A Generalized State Space Averaging Model for Inverting Four-Switch Buck-Boost Converter

This paper proposes a generalized state-space averaging (GSSA) modeling approach for an inverting four-switch buck-boost (FSBB) converter utilizing phase-shifted PWM modulation. The converter achieves inverting output voltage with high efficiency and soft-switching characteristics, making it suitable for communication base station power supplies. By retaining both DC and first-order harmonic components of the state variables, the GSSA model accurately captures the circuit dynamics, enabling the derivation of transfer functions for control design. A Type-III compensator is designed based on the derived model to regulate the output voltage. Simulation results validate the model accuracy and controller performance, demonstrating minimal output voltage ripple and robust transient response under both input voltage and load variations. The findings confirm the feasibility of applying the GSSA methodology to the modeling and control of non-isolated inverting converters.