Adding intelligence to private power distribution networks can improve reliability and efficiency by accelerating fault-finding and enabling new commercial opportunities.
Many industrial, commercial and municipal sites rely on private power distribution networks to keep their operations running. Most of those networks have no intelligence or automation, and have manual switchgear and safety devices. While these networks have the benefit of simplicity and relatively low cost, they can be labour-intensive to manage, especially when faults occur.
In the event of a fault, protection systems will act upstream of the fault to isolate the affected circuit, that may mean power is cut to other circuits in the area too. To find and fix the fault, facilities management teams have to embark on a time-consuming process of trial and error. They must move around the site, selectively re-engaging protection systems to isolate the problem. Each of those actions puts further stress on the equipment, potentially creating additional damage.
Unlike public overhead distribution networks, the circuits used in private networks are frequently underground, which further complicates fault isolation and repair. And while parts of the network are out of action, sites may have to rely on backup power from local diesel generators, which are expensive to run and result in increased CO2 emissions. Moreover, site expansion and the installation of new equipment can drive up electrical demand, while new types of equipment, such as on-site embedded renewable generation capacity, add additional complexity to power flows, sometimes loading the network in unexpected ways.
Time to automate
From our discussions with operators of privately owned distribution networks, they are increasingly interested in ways of improving network reliability and availability of the power supply and to reduce management and repair overheads.
These capabilities can be implemented with various levels of functionality. At the simplest level, remote monitoring devices can be installed across the network, providing information on power flows and assets status to a central monitoring point. At the next level, motorised, remotely operable switchgear can be installed to allow centralised control. A further level of capability is the introduction of Fault Location, Isolation and Supply Restoration (FLISR) technology. In this approach, sensors and fault location devices on the network detect the rapid changes in current flows associated with a fault – typically a sudden peak followed by the operation of a trip device – and determine the specific segment within their network where the fault originated.
The system will then alert the operator, allowing the affected segment to be quickly isolated and power restored to the healthy part of the network. FLISR systems can operate in a fully automated “self-healing” regime, in which the system takes the necessary action without operator intervention. Moreover, because FLISR automatically narrows down the likely location of the fault, it makes problems much faster and easier to fix. Where underground cables are involved, for example, maintenance teams no longer have to dig long trenches as they hunt for the source of a problem which results in cost savings and time efficiencies.
Don’t replace, enhance
While they understand the benefits of automation, the owners of private distribution networks are often concerned about the cost of the technology, and the potential disruptions associated with the replacement of significant parts of their existing control hardware and protection systems.
Those fears are unfounded. Today’s technologies allow sophisticated automation capabilities to be added to an existing private network with minimal changes to the existing installation. Motorised actuators systems can be added to manual switchgear, for example, and the necessary sensors and communication equipment can be installed alongside the existing control system. The software for network visualisation and FLISR can be integrated with the site’s existing supervisory control and data acquisition (SCADA). Capula has installed advanced control capabilities at a number of customer sites, where a wide range of legacy hardware from different suppliers was in use.
Advanced monitoring and control capabilities can provide a range of additional benefits for operators beyond improved reliability and resilience. For example, on-site or cloud-based power quality analysis software can be integrated with the network SCADA, helping owners to track down the root cause of problematic harmonics and imbalance in the network, improving the network’s power quality. In addition, where an organisation has flexibility in electrical loads, or significant on-site backup generation capacity, network automation can allow a site to participate actively in the energy market, providing Demand Side Response services to the grid and turning its existing assets into new sources of revenue.
How Capula can help
With over 50 years of control and systems integration experience in the power generation, transmission and distribution sectors, Capula is ideally positioned to help organisations add control and intelligence to their power networks. We have designed, implemented and supported IMPERIUM control and automation solutions for power applications of all sizes from utility scale down to individual sites. Our IMPERIUM solutions start with simple energy monitoring systems and extend to encompass automation of the most demanding networks. For more information visit Substation Automation.