  Traditional power system frequency dynamics are driven by Newtonian physics,
where a synchronous generator (SG), the historical primary source of power,
follows a deceleration frequency trajectory upon power imbalances according to
the swing equation. Subsequent to a disturbance, an SG will modify
pre-converter, mechanical power as a function of frequency; these are reactive,
second order devices. The integration of renewable energies is primarily
accomplished with inverters that convert DC power into AC power, and which
hitherto have employed grid-following control strategies that require other
devices, typically SGs, to establish a voltage waveform and elicit power
imbalance frequency dynamics. A 100\% integration of this particular control
strategy is untenable and attention has recently shifted to grid-forming (GFM)
control, where the inverter directly regulates frequency; direct frequency
control implies that a GFM can serve power proactively by simply not changing
frequency. With analysis and electromagnetic transient domain simulations, it
is shown that GFM pre-converter power has a first order relation to electrical
power as compared to SGs. It is shown that the traditional frequency dynamics
are dramatically altered with GFM control, and traditional second-order
frequency trajectories transition to first-order, with an accompanying
decoupling of the nadir and rate of change of frequency.
