OPTIMAL SIZING, SITING, AND SCHEDULING OF BESS FOR MITIGATINGVOLTAGE PROBLEM IN DISTRIBUTION UTILITIES WITH HIGHPENETRATION OF PV ROOFTOPS

Abstract

For ambition of reducing CO2 emission and reliance on fossil fuels, solar power generation has been received special supports and deployed rapidly in many distribution networks. However, with a high presence of solar power generation, power grid control is no longer simple as conventional one due to natural variation of solar power and large space dispersion of solar power systems. The negative impacts comprise power system stability, electric power quality involving frequency and voltage criteria and other potential issues. Among these impacts, voltage problem is most obvious. Many solutions have been proposed to solve the voltage problem whereas battery energy storage system (BESS) exhibits technically dominant capability in comparison with other ones. However, the price of the battery is, currently, still high, strategies to minimize the operation cost are necessary. This dissertation investigates the BESS, the selected solution for mitigating voltage problem in LV network caused by high penetration of PV rooftops. Two optimal strategies of BESS are proposed to help utilities minimize their operation cost. These strategies cover sitting and sizing of BESSs which is used for long-term planning and scheduling of the installed BESSs for operation planning. Cost evaluations consider aging degradation of the BESS and some additional cost such as O&M cost and so forth. The effectiveness of the proposed methods is demonstrated on a simplified network of Metropolitan Electricity Authority (MEA), Thailand, using Matlab 2016a and Matpower 6.0.