New challenges in the automation of electric power systems

Power system automation included monitoring, evaluation, analysis, and control of processes associated with generation and transmission of electric energy from power stations to customers.1 Three main processes are included: data acquisition, power system supervision and control, all working in a coordinated automatic fashion. Data acquisition refers to collect data in the form of measured analog current or voltages values or the status of devices (open or closed). Power system supervision is carried out through the acquired data either at a remote site or locally at the device site. Control refers to sending command messages to operate power system devices such as circuit breakers. In this communication these concepts are discussed in the context of the chilean electric sector considering the challenges originated by the recent interconnection of the two main electric system SIC and SING and new interconnection projected with other electrical systems. In November 2017 the two main electric systems of Chile, SIC and SING, have been interconnected by a 500 kV transmission system resulting in an interconnected grid with a geographical extension of about 3000 kilometers from south to north of the country. Concerned with the automation, it is expected that several operational challenges will arise due to this interconnection and additionally due to the sustained increase in the generation coming from renewable energies like eolic generators, geothermal and photovoltaic systems, contributing at present with about 20 % of the produced energy. Traditionally the main issues related with the operation of Chilean electric systems have been those concerned with the control of the frequency and voltage for reaching stability of these variables. Power generation plants have systems that control the injected active and reactive power to the network and several FACTS like SVC are operating in the Chilean 500 kV transmission system. However the growth of this electrical system is leading to more requirements in data acquisition, data processing and control systems. Automation in the management of renewable energies is required considering that due to the variability in the available power, they introduce new uncertainties and parameters’ variations into the power grid, so that automation systems are required to connect these generation systems to the network and inject the corresponding energy in a coordinated way.