An intelligent load and generation shedding procedure in an islanded network using a smart power management system

Abstract

In an islanded power network, the stability of the network is highly vulnerable. In these networks, serious disturbances can easily occur due to different events. Based on this events, imbalance between generation and load demand may lead to overloading or loss of generation cases. In order to overcome to these problems, Load Shedding (LS) is the emergency control action against voltage or frequency instability or even system blackout. An intelligent load shedding scheme and related logics are implemented on smart load management system (SLMS) in order to operate in islanded mode. The important functions of SLMS are Under Voltage Load Shedding (UVLS) and Under Frequency Load Shedding (UFLS) which can play key role in the power system stability. These functions are applied to PLCs (Programmable Logic Controllers) in real power plant. To simulate PLCs' logics and related scenarios, DIgSILENT Programing Language (DPL) is used. In order to investigate frequency/voltage stability in the islanded network, different scenarios (e.g. loss of generation in island mode, loss of grid connection in export/import mode) have been implemented in DIgSILENT PowerFactory software and confirm the efficiency of smart load management system after a severe contingency.