Regional Decentralized Reactive Power Control for Photovoltaic Generation Systems

• Main Authors: Chun-hao Kuo, 郭峻豪
• Other Authors: Jen-Hao Teng
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/de57sz

碩士 === 國立中山大學 === 電機工程學系研究所 === 106 === A large number of Photovoltaic Generation Systems (PVGSs) interconnected to a distribution feeder may cause the sudden change of feeder voltages and further affect the power supply quality. Therefore, control strategies need to be designed to stabilize the feeder voltages. The commonly used control strategies include fixed power factor method, fixed reactive power method, voltage and reactive power method and so on. These control strategies use smart inverter to control the reactive power of the PVGS to which it belongs. However, when there are several PVGSs installed at different buses of a feeder, all the smart inverters operated at the same time due to over voltages may cause the phenomenon of voltage swing and therefore increase the sudden change of feeder voltages. A regional decentralized reactive power control for PVGSs is proposed in this thesis. With the proposed control strategy, an inverter is treated as an Intelligent Electronic Device (IED) and IEC 61850 and Generic Object-oriented Substation Events (GOOSE) are integrated into the inverter. Decentralized power information exchanges of PVGSs in a region of the feeder can then be realized. The sensitivity relations between reactive powers and bus voltages are also derived in this thesis to accomplish reactive power control. The specific characteristic of proposed control strategy is that the PVGSs in a region can be controlled in a decentralized manner. The power information exchanges are carried out before the reactive power control. After the communication was coordinated and power information was exchanged by GOOSE, the reactive power of PVGS inverter with the maximum over voltage will be adjusted. The voltages of regional PVGSs will be recalculated to decide whether to execute the next adjustment. The procedure will continue until the voltages of all PVGSs are under the upper voltage limit. The regional decentralized reactive power control strategy proposed in this thesis cannot only prevent the sudden change of feeder voltages due to the inverters operated at the same time, but also avoid the voltage quality problem caused by PVGSs.