Modelling and controller design for a non-inverting buck-boost chopper

Due to its simplicity, low voltage stress, high reliability, low switch and inductor losses, and small inductor size, the non-inverting buck-boost chopper has found a lot of attentions in applications where it is necessary to step-up or step-down the DC voltage. In this paper, a successful switching strategy for this converter is reported and small signal averaged state-space model is obtained, which lets decide about the control strategy and analyse the stability and performance of the closed loop control system. Appropriate control requirements have been defined and the closed loop performance under several control strategies has been investigated through extensive simulations.