Utilities are facing new challenges in managing their grids with increasing penetration of variable distributed generation. Unclear, fluctuating direction of load flow and, more and more often, critical voltage violations are some of the challenges. There is a growing risk of voltage range infringement and thus malfunctions or even damaged equipment on the consumer side. At the same time, the danger of overloads on lines, transformers and other equipment is growing, which can even result in grid failure.
These were some of the challenges facing UK distribution network operator Northern Powergrid in its Customer-Led Network Revolution (CLNR) project – a comprehensive smart grid demonstration deployed in northeast England with support from Ofgem’s Low Carbon Network Fund. The aim of this the largest LCNF project – to develop new technologies and learnings to help drive the country towards a low carbon energy system in order to meet long term climate commitments.
Customer-Led Network Revolution looks to low carbon future
The CLNR, which was launched in 2010, had two strands. One strand was focused on customers, with more than 13,000 residential and small and large commercial customers trialling a range of technologies and services including solar, electric vehicles, heat pumps, micro-CHP, smart appliances, time-of-use tariffs and demand management.
With these new loads, a second strand was focused on their impact on the network and the potential for active management of the network with storage, enhanced automatic voltage control and real-time thermal and other monitoring, underpinned with an advanced active network management system.
From this has emerged the Grand Unified Scheme (GUS) which was developed by Siemens based on its Spectrum Power network management system technology as a unique and arguably the most advanced system of its type in the world.
Active network management
Markus Reischboeck, Senior Key Expert Renewable Integration at Siemens AG, explains that GUS is a hierarchical solution with central control and autonomous district controllers for local control in the substations.
“We adopted a generic approach that automatically adapts to new conditions and new assets in the network, without the need for manual configuration,” he says, pointing out that a rule-based approach – in which all the field assets must be configured manually – is practical for only a limited number of assets. “With this approach the system is able to take into account all the options for balancing the network, whether to use storage or a capacitor bank or make a demand response call for example, and to select the best option from both the cost and technical perspectives.”
Mr Reischboeck, along with colleague Colin Henry and Ian Lloyd, who led the CLNR demonstration at Northern Powergrid, describe the solution and its potential in an Engerati webinar, The most advanced network management system available today – Enhance and manage increasingly complex dynamic distribution networks.
GUS at Northern Powergrid
Mr Reischboeck says that GUS is aimed at the parts of the network in which the proportion of renewables is growing and traditional management is becoming or likely to become impractical, and can be expanded according to need.
He comments on three interesting learnings that emerged during the development of GUS, which is now available as an off-the-shelf solution and is also being used by other utilities, including Electricity North West and Western Power Distribution in the UK.
These were an underestimation of the effort required to deploy and integrate the primary equipment and controls in the field, an underestimation of the testing time required to move from the rule-based approach to the more complex generic application, and the cultural aspect of the need for personnel to accept that such complex decision making could be automated – a process that took more than 1 year.
“The system met all the project objectives, as assessed by Newcastle University, and has been up and running for over a year now,” says Mr Reischboeck. “We believe it offers a solution for the network management of the future.”
To learn more about Siemen’s active network management solution and its implementation and use at Northern Powergrid, register here for the webinar.