Page - 112 - in Hybrid Electric Vehicles

Based on advantages and disadvantages of the SynRM and the specific applications of ISAB (rated speed up to 10,000 rpm), SynRM is one of the most suitable candidates for direct con- nection to crankshaft. The major advantages are high torque, thermal behaviour (absence of permanent magnets and low average value of iron losses), high value of efficiency at entire drive cycle of functioning, vibro-acoustic behaviour (low noise), etc. In the development cycle of SynRM presented below, the most important step is related to the rotor geometry and the structural behaviour (see Figure 6). 2.2. Power electronics The electrical equipment installed on the vehicles operates at a nominal voltage of 14 V. In the early 1990s, a new standard (PowerNET) for automotive electrical systems has been proposed by a consortium of automotive manufacturers (Daimler-Benz and General Motors). Following a proposal by the PowerNET, the voltage level increases for the electrical installation to 42 V [25]. The goal was to reduce the section of the conductors and gain the possibility to increase the total Figure 6. General design procedure of SynRM. Hybrid Electric Vehicles112