A Parallel Compensation Approach in Controls of Buck-Boost Converters

Buck-boost converters are non-minimum phase nonlinear circuits. Due to which there arises several constraints in selection of proper control approach. What is proposed in this paper is the application of a decoupling technique to isolate the non-minimum phase part of the system. The decoupled non-minimum phase transfer function dynamics are changed to minimum phase using a parallel compensator. Then the control action can be achieved by using a proportional gain controller. This method accelerates the transient response of the converter, removes the undershoot in the response and considerably reduces the oscillations in the transient response. Simulations demonstrate the effectiveness of the proposed control approach.