###### Abstract  
New technological advances based on software, hardware and new materials must be implemented in smart grids. In addition, these advanced electrical grids must incorporate elements of artificial intelligence. 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 smart grid. Therefore, the four areas of research based on the technologies are: Operation and Control, Maintenance and Lifespan Management, Grid Planning and Design, and Metering. The review presents the algorithms, materials, devices and others paradigms applied to smart grids, classifying the works according to the four areas of research. This review has focused on the four fundamental pillars of smart grids, on the one hand, the need for more efficient operation and control, followed by advanced maintenance management, to continue planning and designing the new grids, and for conclude with the advanced measurement. As you will see in the article, new devices, new techniques, and future scenarios will make possible the transition from the current grid to the future smart grid. s 2019 12 1630 10.3390(en12091630)10.390(en12091630)10.390(en12091630)10.390(en12091630)1  
* Disturbances can be corrected due to the technologies on the electric transmission system (e.g., using a phasor measurement unit, PMU). This technology allows measurements in real time throughout the entire electrical system.Supply cuts are less frequent, and this is achieved by the implementation of new generation switches and advanced sensors. * Voltage regulation is being guaranteed within limits by means of new solutions from capacitor banks and other emerging technologies. * The implementation of Smart Meters (SMs) improves the operation of the electrical system, and provides savings to utilities. SMs are Advanced Metering Infrastructures (AMIs), which allow one to measure, collect and analyze the information of a large number of devices deployed in the electrical infrastructure. * Customers are served with a better service. In this sense, demand response (DR) can be understood as the change in the use of electricity by consumers. The changes are caused by numerous reasons, the main one being the hourly incentive of the cost of energy. * Renewable and distributed energy resources (DERs) play a vital role in the SG. The aggregation of small energy sources is DERs, which can be used to satisfy demand or to be associated with renewable systems and storage. Distributed Generation (DG) uses DER, but in points close to consumption, and thus DG breaks with the paradigm of centralized generation. * New scenarios are appearing in the SG landscape. For example, virtual power plants (VPPs) are an integrated system of DG and DERs to guarantee a reliable supply and maximize the economic benefit. The microgrid is a new paradigm of generation and consumption, where the objective is to guarantee the supply to consumers, but trying to maximize the existing resources in the microgrid. * Another scale in which VPP and microgrids appear is the smart building concept. Smart buildings are buildings whose equipment and systems (heating, ventilating, air conditioning, lighting, electricity, security, telecommunications, multimedia, computer, access control, etc.) allow management and control (integrated and automated) in order to increase energy efficiency, security, usability and accessibility. To do so, the infrastructure must be upgraded. For instance, buildings should allow the electrical load/unloading of electric vehicles (EVs). * To achieve efficient and effective operation advanced equipment is needed. The controllers based on microprocessors in the electrical equipment are known as Intelligent Electronic Devices (IEDs).