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An introduction is presented in which the author discusses several topics including power quality aspects associated with solar photovoltaic systems, modeling and analysis of grid connected power electronic interface, and flicker meter accounting for different lamp technologies.

The voltage rise of the low voltage (LV) power distribution grid to which multiple solar photovoltaic (PV) systems are integrated is a critical technical problem that should be addressed. With PV systems that are integrated to the LV power distribution grid (with an R to X ratio greater than unity) via voltage source converters, the opportunity exists to regulate the respective point of common coupling (PCC) voltages by dynamically controlling the active and reactive power response of PV systems. In this paper, two closed-loop controllers that are able to regulate the PCC voltage by dynamically controlling the active and reactive power response of the PV system are presented. The design methodology is presented with considerable detail. The plant model of each controller is derived and the design procedure of each controller is explained in detail. By combining the dynamic active and reactive power controllers proposed in this paper, two novel operating strategies for PV systems, fixed minimum power factor operation and fixed maximum apparent power operation, are introduced. The latter operating strategy has been identified as the most efficient way of regulating the PCC voltage of a PV system. The simulation results and experimental validation confirm the accuracy of the derived plant models, the robustness of the designed controllers and the feasibility of implementing the proposed novel operating strategies in PV systems. [ABSTRACT FROM AUTHOR]

Power generation through solar photovoltaics has shown significant growth in recent years. However, high penetration of solar PV creates power system operational issues as a result of solar PV variability and uncertainty. Short-term PV variability mainly occurs due to the intermittency of cloud cover. Therefore, to mitigate the effects of PV variability, a sky-image-based, localized, global horizontal irradiance forecasting model was introduced considering the individual cloud motion, cloud thicknesses, and the elevations of clouds above the ground level. The proposed forecasting model works independently of any historical irradiance measurements. Two inexpensive sky camera systems were developed and placed in two different locations to obtain sky images for cloud tracking and cloud-based heights. Then, irradiance values for onsite and for a PV site located with a distance of 2 km from the main camera were forecasted for 1 minute, 5 minutes, and 15 minutes ahead of real-time. Results show that the three-level cloud categorization and the individual cloud movement tracking method introduced in this paper increase the forecasting accuracy. For partially cloudy and sunny days, the forecasting model for 15 min forecasting time interval achieved a positive skill factor concerning the persistent model. The accuracy of determining the correct irradiance state for a 1 min forecasting time interval using the proposed model is 81%. The average measures of RMSE, MAE, and SF obtained using the proposed method for 15 min forecasting time horizon are 101 Wm-2, 64 Wm-2, and 0.26, respectively. These forecasting accuracy levels are much higher than the other benchmarks considered in this paper. [ABSTRACT FROM AUTHOR]