Integration of ESS with Renewable DC Micro grids
01 Sep 2021
Renewable energy based micro grids are emerging as a viable solution for isolated rural areas or oceanic islands. The main issue which plagues its development is the variable/intermittent nature of renewable sources, which makes it tough to achieve smooth operation. Such fluctuation may lead to load imbalance, instability, and damage to system components under the influence of varying loads.
In such a scenario,
ESS systems assume significance because of its capability to act as a generator while discharging and as a load, while charging. The popularization of DC loads has shifted the focus to DC micro grids. Below figure-1 explains the importance of
ESS systems, or more particularly,
battery-based ESSs in the distribution network with majority DC loads.
Figure-1: Distributed micro grid integrated with ESS
In any AC micro grid, power from renewable energy based sources should be converted to AC and then back to DC to supply DC loads.
DC micro grid prevents multiple conversions between AC and DC and enhances the efficiency of the whole grid.
An ordinary, simple ESS system is homogeneous which makes the implementation, operation, control, and maintenance easier. Figure 2 depicts a typical architecture of such a system.
Figure-2: Typical architecture of ESS based system
The basic architecture consists of an interfacing power converter (connected to a power source, conventional or non-conventional) and a load (AC/DC) supplying output converter which is controlled by a supervisory controller. The operation of the controller is dispatched from an energy management system (EMS).
