  This paper presents design and control of dual-switch non-inverting
buck-boost converter (CBB). This converter is designed to simplify the
compatibility of electronic ballast with simple and low cost LED drivers. The
converter provides starting voltage and current limitation of electronic
ballasts, which operates at continuous conduction mode (CCM). The voltage of
load terminal is controlled by adjusting the duty cycle of the PWM regulator.
Although both converter switches are controlled separately, one feedback
control loop is needed to obtain the desired compensator level. Appropriate
control requirements have been defined by analyzing open-loop characteristic of
converter transfer function through the small-signal model of CBB, which lets
decide about the control strategy and analyse the stability and performance of
the closed loop control system. In order to obtain the desired output voltage,
Type-III rational controller is preferred because of the non-minimum phase
feature in the converter boost mode. The performance of the synthesized voltage
controller is verified by comparing of the pre-determined performance
requirements and the obtained simulation results.
