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Sep 01 2016

Flexible, scalable microgrid operations with SDN

Microgrid technology has become an important element of many power utility market strategies, and software-defined networking (SDN) improves microgrid operations.

By interconnecting microgrids with main grids, utilities can improve delivery, reliability, and eco-sustainability through distributed energy resources. But to operate microgrids efficiently, utilities need a cost-effective way to extend their communications networks to all microgrids.

SDN offers utilities a flexible, scalable way to extend networks to manage and monitor microgrid operations. With a software-defined network, utilities get smarter end-to-end control, automation, and service agility that lets them address all operational challenges. (See the article Utility communications benefit from SDN for a more detailed overview of how power utilities can leverage SDN to optimize their communications networks, improve operations, and reduce costs.)

The microgrid revolution

Many utilities are either in trials or early deployment with microgrid technology. As the technology matures, microgrid deployments will expand significantly in rural and urban areas for commercial and residential communities.

Why are microgrids so popular?

According to Berkeley Lab the U.S. Department of Energy defines a microgrid as “a group of interconnected loads and distributed energy resources within clearly defined electrical boundaries”. Once deployed, a microgrid acts as a single controllable entity. It can be connected or disconnected from the main grid to operate in both grid-connected or island-mode. This gives utilities more control over service delivery and enables utilities to provide a more reliable supply of electricity to large areas.

Microgrid operations are challenging

To get that control and operate microgrids efficiently, utilities must extend their networks to reach all microgrids. And this extension must support two-way communication between the main grid operations center and the microgrid’s controllers and servers. This is necessary for control and monitoring applications, such as power quality monitoring and volt-VAR optimization.

Getting this level of integration with traditional WAN deployments is challenging.

Utilities could use fiber, microwave, and copper connections to reach substations, but extending the operations network to all microgrids is still a challenge. Utilities usually have fewer access assets to reach commercial premises and residential communities in dense urban areas or sparse rural regions.

Scaling the network is also an issue. Several WAN techniques are available, such as seamless MPLS, pseudowire switching, and hierarchical routing. But managing the initial provisioning and future changes with these approaches requires a lot of network specialist resources.

Finally, the very nature of grid connections presents a significant challenge. Today’s grid applications need point-to-point connections between intelligent electronic devices in the grid and the network operations center.

But the adoption of smart grid technology requires more dynamic any-to-any multi-point connectivity. Therefore, meshed network connectivity is needed to get the full benefits of microgrid technology today and in the future.

SDN addresses microgrid operations challenges

By deploying a dynamic and intelligent SDN over existing infrastructure, utilities can get the full benefits of SDN without changing or upgrading their existing networks (Figure 1).

Figure 1. SDN deployment over an existing network

An SDN operates transparently over a private WAN network, service provider VPN or the Internet. It gives utilities complete flexibility to reach deployed microgrids, and utilities can retain common provisioning and operational procedures. This improves operations and increases the efficiency of service delivery processes. (See the Nokia white paper “Adopting SDN for microgrid communications” for more about SDN and microgrid operations.)

Automated provisioning and configuration management

To enable more flexible management, a software-defined network provides automated provisioning and configuration management.

In an SDN, a network services gateway (NSG) completes the installation procedures with secure authentication. The NSG receives configuration information that is automatically generated by the SDN controller.

When a configuration change or software upgrade is required, the centralized policy and management system informs the SDN controller, and the controller automatically notifies each NSG to distribute new policy changes. This automated provisioning and configuration management process greatly reduces the need for specialist network resources during deployment and operation.

Versatile meshed connectivity

Finally, an SDN also enables utilities to take advantage of versatile meshed connectivity.

An SDN establishes a mesh of stateless tunnel connections among the NSGs without resorting to signaling and dynamic routing in the network. This allows any microgrid to talk to any other microgrid in a distributed grid operation with energy resources scattered among many grid endpoints.

good business for microgrids

Given the advantages over traditional networking, deploying an SDN is a smart business move for any power utility adopting microgrid technology. An SDN makes it easier to respond to market demand dynamically, address microgrid operations challenges, and improve efficiency.

About Hansen Chan

Hansen Chan is senior marketing manager for the IP product portfolio at Nokia with a special focus on industries. With over 25 years of protocol testing, network consulting and product management experience, he’s a go-to speaker at international industry conferences. When he’s not talking networks, he’s reading up on history and religion, and listening to Baroque and 20th century classical music.

Tweet to him @hchan888