Application of electric power alarming and coordinated control system in Jiangsu power grid

With the construction of Ultra-high voltage power networks, the interconnection of regional power systems, and the implementation of power marketing, recently the power grids of China have developed at a fast pace. The security and stability problems of large-scale power networks (LSPN) have become increasingly complicated and incurred increasingly huge risks and costs, and the design and implementation of the emergency plans for power networks have become increasingly difficult. On June 20th 2007, Electric Power Alarming and Coordinated Control System (EACCS), a real-time emergency coordinated control system for large-scale power grid, was successfully put into operation. EACCS has fully utilized a series of international advanced level technological supporting systems, recently built in the Jiangsu power grid corporation, including EMS, Wide Area Measurement System (WAMS), Automatic Voltage Control (AVC) system, and Automatic Generation Control (AGC) system, and it has fully utilized the fiber-optic backbone network and data network, which covers the entire province. Through comprehensive researches, EACCS implements real time early warning, decision-making and coordinated control systems for the security and stability of LSPN, and it can effectively prevent cascading failures in LSPN, which may eventually lead to catastrophes similar to '8.14' US-Canada blackout. EACCS has been carried out in three stages: "Early warning of the security and stability of power grids", "Intelligent decision-making and preventive control" and "Closed-loop control". Under the circumstance that there is no similar international systems for reference, the projects has tenaciously overcome numerous key technological problems for the control of LSPN, including Centralized coordinated hierarchical control (CCHC) of LSPN, Automatic identification of cascading failures of LSPN, Emergency control, Coordinated control, and etc. This online system evaluates and issues early warnings for the security of the real time operations of power grids, and makes real time preventive controls and adjustments. When multiple failures and cascading failures occur in LSPN, it can simultaneously implement emergency control measures to the province's eight power plants with nearly 9000 MW generating units and 21 220 KV substations. EACCS firstly proposed the integrated platform based on EMS, WAMS, AVC and other real time control systems. It implemented monitoring and operations of multiple application systems. It firstly proposed the coordinated control strategy, with multiple objectives including static, transient, dynamic security and stability, etc. It implemented real time quantative evaluation, early warning, preventive control and emergency control for the security and stability of LSPN. It firstly proposed a coordinated defense scheme with CCHC. It implemented hierarchical and sub-area control of LPSN, coordinated defense for entire power network, multiple area operation modes, automatic identification of cascading failures and multiple failur es at various locations, and automatic matching, coordination and online addition of control strategies. EACCS has completely improved the defense capability and comprehensive coordination of the security of LSPN. It has also significantly improved the capacity for the prevention of large-scale blackout, and the accuracy and self-adapted ability of the stability control for LSPN. The security and economy of power grids has been effectively unified.