Research On The Key Technologies Of Interleaved Active Power Filter With LLCL Filter

In the face of traditional fossil energy sources dried up and increasingly serious global environmental pressures,Photovoltaic power generation,Wind power and other renewable new energy density increases,high penetration of new energy power generation continuous random access to the power grid,Utility grid is widely used in switching power supply,uninterruptible power supply and power electronic equipment such as frequency converter,brings to the distribution network into such problems as unstable harmonic and reactive power consumption,brings to the distribution network into such problems as unstable harmonic and reactive power consumption,thus seriously affect the power quality of power system.Active Power Filter is a kind of can restrain harmonic and compensating reactive Power dynamic,improve Power quality of Power electronic devices.In this paper,based on the LLCL filter two level of modular staggered parallel active power filter command signal detection,current tracking and damping control key technology study.First of all,according to the principle of active power filter harmonic and reactive power detection,classification,commonly used to do a simple introduction and current tracking control method.Then the LLCL filter based on two level double module staggered parallel active power filter,abc in three-phase static coordinate system and the mathematical model of two phase rotating dq coordinate system are analyzed,and reasonable design of the LLCL filter and the parameters of the dc bus capacitor.LLCL filter resonance principle is studied,it is pointed out that in the introduction of the necessity of the damping term LLCL filter transfer function.Analysis from the Angle of the transfer function of the high frequency LC filter branch of series and parallel resistance of passive damping method,based on the analysis of the four kinds of modified passive damping method.Introduced from the Angle of configuration damping active damping of three kinds of single state variable feedback method,analyzes its feasibility,pointed out that the most reasonable high frequency LC filter branch current feedback is the best active damping method.Then in order to improve the compensation performance of APF and the dynamic response,we design a specific harmonic compensation based on synchronous rotating coordinate control strategy,the harmonic component of the angular velocity and specific time synchronous rotation coordinate transformation,the specific harmonics into straight flow,through under the two phase rotating dq coordinate system of the PI current controller to realize the specific harmonics astatic compensation.Finally,a simulation model using MATLAB/Simulink to build on the above theoretical study to do simulation verify its feasibility.Experimental platform at the same time,the paper designs the main circuit parameters and control strategy for experimental verification,it is concluded that the main circuit parameters and control strategy design of the effectiveness of the conclusion.