I'm so happy to see I'm not the only pearson with idea to switch the windings to improve drive efficiency. The motor efficiency is not changed much. The copper losses are almost the same, but eddy current losses are lower if the winding is connected in series. But also here the difference is not big. The more importan fact is, that we increase controller efficiency at lower speed. There is quite a big difference in RMS current from barteries, especially peak values of the current are much lower. You are talking about 98% peak efficiency - is this motor efficiency? For EV peak efficiency is not so important. More important is to have very low no load losses and so very high efficiency also at low torque. The next problem are transmission losses. Higher transmission means smaller motor, but also higher transmission losses. Direct drive would be much better. But is it possible to make such a motor with acceptable price and weight? I believe it is.
👍🏼👍🏼👍🏼
I'm so happy to see I'm not the only pearson with idea to switch the windings to improve drive efficiency. The motor efficiency is not changed much. The copper losses are almost the same, but eddy current losses are lower if the winding is connected in series. But also here the difference is not big. The more importan fact is, that we increase controller efficiency at lower speed. There is quite a big difference in RMS current from barteries, especially peak values of the current are much lower. You are talking about 98% peak efficiency - is this motor efficiency? For EV peak efficiency is not so important. More important is to have very low no load losses and so very high efficiency also at low torque. The next problem are transmission losses. Higher transmission means smaller motor, but also higher transmission losses. Direct drive would be much better. But is it possible to make such a motor with acceptable price and weight? I believe it is.