Abstract
Line Commutated Converter High Voltage Direct Current (LCC HVDC) technology’s controllability has provided considerable flexibility for System Operators to maintain the stable and reliable operation of the modern power systems. This paper, based on the Kazakhstan power system, provides a detailed assessment of the impacts from LCC HVDC on the transient stability of the AC system. Different control modes of LCC HVDC have been assessed and the best combination has been proposed and tested in the detailed Kazakhstan power system model. Dynamic simulation studies are carried out for different fault conditions and comparisons are made with the case where AC transmission line is installed instead of DC. Test results are used to show that HVDC links improve the transient stability in comparison to the case with AC transmission line when fault is located at rectifier side or in the middle of the parallel AC line.