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GridEye flexibility service to distribution systems through distributed technologies

Periodic Reporting for period 1 - GiFlex (GridEye flexibility service to distribution systems through distributed technologies)

Reporting period: 2019-07-01 to 2021-06-30

The intermittent renewable generations and electrification of heating, cooling and transport connected to the distribution grid pose increasing challenges to maintain the balance between supply and demand and grid security (voltage and line flows). Therefore, the DSO needs to have provision for flexibilities not only from large resources, but also small-scale resources (generations and demand) connected to the LV grid. Besides, the TSO requires more flexibility resources for ancillary and balancing services from the distribution grid. However, due to the lack of monitoring of LV grids, a large portion of flexibilities remains untapped. In view of this, the following problems are addressed –
•The provision and activation of flexibilities from the LV grid is difficult due to lack of LV grid visibility
•The non-optimal operation of the grid leads to inefficient utilisation of grid resources and assets
•It is difficult to have an up-to-date and accurate LV grid topology information
These problems pose serious challenges for the hosting capacity of renewables. They provide barriers to consumers participation by way of demand response programs and in particular, the transition to decentralisation and decarbonisation of the electricity grids. Therefore, innovative solutions for addressing the problems are important to achieve the reduction of carbon emissions and as a whole, for the society.
The overall objectives of the project are –
•Demonstrate the importance of LV grid monitoring for distribution grid operation
•Provide a flexibility provision methodology for the secondary substations of the distribution grid
•Develop a robust optimisation framework to take into account the worst-case uncertainties of the DER forecasts
•Ensure an optimal operation for the MV and LV grids together
•Develop a methodology to estimate fast and slow flexibilities separately at the interface with the TSO
•All methodologies, based on model-based MV grids and sensitivity coefficients based model-less LV grids, do not require an accurate and up-to-date LV grid topology
Running from July2019 to June2021, the project looked at how the DSO will be able to reduce their costs of operation in terms of technical losses, congestion costs, penalty costs to the TSO by efficiently accessing and utilising the flexibilities available from the LV grids. The scientific results achieved are –
•The project demonstrated the importance of LV monitoring for secure and optimal grid operation
•GiFlex was to develop an algorithm to estimate aggregate flexibilities from the LV grid at the secondary substations and at the primary substations with and without forecast uncertainties
•It developed grid aware algorithms for flexibility activation with model-based MV grid and model-less LV grid approaches
•It proposed a solution for fast and slow flexibility services provision to the grid operators
Further, the work also carried out intensive career development activities and two-way transfer of knowledge. The fellow participated in many webinars, meetings and discussions, organised several seminars and workshops, gained knowledge on project management skills, gained a thorough understanding in the host’s product. Some important professional networks were made through participation in project meetings, webinars and conferences. Through the presentation in conferences, seminars and workshops, the valuable skills of effective communication were learnt. The value of LV monitoring is published in CIRED Workshop 2020. The estimation of flexibility at the secondary substation with and without uncertainties is published in CIGRE Symposium 2021; the activation of flexibilities whilst ensuring grid security and minimum technical losses are demonstrated in the conference publication at CIRED 2021. 1 journal publication addressed the problem of optimal operation with MV and LV grids together and estimation of fast and slow flexibility services separately at the TSO interface. The outcomes of the project were disseminated by maintaining a webpage on the host’s website, by organising seminars and workshops for the commercial teams, by participating in an interview organised by the communications team. The findings of the project were discussed or communicated to the commercial team, who are directly facing the stakeholders (DSOs). The scientific value of GiFlex has tremendous potential to be implemented in the GridEye platform and commercialised in future.
Beyond the state-of-the-art
The project has made significant contributions to the state-of-the-art operation of distribution grids. At the MV level of the distribution grid, monitoring is available only at the feeder-outs of the HV/MV transformer and there is no monitoring at the LV level. The current distribution system operation is based on load disaggregation in proportion to the ratings of MV/LV transformers. This gives rise to sub-optimal operation, voltage violation and overloading of distribution grids. In the current practice, the flexibility from DERs is mainly realised by contractual flexibility or non-firm connection where, the DERs are disconnected whenever there is a security issue in the grid. The technical flexibilities available through optimal grid operation is largely not present in the current scenario as this requires significant grid visibility. The technical flexibilities can be realised by the estimation and activation methodologies proposed in GiFlex.The smart meters have several limitations regarding data storage and faster data transfer. Moreover, the data privacy issues associated with smart meters render them difficult to be used for real-time operation. The μPMUs have the challenge of high accuracy in distribution grids and the requirement of data concentrators. GridEye which provide synchronised and accurate data are particularly beneficial for the estimation and activation methodologies of GiFlex without the challenges of smart meters and μPMUs.
Potential impacts
The objectives and results of the project are in line with the electricity industry requirements in terms of improved resource management, grid security and enabling increased renewable energy capacity penetration. The project outcomes will create new market opportunities for the host. The innovative aspect of model-less LV grids and model-based MV grids approach will be beneficial for the DSOs as the methodology does not require an up-to-date and accurate information on grid topology. The results show that the provision and the activation of flexibilities are pivotal for the DSOs in their journey towards a digitalised, decentralised and decarbonised system while maintaining grid security in terms of voltage and line flows. The solutions provided address the current challenges faced by the DSOs and can be potentially deployed by them. Moreover, the project provides a roadmap for flexibility from resources connected at the LV level. This will increase the hosting capacity of renewables in the distribution grid and help achieve the targets set out by the EU for carbon emissions reductions in the electricity sector. The outcomes are in line with the EU policy objectives and will have further impact on EU strategy and policy making. Furthermore, the results will facilitate prosumers from the LV grid an increasing role to play in demand response programs through EVs, thermostatically controlled loads, ESS, and renewables and also, reduce their energy consumption.
Overview of GiFlex - model-less LV and model-based MV grids showing flex estimation and activation