Characteristics And Identification Of Power System Oscillation Center

The general characteristics China’s west-east power transmission is determined by unbalanced energy distribution and economy development. Therefore, it’s effective to construct a strong and reliable grid to solve our energy and economic development problems. However, with the connection of grid becoming closer, multiple avalanches of serious problems may occur and cause blackouts, if timely and effective prevention and control measures is not taken when disturbance occurs. Thus, it is of great importance to grid security and stability if the oscillation center and the step-section can be predicted as soon as possible and effective control measures can be taken.This paper demonstrates the mathematical expressions and the characteristics of the electric quantity when two generators power system turn into out-of-step state. Then it derives the fast positioning algorithm and puts forward improvement measures in terms of the shortcomings. The algorithm is of strong adaptability and little influenced by the network operation mode as well as the changes of system structure. It studies the drift characteristics of oscillation center in out-of-step process and the affecting factors, and points that the model and the size of load impact the drift significantly. And it summarizes that the fundamental reason of drifting is the nonequivalant voltage amplitude in transmission line. It analyzes the prerequisites of deriving the voltage of oscillation center U cosφ and proposes effective improvement measures in terms with the problems in practice.Finally, this paper proposes a new predicted algorithm which combines oscillation center locating algorithm with out-of-step splitting criterion U cos φ. And the algorithm is proved to be feasible and effective through the simulation of the IEEE11node classic examples. Furthermore, the algorithm is applied to PSD-BPA software and is implemented in the simulation of practical grid data of North China-Central China. It is proved that this criterion can predict the oscillation center before power system being out-of-step. All of this provides important references for taking timely and effective measures.