Impact of Reactive Power on Stable Production of Wind Farms

Increasing the share of wind energy in supplying load demand of power grid has created new challenges in the field of power system stability. So that, the stable operation of each units of wind power producer on interaction with grid could be affected by power system instability. Among them we can mention the phenomenon of voltage instability in power system which eventually will lead to voltage collapse if stability controls are not applied. In this paper the impact of reactive power control on improvement of SCIG-based wind farms operation has been studied. With regard to the asynchronous operation of induction machine, the increment of wind power generation will be possible only by absorption of more reactive power. Increasing in the power reactive consumption of induction generator leads to reduction of voltage in point of common connection (PCC) which the wind farm connects to the grid. Ultimately, this process in lack of proper reactive power control can be lead to instability in whole of power system. The conducted studies in this paper are in framework of quasi-static time-domain simulations (QSTDS) and continuation power flow (CPF) algorithm. The results indicate with increment of wind power penetration in power system if the proper support of reactive power is not used, the stable performance of the wind farm will be threatened and caused to over speed of SCIGs. Another task done in this paper is the employment of SVC and STATCOM as a practical solution in improvement of wind farms-based power system stability.