Research on the Quantitative Evaluation Method for the Reactive Power Support Capability of the Synchronous Condensers Retrofitted from Large Thermal Power Units

As the construction of new-type power system progresses, the power supply tends to be "hollowed out"in load centers, leading to a severe lack of dynamic reactive power support and threatening the security of the large power grid. Retrofitting the soon-to-be-decommissioned outdated thermal power units into synchronous condensers(SC) can not only address the issue of insufficient dynamic reactive power support in the power grid, but also fully utilize the remaining value of the units. Based on an actual retrofitting case, this paper proposes a quantitative evaluation method for the reactive power support capability of SCs retrofitted from large thermal power units. The evaluation work can be carried out from both the steady-state support capability and the dynamic support capability. Finally, by analogy with the performance requirements of a newly built large-capacity SC, the calibrated capacity of the retrofitted unit and the percentage of its dynamic performance equivalent to that of a newly built SC with the same capacity can be obtained. The evaluation results can serve as a basis for grid dispatching departments to arrange production operations and are also the basis for economic compensation for reactive power auxiliary services of power plants, with significant practical implications.