Research On Comprehensive Compensation Method For Distribution Network Based On Angle Cascaded SVG

In recent years,with the continuous development of modern equipment and the rapid rise of various distributed power sources,the power network structure has become complicated and various non-linear loads have been increasing.This has led to a series of problems that harm the power quality of the power grid,such as power factor reduction,increased power grid loss,serious harmonic pollution,unbalanced three-phase voltage,and severe voltage fluctuations,which seriously threaten the user's electricity safety and distribution network.Economic operation.Therefore,compensating for reactive power,suppressing harmonics,and governing unbalanced three phases have become the focus of current research.Among numerous compensation devices,the Static VAR Generator(SVG)is highly respected for its good dynamic response,strong compensation function,and easy modular expansion.Therefore,this paper relies on the structural advantages of the angular cascade(SVG)and advanced control techniques to perform a comprehensive compensation strategy for unbalanced three-phase loads under the premise of meeting the operational reliability and economy of the distribution network.This article mainly completed the following work:(1)Select the appropriate SVG main circuit type according to the research purpose and application environment of this paper,and then design the overall block diagram of the angular cascade SVG,and perform modeling analysis based on the equivalent circuit structure of SVG,and get the SVG The compensation principle,which laid the foundation for the subsequent angular cascade SVG to achieve comprehensive compensation for distribution network.(2)Through the analysis and integration of the advantages and disadvantages of current detection algorithms for commonly used cascaded SVGs,an improved phase current extraction method based on dq current detection method is designed.This method is mainly applied to angular cascade SVG for three phases.The detection of the balance system current can extract the current components other than the positive sequence active component and avoid the influence of the distortion voltage on the detection,and the matrix calculation is simple and easy to implement.(3)This paper studies the comprehensive compensation of distribution network,that is,it needs to simultaneously compensate for positive sequence reactive power,negative sequence,and harmonic current.Therefore,the traditional single-sequence current decoupling control is improved,and the positive and negative double sequences based on dq transformation are designed.The synchronous decoupling control method realizes quantized control of positive sequence,negative sequence,and harmonic current.(4)In this paper,a complete model of angular cascaded SVG compensation system is designed in Matlab/Simulink environment.The parameters of the system are optimized through simulation,and then the current detection method and control strategy of the angular cascaded SVG designed in this paper are further studied.The feasibility and reliability are verified.At the same time,it provides reliable control parameters and adjustment methods for the hardware construction of the post-compensation device.