The energy storage systems described in this publication are a natural addition to PV solar and wind power instal-lations. They facilitate the integration of renewable energy with the grid by virtue of capacity firming and ramp rate control functions. The end result is more eficient utilization and availability.
Now that we have a simple grid-tied system, let’s build onto it by adding energy storage. Article 706.2 of the 2017 National Electrical Code (NEC) defines an energy storage system as: “ One or more components assembled together capable of storing energy for use at a future time.
The Parker 890GT-B Energy Storage PCS employs a unique modular inverter design for ease of maintenance and service. Output power is handled by replaceable phase modules, which are cooled by Parker’s advanced 2-phase cooling system. Each module contains IGBT power semiconductors, DC bus capacitors, and gate drive circuitry.
As mentioned above, PV modules will produce dc power. That power must be converted to ac to be used in most commercial and residential applications. In contrast, battery cells must be charged with dc and will output dc power. The ac-dc distinction has major system design implications.
In addition to its primary purpose of feeding active power (P, measured in watts) from the battery modules to the grid, the Parker outdoor energy storage PCS is capable of providing reactive power (Q, measured in VARs) when called upon.
During a power outage, the multimode inverter—using power from the ESS—will mimic signals from the grid, allowing the interactive inverter to stay online and the PV array to continue producing power to feed the backup loads panel and charge the ESS with any excess power.