CIGRE Study Committee C6 and outcomes of a recent study into limits of distribution feeders for hosting DG

Study Committee C6 is relatively new to the world of CIGRE, having commenced in 2002 in response to the growing impact that distributed/dispersed generation (DG) was having on power systems.

The mission of SC C6 is to facilitate and promote the progress and exchange of knowledge in the field of system impacts of distribution systems integrating DG, by synthesising state-of-the-art practices and developing reports for dissemination amongst people active in the field of power systems.

WG C6 recently published a Technical Brochure considering the Capacity of Distribution Feeders for hosting Distributed Energy Resources (DER).

The last two decades have seen an unprecedented development of distributed energy resources (DER) all over the world. Several countries have adopted a variety of support schemes (feed-in tariffs, green certificates, direct subsidies, tax exemptions, etc) to promote distributed generation (DG). This is especially so for those exploiting renewable energy sources (RES). Under these circumstances, Distribution Network Operators (DNOs) are experiencing a strong pressure to respond to an often excessive demand for access to the network while, at the same time, ensuring that DER connection does not violate the technical standards of the networks.

To address this need in a timely and effective manner, simplified methodologies and practical rules of thumbs are often applied to assess the DER hosting capacity of existing distribution networks, thus avoiding detailed and time consuming analytical studies.

The scope of the CIGRE WG C6-24 was to study the limits of distribution feeders for hosting DER and the derivation of practical guidelines for the connection of DER. The approach adopted by the WG was to study the technical evaluation practices adopted by DNOs all over the world, in order to identify suitable rules and methodologies, as well as the means currently available to increase the hosting capacity.

The focus of the study was on practical and easy to apply methods, as well as on means and solutions currently applied, rather than on research grade solutions, which may become suitable for application in the future.

The WG C6 Technical Brochure summarised the main results of the study, covering rules, methodologies and guidelines applied by DNOs worldwide to determine the hosting capacity of distribution networks. Within this framework:

• The main technical issues and limiting DER penetration levels have been summarised
• Evaluation practices and simplified criteria adopted in numerous countries have been presented
• Means employed to increase the hosting capacity of networks have been reviewed.

Download the Technical Brochure

The Australian Panel of C6 mirrors the international Study Committee and is chaired by Ken Ash of Cairns, Queensland. It has around 20 current members, drawn from a cross section of power utilities, academic institutions, energy system consultants and product/system vendors.

In August 2015, AP C6 is planning to run the inaugural Australian C6 Technical Seminar, in Brisbane, focusing on topics such as Microgrids, Energy Storage and increasing the penetration of Distributed Generation. Details will be posted on www.cigreaustralia.org.au when available.