An interleaving scheme to reduce DC-link current harmonics of dual traction inverters in hybrid electric vehicles

In traction inverters of hybrid electric vehicles (HEVs), DC-link capacitors, which are usually bulky and expensive, present an obstacle for improving the power density and reliability. This paper introduces an interleaving scheme to reduce the DC-link current harmonics of dual traction inverters in HEVs. The DC-link current expression is derived considering the modulation schemes, modulation index, displacement power factor (DPF), and interleaving angle. Based on the current analysis, proper interleaving angles to reduce the DC-link current harmonics are obtained for different operating modes of the electric traction machines. With the proposed interleaving angles, the DC-link current harmonics are reduced. Therefore, the required DC-link capacitance is reduced and the lifetime of the capacitor is improved. The effectiveness of the proposed interleaving scheme is verified by simulation results.