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As more and more renewable intermittent generations are being connected to the distribution grid, the grid operators require more flexibility to maintain the balance between supply and demand. The intermittencies give rise to situations which require not only slow-ramping flexibility capability but also, fast-ramping flexibility capability from a variety of resources connected at the MV and LV distribution grids. Moreover, the intermittencies may increase the costs of grid reinforcement. Therefore, to defer the reinforcement of the grid assets, the grid needs to be operated optimally. This paper proposes - a) such an optimal operational methodology for the MV and LV grids; and b) an aggregated flexibility estimation methodology estimated separately for fast and slow services at the primary substation (TSO interface). The methodologies based on model-based MV grids and a sensitivity coefficients-based model-less LV grids are suitable for LV grids where an up-to-date and accurate model and topology are not always available. The approaches of the paper use the synchronised and accurate measurements from grid monitoring devices located at the LV distribution grids. It is assumed that the implementation of the methodology is centralised, where a grid monitoring device or a central platform is capable to host grid aware algorithms and to communicate control setpoints to DERs. The approaches have been validated on a real MV and LV networks of a Swiss DSO equipped with grid monitoring devices. The results, in terms of technical losses, grid violation costs and flexibility capability curve, show the efficacy of the optimal operation and flexibility estimation methodologies and therefore, can be easily deployed., Comment: 8 pages, 8 figures, IEEE PES Transactions

Due to increased penetration of renewable resources in the distribution grid, the distribution system operator (DSO) faces increased challenges to maintain security and quality of supply. Since, a large proportion of renewables are intermittent generations, maintaining production and consumption balance of the electric system is at stake. The DSO needs to procure flexibilities not only from large resources, but also small-scale resources connected to the LV grid. Therefore, there is a need to estimate the aggregate flexibility at the secondary substation available from the LV grids. The flexibility estimation can only be achieved through monitoring of LV grid and the distributed energy resources (DERs) connected at the LV level. Moreover, the variability of intermittent resources affects the flexibility estimation methodology, and the DSO operation must be robust to the changes in generation or demand outputs. Furthermore, the up-to-date and accurate model of the LV grid is difficult to access. This paper demonstrates a methodology of estimating flexibility by sensitivity coefficients and thus, eliminating the need to have an up-to-date LV grid model. It further presents a robust optimisation based methodology for grid operation to address the impact of forecast uncertainties associated with the variable DER output. The methodologies illustrate the value of grid monitoring with a monitoring equipment. It has been validated on a real network of a Swiss DSO with several grid monitoring devices., Comment: 6 pages, 7 figures, CIGRE Symposium 2021

In order to maintain security and quality of supply while supporting increased intermittent generation and electrification of heating and transport at the LV grid, the provision of flexibility in the framework of distribution grid operation is pivotal. However, the availability of updated and accurate LV grid model is a challenge for the distribution system operator (DSO). This paper demonstrates a methodology of efficient flexibility provision and activation through a sensitivity coefficients-based model-less LV grid and a modelled MV grid approach. The paper further illustrates the value of monitoring and control through a LV DERMS platform for efficient realisation of this flexibility provision and activation. The methodology has been tested on a real MV and LV network of a Swiss DSO. The results show that there is a reduction of cost of operation for a DSO., Comment: 5 pages, 8 figures, CIRED 2021

The increased flexibility requirement needs a flexibility market at the distribution grid level operated by the distribution system operators (DSOs) to resolve challenges to ensure secure operation and, to integrate new renewable productions or loads in the grid. Therefore, the network visibility and monitoring are paramount to distribution network operation. This paper presents a methodology demonstrating the value distribution grid monitoring can bring for the realisation of a local flexibility market. This paper further illustrates the reduction of costs of operation of a DSO with the help of grid monitoring and local flexibility market while maintaining a secure and reliable operation. The methodology has been applied on a real 35 node MV network of a Swiss DSO with several GridEye measurement devices. The performance in terms of losses and voltage and flow violation costs is compared with sub-optimal operation without monitoring., Comment: 4 pages, 5 figures, CIRED workshop 2020