Rassem Ragheb Henry

Design and testing of a belt-driven induction starter-generator

The advent of higher voltages in automobiles constitutes an opportunity for new electrical features and systems. In that regard, a combined starter-generator would have several important benefits, most notably it would enable the turning off of the engine at idle and provide efficient, high power generation, both resulting in improved fuel economy. Several ongoing starter-generator projects have focused on locating the starter-generator around the engine flywheel. This paper describes the design of a belt-driven alternative with an induction machine drive. The proposed system would be easier to package than a flywheel-mounted system, since it would not affect the overall length of the powertrain. The paper presents various models as well as test results from a prototype system. Some specific implementation issues, such as induction generator stability at high speed, are also explored in some depth.

An Engine-Starting Simulation With Friction Estimation: Background and Model Validation

This paper describes an engine-starting simulation that uses models of the electrical, engine dynamics and engine thermodynamics subsystems combining them with engine friction models. One of these friction models uses the physical parameters of the engine as basis for estimating the friction torque. This allows engine performance prediction, hence the ability to size the electrical starting system, without engine availability. The resultant simulation is developed using SIMULINK/MATLAB™ and it has been validated for two engines; the first is a 4-cylinder engine with a conventional valve train, and relatively high friction by today’s standards, and the second is a more recent 3-cylinder engine with lowfriction. Validation of the first engine was done based on matching its published starting tests with results obtained using this paper’s simulation. The validation of the second engine was carried out by comparing engine test results with simulation results. Tests in the first case were for engine starting including firing and in the second case were for cranking only conditions.Copyright