Monitoring critical smart grid components with wireless I/O

By Andrejs Rozitis

Electric utilities are re-thinking how they get electricity to homes and workplaces. The result is a smart grid that can observe and react. As with other process-dependent industries, it is increasingly rare to see electric power processes that rely solely on human decisions and manual interaction. Instead, automation is used to improve reliability, timeliness and quality.

But effective automation requires reliable and efficient communications. Although there are many communication options, certain wireless technologies are gaining in popularity due to ease of deployment and long-term savings. For example, the same frequency-hopping, spread-spectrum wireless technology that reliably serves the military, oil and gas industries is now finding application in electric power. Three examples are in substations, for circuit breakers and for transformer monitoring.

The importance of input/output devices

A wireless communications network consists of transmitters, receivers and transceivers that communicate using radio waves. In industrial application such as the smart grid, the network largely consists of fixed radio locations connected to intelligent devices such as a substation computer, a Remote Terminal Unit (RTU), or a Programmable Logic Controller (PLC).  Input/Output (I/O) devices connect that equipment to a central location where the SCADA network is monitored and controlled.

The newest I/O solutions offer major improvements. Arguably, the biggest differentiator is wireless I/O. Wireless I/O removes the enormous challenge of running cable from the point of measurement to the process controller. It also achieves higher accuracy by taking measurements at the signal source.

Wireless I/O is the most cost-effective way to monitor a process that spans between 100 feet and 100 miles. Savings are realized immediately by eliminating permits, cables and conduits, trenching and construction crews. Additional savings come thanks to quick troubleshooting, over-the-air configuration changes and upgrades, and by eliminating cable management activities.

The importance of expandability

Expandability is another differentiator in new I/O solutions. Some manufacturers offer expansion modules with a high density I/O. This allows users to start with a small amount of I/O in a critical location, knowing that more can be added in the future. Adopting an expandable platform often is justified by:

·         Additional monitoring mandated by the government

·         New process technologies that require more points for monitoring and control

·         Peace of mind knowing that more points are easy to add no matter what the future brings

In addition to wireless and expandability, features such as universal channel configurability, measurement accuracy, device reliability, backwards compatibility and ease of use also enhance the usability of new I/O devices.

Next page: Circuit breaker and transformer monitoring >>