Investigation of a Voltage-Mode Controller for a dc-dc Multilevel Boost Converter

The multilevel dc-dc boost converter (MBC) is well known for its simple circuit structure and high voltage gain. Several controllers have been previously employed for their output voltage regulation. However, due to the non-minimum phase nature of the MBC, these controllers use both the inductor current and output voltage as feedback variables. This increases the complexity of the controller design and cost of implementation. In order to overcome these drawbacks, a voltage-mode controller for the regulation of the MBC is proposed in this brief. By using the generalized reduced-order state-space model of the converter and frequency-domain techniques, the stability of the voltage-controlled converter system is analyzed. In addition, some simulation and experimental results illustrating the ability of the proposed controller to regulate a 3x dc-dc multilevel boost converter in the presence of load and line voltage variations are provided.