Improving the Efficiency of Drive Trains Used in Electric Vehicles by Means of Optimal Modulation

The efficiency of drive trains used in electric vehicles is affected by the employed modulation scheme. This paper proposes an optimal modulation approach, in the form of optimized pulse patterns (OPPs), that limits the converter and winding losses in the machine while minimizing the stator current harmonic distortions. To do so, the OPP problem is reformulated such that the aforementioned losses are constrained. As shown with the presented numerical results, by setting different constraints to the system losses a better trade-off between stator current harmonics and losses is achieved compared with conventional modulation solutions, resulting in increased system efficiency.