A Method for the Frequency Security Level Grading of Power System Operation

• Published in: Engineering letters 2019-08, Vol.27 (3), p.623
• Main Authors: Jin, Cuicui, Liu, Liu, Li, Weidong, Li, Xiaomeng, Rao, Yufei
• Format: Article
• Language: English
• Subjects: Emergency procedures; Frequency response; Grading; Mathematical analysis; Security
• ISSN: 1816-093X; 1816-0948

For the trade-off between the security and economy of power system operation, the control actions such as the preventive control, emergency control, and restorative control, etc. should be selected according to the frequency security level of power system operation. Thus, the theoretical basis for the selection of the control modes of frequency response and the dispatch of the frequency regulation means can be provided. The theoretical research demonstrates that the ratio between the frequency nadir and the quasi-stable state frequency of power system is nearly a constant after disturbance. Moreover, the frequency nadir of power system can be estimated based on the quasi-stable state frequency with the linear regression method of historical data. Hence, the method for the frequency security level grading of power system operation is proposed and the frequency response reserve of generator units and the initial operation frequency of power system, etc. are considered. Because the quasi-stable state frequency involves few parameters and is easy to be calculated, the calculation speed of the frequency nadir is fast and the proposed method can be applied on line. The feasibility and effectiveness of the proposed method are illustrated in the modified New England IEEE 10 generator 39-bus system and the Henan power grid.