Research On Active Power Filter (APF) Based On Multi-level Technology

In the modernized and intelligent power system of the 21 st century,because of the incorporation of micro grids and the diversification of nonlinear loads and their extensive use,the power grid contains more harmonic currents directly or indirectly.And active power filter(APF)can solve this currently facing the problem,it can effectively compensate for reactive power and harmonics.However,due to the continuous increase in the transmission voltage level of the power supply link,the traditional structure of APF becomes hard to satisfy the current development,but the modular multi-level converter(MMC)can be well used in high-pressure and high-capacity engineering.In summary,this paper mainly analyzes and researches the active power filter(APF)based on modular multi-level converter(MMC).This paper first analyzes and discusses a series of factors that affect the quality of power,and do some analysis and research on how to improve the quality of power.The instantaneous power theory is analyzed and deduced,and its physical meaning is explained.Based on this theory,the control strategies of several active power filters are analyzed,and the advantages and disadvantages of various control strategies are discussed.In the analysis and study of active power filter principle and operating characteristics,focusing on its control strategy and topology improvement.The topology of the Active power filter(APF)based on the 13 level is analyzed briefly.The harmonic detection method,the operation mode and the operation mode of the modular multi-level APF are analyzed in detail,and the mathematical model analyzed.In-depth comparison,and ultimately determinethe use of this paper,the operation.In the third section,the principle and modeling process of parallel Active power filter(APF)are systematically studied and analyzed.Based on the topology of MMC main circuit,the mathematical model of voltage and current is established.Based on this model,the input current of MMC is decomposed by the active and reactive components,and the axis components of the input current of MMC are inferred in the rotating coordinate system.By controlling the DC voltage to obtain the fundamental power and then control the subsystem.In addition,the topological structure of the upper and lower arms of the MMC is analyzed and studied.The relationship between the bridge arm voltage and the internal circulation of the MMC is analyzed and studied.And then the MMC arm voltage and internal circulation of the two most important basis for the system of voltage equalization control and the average voltage control for a detailed study and description.Finally,a simulation model is established for 13-level rectifier and inverter status,and a detailed analysis is carried out.In the case of modular multi-level and active power filter topology,mathematical model and working principle Based on the analysis,it proposed the system simulation of the active power filter based on the modular multi-level technology,and the simulation results are analyzed systematically to verify the correctness of the work of this paper.But also on the laboratory modular multi-level experimental platform for a brief introduction,and then in the learning process of the three-level hardware platform to do some experimental analysis.