Navigant Research Blog

Smart Cities and the Smart T&D Electric Grid

— March 9, 2016

Bangkok SkylineMuch of the discussion around smart cities centers around smart buildings and the proliferation of smart meters (i.e., advanced metering infrastructure). Also discussed is the growing importance of distributed energy resources (DER) and the multitude of smart devices that make up the Internet of Things (IoT). However, the criticality of the electric transmission and distribution (T&D) grid that powers the smart city or smart community is rarely or only casually mentioned. Regardless, many T&D technologies and features will likely be critical to the smart city of the future.

Generation: The shift from local coal or nuclear generators supplying urban population centers to remote utility-scale wind and solar generation resources is rapidly occurring and can be seen across North America and Europe. Large-scale wind and solar generation farms are becoming an increasing portion of the generation mix. Electric power must be transferred from these remote sites to urban populations over hundreds (if not thousands) of miles of new high-voltage transmission lines using high-voltage direct current (HVDC) and extra high-voltage alternating current (HVAC) transformers and converter stations.

Transmission grid technologies: In turn, these lines require new approaches to monitoring and control necessary to maintain voltage levels and synchronize the three-phase power delivery at each substation along the way. Relatively new phasor measurement units (PMUs) and digital protective relays collect voltage, current, and power factor information up to 60 times per second, time stamping it for comparison purposes. Synchrophasor analytics make real-time comparisons of status at each end of the transmission lines, warn operators, and automatically correct voltage or power factor when readings diverge from optimal operating conditions. These high-speed incidents go largely unnoticed with traditional SCADA monitoring and control and can sometimes create major reliability incidents.

Distribution substations: The digital substation will also be a critical part of the new smart city. As every device in the substation is upgraded to have digital communications and control, substations will be ringed with high-speed fiber optic networks. These networks connect the various devices, including transformers, switchgear, protective relays, and other intelligent electronic devices. This sets the stage for the virtual substation, where every piece of equipment is modeled, operating data is shared, and system operations are monitored, controlled, and automated at the local and centralized operations centers.

Distribution feeders and low-voltage (LV) distribution transformers: Distribution feeders connect the substation with customers in both urban and rural locations. Urban distribution feeder systems are complex meshed networks, with fleets of disconnect switches, reclosers, and other devices that allow the network to be reconfigured and continually operated when isolated system faults occur. These intelligent electronic devices increasingly include local and autonomous decision-making and control capabilities. They communicate with adjacent devices and reconfigure the network or managing voltage and power factor without control by the substation or central operations center.

There are also millions of LV distribution transformers that operate at the edge of the grid, stepping down voltage for delivery to the customer. These transformers have traditionally been mechanical/electrical devices with no monitoring capabilities, but are now being gradually replaced with smart transformers that measure and report critical operating condition information. Sophisticated transformers may provide control and automation capabilities, which are becoming increasingly critical for managing the distribution grid as DER penetration increases. Retrofit monitoring and control devices are also now available and can be installed close to problematic or overloaded transformers.

 

Physical Security Threats to the Transmission and Distribution Grid, Part 2

— February 11, 2016

Both physical and cyber security threats to the electric utility transmission and distribution (T&D) grid in all regions of the world are real. Part 1 of this blog series discussed the physical security problem and some of the measures North American utilities are taking to respond to the North American Electric Reliability Corporation (NERC) CIP-14 requirements. Regardless of whether replacement high-voltage transformers, switchgear, and breakers need to be ordered from major vendors such as ABB, General Electric (GE), Siemens, or other regional companies, replacement equipment is not warehoused. Instead, it must be special ordered, manufactured, and shipped to the transmission substation where the replacement will be made.

Manufacturing lead times are typically 12 to 18 months, which is an issue the North American transmission system operators are dealing with by participating in Grid Assurance, banding together to create stockpiles of critical equipment in multiple locations across the nation. And while Grid Assurance will own and provide timely access to an inventory of emergency spare transmission equipment, the regional or national shipping and transportation issues are daunting.

Issues of Size

The sheer size of 250 kV to 750 kV high-voltage transformers makes physical transportation a logistical nightmare, regardless of whether large-scale trucks or railroad transportation is used. Companies such as ABB and Siemens have highly specialized trucks and flatbed rail cars dedicated to high-voltage transformer transportation. A huge flatbed truck designed to transport from 100 tons to 500 tons of high-voltage transformers can be seen below. These trucks need to be routed over roads that are certified for heavy loads and often have circuitous routes because of height and width clearance issues.

Transformer Shipping Using Lowboy Flatbed Truck

Jim M Blog

(Source: ABB)

However, the largest 500 kV and 750 kV extra high-voltage transformers may require specialized rail transport with similar clearance issues, bridge weight restrictions, and even access close to the transmission substation. Shipping and transportation from regional sites, vendor manufacturing centers, or overseas shipping yards may take weeks or even months, again lengthening the restoration timeframe. Moving huge transformers by rail has a similar set of constraints, based on the vicinity of rail lines to the transmission substation location.

Unfortunately, extra high-voltage and high-voltage transformers are huge pieces of equipment, and replacement and restoration time following a physical attack or transformer failure is not an overnight event. It could take months for parts to be manufactured, delivered and installed. It is clear that restoration initiatives are intimidating. A series of restoration examples will be provided in Part 3 of the Physical Security blog series.

 

Physical Security Threats to the Transmission and Distribution Grid, Part 1

— February 8, 2016

Idea for problem solvingWhile popular media continues to feature the ongoing cyber security threats to the electric utility transmission and distribution (T&D) grid across the globe, with recent cyber attacks in Eastern Europe, another T&D grid threat is looming on the horizon. Over the past 6 months, there have been repeated physical security attacks on utility T&D infrastructure in Eastern Europe and Southeast Asia. The unfortunate truth is that substations and power lines on the electric transmission system are particularly vulnerable to physical attacks, where large, high-voltage transformers are typically located in exposed outdoor conditions, and transmission towers can be seen stretching to the horizon.

Incidents such as the Metcalf Transmission Substation gunshot attack in 2014 and the recent transmission tower attacks in Eastern Europe have received significantly less attention in the media. However, they have been serious enough that the North American Electric Reliability Corporation (NERC) in 2014 released and revised Critical Infrastructure Protection-14 (CIP-014) regulations that require utilities to secure their infrastructure from physical and cyber security threats, as well as to identify and strengthen weaknesses in key substations.

Equipment Initiatives

In 2015, a group of eight U.S. transmission system operators (TSOs) announced a new initiative to speed their response to major physical attacks or other equipment failures on the transmission grid by establishing regional warehouses and inventories to long lead-time critical replacement technologies. Participants include American Electric Power, Berkshire Hathaway Energy, Duke Energy, Edison International, Eversource Energy, Exelon, Great Plains Energy, and Southern Company. These companies have committed to a memorandum of understanding to develop Grid Assurance, a limited liability company that will stockpile the critical equipment necessary to shield utility customers from prolonged transmission outages in multiple locations across the nation. Grid Assurance will own and provide participants and subscribers with timely access to an inventory of emergency spare transmission equipment that could otherwise take months to acquire.

Since the release of the NERC CIP-014 regulations in 2014, utilities are significantly more aware of potential threats and vulnerabilities in the grid. Aging infrastructure, natural disasters, and coordinated attacks on key substations are all major issues. Unfortunately, on the transmission grid, a single major attack or breakdown can have long-term regional or national effects on the United States. A recent 2015 industry survey looked at initiatives that over 200 TSOs have taken since the NERC ruling. Findings included:

  • 49% of utilities have identified threats and vulnerabilities to critical assets, though 28% haven’t taken further action
  • 42% of utilities surveyed have already developed physical security plans to address potential threats
  • 40% have not taken any hardening measures to limit or prevent damage to critical assets in the last 2 years

While it is clear that TSOs are vulnerable to both physical and cyber security threats, the obstacles they face in terms of timely service restoration are daunting, to say the least. I’ll discuss these obstacles in Part 2 of this blog series on physical security.

 

FAA Regulations Continue to Limit Drone Deployments at U.S. Utilities

— August 10, 2015

Popular media is highlighting the controversy around unmanned aerial vehicles (UAVs)/drones in public airspace, as these devices are disrupting scheduled airline flight patterns near major airports, interfering with planes in wildfire zones, and even interfering with privacy concerns. Yet, the drive to establish commercial uses for drone technology is proceeding at a rapid pace. Companies like Amazon are seeking airspace regulations that establish corridors for commercial drone-based delivery applications. At the same time, transmission and distribution (T&D) operators and utilities across the globe are beginning to look toward UAVs to reduce costs, improve safety, and increase reliability and response times across their T&D systems. These new utility solutions include major operations such as overhead visual transmission line maintenance inspections, T&D storm damage assessment and outage management/response, substation inspection, asset monitoring and condition maintenance, and vegetation management.

Limited Takeoff

While all these applications and use cases sound like ideal methods for utilities to improve their operations and reduce their costs, there are some significant issues that are bringing the adoption of new T&D procedures to a virtual crawl. The typical utility today utilizes line crews and sometimes helicopters to complete T&D line inspections and maintenance, semi-rapidly do storm damage assessments, update asset management systems, and make decisions on vegetation management. As you can imagine, these approaches are cost-intensive, with line crews heading out on search and locate assignments and helicopters being deployed at costs of up to $1,500 per hour.

Many forward-looking utilities are looking at both multi-rotor and fixed-wing UAVs to not only reduce maintenance and operations (M&O) inspection and vegetation management costs, but also improve response times during outages caused by major storms and other events. Although these savings can be significant, the Federal Aviation Administration (FAA) regulatory hurdles and permit and flight approval processes create barriers to this market literally taking off. Under current regulations, the FAA is granting limited-scale pilot project permits for a small number of U.S. utilities, including but not limited to San Diego Gas & Electric (SDG&E), ComEd, Duke, Xcel, and Florida Power & Light Company (FPL). Pilot projects are typically limited to small regions or T&D training facilities. Like Amazon’s proposal that commercial UAV flight corridors be established for delivery services, T&D utilities will need the same, allowing companies to fly drones over T&D systems for both planned M&O and storm damage assessments necessary for outage restoration. In addition, the flight approval process for UAVs must be streamlined, as flight plans currently need to be filed with the FAA 72 hours earlier, clearly precluding timely storm assessment and outage restoration responses. These hurdles must be addressed for the UAV market with T&D utilities to take off over the next 10 years.

Emerging Promise

A number of UAV companies are already positioning themselves for the expansion of this market, including startups like Google-funded Skycatch and an interesting company in Colorado, FLōT Systems. The latter has established key partnerships with both inspection services companies and analytics software providers.

I’m currently writing a report on UAVs/drones and robotics for T&D applications. While I expect the companies manufacturing UAVs and related sensor technologies to do extremely well, I also anticipate that the complex analytics software companies analyzing streaming visual and thermal data, as well as the inspection services companies, will benefit. Look for my continued discussions about emerging technologies across the global T&D landscape in upcoming blogs and reports.

 

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