Advantages of variable DC bus voltage for Hybrid Electrical vehicle

Most research paper on Hybrid vehicle or Hybrid Electrical vehicle propose electrical structures of a DC bus to supply the electrical motor (with or without recovering possibilities). The proposed DC bus has at the majority a constant voltage. As the electrical power is relatively high, it is reasonable to increase the DC bus voltage in order to decrease the current and consequently the Joules losses and to reduce also the sizing of the component and wires. We show in this paper that a variables DC bus voltage is technologically feasible and economically interesting. In this purpose, we compare two different architectures. Both architectures were modelled and controlled (with the proof of stability) and finally the energy balance was proposed in order to compare the two structures and to exhibit the advantages of the variable DC bus voltage.