Analysis on HVDC start-up in system black-start

The start-up of HVDC will bring impact of active and reactive power to the grid, causing voltage and frequency disturbances. This paper analyses the effects of different HVDC start-up modes to AC system and selects the most appropriate one. Besides, the paper puts forward the method of estimating short circuit ratio and effective inertia constant of AC system to meet the operation requirements of voltage and frequency in both transient and steady states and verify the accuracy by the simulation of Yunguang HVDC.