Transmission system-friendly microgrids: an option to provide ancillary services

Liberalization of electricity markets has brought focus on the optimal use of generation and transmission infrastructure. In such a scenario, where the power transmission systems are being operated closer to their critical limits, Ancillary Services (AS) play an important role in ensuring secure and cost-effective operation of power systems. Emerging converter-based HVDC technologies and integration of renewable energy sources (RES) have changed the power system dynamics which are based on classical power plant operation and synchronous generator dynamics. Transmission system interconnections between different countries and integrated energy markets in Europe have led to a reduction in the use of energy from non-renewable fossil-based sources. This review paper gives an insight into ancillary services definitions and market practices for procurement and activation of these ancillary services in different control areas within the European Network of Transmission System Operators for Electricity (ENTSO-E). The focus lies particularly on ancillary services from HVDC systems. It is foreseen that DC elements will play an important role in the control and management of the future power system and in particular through ancillary services provision. Keeping this in view, the capability of HVDC systems to provide ancillary services is presented.

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Ancillary Services Market Design in Distribution Networks: Review and Identification of Barriers

Energies ◽

10.3390/en13040917 ◽

2020 ◽

Vol 13 (4) ◽

pp. 917 ◽

Cited By ~ 13

Author(s):

Konstantinos Oureilidis ◽

Kyriaki-Nefeli Malamaki ◽

Konstantinos Gallos ◽

Achilleas Tsitsimelis ◽

Christos Dikaiakos ◽

...

Keyword(s):

Electricity Markets ◽

Renewable Energy Sources ◽

Distribution Networks ◽

Voltage Regulation ◽

Transmission System ◽

Ancillary Services ◽

Distribution Grid ◽

Specific System ◽

Support Functions ◽

Grid Level

The high proliferation of converter-dominated Distributed Renewable Energy Sources (DRESs) at the distribution grid level has gradually replaced the conventional synchronous generators (SGs) of the transmission system, resulting in emerging stability and security challenges. The inherent characteristics of the SGs are currently used for providing ancillary services (ASs), following the instructions of the Transmission System Operator, while the DRESs are obliged to offer specific system support functions, without being remunerated for these functions, but only for the energy they inject. This changing environment has prompted the integration of energy storage systems as a solution for transfusing new characteristics and elaborating their business in the electricity markets, while the smart grid infrastructure and the upcoming microgrid architectures contribute to the transformation of the distribution grid. This review investigates the existing ASs in transmission system with the respective markets (emphasizing the DRESs’ participation in these markets) and proposes new ASs at distribution grid level, with emphasis to inertial response, active power ramp rate control, frequency response, voltage regulation, fault contribution and harmonic mitigation. The market tools and mechanisms for the procurement of these ASs are presented evolving the existing role of the Operators. Finally, potential barriers in the technical, regulatory, and financial framework have been identified and analyzed.

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DSO Flexibility Market Framework for Renewable Energy Community of Nanogrids

Energies ◽

10.3390/en14123460 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3460

Author(s):

Luca Mendicino ◽

Daniele Menniti ◽

Anna Pinnarelli ◽

Nicola Sorrentino ◽

Pasquale Vizza ◽

...

Keyword(s):

Renewable Energy ◽

Distribution System ◽

Transmission System ◽

Ancillary Services ◽

Energy Resources ◽

Electrical System ◽

Community Based ◽

Market Framework ◽

System Operator ◽

Energy Community

With the introduction of the renewable energy communities in the current electrical market environment, it becomes possible to aggregate small generation resources and users’ loads to exchange power within the aggregation and at the same time provide services to the electrical system. The renewable energy community of users equipped with nanogrid technology allows performing an adequate level of flexibility. It may be the solution to coordinate in the best possible way the energy resources in order to increase the community self-consumption and to provide ancillary services to the grid. In this paper, a model for the interaction between the Distribution System Operator (DSO)—Transmission System Operator (TSO) and the energy community based on nanogrids is proposed and an operational example is presented.

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