Research Of Topology Structure And Current Tracking Control Of Hybrid Active Power Filter

The wide geographical coverage and uneven distribution of energy in China have led to the wide application of HVDC transmission technology.At the same time,due to the basic principle of the technology,there are many odd-frequency harmonics on the AC side of the HVDC power conversion system converter station,causing system damage.Harmonic pollution.In this paper,firstly,the AC side of HVDC transmission system is the object of filtering,and a topology of hybrid active power filter is proposed.The structure uses two kinds of double-tuned filters as the passive filter branch and the injection branch respectively,and reduces the capacity of the active part by the reasonable fusion of the passive filter and the active filter.From the suppression of the resonance with the system,the choice of control strategy,the suppression of the fundamental wave current,the harmonic current amplification effect,the filter characteristics,the influence of the external disturbance and the parameter perturbation,and the advantages of the proposed topology.Simulations show that the proposed topology has better filtering performance.To improve the filter performance of active filter can be started from the aspect of current control strategy.For this reason,a backstepping sliding mode control strategy based on inverse system method is proposed in this paper.This strategy decouples the affine nonlinear model of a hybrid active power filter with strong coupling nonlinearity using an inverse-system approach to form two independent pseudo-linear subsystems.Then,in order to increase the robustness of the control system,the back-propagation sliding mode controller is designed considering the system modeling error and the parameter uncertainty error.Through comparative simulation study,it is proved that the control strategy proposed in this paper further improves the filtering performance of hybrid active power filter,realizes accurate tracking of harmonic current and has good dynamic response performance.The experimental platform verified the effectiveness of the proposed strategy.