Over 400 delegates from all over the world attended the Symposium, which followed a total of 50 Study Committee and Working Group meetings. Study Committees C1, C2, C4, C5, C6 and B2 were joint sponsors, which ensured a wide range of topics and an extensive range of expertise in attendance. Tutorials were provided on power quality issues in future networks, demand side management, investment drivers in an uncertain environment, the impact of battery storage on distribution networks and a number of aspects of transmission line design and construction.
There was also a technical visit to the Eirgrid control room where the management of wind generation output from 3GW to virtually zero was demonstrated. At the demonstration it was noted that there is a full back up provided by conventional generation and a key issue is dealing with managing continuity of supply during the steep generation ramping that can occur for sudden wind changes. Eirgrid calculates real time system inertia and fault levels. These calculations are used to ensure sufficient synchronous plant is dispatched to keep inertia and fault levels above minimum thresholds. It is expected that this type of calculation will become a standard feature in system operation tools.
A key focus of the Symposium related to how the changing generation mix, particularly in relation to wind and solar, is affecting the technical performance of the power system. New methods of power system operation are being developed to minimise these effects. They include the use of conventional generation to provide fast start back up and to help minimize the impact of rapid changes in generator output. Batteries and active load flexibility are also being used to provide ancillary services, manage load peaks and load shifting. However there is a need for markets to move to 5 minute pricing and settlement for wholesale electricity to unlock the value of electricity storage systems. During the Symposium it was noted that the cost of renewable generation continues to fall. An example was given of a recent agreement in the United States of US$45 per MWhr for a 100 MW PV plant with battery storage (30MW/120MWhr).
New methods to quantify the benefits of technology and geographical diversity of variable generation are being developed. In addition, new information is being used to improve risk assessments of asset outages and failures. Real-time weather information and historic outage information is being used to predict fault risks and locations and to dispatch repair crews. In some systems, coordination between transmission and distribution system operators is seen as a growing problem.
A number of working groups held meetings on a range of topics. For example, SC C5 has initiated a number of new working groups on the value of smart grids, systemic market risk, the role and levels of market price caps and regulatory aspects of storage. Australian members remain very active in CIGRE working groups and within C5 they are leading two that are looking at systemic market risk and the drivers for changes to market designs. One of these, WG C5.22 seeks to understand the risk of collapse of an entire electricity/gas market. This is known as Systemic Risk. The WG will examine market collapse risk as opposed to risk associated with any one individual entity.
Generation and load devices that we connect to the power system have changed significantly in recent years. At the same time, how we establish new network connections has also been changing. In addition, the ‘new’ operating scenario of more HVAC cables and fewer synchronous generators deserves special consideration. The collection of large volumes of data and validation of new models will be critical if we are to understand the impacts and potential risks of the new technologies.
Several aspects of overhead lines from design to construction and from line route acquisition to in service performance were covered. Interesting examples were provided on the upgrading of existing lines as well as improving visual appearances and the use of new products and materials. Amongst others, a new working group on “Assessment of Wood Poles” has been approved and an Australian convener appointed.