Digital Active EMI Control Technique for Switch Mode Power Converters

A novel electromagnetic interference (EMI) suppression technique based on field programmable logic array technology is proposed to provide a significant EMI noise attenuation for switch-mode power converters. This technique uses noise acquisition at very high-sampling rate. The noise signal is processed to invert its phase angle and reconstructed with high fidelity to counteract the noise signal before reaching the line impedance stabilization network. Thus, high noise attenuation is achieved. The new technique is validated through simulation and experimental results of a single-phase ac-dc converter. The proposed technique can be extended to dc/dc converters to replace the conventional passive EMI filter where the PCB space is restricted. This technique can be a desired contingent in industrial applications where space is a major design constraint.