Célula a capacitor chaveado para a redução do ganho estático de retificadores monofásicos boost com correção do fator de potência

Abstract

This thesis introduces a novel switched-capacitor cell designed to reduce the voltage gain of single-phase Boost Power Factor Correction (PFC) rectifiers. A key feature of this cell is the inherent voltage balancing across its switched capacitors, which are alternately connected in series and parallel during converter operation. This proposed cell reduces the Boost converter’s voltage gain by half, and its static analysis is thoroughly investigated. Subsequently, the studied cell is applied to a conventional PFC Boost rectifier and an interleaved PFC Boost rectifier. Linearized mathematical models are derived to calculate current stresses, along with simplified transfer functions for closed-loop control implementation. Numerical simulations validate the theoretical calculations. Experimental validation is then performed on two constructed prototypes. For the prototype, designated as a hybrid switched-capacitor PFC Boost rectifier with voltage gain reduction, a maximum efficiency of 96.5% is achieved at 1.4 kW of resistive load power. The second prototype, referred to as a hybrid interleaved switched-capacitor PFC Boost rectifier with voltage gain reduction, achieves an efficiency of 97.21% for approximately 1 kW of resistive load. Both prototypes demonstrate a near-unity input power factor and input current THD compliant with IEC 61000-3-2. In conclusion, the proposed switched-capacitor cell is well-suited for integration with Boost PFC rectifiers, effectively halving the voltage gain compared to the original converter configuration associated with the cell. The proposed cell is designed for applications that do not require higher output voltages in comparison to the input voltage.