Research And Implement Of Single-phase Shunt Active Power Filter

Due to a variety of non-linear loads being used in single-phase power grid, the single-phase power has been seriously polluted. Therefore, the active power filter technology for harmonic suppression and reactive power compensation is very necessary in single-phase power grid. Currently, APF researches are focusing on three-phase APF rather than single-phase APF. The control strategy of single-phase APF is not enough, either. As for this situation, we take a single-phase shunt APF which is the most widely used in practice for example and do researches in depth on the key contents of the control strategy related to single-phase APF, such as construct virtual signal, extract compensation current, design closed-loop control parameters and so on. The research contents are summarized as follows.(1) Doing a research based on an implementation method for single-phase shunt active power filter (APF). In order to solve the problem, we build a double loop control strategy for single-phase APF control. And a compensation current instruction is deduced with the single d-q theory, which is applied with actual and virtual quartered single-phase current and voltage. The compensation includes the harmonic compensation current component, reactive power compensation current component and active compensation current component. The different conditions of APF, such as triggering, normal operation and load change are researched in this paper. And also, the simulation results demonstrate the effectiveness of the proposed method.(2) To simplify the deficiency of double-loop control strategy, a method for single-phase shunt active power filter (APF) with power prediction is put forward. In this control strategy, the practical compensation current instruction is achieved with power predictive algorithm. The different conditions of APF, such as triggering, normal operation and load change are researched in the paper. And the validity of implementation method for APF is proved by experimental results. The power predictive algorithm is adopted since the single closed-loop control strategy can be used in APF application. It is analyzed that there is no voltage control loop in the implementation method. And it has a lot of excellent characteristics, such as easy set-up, fast dynamic responds, etc.(3) Finally, build the experimental platform of single-phase shunt APF and introduce in detail the main circuit parameters design, single-phase PLL design, Single phase space vector pulse width modulation technology, each hardware module function design and software process design.