Research On Online Assessment And Decision System Of UFLS Based On Real-time Load

Since a period of time, UFLS scheme is mainly depending on the meeting to determine the direction and the artificial calculation to determine, supplemented by off-line simulation and verification. In recent years, constantly expanding the scale of power system, power network structure complexity increases apparently, to maintain power system frequency stability, avoid the happening of blackout appears extremely important.Low frequency load shedding frequency emergency control is one of the most effective measures, is the security and stability of power system the third line of defence.Therefore, the scheme of low frequency load shedding is reasonable and affirmatory with further research, we need to develop low frequency load shedding online evaluation and decision system, strengthen the tools of computational accuracy, enhanced real time verification scheme of low frequency load shedding validity and feasibility, enhances the development scheme of low frequency load shedding management level, and for the power grid configuration strong and reliable third defense.This paper discussed the modern power system frequency dynamic characteristics as well as Underfrequency Load Shedding Scheme specific setting method, and based on this, developed to adapt to Tianjin grid structure scheme of low frequency load shedding calculation software. The system software from the EMS dispatching automation system and centralized UFLS device acquires the real-time observation data, low frequency on-line calculation and scheme of setting calculation(Tangential load ratio or capacity). Its main function is to Tianjin power balance work on-line monitoring, on-line setting, package released and the diversification of plan report management. Software consists of system database to establish a data conversion and input, frequency computation and analysis, as well as the load shedding scheme optimization modules, can according to system parameters and running requirements given the optimal scheme, with a minimum amount of load shedding in the shortest possible time to make the system frequency returned to normal.The system software is intuitive and friendly interface, flexible and convenient use, and has strong calculation function.Effectively alleviate the power state of insecurity of supply and demand, realizing the safe, orderly, harmonious, saving electricity and comprehensive emergency state power, to ensure the production and life of orderly use of electricity.