A novel automatic voltage control architecture based on the infrastructures in the smart grid

The smart distribution system is one of the most important aspects of the smart grid and will result in systematic update on the distribution side. In smart distribution grid pilot cities of China, much investment on the infrastructure for the smart distribution system has been done. For example, in Xiamen, the IEC61968/61970 based data base has been established and the smart terminal units, such as transformer terminal units, distribution terminal units, feeder terminal units and load control units have been installed. This paper proposes an automatic voltage control (AVC) architecture based on these infrastructures, all of which have been employed in Xiamen. The objective of this architecture is to minimize the distribution losses by coordinating the on load-tap changer (OLTC) and the capacitor banks. In this paper, the data base, the data communication mechanism and the related terminal units for this architecture are introduced firstly. Then, an optimal power flow (OPF) model for determining the tap position of the OLTC and switching capacitor banks is also formulated. The proposed architecture is verified in a 33-buse system. Scenarios are created to verify the impact of DG on the performance of this architecture. The results show that using the proposed architecture, distribution losses can be reduced by selecting reasonable tap position, operated capacitor banks and DG techniques.