Study on hybrid power system for plug-in hybrid electric vehicles

A simulation analysis has been carried out based on hybrid power system constituted with a parallel structure by ultracapacitor and power batteries for PHEV. In light of the theoretical analysis of hybrid power system simulation widely used algorithm of constant power input incentive shortcomings, using discrete iterative algorithm and an algorithm can meet the power demand of driving conditions change has been proposed and built up. Modeling parameters of lithium battery and ultracapacitor has been obtained through experiments, a comparison simulation study on the single-battery power systems and batteries-ultracapacitor hybrid power system has been carried out applying the algorithm under Chinese typical urban drive cycle. Studies have shown that using discrete iterative algorithm could meet the calculation accuracy needs simulation model of hybrid power system under the input excitation of variation conditions. At the same time in the hybrid power system structure, the ultracapacitor in series with DC/DC is a more reasonable form.