Cooling circuit

Components to be cooled have been integrated into the coolant circuit so that individually applicable and required maximum temperature levels are adhered to. The electrical machine electronics require a lower temperature than the electrical machine and therefore the series connection was configured in this way. A parallel circuit was configured because the electrical drive and the convenience charging electronics (KLE) are not in operation at the same time. The range extender electrical machine and the range extender electrical machine electronics (REME) are initially connected in series. Since these two components are not in operation at the same time as the convenience charging electronics (KLE) and the electrical machine electronics (EME), these components have been connected to each other in parallel. The cooling system also does not have to be designed to cover the sum of all heat output, as in reality, heat must merely be dissipated in one or the other or in two parallel branches. If the vehicle is equipped with a range extender, the coolant circuit features a coolant-coolant heat exchanger for heating systems to cool the engine of the W20.

Courtesy of BMW OF NORTH AMERICA, INC.