Active Online System Identification of Switch Mode DC–DC Power Converter Based on Efficient Recursive DCD-IIR Adaptive Filter

Abstract—This paper introduces a novel technique for online system identification. Specific attention is given to the parame-ter estimation of dc–dc switched-mode power converters; however, the proposed method can be applied to many alternative appli-cations where efficient and accurate parameter estimation is re-quired. The proposed technique is computationally efficient, based on a dichotomous coordinate descent algorithm, and uses an infi-nite impulse response adaptive filter as the plant model. The sys-tem identification technique reduces the computational complex-ity of existing recursive least squares algorithms. Importantly, the proposed method is also able to identify the parameters quickly and accurately, thus offering an efficient hardware solution that is well suited to real-time applications. Simulation analysis and validation based on experimental data obtained from a prototype synchronous dc–dc buck converter is presented. Results clearly demonstrate that the estimated parameters of the dc–dc converter are a very close match to those of the experimental system. The approach can be directly embedded into adaptive and self-tuning digital controllers to improve the control performance of a wide range of industrial and commercial applications. Index Terms—Adaptive filter, dichotomous coordinate descent (DCD), infinite impulse response (IIR) adaptive filter, recursive least squares (RLS), switch mode dc–dc power converter, system identification. I