Transient Stability Assessment for AC-DC Hybrid Systems Based on Bayesian Optimization XGBoost

Machine learning is playing an increasingly important role in transient stability assessment. One of the key challenges of machine learning-based transient stability assessment in the case of dealing with large-scale and high-dimensional data samples of AC-DC power systems is to eliminate redundant variables to improve the training speed and quickly determine the optimal parameters of the adopted algorithms. Aiming at this problem, this paper proposes a Bayesian optimization-based XGBoost (B-XGBoost) method for transient stability assessment of power systems. The method uses serial integration of multiple regression trees to calculate the importance ranking of transient stability features. Combined with correlation analysis, the relationship between input data and transient stability can be explored more intuitively, and redundant variables can be eliminated; Bayesian optimization is used in training to quickly determine the best parameters of the model. Simulations are performed in a 39-node AC-DC system, and the results show that the B-XGBoost transient stability evaluation method has higher accuracy and a significant advantage in speed compared with other machine learning-based methods such as GBDT, DBN, RF, SVM.