A Magnetically Coupled Ripple Compensation Method for Power Converters

The rapid development of renewable energy, energy storage and electric vehicles has led to the widespread use of high-power converters, while the traditional passive LC filter used for high frequency harmonics suppression will significantly increase the weight and volume of converters. In this paper, a shunt magnetically coupled compensation filter (MCCF) is proposed. This filter consists of a coupled inductor and dc blocking capacitors. By sharing the switching circuit to generate a high frequency harmonic which is equal in magnitude and opposite in phase to the ac components of the main inductor, then the harmonic current on the output side can be compensated. Since only the high frequency harmonic components are coupled, the size of the filter is quite small. The whole filters, including the main inductor and the output capacitors, are smaller and lighter than the traditional LC filter, which extends the control bandwidth of the converter. A 2kW laboratory prototype employing the MCCF was built, and the effectiveness has been validated by the experiment results.