Bulletproofing the Grid

Bulletproofing the Grid

This piece was originally published in the September 2016 issue of electroindustry.

Petter Fiskerud, Program Manager, Power Transformer Resiliency, ABB Inc.

There is no visual difference between standard transformers and those with advanced ballistic protection.
There is no visual difference between standard transformers and those with advanced ballistic protection.

Recent events and developing threats remind us that as essential as the grid is to national and economic security—and our very way of life—it is and always has been vulnerable.

The 2013 rifle attack on a California substation that damaged 17 transformers and six circuit breakers, causing 52,000 gallons of oil to be spilled and $15.4 million in estimated restoration costs, puts a fine point on the 21st-century threat of criminals or terrorists attempting to disable the grid using high-powered firearms.

Standard approaches are making way for new technologies. Fencing is certainly insufficient in the face of these new threats. Solid walls have drawbacks: they only go so high, they shield would-be saboteurs from being noticed from the outside, and they can be cost-ineffective if designed to encapsulate the entire substation when protection of large power transformers is really the priority.

Advanced ballistic protection is attractive to utilities seeking to protect their most critical equipment and to comply with new directives like North American Reliability Corporation CIP-014-1, which requires transmission owners and operators to address threats and vulnerabilities to the physical security of bulk power system facilities.

While armor plating would prevent penetration of the transformer tank, advanced ballistic protection also reduces spalling after the bullet’s impact, limiting collateral damage to transformer components or nearby equipment. This technology absorbs the kinetic energy of bullets and meets the level 10 rating of UL-752 Standard for Safety Bullet-Resisting Equipment. This protects the transformer from many of the most powerful firearms available.

This solution does not require changing the customer’s standard design or the dimensions of a normal transformer. With full access to the unit, maintenance and replacement can be done without additional measures. There is no visual difference between standard transformers and hardened transformers. The look and feel of a normal transformer avoids any additional attention from possible perpetrators.

New sensing systems can detect ballistic impact on transformers. These systems send out warnings to alert first responders and activate systems to limit potential damage from ballistic damage to transformer accessories contained outside the main tank.

Due to the long lead time in producing custom-designed transformers, much of the early focus is on transformers. However, this technology is also suitable for protection of switchgear, circuit breakers, and capacitors, as well as other important substation equipment.

Industry is responding to the changing threat profile with new technologies. Properly applied, these technologies can match the level of protection with the criticality of the asset. This allows power producers and utilities to move away from a one-size-fits-all approach, because not all assets are created equal.


Mr. Fiskerud develops effective processes supporting assessment, hardening, monitoring, repairing, and replacing power transformers to improve resiliency against natural or manmade events.

Read the September 2016 issue of electroindustry.

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