The Controller Design of Three-Level Boost Converter using Unified Modeling Approach

Abstract

The unified modeling of the TLB (Three Level Boost) converter and its design of the double loop controller are presented in this paper. Since the TLB converter has two capacitors and one inductor, the state space modeling has 3 state variables in the previous research and publications. Also, the TLB converter has two operational modes depending on duty ratio boundary of 0.5. Due to this, complex calculations are required for controller design. A simple state averaging equations using 2 state variables are presented in this paper, unlike the previous studies which used 3 state variables. The analysis has been conducted for continuous conduction mode (CCM) in two different modes of TLB converter and concluded that the transfer functions of each mode are identical to both modes. The controller has been designed for the double loop control system using unified model. The MATLAB and PSIM simulation have been performed to verify the effectiveness of the proposed controller design. The suggested method is simple and easy to apply to real system applications.