Impact of interleaving on input passive components of paralleled DC-DC converters for high power PV applications

This paper investigates and evaluates the impact of interleaving on input passive components for a paralleled DC/DC boost converter in a high power PV application. A detail ripple reduction analysis for the interleaving topology and inductor design method are provided for the high power application. To reduce the circulating current, a coupled inductor was added to the circuit to reduce the size of input inductor. The benefit of coupled inductor is analysed and the coupled inductor design method is also conducted. The result shows that due to the material limitation (Silicon Steel) if maintaining the current stress on IGBT, interleaving will increase the weight and loss, while the overall current ripple will be smaller, which make the input and dc link capacitor smaller. By adding coupled inductor and interleaving, it is possible to use low core loss material (Amorphous) for coupled inductor, which makes the total loss and weight reduced significantly. Moreover, asymmetric interleaving is also proposed to optimize the total cost of the Silicon Steel and Amorphous material. Detailed analysis is carried on the design and value selection of coupled and non-coupled inductor for different interleaving angle. The design result shows the trade-off of using different interleaving angle to get minimum system weight.