Research On APF Current Harmonic Compensation Control Strategy Based On Predictive Control

Today,with the rapid development of science and technology and economy,China has raised the development of electric energy to the level of national energy security strategy.At the same time as the demand for electricity has increased dramatically,new demands have been placed on power quality.Due to the continuous development and utilization of a large number of new energy sources,the use of rectifiers,converters and other non-linear devices at the power supply end and user end has been heavily used,thus injecting various types of harmonics into the power grid,resulting in grid power pollution.Harmonics are a kind of power quality problems that are commonly found in power generation,supply and use.Harmonics in the power grid seriously endanger the safe and stable operation of the power system,the normal operation of industrial production,and the safety of life and property,So the harmonic problem is an urgent problem to be solved.In order to solve the problem of power quality harmonics in power systems in real life,the development of power quality related technologies is an effective means to ensure power quality.Shunt active power filter(APF),with its unique advantages,has become a common method for controlling harmonic pollution,reactive power compensation and balancing three-phase currents.It is considered to be the most practical for improving power quality One of the methods of sex and feasibility.In the APF system,the harmonic compensation control scheme is a crucial factor that determines whether the APF compensation performance is good or not,which directly affects the final compensation accuracy.At the same time,the precision of the reference instruction extraction in the control system not only directly affects the control performance,but also affects the final compensation effect of the APF.For this reason,through the combination of actual and theory,this paper studies and analyzes the three-phase parallel APF current harmonic compensation control scheme and reference command extraction scheme in detail,aiming to further improve the APF compensation performance.First,a mathematical model of the parallel active filter is established to analyze the functional relationship between the parameters and to discuss the effect of delay on APF from practice and theory.After theoretical analysis of the APF system,the reference command extraction scheme and the harmonic compensation control scheme are adjusted.After adding the corresponding compensation link to the harmonic command extraction scheme based on the instantaneous reactive power theory,the detection of the used extraction scheme is solved to a certain extent.The effect of delay and dynamic response on the extraction accuracy,improve the accuracy of harmonic extraction,and provide a guarantee for the reference of the APF control system;At the same time,for the APF control system,combined with the corresponding current prediction,voltage prediction and SVPWM modulation technology on the basis of repetitive control to form the composite control used in this paper,the parallel APF control system has improved tracking and greatly improved APF compensation performance.And through the corresponding simulation on Matlab / Simulink simulation software and achieve good experimental results.From the simulation experiment results,the rationality and correctness of the harmonic compensation control scheme and related harmonic extraction method are preliminarily verified.Finally,in order to further verify the feasibility of theoretical research and analysis,experimental verification was carried out on the active filter experimental prototype,and the experimental results were obtained.