Cascaded buck-boost converters: Output voltage regulation & constant inductor current

This paper proposes a robust control to the cascaded buck-boost converter for AC-DC applications. The controller model has been developed using the state-space averaging technique and the H_∞ control theory. These concepts are used to achieve regulated output voltage and at the same time it gives constant current at the inductor. The controller strategy is included with two loops controls which are the output voltage and inductor current control. Both controllers were designed using H_∞ control theory. The simulation results show that the controllers are able to respond to the desired target output and has constant inductor current.