I was surprised to read the Bolt uses a synchronous electric motor technology, quite different from Tesla. We know that the battery runs at 400 volts DC, so this implies there is a variable frequency DC to AC converter that can run from over a big frequency range as as the motor turns from 0 rpm to about 8000. Any electrical engineers on the forum? How are they doing this? If there is a maximum frequency for the converter, this would limit the top speed, which I read is 150 km/hr or about 92 mph.