This thesis proposes a hybrid fuzzy SMC (Sliding Mode Control) method to improve the dynamic performance of the PSFB-CT (Phase-Shift Full-Bridge Center-Tapped) converter. In general, the control object of the PSFB-CT converter is the output voltage which is conventionally controlled by a PI (Proportional-Integral) control. When using a PI control to control the output voltage of the PSFB-CT converter, the dynamic characteristic can be undesirable, and it can be vulnerable from outer disturbances. To overcome the disadvantages, the SMC has been used for the PSFB-CT converter. In the case that gain of the SMC is increased to improve the dynamic characteristic, the chattering problem can occur in PSFB-CT converter. In this thesis, as an advanced control method, hybrid fuzzy SMC is proposed to improve the dynamic performance of the PSFB-CT converter. Through fuzzy logic control, the gain of the SMC varies appropriately. As a result, not only the dynamic characteristic of the PSFB-CT converter is improved, but the chattering problem is also decreased. The validity of the proposed hybrid fuzzy SMC for the PSFB-CT converter is demonstrated by the simulation and experimental results.
