OASIS 4 ENERGY

A novel market design for the optimal allocation of multiple ancillary services in future low inertia power networks

State of the art – Reasons for working on the project

The integration of large shares of Renewable Energy Sources (RES) in future power systems is concerning most of the system operators worldwide. Besides the uncertainty and the variability characterizing most of their outputs, RES may not be able to provide ancillary services, such inertial response and fast frequency response, in their standard configuration. This increases the risk of activating expensive demand disconnection schemes or causing a black out.
The current framework for the optimal and secure integration of RES in power systems is limited by three major factors:

  1. The optimal allocation of frequency response services does not recognize the reduction in inertial response. Also, current methodologies do not consider the actual transient dynamic response of generators to frequency variations since they rather implement fixed ramping characteristics as for current market products.
  2. The current market design for frequency-related ancillary services does not allow the trading of inertial response. This condition fosters a market malfunctioning since such an important feature for the system is out of market-reward mechanisms. Moreover, the overall auction price for long term contracts to deliver frequency response may not align with actual economic value for the system, preventing the market participants from receiving the right reward.
  3. Current system scheduling methodologies do not consider competing aspects concerning the provision of multiple ancillary services from different assets, simultaneously.

Objectives of the project

The fundamental objective of this project is to address the three research gaps and limitations highlighted above.

  1. The first objective is the development of a novel security-constrained optimal power system scheduling model where the transient dynamics of the response to frequency changes of the most relevant assets of the system are modelled by means of a more realistic and accurate formulation. In particular, the dynamics of the frequency response provision of synchronous generators will integrate the intrinsic features of the typical governor response of these units rather than translating them into a simplistic linearly-evolving ramping up response.
  2. The second objective aims to develop a market clearing platform which acknowledges the actual value for energy and all the ancillary services. This will increase the fairness and transparency of the energy costs sustained by end users and will provide right signals to the market participants and will improves the operation and planning of the system. Also, the proposed market design would incentivise each participant to submitt truthful biddings.
  3. The third objective of this project is to model and simulate, at the same time, the aggregate behaviour of different types of flexible technologies to study the optimal repartition of the contributions to system requirements for ancillary services among different of flexible assets.