Push-Pull Current-Fed DC-DC Converter Start-up Operation

A novel control mechanism for a boost DC-DC converter operating during EV start-up has been developed. The proposed controller permits limitation of the input current and eliminates the need for additional in-rush current protection circuits, reducing the system cost, volume and weight. It requires no additional hardware and utilizes a transformer leakage inductance energy recovery circuit. In addition, it benefits from a fixed switching frequency in the main power path and provides the smooth transition between the start-up and normal operation modes. A mechanism to limit the auxiliary converter capacitor voltage was introduced as well. The controller implementation for the TI F28379D MCU is discussed and the performance is supported by the Software-In-the-Loop (SIL) simulation results.