The Energy Independence and Security Act of 2007 outlined the need to modernize the U.S. electricity transmission and distribution systems, helping to coin the term “Smart Grid.”
The criteria used to define the Smart Grid included a system that is self-healing from power disturbances, one that enables active participation by consumers, that is resilient to physical as well as cyber-attacks, which enables new products and services, that accommodates all generation and storage options, and that achieves operational efficiency.
(Learn more about IEEE Smart Grid.)
The Internet of Things (IoT) in its most simplistic state is the network of physical devices and is what enables a power grid to achieve the ideals of a smart grid. IoT gained traction after the development and deployment of Internet Protocol version 6 (IPv6). It was with IPv6 that the ability to deploy, monitor, and control an ever increasing amount of physical devices over the World Wide Web became possible, alongside the ability to create a smart grid.
Internet Protocol version 6 (IPv6)
The development of Internet Protocol version 6 (IPv6) by the Internet Engineering Task Force (IETF) alleviated concerns with the exhaustion of available IP addresses and also offers built-in security functions. IPv6 uses a 128-bit address which was designed to replace the 32-bit predecessor IPv4 allowing connections of more than 7.9×1028 times as many devices as was possible with IPv4. This advancement exceeds future requirements, but IPv6 also offers network-layer encryption and authentication because compliance with Internet Protocol Security (IPsec) is mandatory.
IPsec is a protocol suite that authenticates and encrypts each IP packet of a communication session. Data is authenticated and encrypted whether communicating between a pair of hosts, a pair of security gateways, or between a security gateway and a host automatically securing data flow over IP networks. Together, IPv6 and IPsec are ubiquitous to the infrastructure and real-time data updates that are necessary for the smart grid.
Wide-area Monitoring System (WAMS)
Establishing a wide-area monitoring system (WAMS) for the electric power grid is the latest trend that utilizes the abilities of IPv6 and brings the concepts of the smart grid closer to reality. The interconnection of phasor measurement units (PMUs) and phasor data concentrators (PDCs) at the local, regional, and master branches brings together a situational awareness tool that enables operators to respond to power disturbances in real-time.
The technology incorporates a network of PMUs at the distribution level. Each PMU is identified by its corresponding GPS unit relaying time-synchronized measurements of grid status at high data rates. The PDC then compiles the phasor data flowing through the grid at numerous locations. The end result is a powerful insight tool that surpasses the abilities of many advanced SCADA systems.
In support of WAMS, IEEE formulated the standard “IEEE Std C37.118.1-2011,” which defines thresholds for synchrophasors, frequency, and rate of change of frequency (ROCOF) measurement to be taken by PMUs under all operating conditions. The standard sets a benchmark for time tag and synchronization requirements that was superseded by its amendment in 2014, “IEEE Std C37.118.1a-2014,” in order to remove limitations and correct for inconsistencies that previously made compliance difficult to achieve.
The Smart Grid
Achieving the ideals of a smart grid remains a goal that has yet to be reached. WAMS helps to mitigate blackouts, resolve insufficient transmission capacity, and increases operational efficiency. Despite these improvements, however, existing infrastructure fails to augment centralized power stations and power quality stands for improvement.
WAMS is able to identify and correct for power disturbances that, in some cases, seem to uphold the goal of a self-healing power grid. The issue here is that energy demand continues to increase and the adoption of renewable and distributed energy sources fails to fully augment dependency from centralized power stations while adding a further layer of operational complexity.
The unpredictability, variability, and intermittent generation of power from distributed and renewable power sources cause complex power exchanges. This forces aging infrastructure to operate on the fringe of its limitations. One possible solution is the development of IoT-enabled discrete energy systems capable of autonomous operation in what is known as a microgrid.
A case study published in in IEEE Smart Grid Newsletter “Developing of Distributed Generation and Microgrids in China” found that while micro grids are still relatively new, they are becoming an indispensable configuration that may solve issues with transmission limitations. To ensure efficient utilization of renewable and distributed energy, microgrids are being developed to offer reliability and alleviate dependency on high-voltage power transmission systems.
The demonstration projects referenced in the IEEE newsletter are being used to verify that microgrids are a reliable and sustainable power source. The projects can operate in urban, rural, or isolated environments with the ability to tie into the grid. Standardization by organizations like the State Grid Corporation of China (SGCC), IEC, and IEEE has helped researchers address test procedures, integration requirements, as well as technology development.
WAMS and microgrids are evolving to bring a smart grid closer to reality. The availability of grid status updates in real time and optimization of integrate distributed and renewable energy sources are key improvement. Ongoing research revolves around optimal PMU placement, active participation by consumers, and a proper balance of distributed and renewable energy sources. As the nearly decade-old vision of a smart grid takes shape, it has grown clearer that IoT is the tool set that makes that dream possible.