Remote - Winter 2013 - (Page 20)

Feature Article SCADA - The Brain of the Smart Grid Scott Zajkowski, North American Business Development Group IUS Technologies The term smart grid elicits a mental image of a fully automated power distribution system, capable of monitoring usage and voltage levels, constantly making adjustments to keep everything running at optimal levels. This vision does encapsulate what a true smart grid is able to deliver, but load tap changers, capacitor banks and reclosers are not smart enough on their own to make adjustments; they have to be told when and how to respond. At the core of smart grid decision making is SCADA, supervisory control and data acquisition. Line sensors and other connected equipment on a smart grid provide a stream of data back to a central control room where the information is analyzed and decisions are automatically made and executed, regulating voltage levels, optimizing efficiency, routing and generation. The SCADA system in the control room is able to make these automated decisions in real-time by running algorithms based on the data it receives and orchestrate adjustments to optimize voltages and self-heal any disruption issues. Most systems aren't there yet. SCADA systems, in one form or another, have been employed since the 1960s. When first implemented, they worked on a continuous scan basis where requests for data were sent to remotes which responded and SCADA systems relied on mainframe systems to process the data. Duplex communication channels were generally not available, thus limiting SCADA's ability to send and receive information simultaneously. Once received, information was displayed on a human-machine interface so that a controller could decide what action to perform. Over time, SCADA processing moved to PC environments where information was shared and processed on LAN networks. Modern system networks use always-on connections and are able to communicate via the internet. While the next generation of SCADA will rely heavily on cloud computing to have the processing power necessary to analyze continuous streams of data from thousands of sources simultaneously on larger grids. The more sources of information the SCADA system has providing information to it, the more effective it is at making optimal decisions. Most modern electric utilities have a form of SCADA to manage their grids, but all systems are not created equally. Many current systems operate primarily at the substation level, but upgrades are necessary to calculate data from line sensors that are becoming more common to expand control to a more granular level. Significant upgrades will be required not only to analyze the data provided by these sensors, but also to process the complex algorithms that effectively launch responses to the continuous stream of data they provide. By definition, a true smart grid is capable of distribution automation, which is made up of two components: volt/VAR optimization and selfhealing. The accompanying SCADA systems are called upon to make the necessary decisions that carry out these tasks. 20 www.RemoteMagazine.com Volt/VAR Optimization In order to maximize realized grid reliability and efficiency, many utilities are interested in optimizing voltage levels on feeder lines. In fact, this concept of Volt/VAR optimization can yield immediate efficiency results by understanding the lowest amount of voltage to send to consumers. It also protects consumers as more sensitive personal electronics and major investment devices like electric cars start to come online. Lowered voltage in homes preserves the lives of these devices, enabling them to use power and charge batteries more efficiently and reducing the chance of damage to components due to overloading. The barrier to achieving volt/VAR optimization in the past has been the difficulty in predicting peak demand. If voltage is lowered too much and demand spikes higher than anticipated, consumers can experience service disruption. On a traditional grid, utilities typically use a combination of historic data and usage checks at regular intervals to determine peak demand. Using this imperfect system, voltage can not be minimized to the most efficient level without risking disruption should demand spike beyond anticipated levels. Smart meters have made this task easier, but most do not report data frequently enough to achieve truly optimized voltage levels. On a smart grid, usage is constantly monitored throughout the distribution system and the information is reported on a steady stream in real-time. Using this data, the utility is able to adjust capacitor banks and regulators to increase voltage only when necessary, never raising it above minimum levels until actual demand calls for it. Achieving this level of volt/VAR optimization requires not only a series of interconnected control sensors located on feeder lines, but also a back-end SCADA system that is robust enough to analyze all of the reported data while also processing the algorithms that instruct proper responses instantly. Self-Healing Grid Traditionally, utilities rely on phone calls from consumers to notify them of power disruptions. Then, ground crews are dispatched to investigate the outage and determine what measures must be conducted to correct it. Often, considerable time is spent traveling in an attempt to locate the source of the problem before any corrective measures can be undertaken. Conversely, feeder line control sensors on smart grids are able to notify utilities immediately when a disruption occurs. More importantly, precise data on where the disruption is physically located directs crews immediately to the problem area. In many cases, power can be rerouted around a physical problem so that it is immediately restored. Again, this requires a SCADA system that is able to understand the data it is receiving quickly enough to make the necessary adjustments without human intervention. When the sensing equipment and accompanying SCADA system are robust enough, rerouting can often take place instantaneously http://www.RemoteMagazine.com

Table of Contents for the Digital Edition of Remote - Winter 2013

Editor’s Choice
Message Oriented Middleware - The Future of SCADA
Enhanced SCADA Access and Big Data Lead to New Analytics & Optimization Capabilities
Approaches to Powering Telecom Sites
Satellite Communications for Water Metering and Other Water Applications
Remote Magazine Launches Internet of Things North America
Geospatially Integrated Surveillance Systems
Tier 1 Operator Case Study: Intelligent Site Management
SCADA - The Brain of the Smart Grid
SCADA
Networking
Security
Onsite Power
Industry News

Remote - Winter 2013