100% converter-interfaced generation History of engineering & technology Ornstein–Uhlenbeck stochastic process PMU Technology: general issues active power modulation ancillary services battery energy storage system battery energy storage system (BESS) co-simulation compound poisson stochastic process converter-interfaced generation cyber physical system (CPS) demand response distributed energy resources energy management system (EMS) fast frequency measurement fast frequency regulation forced oscillation frequency control frequency nadir estimation frequency stability grid vulnerability analysis grid-forming inertia estimation inverter-based resources inverter-based resources (IBRs) large perturbation angle stability legacy resources line modelling