Regulation of synchronous generators by means of hydrostatic transmissions

In many applications within the engineering world, an isolated generator is needed (e.g. in ships). Diesel units (diesel engine and synchronous generator) are the most common solution. However, the diesel engine can be eliminated if the energy from another source (e.g. the prime mover in a ship) is used to move the generator. This is the case for the shaft coupled generator, where the coupling between the mover and the generator is made via a hydrostatic transmission. So that the mover can have different speeds and the generator is able to keep a constant frequency. The main problem of this system is the design of a speed governor that make possible the desired behavior. In this paper a simulation model is presented in order to analyze the behavior of this kind of system and to help in the speed governor design. The model is achieved with a parameter identification process also depicted in the paper. A comparison between simulation results and measurements is made to show the model validity.