Stochastic Small Disturbance Stability Analysis of Multi-machine System Based on Energy Function

Power system is a nonlinear network with many stochastic disturbances. Recently, with large-scale renewable power integration such as wind power and solar energy, it has caused much more stochastic factors in the power system. The traditional deterministic linear analysis methods need to be improved. Therefore, it has important value to use nonlinear differential equations to analyze the stochastic small disturbance stability of multi-machine system. In view of high dimensional and nonlinear factors in the multi-generator system, the nonlinear system model with random disturbances is applied in the paper and combined with the energy function method to analyze the power system stochastic small disturbance stability. The stability problem can be simplified from the complex high-dimensional vector problem into the simple one-dimensional vector problem by using energy function. Moreover, the Monte Carlo method is used to analyze the stability probability of the multi-machine system which is subject to random disturbances. The 4 machine 11 bus system is chosen as an example and the system stability probabilities under different stochastic disturbances can be got by simulation. By analyzing the simulation results, the practicality and validity of this analysis method is verified.