by Scott Zajkowski, IUS Technologies
The U.S. demand for power is continuing to move along an upward trajectory that is unlikely to be curbed soon. And utilities are facing government regulation to be cleaner and more efficient while still relying on their aging infrastructure. The challenge to deliver enough electricity to an increasing volume of customers while reducing emissions and keeping necessary generation in check must be met by smart grid technologies.
The main objectives of transforming a legacy grid into a smart grid are to increase efficiency and distribution reliability. Achieving these goals will lead to a steady stream of power with fewer interruptions to more people using fewer resources while emitting fewer carbon gases. This upgrade is necessary based on customer demand, both from an efficiency and cost standpoint, but also for today’s modern customers who use increasingly more electronic devices and adopt new power-hungry technologies such as electric cars.
When power grid efficiency is spoken of, it equates to optimization of existing infrastructure. Grid efficiency is impossible without high-quality, real-time information, which can be achieved only through the full integration of capacitor banks, changers and voltage-sensing equipment at the midline and end of line.
Once complete information is available, utilities are equipped to control volt/VAR levels, minimizing losses while increasing efficiency. The largest efficiency gains are obtained here because when volt/VAR is optimized voltage can be reduced. The benefits include reduced demand on power generation and increased life spans on plugged-in consumer electronics and utility-owned assets. This is largely made possible by managing peak demand. In legacy situations, the greatest inefficiencies occur when additional generating power is needed to satisfy relatively brief periods of peak demand, which can be difficult to predict. These periods vary depending on geography. In warm regions, they are typically during summer when air conditioners are running, but cooler climates where electric heating is common might experience peak demand during the coldest days. A properly implemented volt/VAR optimization strategy can reduce the generation capability needed to satisfy peak demand, but this requires enough data from the grid to predict it.
Volt/VAR programs provide utilities the ability to improve grid reliability and efficiency significantly, but to implement volt/VAR optimization (VVO) or volt/VAR control (VVC) programs, utilities need real-time data measurement and monitoring throughout the distribution line. IUS Technologies’ VS series of sensor products, the VS1000, VS2000 and VS3000, play a significant role in this distribution automation application. To implement grid optimization, utilities need to know what is happening on their distribution or feeder lines, and currently utilities lack this knowledge. They are unaware of voltage, VAR, harmonics and other vital power measurement levels on their feeder lines. The condition and load on these feeder lines vary by day and require real-time intelligence throughout the distribution system.
Voltage sensors can provide utilities with powerful, flexible and economical solutions for single-or three-phase measurement, monitoring, alarming and recording. The VS products allow electric utilities to monitor voltage and current anywhere along the distribution line, providing real-time data to make decisions at the edge of the electric grid. When lowering the voltage levels on the distribution line, accuracy is paramount. Implementing sensor points and VVO or VVC software allows the utility to be more responsive to changes in the distribution line.
Linked sensing equipment and controls that monitor and report power usage in real time can provide utilities with the necessary information to reduce voltage without risking a drop in the amount of electricity provided to customers. Even a 3 to 5 percent drop yields significant results that lead to measurably lower costs, the prolonged life spans of assets and reduced maintenance expenses. In addition, lowered voltage levels enable utilities to meet government regulations for generation and emissions. When voltage levels are dropped without instant demand data, however, service disruptions might occur.
One of the most troublesome power distribution issues for customers and utilities is outage notification. On a traditional grid, customers who experience service disruptions must notify their utilities, which must dispatch line workers to locate and correct the problems. Each with his or her own threshold and requirements, a line worker-after the quota is met–then must search and find disruptions. This takes time and money and causes frustration.
Sensing technologies that construct the smart grid can detect problems as they occur and, if robust enough, can solve problems without human intervention, thus a “self—healing” smart grid. When smart sensors detect problems, they notify reclosers, which isolate locations of the issues and often reroute power and avoid disruption. If a worker is required to correct a physical problem, the exact location is provided so no time is wasted investigating and troubleshooting the line, leading to shorter outages and happier customers.
In a fully self-healing scenario, sensors report the problem and confirm the system has corrected itself. Voltage levels automatically optimize and this information is reported to the utility so it knows no further action is necessary. Retrofitting legacy equipment has made parts of this process possible on traditional grids, but full self-healing requires integration of equipment that can communicate in real time. Most retrofitted equipment relies on cellular communication technology–a problem because communication more frequent than 15-minute intervals is rare.
The Dynamic Modern Grid
Power use is changing quickly. As more alternative energy resources come online, it adds a layer of complication to maintaining optimal voltage levels. Many utilities also allow customers to generate their own power and push it back into the grid when they are not using it.
Smart meters relay this information back to the utility about how much power is being fed back into the grid, but workers on the line also need this information. For example, imagine a worker is conducting maintenance, thinking a line is not live because power has been disrupted from the generation end. If a customer generating his own power is feeding the line, this can create unknown live wires and present real danger to utility workers. Smart line sensors build a much more complete picture of what is occurring on the line at any time, improving safety for anyone who comes into contact with it.
Utilities across the nation are implementing many innovative programs to improve efficiency and distribution reliability: Demand response, smart meters and secondary transformer monitoring are all steps in the right direction. Voltage optimization and a self-healing grid, however, can be realized only through the integration of a fully smart grid.
Scott Zajkowski is part of the North American Business Development group with IUS Technologies, which develops end-of-line devices for the smart grid, including the Born Smart series of sensors. He has an MBA from Indiana University Kelley School of Business and an undergraduate degree in packaging engineering from Michigan State University. Previously Zajkowski worked at International Truck & Burger King in packaging engineering and management.
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