Running Cool seeks to challenge current Active Network Management (ANM) curtailment arrangements by creating a new post fault capability for overhead lines and a new ANM architecture which will help to avoid curtailment. An improved system of short term dynamic OHL ratings (informed by real-time conductor temperatures) and a new corresponding ANM control system architecture will be the key outputs of this work.
Benefits
Running Cool seeks to challenge current Active Network Management (ANM) curtailment arrangements by creating a new post fault capability for overhead lines and a new ANM architecture which will help to avoid curtailment. An improved system of short term dynamic OHL ratings (informed by real-time conductor temperatures) and a new corresponding ANM control system architecture will be the key outputs of this work. By improving the overall capacity of the distribution network WPD can look to accommodate more clean embedded generation connections, which would lead to a reduction in the overall carbon intensity of energy delivered to customers and thereby help to deliver and achieve ‘decarbonisation and Net Zero’ – a priority area in our Innovation Strategy.
Learnings
Outcomes
At the time of writing, six installations of SN2.0 devices have been completed as part of the project: three in East Midlands, two in South West and one in South Wales licence area.
A preliminary analysis of the temperature, and STPFR data collected by the SN2.0s installed in Rame (South West) indicates that there has been a potential average uplift in capacity of 18%, when compared to the static winter post-fault rating during the two weeks that the equipment has been installed. When compared to the seasonal static pre-fault rating, a more significant uplift is shown, with an average of 29%, up to a maximum of 34%. Lower ambient temperatures in January contribute to higher STPFR values as the overall conductor temperature remains low despite operating at an equivalent load. Data collected between the winter months, December to February, will provide a representative example of the maximum possible uplift that is expected for the circuit. This is due to the static post-fault rating value operating at its lowest level.
As more data is collected throughout the various seasons in the year, it will be possible to assess the total potential uplift capable when implementing a STPFR in Rame and other locations of interest.
Full detail will be shared once all equipment is installed, data gathered and analysis complete.
Lessons Learnt
- To quantify potential benefits (deferral of curtailment), it was required to install equipment on 132kV OHL network to gather data. The original project plan accounted for all equipment to be installed within 6 months in autumn/winter period which has been proven to be inadequate due to complexities and risks associated with 132kV line operation, specifically 1) requesting 132kV outage in winter period is associated with a significant risk of thousands of customers left off supply in winter period where the probability of storm hitting the network is noticeably higher than in summer; 2) a lot of network sections of interest to Running Cool have distributed generation connected/bordering with other DNOs which means arranging an outage is time consuming and involves coordination with a lot of parties. Taken that NGED Major Projects teams schedule outages predominantly in warmer periods, the probability of them arranging additional outage on the same part of the network on 132 kV OHL line with identified complexities specifically for Innovation purposes is low. For any future 132kV OHL installations it is recommended to target summer period for any works required and to consult outage schedule ahead of project commissioning with close liaison with local major projects teams. Three months lead time for liaising with major projects teams is recommended for future installations.
- The short-term rating of an OHL exploits the thermal capacity of the conductor material (such as aluminium, aluminium alloy or copper). The calculation of the adiabatic rating, based on CIGRE Technical Brochure 601, is not dependent on the measurements of other heat transfer mechanisms (such as convective cooling, solar heating and radiative heating/cooling). The conductor temperature measurement is the only parameter required to be monitored in real-time to provide a rating to cover short-term (up to 10-minute) post-fault generation curtailment events. A 10-minute rating was selected to allow ANM systems to take “post event” actions, since ANM reaction and enaction times have been shown to be as long as 10 minutes.
- There are three available strategies for passing STPFR value from the source of STPFR system to the ANM, specifically 1) The STPFR system can send the STPFR value(s) directly to the WPD PowerOn. These are then included in the PowerOn to ANM ICCP transfer set, in conjunction with the majority of other ANM signals; 2) The STPFR system can send the STPFR value(s) via DNP3 directly to the ANM system FEP (Front End Processor); 3) The STPFR system can send the STPFR value(s) via a RESTful API directly into the ANM database. The preferred method for passing STPFR values from the source to the ANM system is to send the values directly to NGED PowerOn system This avoids the creation of multiple interfaces to the ANM system which in turn has an undesirable IT maintenance burden. It also aligns with a long-term plans for the ANM system being managed in-house by PowerOn.
- Interim results using a year-long data recorded as part of OHL Power Pointer project have shown that 132kV circuits with limited available capacity (e.g. K-line in NGED South West licence area), operating at the seasonal pre-fault static rating, and consequently higher temperatures, will not produce a significant potential uplift in current. For circuits where this is the case, the implementation of a STPFR is to be assessed further. The data from the OHL Power Pointer project was used due to the delay to Running Cool install as indicated above, and the desire of the project team to test the initial methodology. At the moment of writing Running Cool is gathering data to perform comprehensive analysis and to establish cases where the STPFR capability would bring most value by potentially creating headroom and reducing curtailment.
- Communications failure: SN2.0 installed in South West in January 2023 lost signal after two weeks of normal operation. The investigation of the issue involved engagement with mobile network provider and SN2.0 manufacturer to establish a route cause of the issue. It was revealed that sim cards installed in two SN2.0 devices were purged and stopped transferring data. It was one off event which lasted three weeks. After mobile provider was contacted and pushed through the signal to the sim card they came back online. However, the mobile provider could not provide a sufficient detail as to what exactly happened and caused the disruption. This incident raised a concern for reliability of mobile network for a functionality proposed by Running Cool if SN2.0 are used for this purpose. Further considerations will be given into looking at alternative temperature measuring device that doesn’t require a sim for data transfer or potential use of FTE network.
