A controllably inductive power filtering method for large-power industrial rectifier system

This paper proposes a new controllably inductive power filtering (CIPF) method to solve the power quality issues of the large-power industrial DC power supply system. This method is based on the theory of magnetic potential balance and combined with the hybrid active power filtering technology. First, the system topology and the wiring scheme are proposed, and the equivalent circuit model and the mathematical model of the new system are established. Then, the technical features, such as the harmonic suppression nearby the nonlinear loads and the harmonic resonance damping for the grid side, are revealed by means of mechanism analysis. Furthermore, to achieve a better filtering performance, an improved control method is discussed in detail. Finally, according to the design parameters of a practical DC power supply system for electrolytic aluminum loads, the simulation model of the new system is established. The research results validate the theoretical analysis, and indicate that the proposed CIPF method can effectively dampen the parallel/series harmonic resonance at the grid side, and has a better filtering performance than the traditional filtering method.