Computing the energy and the momentum in smart grid

Modern energy grid monitoring tools use data from different nodes on a daily basis and under system contingencies. The asynchronous data retrieval modality does not provide accurate and timely difference information from pairs of nodes on the network. The synchronous data retrieval at very high data rates is not yet achievable in smart grid. The simultaneity is not an absolute property between events, but depending on the frame of reference. What is simultaneous in the physical media of smart grid (one frame of reference) will not necessarily be simultaneous in the cyber component (another frame of reference). This paper analyzes the role of true measurements in space-time. It proposes a special modality to cope with the off-nominal frequencies issue.