Dynamic Interaction of Power Plants and Power System in Deregulated Energy Markets - Practical Realization of Measures to Reduce Power Plant Stress

Project Number 332

The results of the VGB research project 306 "Dynamic Interaction of Power Plants and Power System in Deregulated Energy Markets - Measures to Reduce Power Plant Stress" accomplished by the University of Stuttgart under the management of Dr. Tobias Weißbach have attracted much interest and acknowledgment among experts.

The key findings are as follows:

  • The electric power market in Europe is almost exclusively based on 1-hour-schedules with a constant power target value for each 1-h-interval. The corresponding current market boundaries and system rules lead to remarkable power imbalances arising from the power difference between the continuous ramp-wise physical load behaviour and step-wise power schedule - especially at the change of the hour. These in the long term increasing power imbalances entail equally increasing frequency deviations which result in considerable disadvantages for the power plant and power system operation already today.
  • The resulting higher power plant stress which has to be included in the cost calculation for primary control, as well as the increasing amount of required secondary control energy are inevitably going to lead to higher control energy costs.
  • Furthermore, especially during the evening hours, a large part of the primary control reserve power is repeatedly activated, which means that the respective UCTE design hypothesis for the primary control reserve activation after a sudden loss of 3,000 MW generating capacity cannot be ensured during these time periods.

The within the framework of the VGB research project 306 presented proposals for improvement aim at measures, which lead to a better approximation of the ramp-wise physical load behaviour by the power trade, while keeping the power product discretization in 1-h-intervals.

The developed scientific well-founded approaches have now to be transferred into concrete measures on the power system and generator side as well as into the common rules of the electric power market. Respective discussions are required both on a national and a European level.

These technical discussions will be scientifically supported by the department Power Generation and Automatic Control of the Institute of Process Engineering and Power Plant Technology at the Stuttgart University. Further on, the development of the frequency behaviour as well as changing market conditions and regulations have to be monitored and evaluated promptly. If necessary, the proposed measures have to be specified and/or adapted.