Abstract :
The requirements for improvement in the stability of electric power systems and reduction in the effect of short circuit faults or other abnormal system conditions on sensitive customers can be met only by optimised configuration of the different protection and control systems at the transmission and distribution system level. The definition of requirements for protective relays performance, the possibility for adaptive protection applications in case of dynamic changes in the system configuration and the need for special remedial action protection systems are based on the use of advanced analysis tools. They model the primary and secondary components of electric power systems and analyse its operation under normal or abnormal conditions. The accuracy of the different simulations is determined to a great extent by the accuracy of the models. The paper describes different types of protection related analysis tools: • Short Circuit and Protection Co-ordination • Dynamic Stability • Electromagnetic Transients 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. The wide spread use of distributed generation in distribution systems introduces a new level of complexity of the modelling. This is due to the fact that the different types of distributed resources (Reciprocating Diesel or Natural Gas Engines, Microturbines, Combustion Gas Turbines, Fuel Cells, Photovoltaics (PV) and Wind Turbines) have different behaviour under different abnormal conditions. The recording capabilities of multifunctional IEDs are described and different recording modes are identified and proposed for specific needs. The architecture of a distributed system for recording system disturbances is presented. Requirements for time synchronisation of multifunctional IED located throughout the system are discussed.
