Network Infrastructure Considerations for Smart Grid Strategies

by Jim Krachenfels, GarrettCom, Inc.

Key smart grid components include remote control and automation, two-way communications and enhanced information technology targeted to both utilities and their customers. In addition to upgrading and hardening the power utility infrastructure, the smart grid is designed to help consumers and power companies make smarter decisions about how they use power. That requires much information and much data analysis.

The implications for infrastructure providers are huge. As in other information intensive markets before smart grid, data creep is well underway. According to a December 2010 SBI Energy study, “The Smart Grid Utility Data Market,” the volume of smart grid data moving through the infrastructure network will grow from 10,780 terabytes (TB) in 2010 to more than 75,200 TB in 2015.

Data Influx

It is clear that the infrastructure in the substation and distribution segments of the smart grid must undergo changes to accommodate this dramatic increase in data (see Figure 1). First, it is easy to predict that Internet protocol (IP) technology is a key smart grid enabler because it is standards-based, flexible and scalable. Second, the switches and routers deployed throughout the infrastructure must adapt to the increased data demands by supporting greater throughput and also by assisting in intelligent bandwidth—protective routing of information through protocols such as Internet Group Management Protocol (IGMP). Third, new software applications and protocols that support security, optimize routing and simplify and streamline data management must be developed. To make smart grid work, most data management, analysis and visualization must be automate—allowing humans to deal with the exceptions.

There is no “right” way to implement a smart grid. Solutions are as disparate as the types of utilities and the regions in which they operate. A municipally-owned utility in the Northwest, a public/private collaborative venture in the Southwestern desert and a rural cooperative in the mountains of Appalachia all have different operational challenges as well as differing political and financial considerations.

As electric utilities contemplate their strategies for data collection and management, they need a variety of options. Following are some critical considerations:

  • Standards-based implementation,
  • Bandwidth scalability,
  • Redundancy,
  • Wireless communications, and
  • Powerful and robust software.

Smart grid network infrastructure needs to be IEC 61850-3 compliant to support interoperability and scalability, and it needs to be substation-hardened to withstand challenging environments in remote locations. IEC 61850 is an international standard for communication in power generation facilities and substations. By integrating key functions within a substation, such as protection, control, measurement and monitoring, and by providing the means for high-speed protection applications, IEC 61850 simplifies power management and paves the way for other initiatives, such as smart grid.

Additionally, IEEE 1588 v2 is a breakthrough timing protocol that offers, for the first time, sub-microsecond synchronization for clocks in various substation and power delivery devices such as sensors and actuators over an Ethernet network. It is a critical component for allowing utilities to offer the precision timing required to support the control algorithms required for modern power management and delivery systems. While sub-microsecond synchronization is valuable, increasing automation is likely to require synchronization at tens of nanoseconds rates in the near future, and equipment suppliers must develop, market and support the standards-based hardware and software required at that level of precision, based on the IEEE 1588 v2 standard.

Bandwidth Scalability and Redundancy

With smart grid, an emphasis exists on distributed energy sources, some of which will be consumer supplied, such as solar panels and small wind farms (see Figure 2). These distributed energy sources pressure utilities to track and manage load. Most green power sources are intermittent, requiring more communication along the grid to ensure that power is supplied when and where needed. At the same time, automatic meter reading (AMR), with its potential not only to measure power use at a customer site in real time but also to provide feedback on power usage, generates enormous amounts of data. On the physical security side, surveillance developments provide streaming video information, often in high definition, that can overwhelm a network that is not sufficiently scalable and intelligent in its data transmission through the use of routing tools such as IGMP at the router level, and even switch-based Layer 2 IGMP-based data management tools.

Switches and routers can support greater numbers of ports, particularly fiber ports, with the introduction of small-form-factor fiber ports. Small-form-factor fiber ports for both 100Mb and gigabit provide bandwidth to accommodate the increased video security demands for the power utility industry. In addition, the reduced cost of fiber media has made IT physical security more affordable. The increased port density also increases network reliability by providing fewer failure points.

Reliability is a leading smart grid driver. The impetus for redundant network paths to enhance reliability has been in place for years. With security threats and increased power demands, redundancy is no longer a luxury. In addition to an insatiable need for continuous flows of data to monitor and manage the smart grid, the industry is also contemplating a surge in energy demand. Consider, for example, mass-market electric cars, each of which can draw as much power as all other electrical devices in some homes. A large number of cars plugged in at the same time could tax power delivery and possibly bring a utility to its knees. The impending electric-vehicle power demand tops the growing list of devices that are increasing electricity demand, from communications devices, industrial facilities and even gadgets at home and work.

Switches, routers and other networking products for the smart grid will require redundant power supplies along with network-path redundancy to ensure that data continues to flow. For example, security concerns and increasing demand suggest that even 1U rack-mount switches need hot-swappable power supplies to reduce downtime. Networking software that incorporates features such as RSTP-2004 is also key in minimizing downtime for critical utility applications. Designing redundancy into network paths to every important device is critical to maintaining uptime in power substations and distribution systems in smart grid communications networks.

Wireless, Robust Software and a Firm Foundation

Wireless extensions to Ethernet networks have been gaining in popularity as the power industry has embraced distributed data collection, monitoring and control. Wireless communications technology is a major enabler of AMR device installations on the consumer side, where fiber cabling would be cost-prohibitive. Wireless has also made it possible to cost-effectively bring remote substations, particularly in rugged terrain, into smart grid management systems.

Routers, hardened to meet the demands of substation conditions, must offer reliable cellular communication to quickly and economically support AMR applications and to reach dispersed power facilities, including widely distributed green power generation sites. Work remains to be done in this area as wireless technology brings its own challenges into smart grid infrastructure development with both security and regulatory concerns. As wireless deployments increase, equipment vendors and the power industry continue to review and refine wireless functionality.

Smart grid systems require extensive software support for success. Substation switches and routers are at the heart of data collection and management activities, thus switch and router operating software must support the latest precision timing (IEEE 1588v2) and fault recovery (RSTP-2004) protocols. Security is another issue. Security protocols and standards are mandated by NERC CIP regulations and other security initiatives that help drive increased tools and protocols for ensuring that critical smart grid installations can withstand cyber attacks and reliably manage and direct huge data volumes.

Vendor-supplied software provides increasingly sophisticated ways of sorting and managing data to support the overall smart grid infrastructure. Equipment providers must look to provide increasingly sophisticated and standards-based network management and network operating systems. In addition, systems vendors such as Industrial Defender and SUBNET Solutions supply integrated security and management systems that use interoperability standards to ensure smooth data flow and infrastructure management among different smart grid vendors’ equipment.

A firm hardware and software foundation that provides security and multiple options for power utility network designers will ease the way to implementing networks that meet utilities’ varying smart grid solution needs. Because new power systems also bring increased security concerns and government regulations, and because evolving standards and increasing precision packet timing demands are the norm today, utilities must identify equipment, software and network protocols that can adapt to changes. Flexible solutions, built on industry standards, provide the best platform for smart grid data movement and manipulation, because they provide a platform capable of evolving over time.

Jim Krachenfels directs the GarrettCom marketing efforts. Krachenfels has more than 10 years experience in marketing programs and product management in the networking industry, including positions at Cisco Systems and SPEEDCOM Wireless. He can be reached at jkrachenfels@garrettcom.com.

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