Triggering Bess Inertial Response With Synchronous Machine Measurements

Synthetic inertia devices must deliver power during maximum RoCoF, which is observed to occur during the first 500 ms post fault. The use of a droop characteristic with a deadband is demonstrated to be unfit for purpose. The ideal response (with present technologies) is demonstrated to be a maximum power ramp in minimum time post fault. This paper demonstrates a method of rapidly detecting and categorizing under frequency events by monitoring synchronous machines. PMU and point on wave data, sampled at 6.4 kHz, from a power station and a laboratory set up, under transient events, is presented. A rapid inertial power ramp signals the onset of the events. Sub-cycle voltage and current variations are demonstrated as a potential method for reliably detecting frequency transients and triggering a synthetic inertia response.