The Self-healing Grid: A Concept Two Decades in the Making
- Written by Massoud Amin
For most Americans, President Obama's mention of a self-healing grid was probably the first they had ever heard about a power system that could identify and fix its own problems, without direct human intervention. But the concept of a self-healing grid goes back twenty years and by now is well developed.
At one point in his 2013 State of the Union address, President Obama aroused excitement and also some confusion regarding a self-healing grid.
What the president said was: “America's energy sector is just one part of an aging infrastructure badly in need of repair. Ask any CEO where they'd rather locate and hire: a country with deteriorating roads and bridges, or one with high-speed rail and internet; high-tech schools and self-healing power grids?”
Since the president’s speech, I have been asked the following questions:
What is a self-healing infrastructure?
A self-healing grid uses digital components and real-time secure communications technologies installed throughout to monitor its electrical characteristics at all times and constantly tune itself so it operates at an optimum state. It has the intelligence to constantly look for potential problems caused by storms, catastrophes, human error or even sabotage. It will react to real or potential abnormalities within a fraction of a second, just as a military fighter jet reconfigures itself to stay aloft after it is damaged. The self-healing grid isolates problems immediately as they occur, before they cascade into major blackouts, and reorganizes the grid and reroutes energy transmissions so services continue for all customers while the problem is physically repaired by line crews.
A self-healing smarter grid can provide a number of benefits that lead to a more stable and efficient system. Three of its primary functions include: real-time monitoring and reaction, which allows the system to constantly tune itself to an optimal state; anticipation, which enables the system to automatically look for problems that could trigger larger disturbances; and rapid isolation, which allows the system to isolate parts of the network that experience failure from the rest of the system, to avoid the spread of disruption and enable a more rapid restoration.
As a result of these functions, a self-healing smart grid system is able to reduce power outages and minimize their length when they do occur. The smart grid is able to detect abnormal signals, make adaptive reconfigurations and isolate disturbances, eliminating or minimizing electrical disturbances during storms or other catastrophes. And, because the system is self-healing, it has an end-to-end resilience that detects and overrides human errors that result in some of the power outages, such as when a worker error left millions of California residents without electricity in September 2011.
Beyond managing power disturbances, a smart grid system has the ability to measure how and when consumers use the most power. This information allows utility providers to charge consumers variable rates for energy based upon supply and demand. Ultimately, this variable rate will incentivize consumers to shift their heavy use of electricity to times of the day when demand is low and will contribute to a healthier environment by helping consumers better manage and more efficiently use energy.
How can we set about building a self-healing grid?
To transform our current infrastructure into a self-healing smart grid, several technologies must be deployed and integrated.
The ideal smart grid system consists of microgrids, which are small, mostly self-sufficient power systems, and a stronger, smarter high-voltage power grid, which serves as the backbone of the overall system. Where do we begin?
The first step is to build a processor into each switch, circuit breaker, transformer and busbar, which are the huge conductors that transport electricity from generators. The processors will allow transmission lines to securely communicate with each other and monitor their individual pieces of the grid.
From there, the millions of electromechanical switches currently in use will need to be replaced with solid-state, power-electronic circuits to handle the highest transmission voltages of 345 kilovolts and beyond. This upgrade from analog to secure digital will allow the entire network to be digitally controlled, making the smart grid’s key functions of real-time self-monitoring and self-healing possible.
Upgrading the grid infrastructure for self-healing capabilities requires replacing traditional analog technologies with digital components, software processors and power electronics technologies. These must be installed throughout a system so it can be digitally controlled, which is the key ingredient to a self-monitoring and self-healing grid.
Does the smart grid need to have a self-healing infrastructure?
It needs a self-healing infrastructure to ensure it can continue to operate reliably for businesses and consumers who depend on it. A smart grid that is overlaid with the various sensors, communications, automation and control features that allow it to deal with unforeseen events and minimize their impacts will be resilient and secure.
As I mentioned previously, the annual business losses in the U.S. from electrical failures average about $100 billion. Much of this is from short power interruptions. On any day in the U.S., about a half million people are without power for two or more hours.
Not only can a self-healing grid avoid or minimize blackouts and associated costs, it can minimize the impacts of deliberate attempts by terrorists or others to sabotage the power grid. Its ability to seamlessly maintain services under all of these types of conditions makes our country more secure. And overall, it improves the quality of electricity services for end users.
Where did the concept of a self-healing grid come from?
It was first formulated in the context of the Complex Interactive Networks/Systems Initiative (CIN/SI), which was launched as a joint project of the Electric Power Research Institute and the U.S. Department of Defense in 1998, which involved six university research consortia, comprised of 240 graduate students and 108 professors in 28 U.S. Universities along with 52 utilities and ISOs and the U.S. DoD, to address security and reliability challenges posed by interconnected and complex critical infrastructures. The key goal was to develop new tools and techniques to enable large national infrastructures to self-heal in response to threats, material failures and other destabilizers. Among the deliverables was the development and deployment of layers of secure sensing, high-confidence communications and automation that enabled a "smart grid" - an integrated, "self-healing" and electronically controlled secure and resilient power system. I was involved in a leading role at EPRI from the outset, having developed some key ideas while working during the previous years on fault-resilient DoD logistic networks and damage-adaptive aircraft control and stabilization systems, which will be described in an article in the next issue of the IEEE Smart Grid Newsletter in April.