Research Of Conducted Electromagnetic Interference(EMI) Of Servo Drive System In Ultra-high Speed Cigarette Making Machine

With the application of independent servo drive technology,servo drive system has become the most important part of Ultra-high speed cigarette making machine control system,but the servo drive system will bring about serious electromagnetic interference(EMI)at work,which conducted interference is most serious,affecting the reliability and safety of Ultra-high speed cigarette making machine,so it is necessary to analyze and study the electromagnetic compatibility(EMC)of servo drive system.In this paper,taking SIEMENS S120 servo drive experimental platform of Ultra-high speed cigarette making machine as the research object,focusing on the mechanism of conducted EMI,spectrum of source of conducted EMI,the suppression method of source of EMI,and which has been verified by experiment,these researches can provide theoretical and technical support for the inhibition of the EMI of servo drive system and EMC performance of Ultra-high speed cigarette making machine improving.First of all,the mechanism and the main propagation path of the conducted EMI of the servo drive system are analyzed.The mathematical expression of the source of the conducted EMI is established,and the spectrum of the source of EMI under the SVPWM modulation is obtained.Secondly,the conducted EMI spectrum of SIEMENS S120 servo drive experimental platform is tested by using the constructed test system of conducted EMI.By comparing the test results with the analysis results,the source of the system conducted interference is determined,and the influence of different speed and load on the source of EMI is compared and analyzed.Then,to suppress the peaky conducted EMI at switching frequency and its multiples generated by the servo drive system,a asymmertic carrier and zero vector dual random SVPWM with fixed switching frequency is proposed.In this method,all vectors action time was randomly assigned between the ascent and descent stage of each triangle carrier by randomly assigning slope of triangular carrier between the ascent and descent stage,while zero vectors are randomized between the ascent and descent stage of each triangle carrier to futher reduce the peaky conducted EMI at switching frequency and its multiples.In addition,because of the difficulty of generating random numbers and the random effect is not good,one dimensional chaotic map is used instead of random numbers.The simulation results show that the proposed method can greatly reduce the peaky value of EMI at switching frequency and its multiples,and the suppression effects of different algorithms and different chaotic maps are compared.Finally,aiming at the limitation of the suppression method of the source of EMI,starting from blocking the propagation path,four kinds of anti electromagnetic interference measures are proposed:reasonable layout and wiring,shielding,grounding,filtering,and verify the validity at the SIEMENS S120 experimental platform.