L2 disturbance attenuation of Marine Diesel Engine Generator by regulation for the excitation and speed

The stability problem of a ship power system is primary and basic for its safe operation. In order to improve the robust stability of diesel engines of the ship power station. a coordination control method for excitation and speed regulation is proposed based on L₂-gain robust control theory. Firstly, a five-order double inputs and robust nonlinear mathematic model is established, which includes unknown disturbances. Then the speed regulation controller is designed using the combined method with Backstepping and L₂ Disturbance Attenuation. The designed control algorithm consists of two parts. The speed regulation controller for zero dynamic subsystem without excitation inputs is first designed, which makes close-loop subsystem inner stable. And then the strictly dissipative inequality of the whole system is obtained by computing excitation controllers. Different from the existing results, the obtained control law explicitly formulates the function relations of the influence of propeller on control performance. Lastly, the simulation shown that the designed controller is effective to reject the unknown external disturbances, hence robustness of the controller is largely improved.