Energy storage inverter response time

The fast frequency response (FFR) of inverter-based resources is an important mitigation option for maintaining grid security under the conditions of low inertia and insufficient primary frequency response capability. However, the understanding and technical characteristics of the FFR of inverter-based resources are still unclear.

. The value of energy storage systems (ESS) to provide fast frequency response has been more and more recognized. Although the development of energy storage technologies has made ESSs technically feasible to be integrated in larger scale with required performance

Energy storage systems (ESSs) are becoming key elements in improving the performance of both the electrical grid and renewable generation systems. They are able to store and release energy with a fast response time, thus participating in short-term frequency control.

Here, both inverters are set to an active power reference of 30 kW and a reactive power reference of 5 kVAR. Note that the initial battery charge levels are set to 80% for the first and 50% for the second battery to allow evaluation of the inverter's capability to disconnect a battery as it approaches its lower SoC limit.

The proposed approach utilizes a droop control strategy to adjust the reference power of the BESS-fed inverter, potentially enhancing the battery's cycle life, state of health, and remaining useful life by managing the SoC [27, 28].

Step changes in the inverter's reference power show the strategy's quick adaptation to reactive power demands, while maintaining a stable active power supply. Furthermore, active power control disconnects the BESS when it approaches its lower SoC limit in a near-depleted battery scenario.