Reverse Engineering of an Electric Vehicle Motor and Tests of a Charging Station

The thermal analysis of the motor is presented in Section 1.7, with a large attention to the trend of the temperatures into the different part of the motor during a Drive Cycle. The purpose is to try driving the car according to the US06 drive cycle.

At the end of the cycle the temperature of the motor is measured, with a thermal camera and afterwards the results are compared. The uncertainties regarding the feasibility of this test have been known from the beginning. Lacking a test rig with rollers, we’ve tried to carry this first drive cycle out on a freeway. The US06 cycle presents great changes in speed, it goes from 0 km/h to 130 km/h in a short time and this is the biggest problem. It is obviously not possible to stop the car on the freeway. Therefore unable to carry out this cycle we have searched for a solution.

Trying to change the cycle, but trying to keep as many points as possible of it, there were two possible solutions. To delete points at low speed, in order to be able to run the test on a freeway or motorway, or to delete points at high speed, in order to be able to perform the test in a city or on a not very busy road. The second solution has been chosen.

First of all we have tried to get in a big empty parking at about 20km from the company to perform the cycle. The problem was that to get into the parking the temperature of the motor increased considerably. Even waiting half an hour the temperature did not decrease a lot because the motor has a big thermal inertia. We decided to do the test anyway, but changing the starting temperature of the motor into the simulations. At the end of the cycle the temperature was increased of less than a degree, and it did not seem to be very representative,for this reason it is not presented. Near the company there is a long road not very busy, but it is an uphill.

The uphill is not really a problem, because in Motor-CAD there is the possibility to choose the altitude of each single point of the drive cycle. Hence with a little bit of patience it was measured the difference in altitude from the starting point to the ending point, which is of about 133m. Thus for each point in the Motor-CAD cycle the altitude has been changed. [...]