Reliability in Smart Grids with Energy Storage Systems

Abstract

A reliable supply of electricity with the requisite high quality to industrial consumers, in particular, is essential for society’s continued development and welfare. The standard DIN 40 041 defines reliability as an entity’s quality in terms of being able to meet the demand for reliability during or after specified time intervals and under specified conditions of use. The electricity supply is considered to be reliable when it continuously meets customer demand (just-in-time), and this must be so while the complete system of primary-energy production, conversion, transport and distribution are always necessarily factored in. Various malfunctions or events characterized by their intensity (insufficient energy) and duration also affect the security of supply in various ways, e.g. affecting varying numbers of consumers. Causes of malfunctions are external, e.g., storms and lightning strikes, terrorism or solar winds, or internal, e.g., planning and design errors or operational errors such as overloaded system components, short circuits caused by incorrect operation, switching surges, and have various points of origin. Statistical data on this are plotted in unavailability graphs, see, e.g., Fig. 8.1. Malfunctions that go undetected or cannot be assigned to any of the predefined groups/criteria are placed under the category “no identifiable cause” [1].