Stability Mechanism Analysis and Improvement Measures for Sending End Near Area Power Grid with UHVDC Transmission System

In hybrid power grid, mutual support, coupling and influence exist between AC and HVDC. Unbalanced development situation of the two transmission modes will profoundly change operating of hybrid power grid. In today's China, power system has entered a new era of “large-scale hybrid UHV AC/DC power grids” pattern. Within this paper, the main hazards to sending end power grid with UHVDC are proposed based on reviewing development history of the hybrid power grid. Besides, take a typical sending end near area power grid with UHVDC as an example, to analyze stability characteristics and mechanism for sending end power grid with UHVDC, some security and stability control measures are put forward to enhance stability of sending end near area power grid with UHVDC.