Every day, the expectations of energy consumers increase in terms of grid reliability and energy’s environmental impact. Anyone who runs a business, large or small, has networks dependent upon the stable availability of power. Beyond having the assurance that all of their electronic devices will be supplied, consumers want to benefit from the technologies that can empower them and put them in control of their energy.
To address these growing expectations, the way energy is produced, distributed and consumed must evolve. The solution involves both smarter demand and smarter supply. The grid is the glue between supply and demand, the network across which power is produced and consumed, bought and sold.
The biggest concern when it comes to power grids is unanticipated downtime. This story is about one aspect of the Smart Grid, the story of how reliability is improving.
The self-healing grid example
Enter the concept of a self-healing grid. Such a grid comprises sensors, communications, automated controls and advanced software that utilizes real-time distribution data to respond to abnormalities. A self-healing grid constantly looks for potential problems, identifies the presence of a fault and pinpoints the location of the event. It automatically isolates the faulty section within a fraction of a second; then reconfigures the grid to re-energize faulty sections as quickly as possible.
This automation and control solution performs like a super immune system for the distribution network, making it more resilient to faults that might otherwise cascade into a major blackout — all with minimal human intervention. For increased resilience, the self-healing system can be decentralized, just like the immune system does not need coordination from the brain to be effective.
Such tools minimize costs related to service failures. They also reduce the utility’s SAIDI — the measure of average outage duration for each customer served — and minimize damage from deliberate attempts to interrupt the power grid.
The self-healing grid concept is built upon new analysis tools, next-generation substation automation equipment and communication with smart meters at consumer locations. It also incorporates decentralized energy generation based on renewables, as well as the potential to use stored energy from electric vehicles.
Stedin is one of the Netherlands’ largest utilities, based in Rotterdam, and has put the self-healing grid concept into practice. Stedin provides electricity to over 2 million customers, including government offices, major financial customers and Europe’s largest port. Stedin has to comply with strict reliability and quality regulations or face costly penalties, so customer service is a top priority. Improving network operations to avoid disturbances is core to the Stedin philosophy, and innovative smart solutions are deployed when existing assets are upgraded and improved.
Schneider Electric and Stedin worked together to build a self-healing grid solution based on motorizing existing Ring Main Units in downtown Rotterdam. The solution faced its first test in January 2015 when a potential protracted blackout situation occurred due to a broken power cable. Instead, the Smart Grid technologies responded and roughly 600 households, shops and businesses barely noticed the fault when it was resolved in 18 seconds rather than the average two hours. Targeted sections of the distribution network were re-energized automatically when the fault occurred, localizing it through simple but effective peer-to-peer communication between substations in the loop. As a result, affected customers were rapidly reconnected. Stedin’s smart technologies also harness more network data about power flows thanks to upgraded sensors which help to speed up equipment repairs since faults are isolated so quickly.
“After tests and simulations, we were really pleased to see the system work in practice. A first for the Dutch grid, this technology automatically limits both the duration and the broader impact of network failures,” confirmed Marko Kruithof, manager of sustainability and renewal at Stedin.
Additional Smart Grid components
The roadmap to Smart Grid–enabled utility operations includes new technologies that are designed to support fluctuating demand and the increased need for utility / customer interface and interaction. Below is a list of major technology areas that provide the cornerstones for this new development.
Linking the large variety of smart devices distributed throughout the network requires secure communications. Each utility that envisions a Smart Grid needs to build a communications network that parallels and can monitor, operate and optimize the electrical grid. But the technology and drivers that determine the right wide area network (WAN) for each company can vary widely.
AMI can enhance meter operations by reducing the cost and improving the accuracy of reading / collecting energy usage information while providing a mechanism to both inform and empower customers as they choose better energy consumption patterns. This is a broad topic, but a utility needs to evaluate current metering status and gain at least a high-level view of the requirements for the future.
MDM software focuses on properly managing and integrating all meter-generated data: historical data for analysis, as well as billing, power quality and system events data. This integration tool is the hub that shares data with other critical applications such as customer information systems (CIS), customer relationship management (CRM) systems, advanced distribution management systems (ADMS) and outage management systems (OMS). An effectively implemented MDM system can allow the utility to integrate whatever technologies are needed (consumer, industrial and/or multi-utility) into one cohesive system, now and in the future.
Distribution Automation (DA) involves devices and secure communications between them in the distribution network. DA can be broken down into two major divisions: substation automation (SA) and field automation (FA). SA enables electric utilities to remotely monitor, control and coordinate the distribution components installed in the substation, typically breakers, switches, transformers and load tap changers using sensors, meters, protection relays and controllers — often referred to as intelligent electronic devices (IEDs) — RTUs and SCADA systems. FA extends to circuits beyond the substation fence, and typically includes reclosers, sectionalised switches, capacitor banks, voltage regulators and fault indicators, plus their associated monitoring and control equipment and SCADA systems.
Within the FA domain, fault passage indicators are linked to circuit breakers and reclosers, making networks more reliable. DA is very beneficial in improving system reliability, safety and efficiency — especially when used in conjunction with other Smart Grid technologies. Systems like ADMS can help manage and optimize DA and provide guidance on best locations for placing DA devices.
At the end-consumer level of the Smart Grid, Schneider Electric is applying a variety of new technologies to engage businesses and homeowners. The cloud-based StruxureWare™ Demand-Side Operation platform will enable participation in programs like Demand Response that offer financial incentives for adjusting energy consumption when required. For homeowners, Schneider Electric has developed the innovative Wiser™ system, which monitors and controls all electrical equipment. A computer or mobile device can be used to view energy use by zone or type of use (e.g., heating system, water heater). It’s also possible to remotely adjust room temperature, schedule lights to turn on or off or program an energy-saving mode. And at the end of the month, the homeowner can create a provisional bill to see his or her energy savings.
Benefits focus on cost savings and reduced waste
New technologies enable the further development of Smart Grid initiatives by allowing utilities to improve operational planning and better manage grid assets and their workforce, but also to respond quickly to marketplace pricing actions and customer demands.
As customers and prosumers get more involved in the power and distribution process, utilities can realize cost savings by enabling more flexibility and faster response. Operating in such a manner implies tight interfaces between the public Smart Grid and the local participants that are standardized and compatible in both directions. Although investments in these new technologies may increase short-term capital costs, long-term advantages will include lower operating costs, reduced energy waste and a more integrated and flexible network.