Small Signal Analysis of High-Gain Transformer-less Hybrid Boost Extender Converter Based on State-Space Modeling

This paper presents small signal analysis of multistage, high conversion ratio, hybrid boost converter with voltage closed loop control. The analysis employs a multistage small signal model to evaluate the small signal response, aiding in modeling of closed-loop converter parameters. The complete state-space analysis is conducted to derive control-to-output transfer function of the converter with variable number of amplification stages. A PI controller is designed. The converter model, with closed loop voltage mode control, is designed and simulated using MATLAB Simulink, incorporating a load disturbance. The hardware prototype of 9 stage converter with 1200V output and gain of 30 is implemented and evaluated experimentally. The experimental results are found to be in good agreement with theoretical derivations.