by Curt Goldman, FreeWave Technologies

Wireless technology is accepted as an optimal communication solution for applications in many industrial settings. As utility operators and decision-makers look for ways to improve the power grid, it's becoming clear that a secure communication network is critical in ensuring efficient, effective power delivery. Each layer of the grid--generation, transmission, distribution and consumption--has varying requirements for monitoring and control. In many cases, wireless solutions are the glue that holds the smart grid together.

There is a challenge, however, because although the use of wireless technology has increased, the electric power industry traditionally has relied upon wired technologies for communication. Some utility operators still question the security capabilities of wireless because they are unfamiliar with the options. There are wireless communication solutions that offer security features trusted for critical government and defense operations. For more than a decade, these technologies have offered the same level of secure data transmission as a wired solution, if not more. As more utility decision-makers learn about this type of wireless technology and see it in action, they are adopting it as a viable solution. Wireless providers consistently are developing new control and monitoring technologies for distribution automation applications. These applications include advanced metering infrastructure (AMI) backhaul, distribution management systems, substation automation, demand response, supervisory control and data acquisition (SCADA), load management, Volt/VAR optimization and energy–management systems.

Key Wireless Applications for Distribution Automation

Many critical functions and actions are automated at the distribution automation layer--the monitoring of critical feeders, fault detection, isolation and restoration--to reduce the duration and impact of outages, supporting the shifting of loads between sources to help avoid or alleviate overload conditions, controlling capacitor banks and more. The extension of intelligent control over electrical power grid functions to the distribution level and beyond via distribution automation is a key enabler for the smart grid.

For example, many electric utilities have implemented wireless communications solutions in SCADA systems for better control over transmission-level equipment. As reliability and load requirements continue to increase, however, so does the need for data communications solutions to serve automation functions within the grid. Automating distribution fulfills a utility's objective to provide communications to all critical points in the infrastructure so uptime is maximized and achieved affordably.

Capacitor bank control. Operators use capacitor banks to help correct problems such as power-factor lag or phase shifts in alternating current (AC) electrical power supplies. They also can be used to increase stored energy and improve system power quality. Using a reliable wireless network to control and monitor capacitor banks ensures greater energy efficiency and a smooth operating distribution system. Real-time data allows operators to receive critical data faster and from remote locations.

Fault circuit indicator monitoring. Fault circuit indicators (FCI) along power lines are deployed to detect fault current. As many operators know, if the current defaults on a line with an FCI, it will know the distance the current has failed from pole to pole. Operators then can pinpoint the location of a fault along a power line. Many operators, however, are unaware that technologies can be embedded within the FCI, extract fault data and send it back to a central information center in real time. Previously, this application required a relay of data to several points before it returned to a central point.

Wireless technologies available for this application are embedded within the FCI and can transmit data up to 60 miles, ensuring fast fault identification. This prompts fast utility reaction to help prevent major blackouts. It also contributes to the mentioned goal of distribution automation by narrowing problems when they occur along the line. This helps maximize uptime, prevents power-delivery issues and saves utilities' money.

Differentiating Wireless Technologies

When utility decision-makers, operators or both begin their search for building a communications network, they find many wireless options. Operators might find technologies are suited for different layers of the smart grid. The most important caveat in selecting such a system is that people must understand communication requirements for their systems before choosing solutions. No single technology can satisfy every requirement, especially in a system as complex as the smart grid.

For example, standardized wireless technologies often are used for smart grid applications. These solutions offer many positive attributes such as cost savings; however, the only requirement to connect this wireless system is an off-the-shelf, standards-based device (i.e., Wi-Fi).

As for security, there is widespread knowledge of protocols to access this type of system and what makes this wireless technology work. If someone wanted to access a standardized wireless network, all it might take is a Wi-Fi card, password and a location within Wi-Fi signal range.

It has been proved that proprietary systems and devices offer more security. Intruders find it much more difficult, if not impossible, to access the signal of proprietary wireless technology such as frequency-hopping spread spectrum (FHSS) data radios. In the distribution layer, where secure data transmission is essential in preventing blackouts and other detrimental events, FHSS might be an ideal communication option. FHSS radios include unlicensed systems such as 900-megahertz spread spectrum radios.

What makes FHSS technology secure? FHSS was developed in 1941 when Hedy Lamarr and George Antheil co-patented a secret communication system that allowed radio control of torpedoes that could not be discovered, deciphered or jammed easily by the enemy.

The key to developing the system was frequency hopping: coordinated, rapid changes in radio frequencies that hop in the radio spectrum, thus evading detection and potential interference (being suppressed or jammed).

Lamarr's idea was not implemented in the U.S. until 1962, when U.S. military ships used it during a blockade of Cuba (after the patent had expired). Now it is the basis for modern, industrialized FHSS wireless communication systems that use very small amounts of radio spectrum at a time and do not remain at that frequency long, instead hopping quickly to another frequency.

Identifying Security Concerns With Wireless

For wireless technologies, the two most common threats to data communication networks are denial of service (DoS) and intrusion.

DoS is an attempt to make a network unavailable to its intended users. DoS could be as simple as jamming an electromagnetic signal or as sophisticated as saturating a system or network with communication and data traffic intended to overwhelm and prevent legitimate data from getting through and being processed. The consequences of DoS in the smart grid could lead to a transformer explosion, for example, if the technology is unable to monitor levels of cooling oil because it has been jammed or interrupted. Penetrating and intruding into a network or computer resource requires a different level of sophistication. The consequences can range from spying or stealing information to corrupting data or intentionally causing harm by taking over network control systems.

When using a reputable FHSS technology provider, these types of security problems can be nearly eliminated. The military has used wireless FHSS communication networks for years; the networks are reliable and easy to install.

If done properly, the FHSS wireless networks can offer the same reliability and security that wired systems offer at a much lower cost. Because of the strengths of FHSS wireless data radios, utility decision-makers increasingly are implementing wireless communication systems into their smart grids, especially in distribution.

What's Best?

When evaluating smart grid communications systems, utility decision-makers must be prepared to face many options, especially relating to wireless. If security, reliability and real-time data are key criteria for a utility's communications system, then FHSS wireless data radios might be the best choice. Decision-makers should research vendors, as well. Reputable wireless providers provide path study network design, offer excellent customer support and allow potential customers to conduct pilots before purchasing. Knowing the communication options on the market, a utility is much more likely to find the technologies that meet its requirements. Effective data transmission keeps utility operators informed of smart grid health, allows it to run smoothly and ensures proper power delivery. By deploying a communication network for key grid applications, especially within distribution automation, operators can get critical data at their fingertips in real time. This allows them to monitor and react to problems constantly and quickly, whether it is a transformer running low on cooling oil, a fault on the power line or the need to increase stored energy in capacitor banks. This data can be delivered with secure wireless technologies that are trusted for mission-critical applications in multiple industries.

Curt Goldman is the utilities market manager at FreeWave Technologies, a radio frequency design and manufacturing organization. Before FreeWave, Goldman was the regional accounts manager for Two Technologies Inc. He has a Bachelor of Science from Shippensburg University and a Master of Business Administration from La Salle University in Philadelphia. Reach him at cgoldman@freewave.com.