view of the problems of complex control system,low power factor,serious heating,aging of components,high failure rate and poor system fault diagnosis ability existing in the electric control system of the main shaft hoist of suburban coal mine,this paper analyzes the research status of power converter,compares and analyzes the diode clamped three level power converter and AC-AC converter,and the constant frequency and direct current of three-level PWM rectifier.The key technologies such as power control,vector control of double winding synchronous motor,intelligent fault diagnosis and protection unit of three-level inverter,nonlinear hover controller of mine hoist are deeply studied,and the idea of double independent electric control is constructed,that is,"AC double winding synchronous motor,double three level AC-DC-AC converter,digital DSP regulating control,PLC network control,upper position control,Machine fault diagnosis and monitoring,industrial Ethernet interconnection" mode,instead of ABB AC-AC frequency conversion speed control system.Based on automation,information technology,power electronics and other technologies,this paper calculates the selection of dual independent electric control main circuit,puts forward the overall design scheme,and installs and applies two sets of dual three-level frequency control system of the same model,two sets of gatecontrol system,two sets of signal system and corresponding sensors,among which the dual three-level frequency control system mainly includes AC dual winding synchronous motor.The main equipment includes high-voltage cabinet,low-voltage cabinet,transformer,regulating cabinet,PLC control cabinet,frequency conversion cabinet,excitation cabinet,operation platform,upper computer and so on.The electric control system has been tested in factory and debugged on site,and all working conditions have been tested.The performance effect and benefit of the main well lifting system are analyzed.The done work is summarized,and the next research content and problems to be solved are prospected.The two systems of the main shaft hoist are standby and redundant to each other.When any electric control system fails,it can be switched within 5 minutes,effectively reducing the impact time of the main shaft hoist system.Since the dual independent electric control system was put into operation,the lifting system has been running steadily,the protection is complete and reliable,the fault diagnosis ability is strong,the speed curve travel tracking is accurate,the power grid harmonic is low,the power factor is high,the fault rate is low,the vibration is small,the noise is low,the economic and social benefits are significant,and it has a wide application prospect and promotion value.There are 76 figures,18 tables and 85 references in this paper. |
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