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With the rapid development of DC asynchronous interconnection, in order to ensure the frequency quality, higher requirements are put forward for the primary frequency control of hydropower units. In the high proportion hydropower system, it is difficult for the governor parameters to meet the requirements of primary frequency control and dynamic stability simultaneously. In order to solve the problem, this paper proposes a recommended parameter switching method by referring to the Nordic system. The parameter optimization methods before and after switching are proposed, and the effectiveness of the method is verified by time domain simulation.

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In this paper, Computational Fluid Dynamic (CFD) methods are adopted to predict the manoeuvring behaviour of the KCS benchmark model. At first instance, the model is calibrated on the basis of three factors namely (a) turbulence model, (b) grid size and (c) time step. Secondly, a Static Oblique Towing Test (OTT) that utilises the SST K-ω turbulence model with a grid number of 1.64 million and a time step of 0.01 s is conducted. The maximum difference of the lateral force between the port and starboard ship sides is observed at x/Lpp = 0.055. Finally, application of Reynold Averaged Navier Stokes (RANS) and Dettached Eddy Simulation (DES) CFD models indicates that the latter may be preferable in terms of capturing the oblique flow field.