Effect of sampling time and sampling instant on the frequency response of a boost converter
DC DC converters like boost, buck boost and flyback converters have unstable internal dynamics and are classified as non minimum phase systems. The linear approximation of these DC DC converters around the equilibrium point shows a zero that maps to the open right half plane (RHP) of the complex s plane. This paper models the boost converter using State Space Averaging (SSA) and Enhanced State Space Averaging (ESSA) to show changes in bode response as function of sampling time. Further, we use Discrete Modeling Analysis (DMA) to model the changes in transfer function with change in sampling instant when sampled during off time of the switch. The result shows that significant bandwidth improvement can be achieved when sampling instant is rightly chosen during the off time. Such a choice is easily achieved with a digital implementation for a DC DC converter.
IECON 2016 42nd Annual Conference of the IEEE Industrial Electronics Society