DC-Link Voltage Control Of Shunt APF

With the development of modern industrial and power electronic equipment's extensive using,non-linear loads in electric power system largely increased.The grid system has being polluted,and power quality has become worse and worse.Using the APF to suppress the harmonic and compensate the reactive power is an effective way to resolving the harmonic contaminator in grid system.By comparison to conventional passive LC-filter,APP has the advantage of quick response,good output wave shape and dynamic performance.The focus of this paper is about the influence of the APF DC-link voltage to system performance.Deadbeat control with adaptive predictor for DC link-voltage is presented.This article firstly narrated the development present situation of harmonic suppression and the reactive power compensation technology;the basic principle, assortment,and structure of APF are introduced,this paper put emphasis upon structure and principle of shunt active power filter.The performance of active power filter is affected by the reactive and harmonic current detection link and the instruction current tracking control link.There are many measurements to pick-up the harmonic current and reactive power,lots of them based on the instant reactive power theory.This paper discusses the p-q and i_p-i_q method for the detecting current.Thei_p-i_q method is used for the simulation.In order to make the injecting current sinus,we have to use some control method to make the compensation current track the command current.There are some ways to trace command current:linear control of triangular wave carrier,hysteretic current control,the periodic current control and deadbeat current control.In this paper,a robust sliding model control is used,and the results are simulated.This section emphases the energy exchange between the DC-link and AC-side, and the influence of DC-link voltage to system's compensating affection.The advantage and disadvantage of the conventional control method is discussed.Then this paper analysis the factor effecting DC-link voltage with the energy balance direction.The math-mode of APF DC-link was build,and deadbeat control with adaptive predictor for DC link-voltage is presented.This paper introduce the principle of dead control and adaptive predict,and the results of De-link voltage control are simulate in MATLAB/SIMULINK platform.At last,this paper summarizes the control strategy of the APF,sliding-mode current control and the deadbeat control with adaptive predictor of the DC-link voltage,and design the double CPU control system based on TMS320F2812 and AT89S51 of parallel active power filter,and its hardware circuit and the system software is given.