Voltage Profile Improvement Employing a Synchronous Distributed Generator: A Case Study of Thailand's Distribution Network

The high penetration of distributed generators (DGs) poses several challenges for distribution networks, including issues such as reverse power flow and voltage deviations. In response, this study presents a potential method of enhancing the voltage profile within distribution networks managed by the Provincial Electricity Authority (PEA) in Thailand. To address these challenges, a very small power producer (VSPP) acting as a DG can be deployed to operate in a voltage control mode to compensate for reactive power and stabilize the voltage across the distribution network. This study focuses on a specific 22kV distribution network, known as the U-thong substation, Feeder 7 (UTG07), performing simulations using DIgSILENT PowerFactory software. Simulation scenarios are designed to reflect both normal power flow conditions and instances of reverse power flow, where electrical energy flows back toward the substation. When controlling the VSPP using voltage control mechanisms, the simulation results demonstrate improvements in the distribution network's voltage stability, as evidenced by enhancements in the voltage profile index. Furthermore, this method shows promise in reducing energy losses within the distribution network.