Simulation and investigation of load shedding algorithms for a real network using dynamic modeling

Load shedding schemes are important and powerful tools in the present day power systems to maintain system stability. They have become quite important in present day systems, where there is a lack of adequate spinning reserve margin and a shortage of tie line capacity to make up for the lost generation. Loss of system major sources or loss of critical interconnections could cause mismatch between system load and generation. Static analysis has been widely used for designing under frequency load shedding schemes. In this manner all of the system is considered as a single mass and the inter machine oscillations, transmission system, governor and AVR response and load modeling are not considered. Optimization of load shedding schemes performance depends on power system dynamic characteristics as well. In this paper several conventional and dynamic load-shedding schemes are examined and compared. Due to the importance of load modeling on dynamic studies, different software has also been developed. This software could be used to model system loads, induction motors and static loads which are dependent on voltage and frequency.