Reliability of Smart Grids

Abstract

Smart grid is a term representing an electrical power system, which efficiently deliver sustainable, economic and secure supply of electric energy of required quality to its customers employing innovative products and services together with intelligent monitoring, control, communication, and self-healing technologies. It is realised with the increased use of digital information and controls technology to improve reliability, security, and efficiency of the electric power system including the dynamic optimization of system operations and the distributed resources, with full cyber-security. The term smart grid includes the real-time, automated and interactive technologies that optimize the physical operation of appliances and consumer devices for metering and communications concerning the power system operation and status. It includes the advanced electrical energy storage and technologies including plug-in electric and hybrid electric vehicles. The system is far more complex in many layers compared to the traditional power system and thus brings more and more challenges to its reliable operation. The issues related with evaluation of the power system reliability are reviewed in sense of their applicability for evaluation of future smart grids. Traditional and advanced reliability methods are discussed regarding their use in traditional and in advanced power systems. The focus is placed to those related with the intermittent power generation sources which are more and more distributed. The discussion concludes with some findings including the fact that more reliable systems and subsystems face smaller probabilities of faults, but even rare faults can cause much larger undesired consequences than before because the systems are more and more complex.