Research On Decision-making Method Of General Security Control Strategies Of Power Systems

"Three lines of defense" is the successful experience of safe and stability operation of power systems, and the second line of defense relies mainly on the emergency control measures of tripping machines and load shedding and other measures. These measures can ensure the security and stability of power systems, even in the case of severe faults with low probability. The safe and stability control strategy is the core and foundation of security and stability control device, so it is of great research meaning and practical value.According to the problems of the traditional off-line look-up table type safety control strategy of lookup table setting method which includes large amount of calculation and the complex setting and maintenance, this paper propose a general control strategy based on the formula calculator of the tuning method. According to the stable form of transient stability, dynamic stability and thermal stability under different grid structure, the control strategy and influencing factors on the different stable form are studied respectively and a linear model which can revise parameters is established to describe the control quantity and the section power flow value, which also put forward the tuning method of the typical key parameter. By using single machine equal area criterion proves that the relationship between the section flow and the safety control of transient stability is "concave curve", which provides a basis for the range of key parameters and the linear model of transient stability. Practical application case shows that the proposed control strategy model is more convenient and has clearer physical significance compared with the traditional method, which has great application.In addition, transient stability control strategy should be given short time and satisfy the requirements of reliability. For this reason, the paper presents a fast algorithm to estimate the quantity of cutting generator under transient stability emergency, and the strategy reduces the workload significantly. Based on the single machine equal area criterion, the estimation power resection volume value is obtained by comparison between the acceleration area and deceleration area, then the method to estimate the amount of cutting machine is put forward. The multi-machine system is equivalent two machines through the center of inertia, then to the OMIB system, and thus it can be used to estimate the amount of cutting generator based on single system. On the basis of theoretical analysis, the simulation model is built by PSD-BPA, and the estimation of the amount of cutting machine combined with MATLAB. Finally, the strategy is verified through the example simulation, and results show that the proposed method is effective.