Minimum Distortion Point Tracking

This article introduces the notion of minimum distortion point tracking (MDPT): a control strategy where switching waveforms are optimally phase shifted to minimize aggregate ripple power for networks of dc-dc converters that are connected in series or parallel at the input or output. In a sense, MDPT generalizes the ubiquitous concept of interleaving in balanced systems to a broad class of asymmetric series- or parallel-connected dc-dc converters. For networks of up to one hundred interconnected power converters, MDPT demonstrates a one to two order of magnitude reduction (-14 to -22 dB) in distortion power. We present and experimentally verify three algorithms that can dynamically solve the MDPT optimization problem on a network of three input-parallel connected dc-dc buck converters handling 1.8 kW. The experimental results illustrate an up to $\text{3.06}\times$ reduction in the peak-to-peak ripple of the parallel-side bus voltage and convergence close to an optimal steady-state solution in 5 ms.