Principles and Design of an Integrated Magnetics Structure for Electrochemical Applications

This article presents an integrated magnetics (IM) structure that functions as a current-doubler rectifier (CDR). The proposed IM-CDR is suitable for electrochemical wastewater treatment applications where low-voltage high-current power converters are required for effective treatment. Electrochemical wastewater treatment is a promising technology that has several advantages compared to the traditional biological methods currently employed in the mining industry. However, the technology suffers from high operating cost due to the conduction losses associated with long cables or busbars that run from the source to the treatment cell carrying high current. The IM approach integrates the transformer and two filtering inductors of the discrete CDR (D-CDR) into one magnetic structure which allows for the secondary side of the structure to be packaged with the electrochemical cell, thus resulting in a HVdc distribution network, and as a result, lowers the conduction losses while still benefiting from the ripple cancellation offered by the CDR architecture. This article presents a design example to help the designer relate the required electrical characteristics of the D-CDR to the design parameters of the IM-CDR. A finite element analysis simulation is performed on the IM structure to validate the derived electrical equivalent model. The IM structure is also experimentally built in our lab, achieving a 97.8% efficiency over a 20-40 A load range.