Analysis and voltage-mode controller design for a single-switch fifth-order boost converter

In this paper, a digital single-loop voltage-mode controller (VMC) is designed for the non-isolated fifth-order boost converter, which exhibits low source current ripple. A detailed analysis is performed, in continuous inductor current mode of operation, to obtain the design expressions and relevant differential equations. Later on, a state-space modeling approach is extended to formulate the discrete-time models. A pole placement technique is utilized in the digital controller design to achieve required stability margins. The robustness of the closed-loop controlled system is analyzed using modulus margin (MM) concept. Simulation studies have been conducted to validate the steady-state and transient performances of the digital VMC. To confirm the analytical results, a 12 to 48 V, 25 Watt, 100 kHz prototype is developed and the closed-loop system (CLS) stability is verified for a given range of parameter uncertainties. Both simulation and experimental results depict the efficacy of the controller against source and load disturbances.