Voltage stability analysis for the receiving-end grid of UHV-DC transmission system

Ultra high voltage direct current (UHV-DC) transmission system presents certain adverse reactive characteristics to its receiving-end grid. Voltage stability analysis for the landing point of UHV-DC transmission system is needed to find the available transmission capacity and its influence factors. First, this paper sets up test systems to discuss key influence factors, which are classified into grid limit and components limit. Secondly, with the real UHV-DC project of ±800kV HaZheng in China, a comprehensive analysis approach is presented to analyze the available transmission capacity of the landing point. The assessment procedure takes into account the normal, N-1 and N-2 operation conditions as well as the UHV-DC system operation variables, including commutation failure. Finally, the voltage stability assessment for the ±800kV HaZheng project is demonstrated. This presented method is simple and effective, which is usable for planning and operation of UHV-DC transmission system.