Abstract:
With the construction of HVDC transmission projects and the increase of new energy projects, more and more wind farms appear in the near area of the grid commutated-converter based high voltage direct current (LCC-HVDC) receiving converter station, both of which constitute the system with the risk of oscillation. To this end, this paper investigates the oscillation characteristics of the DC receiving feed-in station and the wind farm system in the near zone. First, a state-space model of the system is developed and validated. Based on the model, the system characteristic values are calculated, and the dominant oscillation modes involving LCC-HVDC and wind farms are selected and analyzed as participation factors. Furthermore, by comparing the dominant modes with and without access to LCC-HVDC, it is concluded that the access to LCC-HVDC weakens the system damping. Finally, the influence factors of system stability are explored in terms of system rated capacity, AC system short-circuit ratio, as well as wind farm grid-connected line length. And the effects of different short-circuit and tidal ratios of the system on controller performance are analyzed.