Verification of system models for steady-state and dynamic security assessment

The requirements for improvement in the stability of electric power systems and reduction in the effect of abnormal system conditions on sensitive customers can be met only by better understanding of the behavior of the system and optimized configuration of the different protection and control systems. The planning, design and implementation of such systems are based on the use of advanced analysis tools. They model the primary and secondary components of electric power systems and analyze its operation under normal or abnormal conditions. The accuracy of the different simulations and the assessment of steady-state and dynamic security is determined to a great extent by the accuracy of the models. The paper describes different types of system security related analysis tools: short circuit, protection coordination and dynamic stability. The models of power system equipment and the requirements for verification of these models in the different types of software are discussed later in the paper. Recording of system parameters during abnormal system conditions and comparison with the results from steady-state or dynamic stability simulations of the same event based on the model system allows the verification of the system models and building confidence in the assessment of possible system disturbances. The recording capabilities of multifunctional intelligent electronic devices (IEDs) are described and different recording modes are identified and proposed for the verification of system models. The architecture of a distributed system for recording of local or wide area system disturbances is presented. Requirements and methods for time synchronization of multifunctional IED located throughout the system are discussed.