###### Abstract
Some examples of these devices are protective relaying devices, load tap changer controllers, circuit breaker controllers, capacitor bank switches, recloser controllers, voltage regulators, etc. However, these devices need to be improved and evolved. As [PERSON] (spokesperson of the DERlab Board DNV GL) explains [3]_\"We have to move to system verification including not only component testing but also component and system interaction\"_. [PERSON] (Craciun) Research Coordinator of DERlab adds [3]_\"The identification of best practices and use cases for laboratory testing of systems and components in a system context is necessary in order to define future testing requirements\"_. Therefore, it can be said that the new \(SG\) will be based on its control elements, the tools that make its operation and maintenance better, better planning and design of existing and future grids, and advanced information from the measure next generation. Considering the above (Smart Grids European Technology Platform, DOE and FutuRed) the four research areas that are the pillars of SGs are presented. These research areas are (Figure 1):  
* Operation and Control: the new future grid (\(SG\)) must support new elements and developments that allow for more dynamic and advanced operation and control. * Maintenance and Lifespan Management: the current and future infrastructure must be properly monitored and managed; this will allow advanced maintenance management. * Grid Planning and Design: the planning of the new future grid must be supported by new advances in planning tools. Thus, the advanced design of new renewable and storage integration scenarios must be undertaken. * Metering: moving from iron and copper to the era of communications means having an advanced measure, therefore, it can be said that the _SG_ needs (as a priority) an advance in communication and measurement systems. In order to develop the areas of Figure 1, new technological advances based on software, hardware and new materials must be implemented in the SG. In addition, these advanced electrical grids must incorporate elements of Artificial Intelligence (AI). Advances in software development must be complemented with the development of new hardware (power electronics and active distribution among others). The aforementioned must rely on the development of new materials and sensors, which should be integrated into the SG. Therefore, the four areas of research are based on the technologies shown in Figure 2. Each research area of Figure 1 may belong to one or more of the technologies presented in Figure 2.  
Figure 1: Research areas of SGs. The arrows indicate that all areas are interrelated, since SG can serve information from one area to another. Figure 2: Technology to be developed for research areas of SGs. From the explanation in this introduction, the review presents the algorithms, materials, devices and others paradigms applied to SGs, classifying the works according to the four areas of research. According to the author, this classification has been made after a grouping exercise of the works found in recent years. In this work, the author will present 316 scientific works. The review is divided into the following sections: Section 2 shows the work of Operation and Control. In this section we have selected works grouped in the following areas: Advanced Electrical Equipment, Communications and Automation, Fault Detection, Replacement and Quality of Service (QoS), DERs, Operation Support Tools and Connection to the Control System, Integration of Applications; Section 3 presents the works of Maintenance and Lifespan Management. In this section, we have selected works grouped in the following areas: Developing the Means that Enable Signals to be Digitally Acquired, Maintenance based Asset Lifecycle Management and Advanced Decision-Making Systems; Section 4 introduces the work of Grid Planning and Design.