Research On The Key Techniques Of Shunt Active Power Filter

In recent years, with the development of power electronics technology, power electronic devices have become an increasingly widespread application. They generate harmonic and reactive power which leads to variety of hazards of power grid by greater and greater. As a new kind of harmonic and reactive comprehensive compensation system, shunt active power filter (SAPF) is the focus of research in the field of power quality. Now, Product of SAPF is looking forward to come out in our country. It is bound to promote the industrialization development of APF. Therefore, applied research on the key technologies of SAPF has become one of the most cutting-edge issues of the most important research on SAPF.Through theoretical analysis and simulation tools the working principle and developing situation of SAPF are analyzed in this paper. In order to shunt active power filter can be used in high-voltage, high-capacity, high control requirements of the occasion, proposed cascaded multilevel converter as the APF's main circuit structure, and select the CPS-SPWM technique as modulation strategy.The CPS-SPWM technique and cascade multilevel converters combine can be achieved at lower switching frequencies as higher equivalent switching frequency, the simulation analysis show superiority of method. According to defects in traditional harmonic and reactive current detection part, the instantaneous reactive power theory and the synchronous reference frame detection method has been improved through the use of an improved three-phase Harmonic and reactive current detection methods. It can be used in distortions system and the asymmetrical three-phase voltage.While simple in structure, but also easy hardware achieved. For cascade multilevel converter structure of DC capacitor independent features, design a simplified control method.use each phase and the DC capacitor voltage as the control object, to achieve the overall control of DC voltage. Tianjin Pipe Corporation SAPF used to distribution power systems, load-specific analysis of the practical issues, including the choice of the main circuit, parameter design and so on. Establish simulation model of active power filter, examine the effect of active power filter compensation, the results show that the design of shunt active power filter compensating current harmonics with good results.In this paper, applied research on the key technologies of SAPF is done, which has laid a theoretical foundation and provided technical support for the future developing with the device of SAPF to promote the further development of domestic industries.