Patent ID: 9705332
Date: 2017-07-11
CPC Classifications: H02J

Claim:
1. A method for controlling a hybrid energy storage system for connection to a power system, wherein: the hybrid energy storage system includes a first energy storage element and a second energy storage element; the first energy storage element is configured to absorb power from a grid and provide power back to the grid; the first energy storage element having a charging/discharging rate such that the first energy storage element is charged and discharged as the first energy storage element absorbs power from the grid and provides power back to the grid, respectively; the second energy storage element is configured to absorb power from the grid and provide power back to the grid; the second energy storage element having a charging/discharging rate such that the second energy storage element is charged and discharged as the second energy storage element absorbs power from the grid and provides power back to the grid, respectively; the first energy storage element and the second energy storage element having a first operational characteristic and a second operational characteristic, respectively, wherein the first operational characteristic is a slow energy storage and the second operational characteristic is a fast energy storage, the method comprising: determining respective desired charging/discharging rates for the first and second energy storage elements in dependence upon state of charge predictions from respective models of the first and second storage elements, using model predictive control; and adjusting respective charging/discharging rates of the first and second storage elements in accordance with the determined rates, thereby exchanging energy between the first energy storage element and the second energy storage element.