一种具有输入端电容均压的串-并型双管正激组合变换器研究

A STUDY ON SERIES-PARALLEL CONNECTION OF DUAL TWO-TRANSISTOR FORWARD CONVERTER MODULES WITH VOLTAGE SHARING BETWEEN INPUT-CAPACITOR

针对该双管正激组合变换器电感电流连续模式工作时,由于参数不对称导致输入端电容不能均压,须采用专门电压控制闭环来保证输入端电容均压,因而增加系统的控制复杂程度和降低了系统的可靠性。该文在分析工作原理基础上,揭示了组合变换器在电感电流断续模式工作时输入端电容自然均压的机理,使得功率开关管只承受一半的输入电压,并得到实验验证,从而简化系统控制、提高了系统可靠性。

While working in continuous conduction mode, the Combined Two-Transistor Forward Converter (CTTFC) will lead to voltage not sharing between the two input-capacitors, and an additional voltage control-loop must be used to ensure voltage sharing between the two input-capacitors. Based on the operational principle of the CTTFC, this paper drew a conclusion that voltage sharing between the two input-capacitors can be achieved naturally only when the CTTFC in discontinuous conduction mode, and experimental results have shown that as well. The voltage stress across individual switches is reduced to a half of input-voltage, and MOSFET can be used as switches in high input-voltage applications. The CTTFC has some advantages such as simple control and high reliability.