Improvement of Energy Consumption of an Electric Bus with Loss Minimization

This paper presents calculation and experimental results for two different Permanent Magnet Synchronous Machines (PMSM) used in a drive train of an electric bus. It focuses on the calculation of energy consumption and shows improvements in efficiency and lower energy consumption when the control algorithm is optimized with respect to loss minimization. Two PMSM's are used in this paper, one with Pn = 100kW, nn = 5000 min-1 with dominant (large) copper loss, the other PMSM with Pn = 162kW, nn = 1684 min-1 with dominant iron loss and small copper loss. The first PMSM was used to validate experimentally the presented PMSM model. The calculation results show that when the PMSM parameters are suitable for loss minimization, an improvement in the order of few percent (up to 10 percent in this case) can be expected. On the other, when the PMSM has unsuitable parameters for loss minimization, as it is the case for the first motor, the effect of loss minimization is negligible.