A Novel Model Free Cascade Control System with Accelerated Newton-Raphson Method for Boost Converters

The performance of model-based control for Boost converters are affected by model accuracy. To get accepted control profile, sophisticated robust control law or model identifying process is needed, which leads to complexity. As an alternative method to maintain simplicity, a model free control scheme for Boost converters is proposed in this paper. Firstly, the voltage regulation problem is transferred into current tracking via the Newton-Raphson method to guarantee convergence based on static characteristics without considering about the exact Boost model. Then for current tracking, a Quasi-Hysteresis comparator is employed. The control output is the switching signal and for each sampling period the control output remains the same. For rapid response, a least squares iterative algorithm is given to calculate the static values of each Newton-Raphson process for saving transition time. Finally, all the proposed methods are validated by experiments based on a FPGA platform.