Supply/demand correlation as an auxiliary variable for smart grid control design

Abstract Stable and efficient operation of a smart grid requires coordination of the actions of many independent decision makers or agents that must cooperate in globally balancing the demand for power to the partly unpredictable and uncontrollable supply. This paper proposes the use of the correlation coefficient between the renewable supply and the (controllable) demand, measured in a given region over a specified time scale, as a performance measure that is imposed on lower level control agents by a higher level controller in order to achieve coordination between the actions of these individual agents. Using elementary calculations for simple distribution networks this paper illustrates that the expensive peak value of power imported from the grid, and the distribution losses, depend linearly on this correlation coefficient. Operational behavior is improved way by achieving a high correlation coefficient. The correlation coefficient they achieve can be used as a measure for determining the rewards control agents should get for their contribution to the ancillary services. Achieving a high correlation coefficient clearly will contribute to the stability of the smart grid. In this paper we briefly discuss some requirements for implementing a coordination strategy based on the correlation coefficients. Broadcasting of signals from a top level in the control hierarchy to the lower layer controllers only is needed.