A Novel Energy Balancing Considering Periodic Behavior Pattern of Power System

Renewable Energy Sources (RESs) such as wind and photovoltaic are environment-friendly energy sources for power generation. However, the largely varying output energy of RESs is a major obstacle to their integration into the power grid. In addition, variations in consumer activity increase the risks of power fluctuations. The ability of power systems to deal with power fluctuations caused by renewable sources and dynamic demand has to be improved to keep the stable operation of a power system. This paper proposes a novel robust energy balancing concept to reduce energy imbalance due to the mismatch between fluctuating generation and demand. The proposed concept targets the long-term operation of a power system and aims to guarantee its safe operation under any dynamic fluctuations of RESs and demands. The key ideas behind this concept include the periodic power level patterns of fluctuating sources and loads, and their upper bound envelops and lower bound envelops, which enable us to analyze the long-term system behavior by the analysis of one cycle operation. The extracted non-trivial upper bound envelops and lower bound envelops provide us with a novel interpretation of the collaboration between storage systems and controllable sources/loads in power balancing, as well as their minimum sizes.