Design of double loop controller for three-level boost converter

Abstract

Abstract Three-level Boost Converter (TLBC) is widely used in new energy generation grid-connected technology. This topology not only reduces the voltage stress of the switching tube and the diode, but also has a smaller size, lighter weight and higher power density. However, it has the problem of midpoint potential shift. In this paper, a dual closed-loop controller is designed by establishing the AC small-signal model of the system. while stabilizing the output voltage, the upper and lower capacitor voltages are dynamically adjusted to ensure the balance of the midpoint potential. Finally, this paper establishes a simulation platform in MATLAB/Simulink and verifies the dual-loop controller scheme.