摘要：For the trade-off between the security andeconomy of power system operation, the control actions such asthe preventive control, emergency control, and restorativecontrol, etc. should be selected according to the frequencysecurity level of power system operation. Thus, the theoreticalbasis for the selection of the control modes of frequency responseand the dispatch of the frequency regulation means can beprovided. The theoretical research demonstrates that the ratiobetween the frequency nadir and the quasi-stable statefrequency of power system is nearly a constant after disturbance.Moreover, the frequency nadir of power system can beestimated based on the quasi-stable state frequency with thelinear regression method of historical data. Hence, the methodfor the frequency security level grading of power systemoperation is proposed and the frequency response reserve ofgenerator units and the initial operation frequency of powersystem, etc. are considered. Because the quasi-stable statefrequency involves few parameters and is easy to be calculated,the calculation speed of the frequency nadir is fast and theproposed method can be applied on line. The feasibility andeffectiveness of the proposed method are illustrated in themodified New England IEEE 10 generator 39-bus system andthe Henan power grid.
关键词：security and stability control; frequency;response; frequency security level grading; constant ratio; linear;regression method
