Integration of Distributed Generation in the Volt/VAR Management System for Active Distribution Networks

This paper investigates the use of voltage source converter interfaced distributed generators (DGs) for reactive power support in active distribution networks. Integration of DG management systems into decentralized parts of the Volt/VAR management system is proposed. The solution is designed to address issues connected to increased DG penetration, while at the same time avoiding the technical challenges and high costs related to state-of-the-art model-based Volt/VAR management. Coordination of DGs with conventional voltage regulation equipment is based on predefined control hierarchies. However, to reduce requirements for data handling capability, the distribution grid is divided into zones with individual voltage regulation and reactive support schemes. To add flexibility and scalability, these zones can be combined into larger zones with a common Volt/VAR management scheme. This is referred to as adaptive zoning. The results indicate that the control schemes successfully restore voltage to within limits after disturbance of grid conditions. Adaptive zoning effectively reduces system complexity and requirements for data handling capability, while still ensuring a grid-wide solution.