LCLC Based AC-DC Single-Stage Resonant Converter with Natural Power Factor Correction

LLC-based AC-DC resonant converters make excellent EV chargers because of their high efficiency, high power density, and soft switching properties. Efficiency is increased and the need for a larger series inductor is lowered by connecting a capacitor across the magnetising inductance of the LLC resonant architecture (LCLC configuration). Switching frequency control is commonly used to regulate the converter's output DC voltage. However, there is a significant relationship between the converter's power factor and switching frequency. As a result, any changes in load may result in a lower power factor for the converter. This paper suggests a single-stage topology based on the LCLC resonant structure. The LCLC resonant configuration ensures zero voltage switching (ZVS) of the IGBTs used in the converter. Converters have a power factor correction (PFC) stage on the front of the converter to achieve natural power factor correction. Since the PFC stage and the resonant stage are controlled by the same switches, the converter is smaller and less expensive. A bridgeless rectification method is applied in the proposed topology to reduce the number of switching devices. MATLAB/Simulink simulations are used to validate the topology.