Hybrid Power System Model and the Method for Fault Diagnosis

The power systems become more and more complex for the tendency to be interconnected and large scale. It is very important to detect symptom in the early of large scale blackouts and take necessary precaution measures. The analysis and control of complicated systems can not be completely solved by only mathematic tools or knowledge-based method for the reason that power systems are typical hybrid systems in nature. So we introduce a hybrid method based on hybrid system theory, which can combine knowledge-based methods and model-based methods quit well for system fault diagnosis problems. A hybrid analysis model based on CGHDS (controlled general hybrid dynamical systems) for complicated fault diagnosis of power system is proposed, which covers most important characteristics and behaviors of power systems. The main ideas and procedures of hybrid diagnosis are also discussed in detail. A typical case is tested on WSCC-9. And the results show feasibility and effectiveness of the above approaches

I. Introduction

MODERN power systems tend to be interconnected and much larger in scale. In the meantime the control measures continue to develop. So the efficiency of power system operation and the automation level continue to increase. But the systems become more and more complex: they often consist of multimode subsystems; there are complicated relationships among subsystems of different mode; the information exchanged between subsystems of different mode can be quantitative or qualitative, so far as to fuzzy or stochastic. So the systems have multiple complexities, such as the complexity of behavior and characteristic, the complexity from uncertainty, the complexity from multimode integration and multimode control strategy, et al.