Brushless Fast Starter for Automotive Start/Stop Application

In this paper, a low-cost 48V, 4kW brushless fast starter system for automotive Start/Stop (S/S) applications is presented. The design and analysis of the machine, inverter, controller and control algorithm are discussed in detail. The inverter and motor are integrated within the same assembly housing as the original brush-type starter to enable a drop-in replacement. Simulation models were used to assess the performance benefits of the brushless drive during engine AutoStart events and were compared to the conventional starting system with brush-type dc motors. Simulation results showed superior engine AutoStart performance due to lower inertia, higher torque and wider power band capability of the brushless motor, especially at higher speeds. Performance was also improved due to significantly lower rotor inertia. Finally, a prototype brushless fast starter system was built and tested and found to meet the cost, performance and packaging requirements.