Conventionally,a ‘grid’ is an electromechanical system that provides one-way communication ofelectricity from the generation station to the consumers. This paper introducesthe concept of two-way communication of electricity using a ‘smart grid’. A’smart grid’ uses a sensor networks to collect data and is programmed to act onits own based on the data collected without requiring human intervention.
Theidea of Smart Grid(SG) was introduced to improve energy efficiency andreliability with the capability of self-healing (in case of natural disasters).A SG is divided into three major systems. The first is a ‘Smart Infrastructure’that is the system that enables for the two-way flow of electricity andinformation from the sensor networks. Like the classical power grid, the Smartinfrastructure is divided into Power Generation, Transmission and Distribution.The smart energy subsystem consists of the power generation, transmission anddistribution. At the generation side, a concept of distributed generation(DG)is introduced to account for the power generated by the consumers usingdistributed generation resources such as solar panels, wind turbines etc. Largedeployments of DGs lead to a decentralized power system that enhances thereliability.
Transmission in SGs involve control centers, smart powertransmission networks and smart substations, that are built on the existingones to control, visualize, analyze and monitor the SG. At the distributionend, electricity may be delivered as packets that contain information of theelectricity that is to be distributed. Deployment of DGs also promotes theconcept of ‘microgrid’, which is a local grouping of electrical generations andstorage of energy.
The concept of microgrid is to be connected to macrogrid butcan be isolated during the generation stage locally. Another concept thatemerges from the SG is the ‘Vehicle to Grid’ and ‘Grid to Vehicle’ with themodern world developing more electric vehicles(EV). EVs can communicate withthe grid when parked. The future work in ‘Smart infrastructure’ are ineffective utilization of the renewable energy sources, utilization of G2V andV2G concept from EVs, large deployment of SGs.
Thesmart information subsystem mainly is divided into smart metering and smartmonitoring and management. The smart meters the measures the consumption ofusers and also connects and disconnects based on the usage of consumers. Italso acts as support system for two-way communication between central systemand meter. The information exchanged is used to regulate power flows.
The smartmonitoring and measurement system consists of sensor networks and Phasormeasurement units. Sensor networks are embedded into the power grid thatcontinuously assess the condition of the grid and transmission lines. The datais collected in real time and appropriate control measures are taken to when asituation such as a power failure occurs. With all the advantages, the sensorsmust be calibrated appropriately and maintained remotely with high security toprevent hacking. The Phasor measurement unit(PMU) determines the health of anelectrical grid by measuring the electrical waves. Since, there is a delaybetween the power generation and reaching the consumer, phasors play animportant role to measure the heath of the system.
PMUs are mainly used forgrid protection and health maintenance of the power system. The informationobtained from these sensor networks, PMUs and smart meters need to be managedefficiently. The task of information management systems is to model the dataobtained, analyze the data and find optimal solutions for the system based onthe information obtained.Thesmart communication subsystem mainly consists of wired and wirelesstechnologies. Wired technology is mainly fiber optics and powerlinecommunications. Fiber optics is used for its high bandwidth and reliability. Powerlinecommunications(PLC) is used in the modern day of remote metering and loadapplications.
Wireless technology consists of cellular communication, wirelessmesh network, radio communication, satellite communication and opticalcommunication. Wireless mesh networks are used for increased reliability andhigh data rate. Radio communications is carried out in antennas and providereliability and latency in coverage. Mobile communications are used to remotelymonitor using mobile phones. Satellite communications is also used for remotemonitoring and coverage of a wider area but has a delay issue. Opticalcommunication is more secure way of transmitting information but has adisadvantage of getting blocked or disturbed by obstructions in between theline of sight.The’Smart Management System’ that manages the ‘Smart Infrastructure’ by regulatingthe norms based on demand and improve the efficiency.
The management objectivesare energy efficiency, utility cost and emission control. Energy efficiencymainly focuses on managing demands and reduce energy losses. Utility costfocuses improving utility quality while increasing profit and reduce cost ofutility. Emission control is used to reduce the emissions of CO2 caused byelectricity generation. The managements methods and tools involve optimization,machine learning, game theory and Auction. Mathematical tools such as convex,dynamic, stochastic, robust and particle swarm programming concepts are used tooptimize problems quickly with the limitations of the system.
Machine learningalgorithms are used to train the system to emulate human behavior and predictfuture trends based on the data collected. Game theory is used to analyze andaccount for differential pricing and marketing trend. Auction can be used in futurewhen users have their own microgrids.Thethird is the ‘Smart Protection System’ that acts as a backup plan if theexisting system fails due to some reason (such as natural disasters). The Smartprotection system provides reliability and contains failure protectionmechanism. System reliability comes into picture when DGs get deployed into thesystem. Failure protection mechanism mainly consists of prediction andprevention mechanism and failure identification, diagnosis and recovery. Sincemachine learning is used to predict future behavior based on the data obtained,preventive measures can be taken before a disaster (such as blackouts) can beavoided.
In case a failure occurs, wide deployment of PMUs on the SGs can beused to check for phasors, network parameters and error identifications.Self-healing capabilities of the SG are introduced by dividing into microgridsthat function independently. Securityand Privacy is another aspect of ‘Smart Protection System’ to prevent hackingof the system.
Smart meters must be provided with security to prevent fromhackers to manipulate meter readings and data. Individual meter privacy alsoshould be maintained to prevent other users to study the trend of data. Also,since data is transmitted at every instant, the transmitted data also should beprevented from malicious attacks. Various protocols and intrusion detectionmechanisms are used to protect and prevent against attacks. Supervisory Controland Data Acquisition(SCADA) systems are used to monitor the SGs, with the dataobtained from different grids in the system and control the SGs from a centralstation.WithArtificial intelligence gaining a steady growth in the modern day, theimportance of smart grid is also increasing. This article provides a summary ofthe smart grid and the different system partitions. Though it has a lot ofadvantages, many aspects are to be considered for practical use of the smartgrid system.
Firstly, due to large initial costs, the deployment of the SGsshould be analyzed and should be done efficiently. Secondly, the SG being acomplex system, experienced information and communication technology sectorsare required for accurate analysis. Thirdly, with all the advantages, the SGshould be widely accepted by the customers. Initiatives should be taken tocreate awareness among customers to opt for Smart Grid Technology.
Fourthly,the protection becomes another important perspective. Security is generallycompromised to increase the profit and reduce the costs. In summary, Smart Gridis an environment friendly, reliable and revolutionary technology. However, topractically deploy these, improve the technology to be safe from maliciousattacks and completely make it self-capable is a farfetched agenda.
