A cloud shadow model and tracker suitable for studying the impact of high-penetration PV on power systems

Field measurements show that rapid cloud movement on solar panels ramps their maximum power output from full power to about one-third of full power in approximately five seconds, and vice-versa. When combined with high-penetration PV, this ramping may introduce the old problem of voltage flicker on distribution feeders. To study the potential flicker problem, this paper presents 1. a cloud shadow model suitable for use in successive loadflow simulations of distribution feeders with distributed PV, and 2. a field testing system to measure shadow speed and heading azimuth angle.