PROJECT TITLE :

Impact of Inertia and Effective Short Circuit Ratio on Control of Frequency in Weak Grids Interfacing LCC-HVDC and DFIG-based Wind Farms - 2017

ABSTRACT:

Although nearly every overhead HVDC line is predicated on LCC technology, hardly any work has been reported on modeling and analysis of the impact of inertia and effective short circuit ratio on management of frequency in weak grids interfacing LCC-HVDC and onshore DFIG-primarily based wind farms. This paper develops a comprehensive modeling and stability analysis framework of a weak grid that interfaces an LCC-HVDC station and a DFIG-based wind farm. To that finish, a nonlinear averaged phasor model of the system comes, which is then benchmarked against an in depth switched model. The averaged model is linearized to design a frequency controller for the LCC-HVDC rectifier station. Participation issue and eigenvalue sensitivity measures indicate that the AC system electromechanical mode and also the 'HVDC PLL' mode are highly sensitive to changes in Effective DC Inertia Constant and Effective Short Circuit Ratio, respectively. Root-locus analysis in an exceedingly progressively weak grid validates these results. A systematic style process of the frequency controller parameters reveals a negative interaction between the 'generator speed-HVDC PLL-frequency controller' mode and the 'DFIG-GSC controller' mode.