Research And Application Of SFC Static Converter Starting System For Large Power Synchronous Motor

High power synchronous motor is widely used in practical engineering,but it is difficult to start and the starting surge current is large.At present,the static frequency conversion(SFC)equipment,which is imported from abroad,is widely used.This paper aims at the research of high power synchronous motor SFC static converter starting,mainly including the different topologies of the SFC static converter,the synchronous motor without position sensor starting and minimal grid connection surge current,making preparation for high power synchronous motor SFC static converter domestic.In this paper,the basic principle of SFC static converter is analyzed,including the commutation process,the mathematical model of the commutation remaining angle and the basic relationship.Then it focuses on the high-high 6/6,high-low-high 12/12 and high-low-high 12/6 three topological structures.From the simulation and experiment two aspects analysis of its harmonic,and compares the advantages and disadvantages of each.On the basis of this,the SFC static converter starting device of a pumped storage power station is carried out.In this paper,the control method of SFC static converter without position sensor is studied.When the motor is at rest,a sudden excitation method is used to determine the initial position of the motor;when speed is low,the rotor signal injection method is used to detect the rotor position;high speed use the back EMF zero crossing detection method to get the rotor position.When motor gradually accelerates to the rated speed,make control of the motor back EMF,so that the back EMF almost equals the power voltage amplitude,phase and frequency difference,which are the engineering grid connetion conditions.The correctness and reliability of the SFC static converter starting control method are verified by experiments.The DSP TMS320F2812 is selected as the main control chip.The starting process of the motor without position sensor is stable and reliable;at the grid connetion experiment,the synchronous motor has small current surge;on the basis of the no-load test,the synchronous motor experiment with load.