Hierarchical Volt/Var Control Applied to Distribution Systems with High Penetration of PV Generation

Abstract

The operation of distribution systems benefits from an efficient voltage and reactive power control, which nowadays is generally achieved by local and independent actions performed by voltage regulators, on-load tap changer transformers, and capacitor banks. However, the modernization of distribution systems has been accompanied by the integration of a communication infrastructure and new controllable equipment allowing the development of innovative procedures to control the voltage and reactive power. In this context, an alternative is the implementation of an Integrated Volt/Var Control (IVVC), consisting of the integration of voltage and reactive power controls in a centralized structure. This work investigates a hierarchical Volt/Var control methodology that considers the use of both local and centralized controls in a coordinated manner aiming to optimize distribution system operation and overcome the disadvantages of using either of the approaches separately. In this methodology, the centralized control acts when the local control is not enough, overriding its commands. The methodology is tested in a distribution system with photovoltaic generators and considers the use of inverters’ advanced functions into the hierarchical control. The results show that the proposed methodology allows improvements in the performance of the test system operation increasing its efficiency.