This paper proposes a system to detect power system events based on relational database in power dispatching automation system and real-time database. With the developed models, the system sharply detects and analyzes abnormal grid events, such as switch trip and shock load. The real-time data is taken into consideration while doing analysis, which makes results more accurate. Taking the tripping of circuit breaker as an example, the process of fast detection of the power grid events is analyzed in detail. The proposed system has been successfully applied in the support system of smart dispatch for power systems in Suzhou. Test results show that the proposed system is able to reduce the working load of operators and can therefore provide a comprehensive protection for the secure operation of power systems. Operation records also show that the developed functions of the system have been running smoothly and can meet the requirements of power system automation of large-scale regional power systems.