A monitoring system for obtaining high-quality one-second spaced PV maximum power and solar radiation measurements

A major concern with future high penetration PV levels is the impact on electric utility power distribution systems due to abrupt changes in power generation caused by cloud shadows and the resulting voltage flicker. The time period of interest in this phenomenon is seconds. This paper describes the process used to obtain GPS time-stamped 1-second spaced maximum panel power output and solar radiation estimates from a data logger controlled system. The key is to operate the system quickly during each repetitive 5-second period, taking a string of measurements and sweeping the test panels current-voltage curve, and then using cubic splines to compute high-quality estimates at integer 1-second spaced intervals.