NewSART automatic voltage and reactive power regulator for secondary voltage regulation: Design and application

Secondary Voltage Regulation (SVR) is part of the hierarchical control system of EHV transmission network, currently operated by the Italian Independent System Operator. SVR is being actuated using automatic voltage and reactive power regulators, named SART, in power stations rated more than 100 MVA. Each SART receives from the Regional Voltage Regulator a reactive level signal and implements it by controlling the reactive power of plant generators, in a balanced way. In this paper, hardware and software architectures of the SART version developed by the authors (NewSART) are presented. NewSART implements control and communication functions using an open-source Real Time Operating System installed on an industrial PC. Such a platform takes advantage of the availability of high-level development tools and complete communication software libraries. The paper presents the design and principle schemes of the NewSART, along with experimental results of tests carried out during a SVR commissioning campaign.