IEEE Electrification Magazine / MARCH 2022 49 50.8 50.7 50.6 50.5 50.4 50.3 50.2 50.1 Frequency By Phase V12 Frequency By Phase V23 Frequency By Phase V31 6 5 4 3 2 1 Inertia Response FCAS Response Active Power Total (a) (b) 50.28 50.24 50.2 50.16 50.12 50.08 100 50 Frequency By Phase V12 Frequency By Phase V23 Frequency By Phase V31 -50 -100 Waveform l1 Waveform l2 Waveform l3 (c) (d) Figure 13. A positive RoCoF event shows the inertial response from the Dalrymple BESS. (a) The 8-s frequency view. (b) The 8-s active power view. (c) The 300-ms frequency view. (d) The 300-ms current waveforms. (Hz) (Hz) (A) (MW) 6:05:17 p.m. 6:05:18 p.m. 6:05:19 p.m. 6:05:20 p.m. 6:05:21 p.m. 6:05:22 p.m. 6:05:23 p.m. 6:05:24 p.m. 6:05:17.700 p.m. m. 6:05:17.750 p.m. m. 6:05:17 p.m. 6:05:17.800 p.m. mm. 6:05:17.850 p.m. mm. 6:05:17.900 p.m. mm. 6:05:21 p.m. 6:05:17.950 p.m. mm. 6:05:22 p.m. 6:05:23 p.m. 6:05:24 p.m. 6:05:17.700 p.m. 6:05:17.750 p.m. 6:05:17.800 p.m. 6:05:17.850 p.m. 6:05:17.900 p.m. 6:05:17.950 p.m. 6:05:18 p.m. 6:05:19 p.m. 6:05:20 p.m.