A survey of protection, automation and control systems in the Portuguese Distribution Substations

In terms of cost reduction and productivity improvement, the protection, automation and control systems of Portuguese Distribution Substations have experienced major developments during the last three decades. Those changes aimed to increase the quality of service, financial performance, flexibility, reliability and more capacity to monitor and control all the primary equipments of a substation. The trend of the Substation Automation System (SAS) is established using multifunctional Intelligent Electronic Devices (lEDs) and advanced communication technologies to provide a more effective locally and remotely substation monitoring and control. The key objectives for designing substation architecture are interoperability between lEDs and long term stability. So that, the International Electrotechnical Commission (IEC) has developed and released standards for substation automation (i.e. IEC 61850 standards). These standards define the substation Ethernet Local Area Network (LAN), plant and equipment models and support communication services. This work presents a survey of the past and present trends in protection systems, automation and control systems in Portuguese Distribution Substations.