Publications

Input Signal for Synthetic Inertia: Estimated ROCOF Versus Remote Machine Acceleration

Wilches-Bernal, Felipe; Wold, Josh; Balliet, W.H.

This paper studies the differences in a synthetic inertia controller of using two different feedback measurements: (i) an estimate of the rate of change of frequency from local voltage measurements, and (ii) a remote machine acceleration from a generator nearby to the actuator. The device that provides the synthetic inertia action is a converter interfaced generator (CIG). The paper carries out analysis in the frequency domain, using Bode plots, to show that synthetic inertia control using frequency estimates is more prone to instabilities than for the case where a machine speed is used. The paper then proposes a controller (or a filter) to mitigate these effects. In addition, the paper shows the effects that a delay of the machine speed signal of the nearby generator has on the synthetic inertia control of the system and how a controller is also needed in this case. Finally, the paper shows the difference in performance of a synthetic inertia controller when using these different measurement signals with simulations in time domain a electromagnetic transient program platform.