Topological structure of LCC-VSC type hybrid DC transmission system and starting method of LCC-VSC type hybrid DC transmission system

The invention relates to a starting method of an LCC-VSC type hybrid DC transmission system. The method specifically comprises the steps that an LCC current converter is unlocked to conduct fixed DC current control, a DC side capacitor is charged, inertial element filtering is added for a current measuring value, current instruction values gradually rise to a rated value from zero, when the DC voltage rises to the rated value, a VSC current converter is unlocked to conduct fixed DC voltage control, power is gradually transmitted to a VSC side from an LCC side, and the starting process is completed. The starting method enables the LCC-VSC type hybrid DC transmission system to smoothly transit to be in a normal operation state from a dead halt state, the entire starting process is smooth and stable, meanwhile, the control strategy of the hybrid DC transmission system is complete and clear, and the system can accurately track target reference values to stably operate after starting is completed.