Reserch On DC-side Voltage Control Method Of Active Power Filter

Along with the entering into the new century, the industrialization of the society accelerated obviously, and the environment also caused the pollution. Power system is a kind of "environment", the main pollution from power device and the wide use of non-linear load,make in the power grid harmonic and reactive power increasing, resulting in a decline in the power quality,and brings great losses for social production,so control the grid is urgent.Traditional passive filter can only compensate specific harmonic component, there are some limitations and shortcomings. Active power filter can dynamically control the harmonic, and good for reactive power compensation. So the active power filter is an effective device to control power grid pollution.Firstly,this paper describes the development of active power filter, structure classification and basic principle.. Then, the harmonic current detection method based on instantaneous reactive power theory is analyzed, and the detection method of ip-iq and p-q is presented. The hysteresis current control strategy is adopted to track the instruction current and the compensation current. In order to guarantee the normal work of active power filter, the voltage loop output coupling to the harmonic current detection of active loop. Controlled of DC side voltage within a certain range, which makes the stability of active power filter, ensure that the control effect and precision.This article focuses on the control and analysis of the source of Shunt Active Power Filter DC side capacitor voltage. It discusses the energy exchange between the APF DC side and AC side, and the DC voltage fluctuation in-depth analysis. To stabilize the DC side voltage to guarantee compensation effect of active power filter. Fuzzy control PI control features built on the design of both the advantages of both fuzzy control PI complex controller. On Matlab simulation software platform to build a model of active power filter system, the whole system simulation experiments, especially more complex fuzzy PI controller design performance were analyzed. The simulation results can be seen, Fuzzy PI Control of DC side voltage can be effectively controlled to improve the dynamic response of the controlled system, eliminating the steady-state error, robust, and achieve the desired effect. For large-scale impact of current and voltage fluctuations when the system starts, it threatens the security of the system, for which the design of the main circuit soft-start methods to ensure that the APF can start safely and smoothly. The simulation results confirm the soft-start with good impact resistance current suppression effect.In the end of this paper,completed the system control software design of the active power filter control system on the controller hardware platform of digital signal processor TMS320F2812.