Flicker measurement
Voltage quality - Fluctuations and flicker

For the case of regular voltage variations in steps of equal depth, which gives the most penalizing flicker, the curve in figure 3 shows the tolerable amplitude of the steps as a function of the number of steps per minute. A rectangular variation corresponds to two steps (one step in one direction, followed by one step in the other).

Document [2] gives the correction factors for the various possible forms of jerk. For jolts whose voltage amplitude envelope varies sinusoidally, triangularly, trapezoidally,...