CONTROL PERFORMANCE OF LARGE SCALE STEAM POWER PLANTS AND IMPROVEMENTS

Current energy market developments stimulate a dual electric power supply, which correspondingly increases the demands concerning flexibility and manoeuvrability of large-scale steam power plants. For these purposes, a joint research project between the University of Stuttgart and Vattenfall Europe Generation1 has been initiated with the objective of creating an improved unit control concept, using advanced control techniques like nonlinear model-based and flatness-based feed-forward control. In a first step, however, the dynamic behaviour of existing large-scale generating units had to be analysed, which not only included an isolated analysis of each considered unit, but also the novel approach of a comparing analysis. Discrepancies in the control behaviour even between structurally identical units were detected. Considering the mentioned background, the overall results show that the currently dominating linear unit control concepts have several dynamic and static restrictions, especially when a unit is participating in the network frequency control.