RSE
A A
Login
login name
password
login
GSE
ITA english

Report RSE 17001180

Methodologies for the analysis of active network: applicative example

Report

2016.

Request Document (5.50 MB, .pdf)

G. Viganò (RSE SpA), C. Carlini (RSE SpA), D. Clerici (RSE SpA), C. Michelangeli (RSE SpA), M. Rossi (RSE SpA), D. Moneta (RSE SpA)

RETE-DIS 2016 - Evolution and development of distribution networks

The progressive decarbonisation process of the European continent, reaffirmed in 2014 by the European Council, confirms the crucial role that electricity networks. Ultimately, it is reasonable to expect further development of distributed generation (DG), mainly from non-programmable renewable source (mainly photovoltaic), and the diffusion of electro-technologies to replace other vectors (heat pumps, electric vehicles). In addition to the more technological aspects, the hypothesis to extend market share for ancillary services to generation from non-programmable renewable sources and DG is also shared. In order to better investigate these critical issues, the research activity has followed four main directions. Firstly, continuing the previous activities, the Italian smart grid pilot projects have been analyzed, in order to identify the most promising control solutions and the most common issues. Secondly, methods for the artificial generation of distribution networks have been identified to conduct relevant scenario analysis on distribution networks and available control systems. Furtherly, the effects of local droop controls (Q-V) of generators on the distribution network has been deeply examined. Finally, the Hosting Capacity evaluation method (developed during the previous reference period) has been further developed. Its approach, based on the stochastic allocation of generation resources on the distribution network under test, has been completely redesigned in order to allow, first of all, a lower computational burden (which is one of the most critical aspects in Monte...

The progressive decarbonisation process of the European continent, reaffirmed in 2014 by the European Council, confirms the crucial role that electricity networks, particularly distribution networks, will cover over the next few years in pursuing the CO2 reduction targets and the exploitation of renewable sources. Ultimately, it is reasonable to expect further development of distributed generation (DG), mainly from non-programmable renewable source (mainly photovoltaic), and the diffusion of electro-technologies to replace other vectors (heat pumps, electric vehicles). Network infrastructures themselves will have to participate in energy efficiency increases, improving their performance. In addition to the more technological aspects, the hypothesis to extend market share for ancillary services to generation from non-programmable renewable sources and DG is also shared, and in perspective also to loads and storage systems. However, the role of the various actors and mutual interactions are still to be defined, in particular the ways in which the distribution system operator (DSO) can reconcile the provision of services (global nature) by DG with the (local) needs of quality of supply. The DG will be able also to interact with the DSO in order to increase network observability and provide also local services such as voltage control support. The expected changes both on the generation side and on the demand side, briefly recalled, require the revision of methodologies of planning, operational planning, operation and ex post evaluation of DSO actions, in a context of uncertainty about developments that will actually go to affect the different geographic areas and the different levels of concentration (urban, rural).

In order to better investigate these critical issues, the research activity has followed four main directions. Firstly, continuing the previous activities, the Italian smart grid pilot projects have been analyzed, in order to identify the most promising control solutions and the most common issues. From these projects, a cost and benefit analysis has been conducted about the installation of electrical storage systems in distribution networks.

Secondly, methods for the artificial generation of distribution networks have been identified to conduct relevant scenario analysis on distribution networks and available control systems. These methodologies has been elaborated from the existent algorithm for the generation of random transmission networks. In parallel, the elaboration of these methodologies allowed to identify synthetic parameters of distribution networks (e.g. mean resistance, number of branches for node…), which allow to simply describe their main characteristics and behaviour.

Furtherly, the effects of local droop controls (Q-V) of generators on the distribution network has been deeply examined. In fact, the local control is one of the available solution to DSOs to foster the performance of the networks (CEI 0-16; 0-21). However, their effects on distribution networks and on the whole power system are still unclear. Besides, it is necessary to compare their performance with other available solution, like centralized controls, which have been largely implemented in the previously mentioned pilot projects.

Finally, the Hosting Capacity evaluation method (developed during the previous reference period) has been further developed. Its approach, based on the stochastic allocation of generation resources on the distribution network under test, has been completely redesigned in order to allow, first of all, a lower computational burden (which is one of the most critical aspects in Monte Carlo simulations). In addition, the method has been adopted as an evaluation tool aimed at quantifying the performance of Smart Grid technologies in terms of Hosting Capacity increase. Two application examples have been reported within the document, where the effects of active and reactive power local controllers of distributed generation units are simulated in order to evaluate their impact on the network quantities and containment of network constraints violations. In the first case, the results show how reactive power injection is beneficial for the integration of distributed generation when networks are voltage constrained, while a counter effect can be easily recognized when also network loading constraints are taken into account. Secondly, different active power curtailment strategies have been investigated and the study highlights how the intermittency of renewable based generation can be exploited in order to drastically increase the Hosting Capacity with a very marginal impact on the production losses.

Related Links

Topics