Voltage and var control to enable high penetration of distributed photovoltaic systems
Yuan Liao, Wen Fan, Aaron M. Cramer, Paul A. Dolloff, Zongming Fei, Meikang Qui, Siddhartha Bhattacharyya, L.E. Holloway, Bob Gregory · 2012
Increasing utilization of renewable energy will reduce reliance on fossil-fuel-based generation and reduce greenhouse gas and pollutant emissions, benefiting the environment and economic growth. However, the intermittent nature of renewable energy sources such as photovoltaic (PV) and wind energy systems imposes great challenges on power system voltage and reactive power control. This paper presents a novel solution based on Cyber-Physical System (CPS) design principles that removes this technical barrier so that more renewable energy sources can be deployed and integrated into the power grid. This paper focuses on solar power integration and control, but the proposed solution is expected to be also applicable to integrating other intermittent renewable energy sources such as wind energy. Camera and weather stations will be installed to capture weather data. The solar generation in a future time horizon will be estimated. An intelligent algorithm is then applied to maintain the required voltage levels. Proper communication schemes will also be designed to ensure interoperability and security of the CPS. This paper presents the overall framework of the proposed solution, designs of the major components of the system, and preliminary results.