Research On Random Zero Vector Control For Induction Motor

PWM pulse width modulation technology in the induction motor frequency control system is more and more widely used,the technology use fixed switching frequency controlling switching inverter to turn on and off,at an integer multiple of the switching frequency Department The higher harmonics are produced.This amplitude of the harmonics causes annoying high-frequency noise and mechanical vibration.To solve this problem,the random pulse width modulation(PWM)technique is used.From the spectrum distribution of the harmonics,the harmonics of the high-frequency output of the inverter are distributed over a wide frequency band.The main contents of this paper are as follows:Firstly,this paper summarizes the basic theory and classification of the random PWM technology by comparing the traditional PWM control technology are summarized,the application and development of the random PWM technology,and introduces in detail the principle and different points of each kind of random PWM technology.Secondly,analyzing the function of Markov chain in random PWM technology,and proposing the random PWM technique based on Markov chain,the results of Matlab/Simulink simulation based on fixed switching frequency,Markov chainless algorithm are studied and compared respectively.Lastly,a simplified pulse width modulation(PWM)technique is introduced in detail.Based on this technique,a novel random zero vector PWM algorithm is proposed,simulation results show the correctness of the proposed method.Simulation and experimental results verify the Correctness of the algorithm,and not change structure of inverter and other parameters.It can be easily applied to the existing frequency control system to meet the AC transmission system noise characteristics of the motor requirements.