Development and application of on-line dynamic security early warning and preventive control system in China

This paper presents an early warning and preventive control system for dynamic security, which has been used in several provincial power grids in China. The framework and the main modules of the proposed system are introduced. The system architecture is based on a Multi-agent system which is developed by our team. The modules like on-line contingency assessment, total transfer capacity evaluation, preventive and corrective control schemes etc. are developed in this system. To estimate the forthcoming state´s security level, all these modules also run in the forecasted 15-minutes ahead operating state. And some key technologies, such as PEBS based contingency screen and distributed computing technology, are used to improve the efficiency of the system to accommodate real-time application. Enhanced total transfer capacity calculating (TTC) method are developed which can both calculate pessimistic value and optimistic value of TTC in the same time. The preventive control algorithm is developed which is based on transient energy function sensitivity. Some engineering-oriented methods are also introduced which are used to solve practical problems emerged in real application. In the last part of the paper, some data from a real system in a provincial power grid is introduced.