The Research Of High Voltage Variable-Frequency Drive In Alumina Hyper Dense Phase Conveying System

Variable frequency driving technology of high voltage of super dense-phase conveying is the common-attention hotspot contents of electrical academe.internationally .is, also, the supporting industry of nonferrous metal. In this paper, on basic of practical engineering project, the key content of Alumina conveying in the process of aluminium electrolysis is overally investigated, probing into newline system structure and control mode of variable frequency driving of high voltage make the theoretical and practical value significance to variable frequency driving technology of high voltage and nonferrous metal industry.The mathematical model of asynchronous motor under the condition of 2 phase quiescency and 2 phase rotating frame is gained, and then the mathematical mode of super dense-phase conveying load is founded. Combining the situation of the effect of pipe network resistance on machinery characteristic, the simplified model is gotton. The dynamic mathematical model deduced about motor driving blower is specificly achieved. The simulation result testifies that this simulation model is capable of reflecting practical physical model of motor, possessing upper reliability. Secondly, this paper particularly analyzed the topological structure of high voltage frequency converter in unit series, connection mode and operation mechanism of transformer, gave out the control method of pulse duration modulation in unit module, made emulation and calculation about harmonic content of voltage and current in line side and output side. The result indicates that multi- commutation makes system reduce harmonic pollution in power network; that the circuit structure in unit series makes harmonic distortion little, motor damage small; with voltage modulation ratio debasing, output harmonic component is added; the whole modular design, maintenance convenience, simpleness. Thirdly, from dynamic equivalent circuit of asynchronous motor, by comparison and analysis of every control method of asynchronous motor, the directed control strategy of stator flux linkage is ascertained, the directed vector control method of stator field is presented. The theoretical analysis and simulation result certify that making use of directed...