Feasibility study of the electric power generation unit start-up using the three-phase synchronous generator with the AC exciter

The article presents the feasibility study of using the three-phase synchronous generator with the AC exciter as a starter for the Fiat 0.9 TwinAir CNG 80 HP internal combustion engine. The investigated power generation unit consists of the above mentioned internal combustion engine which can be powered by a biogas and the three-phase electric power generator MeccAlte 16 kW with the AC exciter. The use of an electric generator for starting a combustion engine is an innovative approach, which eliminates the need for additional components like starter reducing the mass and the failure frequency of the device. Similar approaches have been already investigated by the aircraft manufacturers for starting the jet engines of the airliners and are widely used in the hybrid engines for vehicles. The field winding of the three-phase synchronous generator described in the paper is connected to the AC exciter via a rotating rectifier bridge. This solution eliminates the necessity of using slip rings and facilitates a voltage regulation of the generator. The authors of the paper analyse the technical and practical possibilities of using such a synchronous generator with the exciter as a starting motor by measuring its output power and starting torque. The economic aspects of such a solution for unit and mass production have been also considered.