Analysis Of SVPWM Modulation Technology

The control principle of the motor controller is based on pulse width modulation(PWM)technology.The utilization efficiency of the DC bus voltage is an important factor in determining the control performance.The SVPWM modulation technology introduced in this paper has greatly improved the voltage utilization ratio compared with the previous SPWM modulation technology.This paper first introduces the basic structure of the motor controller,discusses the significance of the motor controller to improve the voltage utilization,and then analyzes the principle of the SVPWM modulation technology and the specific implementation algorithm,and then uses the MATLAB Simulink to build the SVPWM simulation model.Next,a systematic analysis of the SVPWM modulation strategy was performed.Firstly,the linear modulation area and the over-modulation area are analyzed.According to different modulation targets,the over-modulation area is divided into two parts: over-modulation and over-modulation,and then the target voltage vector amplitude and phase in different over-modulation areas.The different follow-up strategies proposed two over-modulation methods: phase-angle-following over-modulation and amplitude-following over-modulation,and then based on amplitude-following over-modulation,a six-step over-modulation strategy for over-modulation two-region was proposed.In the fourth chapter,this paper also analyzes the harmonics generated in the SVPWM modulation process,discusses the influencing factors of harmonics and the influence of harmonics on the system control.Finally,in order to meet the situation that the over-modulation reaches the limit state,this paper introduces a rectangular wave voltage phase control strategy.At present,the AC motor generally adopts the vector control method.Therefore,in the rectangular wave phase control,we analyze the two methods of torque closed-loop control and current closed-loop control.Through comparison and analysis,the current closed-loop control strategy is more reasonable and optimized.The control algorithm was simulated by Simulink and the experimental results were compared and analyzed.