• Voltage Security
• 14-bus System
• 2-bus System
• PV Curve
• Operational Problem
• Overload
• Components Failure
• SEEKS

Security Assessment is a term used to describe the process of ensuring system operating security. Typically, power systems operating in an N-1 condition are considered secure. N-1 means that the system will remain in a secure operating state if any single event or failure occurs. In a secure state all system parameters are operating as desired with all voltages within their specified limits, no power lines overloaded, all loads on line and being provided with power.

Modern power systems are often operated near capacity. During periods of peak demand, power lines may be loaded to near capacity. Operating a power system near capacity requires quick response by operators in the event of an unexpected change in the system operating configuration. Rapid security assessment is needed in order for the system to continue to operate normally when contingencies occur.

As the demand for power increases, existing power grids are being more frequently loaded nearly to capacity. As a result, system operators must rapidly respond to sudden or unexpected changes in the systems operating configuration. For example, wind or lightning may suddenly damage power lines taking them out of service. When contingencies occur, operators must rapidly assess and reconfigure systems if a normal operating state is to be maintained.

Because rapid assessment is becoming increasingly important, expert systems have been developed to assist operators in making decisions regarding security assessment. When sudden changes occur, there may not be sufficient time for operators to run numerous power flow scenarios. This is where an expert system can be very helpful.

An expert system is a computer system that can behave like an expert. In this case, the system will behave like a power system expert. In the event of a failure or sudden change, the expert system can rapidly assess the power system operating condition and provide the operators with a weighted list that indicates which power lines in a network are most critically loaded and which are least critically loaded using a knowledge based approach. This greatly reduces the operators work load and can vastly improve response time. The end result is improved system reliability.