by Larry Colton, Echelon
It is well-documented that the U.S T&D system is aging and becoming less-stable. In addition, it is becoming more difficult to add new transmission lines and generation sites needed to address the growing supply and demand challenges. Utilities must leverage and enhance their existing infrastructures to eliminate or at least delay the enormous investments required to upgrade them.
One way to achieve this is to implement a smart grid. A smart grid creates a digital energy system that detects and addresses emerging problems on the system before they affect service; responds to local and systemwide inputs and offers details about system problems; and incorporates extensive measurements, diagnostics, communication and control that quickly can stabilize the system after interruptions or disturbances.
The initial investments in a smart grid should be implemented wisely and focus on the underlying architecture and technology needed to create a foundation that can support all future needs including energy efficiency, renewable energies, storage and plug-in electric cars. In addition, the smart grid will not be smart until it connects every customer—residential, commercial and industrial.
Installing and implementing advanced metering infrastructure (AMI), including smart meters, is the first step in modernizing the electrical grid. AMI systems provide the foundation necessary to establish a future-proof smart grid and extend the view and control of T&D assets to all customers.
AMI systems with smart meters provide multichannel data logging for billing data and power-quality data such as voltage sags and swells, over-current and under-current conditions and frequency and power factor information. This data can be used to detect, anticipate and respond to system problems, which will allow a smart grid to avoid or mitigate T&D system problems including power outages, power quality problems and service disruptions.
Smart meters should also include an integrated disconnect switch that can help implement maximum energy limits, which can help reduce blackouts or brownouts. The information and functionality that smart meters provide can offer the T&D system many operation benefits including:
- End-of-line voltage monitoring,
- Customer voltage levels (increasingly important because high-tech devices such as HDTV require adequate voltage levels),
- Load profiling and balancing of transformers and feeders,
- Detailed customer supply power-quality statistics,
- Improved energy forecasting and conservation,
- Optimized asset (such as transformers and lines) use via detailed customer-usage summaries by transformer, line section and feeder,
- Outage detection and data analysis to help understand problem areas that experience frequent extended outages and very short-duration outages,
- Blackout prevention through the use of maximum energy-limiting capabilities for customers during extreme peak system conditions in specific areas,
- TOU or RTP rates to encourage shifting usage to off-peak periods,
- Demand response to turn off or cycle power for customers’ equipment, and
- Bidirectional metering to support distributed generation, which is expected to affect T&D systems in the future.
An AMI system provides the foundation for creating a smart grid. This system, along with its associated smart meter information, will let utilities optimize their existing assets. It will prevent utilities from exceeding capacity ratings of electrical lines and transformers, extend the life of the T&D system and delay the large investments needed to upgrade energy infrastructures.
Larry Colton is marketing manager of networked energy services with Echelon Corp. He is a professional engineer and certified project management professional who has received several patents associated with advanced metering and communications systems.