Deviation Reduction of On-line and Off-line Computational Results of Short Circuit Ratio for Multiple Renewable Power Sources

This paper examines the numerical characteristics of short circuit ratio for multiple renewable power sources (MRSCR) and reveals the causes of deviation between on-line and off-line computational results of MRSCR. It is found that model and parameter inconformity of on-line and off-line computational programs is the main factor leading to the deviation. In addition, difference of steady-state voltage of point of common coupling (PCC) of renewable power sources (RESs) also contributes to the deviation, yet the deviation is reasonable and can be compensated. On-line computational results of MRSCR are based on real-time power flow conditions and thus help improve the capability of power systems to accept renewable power. However, currently only off-line computational results are generally acknowledged as the certified reference in power system dispatching. Therefore, it is required that the deviation between on-line and off-line computational results has to be controlled to an acceptable level before on-line computation is officially put into service. In this paper, through model and parameter modification, the deviation of MRSCR in Ximeng Region between on-line and off-line computational program is reduced to a reasonable and acceptable level, effectively proving the reliability of on-line computational results and thus paving the way for the application of on-line computation of MRSCR in power system dispatching.