  As a core device of energy Internet, the energy router is deployed to manage
energy flow between the renewable energy and electric grid. In this paper, a
hierarchical structure of grid energy router is proposed to greatly facilitate
peer-to-peer energy sharing among energy routers. It can be placed at critical
buses to make active distribution networks develop into multiple interconnected
prosumer-based autonomous systems. To alleviate the mismatch between the
medium-time dispatch and device-level control caused by the forecast error of
distributed generation, a bi-level primary energy dispatching strategy is
proposed to fully utilize the energy buffer of multiple grid energy routers.
The power variation in short-time scale is well suppressed by sharing energy
buffer in the upper-level control, and the energy buffer is further optimized
to better absorb the variation. Combining measured information, the lower-level
control is designed to track the optimized instruction of energy buffer in
real-time scale, which is a distributed process. The power flow constraint is
assumed to be handled by medium-time dispatch, and the current constraint of
the device is only taken into consideration. Finally, simulation results
demonstrate the effectiveness of proposed hierarchical structure and primary
energy dispatching strategy of the grid energy router.
