Research on DC Short Circuit Ratio Correction Index Considering the Influence of Induction Motor

With the rapid development of large-scale wind power, photovoltaic, induction motor and other types of active equipment in Large-scale power system, different equipment has shown significantly different characteristics. However, in the traditional short-circuit ratio (SCR) and improved SCR calculation, there is still no differential analysis of active equipment with “various types and different characteristics”, which leads to the evaluation failure of SCR, that is, the larger the SCR is, the weaker the voltage support capacity is, which is contrary to the existing evaluation logic. Considering these problems, this paper studies the SCR correction method considering the influence of short-circuit current provided by active equipment such as induction motor, and the DC short-circuit ratio correction index considering the influence of induction motor is proposed, which can quantitatively evaluate the influence of the induction motor on power grid voltage stability. The proposed DC short-circuit ratio correction index can effectively reflect the change trend of voltage stability and improve the accuracy of quantitative evaluation. The experimental results on a power grid in Southeast China show the proposed correction index is consistent with the change trend of power grid strength or voltage support capacity, which shows the rationality of the proposed correction index.