Study On Modeling And Control Of DC Side Series Active Power Filter

With the widely usage of power electronic equipments in the power system, industry department as well as the family and the civil enterprise, the harmonic from these electronics equipments has become the main harmonic source in the power system. As the damage caused by the harmonic is increasingly serious, all country over the world attached importance to the problem. They not only constituted corresponding harmonic standards and rules, but also carried out study of harmonic process. Active power filter (APF) is able to control the harmonic from the electronic equipment and is considered to be an effective and good future method for harmonic process. Shunt APF and series APF are two main circuit configurations. And the series APF has the obvious advantage to the voltage type harmonic source. A novel-style DC side series APF was proposed in this paper in response to the widely used power electronic equipments, just like the rectification bridge. The novel APF can eliminate the harmonic from these equipments. And the paper conducts an in-depth study on the new-style DC side APF.The content mostly includes the topology and the principle of the DC side series APF, mathematical model, and the best control method for the topology as well as the DC side application in the three phase rectification bridge.The main contents and works are as follows:A single-phase DC side series APF topology with Bidirectional voltage converter was proposed in the paper, the control strategy was proposed in response to the character of voltage type harmonic source load based on the deep study of the principle of the APF main circuit, the control strategy was derived, and the method for determining the parameter of key component in the circuit was proposed.The paper comparatively analyzed the relationship of circuit structure between the DC side DC-DC converter, PFC and APF, the design idea and principle of DC side APF circuit structure were studied.Acorrding to the characteristics of the double frequency work mode in the circuit, the mathematical model of DC side series APF was established with the state space average modeling. The static and dynamic state was also analyzed, the static working point and transfer function of different input and output were derived, and all these laid a foundation for the further study.According to the main circuit of the designed DC side Series APF, the hysteresis control strategy based on the power balance principle was proposed, the control circuit equation is derived and the closed-loop system simulation models was established. The simulation result shows that the DC side series APF based on the control strategy can have rapid response whether in light load or heavy load.With the large-scale usage of three-phase rectifier bridge load, based on the single-phase DC side series APF, the DC side three-phase series active power filter was proposed by adding a group of bidirectional switches to achieve the decoupling of the three-phase system. So the three-phase system can become two independent single-phase systems. The simulation result verified the correctness of the circuit structure and effectiveness of the control method, so we can apply it to the high-power rectifier circuit in the field of harmonic process. The whole three-phase system was designed.We developed a single-phase prototype and carried out the experiments, such as rated load experiment, dynamic load experiment. It gives the same result as the theoretical analysis and simulation. With the test results, we proved the accuracy and effectiveness of the topology and control method based on the power balance principle.