A Balancing Control Method with Single voltage Sensor for Five-Level Buck/Boost Converter

Multilevel DC-DC converters have many advantages over traditional two-level DC-DC converters, such as decreasing voltage stress of switches, reducing inductor volume and switching losses. To apply multilevel topologies, some measures must be considered to deal with the risk of the capacitor voltage unbalanced. The traditional voltage balance scheme requires a large number of sensors to measure the voltage of each capacitor, which is not conducive to low cost and small volume. To solve this problem, this paper proposes a balancing control method based on decoupling single voltage sensor signal for five-level buck/boost converter. The proposed control method can balance the voltage of the divided capacitors through adjusting the duty cycle of the power switches. And the working principle is introduced in detail, and the decoupling algorithm is derived and analyzed. Finally, the simulation results verify that control method with single voltage sensor is feasible to balance all capacitor voltages.