Energy Savings With Lqr Control Of Dc/Dc Converters

This paper demonstrates the advantages of using state-space based control of dc/dc converters, as a time-domain waveform optimization tool. The optimization goal is considered to be the loss reduction for a converter working under a power management system with multiple changes of the operation point. The design sees a paradigm shift from achieving fastest response to achieving best efficiency during multiple transients, with transient being also time-constrained. The Linear Quadratic Regulator (LQR) optimization is herein configured with converter loss equation as cost function. The solution to Algebraic Riccati Equation produces the best system efficiency for this case-study. The closed-loop control software yields very simple, running under 4 mu sec (or 250 kHz switching capability) on a general use processor, without dedicated digital hardware controller. Design and implementation are followed up with experimental results from a Microchip microcontroller platform.