Research On A Novel Three-Phase Hybrid Active Filter

Currently,electric power is the most widely used energy,whose high quality is of great significance for promoting production and maintaining social stability.The widespread use of power electronics has introduced enormous harmonics and reactive interference to the power system,reducing the power quality.Hybrid active power filter(HAPF),an integration of passive filter and active power filter,has both the advantages of passive filter and active power filter.It is an efficient and stable method to deal with harmonics and reactive power,playing a key role in improving power quality.This paper launchs a research on the three-phase HAPF,and mainly carries out the following work:Firstly,this paper discusses the generation,harm and main control measures of harmonics and reactive power,focuses on the working principles of different topological structures of HAPF,and compares their advantages and disadvantages.Than,the harmonic current detection algorithms of HAPF are summarized and the practical significance of specific subharmonic compensation is discussed.In view of the fact that the specific harmonic content is seriously exceeded and the reactive power is insufficient,from the perspective of reducing the system capacity,this paper proposes a novel three-phase HAPF topology that can compensate for reactive power and specific subharmonics.By utilizing the low-impedance characteristics of series resonance,this topology has the advantages of high compensation accuracy and low capacity.Afterwards,the working principle,filtering characteristics and reactive compensation characteristics are analyzed in detail.Secondly,the proposed mathematical model of the HAPF is derived,and a simplified mathematical model of compensated current against the specific harmonic is established.The simplified model brings convenience to the decoupling control of the system.At the same time,the intrinsic relationship between system performance and parameters is analyzed in detail,and a set of methods for setting filter parameters according to design requirements is given.Then,the control system of the HAPF is constructed,and the harmonic extraction algorithm based on the instantaneous reactive power theory is analyzed.The DC voltage controller and the specific harmonic current controller are designed,according to the established mathematical model and the requirements of the system for dynamic performance and stability margin.Finally,the TMS320F28035 DSP is used as the main control chip to set up the HAPF experimental platform proposed in this paper.The overall framework of the experimental platform is introduced,the software algorithm flow is analyzed,and the experimental platform is used to carry out simulation and experimental research.The simulation and experimental results verify the feasibility and advantages of the experimental scheme of the proposed three-phase HAPF.