This project aims the development of a methodology and an operational tool for the Dynamic Line Rating (DLR) analysis of potentially congested electrical networks for optimal integration of renewable energy sources (REs) in a cost-efficient way. DLR steady-state analysis is traditionally used to assess the seasonal capacities of power systems lines. The OptiGRID project will demonstrate the benefits of using DLR techniques namely in terms of 1) increasing the RES penetration levels and reducing the need for curtailment in the power system and 2) reducing the number of market splitting hours in the Electricity Market and consequent impact on electricity market prices, thus contributing to a more sustainable, energy and cost-efficient economy. The implementation of DLR analysis will play a key role in increasing RES penetration levels into the existing power system, without requiring grid reinforcement. The resulting additional power line capacity from DLR analysis alleviates congestion problems and allowing higher levels of distributed RES capacity in the power system. This becomes of particular importance in systems with high generation of wind power (as in the Portuguese case) because of the existing correlation between the higher line rating and the increased wind power generation achieved under high wind speed conditions, where the extra cooling effect of wind speed provides the alleviation of congestions and the consequent accommodation of higher wind power levels.
Schematic representation of a quasi-stationary approach for DLR analysis of potentially congested networks.
Although the benefits of applying DLR techniques have local nature and depend on weather conditions, preliminary studies indicate an increase of the line capacity up to 20%, significantly more than the one obtained by the usual conservative static approach. This increase on the line capacity is also important for system operators concerning power exchanges with neighbouring countries. The Import/Export capacity is dependent on some relevant branches (not only the tie-lines) which will benefit from the increased capacity allowed by applying DLR techniques. This is especially important when the power exchanges limited by line capacity may cause a market split with an impact on the corresponding market prices. The envisaged tool will allow the assessment of DLR analysis facilitate massive integration of RES considering not only actual operational conditions, topology, and electrical characteristics of the transmission network (TN) but also the foreseen expansions of the TN accommodating higher renewable levels. Suitable case studies will be developed under OptiGRID considering current and future scenarios of high RES penetration levels in the power system, as well as different constraints.
This work is funded by national funds through the FCT – Fundação para a Ciência e a Tecnologia, I.P., under the grant PTDC/EEI-EEE/31711/2017.
Date of approval: 06.07.2018
Total eligible cost: 239.874,06€
Start date: 01.10.2018
End date: 30.09.2021