The Research And Realization Of 30A Single-phase Shunt Active Power Filter

With the rapid development of power electronic technology,more and more power electronic equipments are used in industrial production and people's daily life.These power electronic equipments are helping people to use power more efficiently,but also inject a lot of harmonics and reactive power into the power grid because of their nonlinear characteristics.The power quality of power grid has fallen seriously.In harmonic governance issues,active power filter(APF)is efficient,fast,real-time and stable,and has been widely applied.In this paper,30 A single-phase shunt active power filter for the study,from the mathematical model,main circuit topology,harmonic current detection algorithm,the realization of digital phase locked loop,control strategy of APF,dead time compensation method and other aspects are conducted in-depth research.Firstly,this paper analysis the working principle of the single-phase SAPF,and establishes the mathematical model of the single-phase SAPF based on the working principle.On the basis of the mathematical model established,this paper finishes the parameters of the main circuit design.Secondly,this paper focus on the shortcomings that poor real-time performance of the traditional coordinate transformation method for the ip-iq harmonic current detection algorithm used in the single-phase system,proposes an improved differential method.Then,this paper demonstrates that the error is approximate to zero when the improved differential method is applied to the single-phase SAPF with high switching frequency,and apply the improved differential method to the realization of digital phase locked loop.This paper effectively improves the dynamic and steady-state performance of single phase harmonic current detection algorithm and PLL,and then verifies the performance by simulation.Thirdly,this paper studies the control strategy of APF and adopts the control strategy of double closed loop feedback PI control.The control effect of the control strategy is verified by simulation.Then,this paper analysis the influence of dead time on the compensation performance of APF,and demonstrates the relationship between effect effect and switch frequency.In order to reduce the negative effect of dead time on the compensation effect of APF,this paper proposes a no dead time control method.The effectiveness of no dead time control method is verified by simulation.Finally,this paper selects Si C-MOSFET and FPGA as switching devices and digital processing unit,builds the experimental prototype of 30 A single-phase SAPF.The experimental results of the 30 A single-phase SAPF shows that the control strategy and no dead time control method are effective and practical.