Research On SVPWM Power Control Strategy Of Vienna Rectifier

The continuous development of power electronics technology enables power electronic devices to be applied in various fields,but at the same time,due to its own nonlinearity,it also injects a large amount of harmonics and reactive power into the power grid,causing "contamination" to the power grid.Therefore,how to study a rectifier with high efficiency control method to suppress harmonic pollution has become a hot issue today.As a three-level topology,the Vienna rectifier has the advantages of high power factor,low current harmonic content,few switching devices,and low voltage stress on power devices compared to conventional PWM rectifiers.Therefore,this paper takes the Vienna rectifier as the research object,and proposes a predictive power control strategy using SVPWM algorithm,which realizes the fixed frequency control of the rectifier and reduces the harmonic content of the grid side current.In order to make the SVPWM algorithm better in power control,this paper studies the simplification of its sector partitioning method and algorithm.Firstly,based on the traditional six-sector partitioning,a method of subdividing each large sector into six small regions is proposed to achieve a more accurate tracking effect.Then,the traditional SVPWM algorithm has the problem of complicated operation and long time.A SVPWM algorithm based on 60-degree coordinate system is proposed.The method of label transformation and rotation transformation is proposed for voltage vector,and the reference vectors of other sectors are unified.Conversion to the first sector,the operation process is simplified,and the operation speed is improved.Finally,the correctness of the proposed algorithm is verified by simulation analysis.In this paper,the power control strategy is studied based on the instantaneous power model in the ?? coordinate system.Firstly,the traditional voltage directed direct power control is studied.The system structure and working principle are analyzed in detail.The power control hysteresis and the switching frequency are not fixed.The predictive power control strategy based on SVPWM algorithm is proposed.Firstly,the predictive power control model is constructed,and the algorithm for predicting power is deduced in detail.Then the SVPWM algorithm is applied to the predictive power control,the problem of control lag is solved and a constant switching frequency is obtained.Finally,the simulation model of the Vienna rectifier was built using Simulink.Thetraditional voltage-directed direct power control strategy and SVPWM predictive power control strategy are simulated and compared,and the correctness and effectiveness of the proposed algorithm are verified.