Demonstration of an inertia constant estimation method through simulation

The inertia constant of a system describes the initial, transient, frequency behaviour of that system when subjected to a real power disturbance. Therefore, the inertia constant of a system can be a useful tool when investigating the frequency stability of a system. The use of the swing equation is a viable method for estimating the inertia constant, if a measurement system that can provide time stamped measurements of the frequency and power dynamics during a disturbance is available. An example of such a system is a Wide Area Monitoring system that is capable of monitoring the frequency at all, or a select set, of generation sites. A method for estimating the inertia constant based on this data is developed and demonstrated for two simple networks. This demonstration is performed using computer simulations in the DigSILENT PowerFactory software package. The inertia constant estimation method is implemented in the MATLAB environment.