Available Transmission Capacity Analysis for the Receiving-End Grid of UHV-DC Transmission System

UHV-DC transmission system presents certain adverse reactive characteristics to its receiving-end grid. Based on the approach of P-V curve and V-Q curve, this paper presents a method of voltage stability analysis for the receiving-end grid of UHV-DC transmission system, which gives its available transmission capacity (ATC), voltage limit and reactive power margin, with the consideration of the normal, N-1 and N-2 operation situations and the situation of the commutation failure. Different with traditional ATC analysis, the characteristics of UHV-DC transmission system is included here. With the real UHV-DC project of ±800kV HaZheng in China, the effectiveness and efficiency of the proposed mothed are verified.