Fault ride-through method for high-voltage and high-capacity flexible DC transmission system for overhead line

The invention relates to a fault ride-through method for a high-voltage and high-capacity flexible DC transmission system for an overhead line and belongs to the field of fault protection of the flexible DC transmission system. A control method for AC/DC fault ride-through of the high-voltage an high-capacity flexible DC transmission system for the overhead line is provided on the basis of cooperative control of an LCC and an MMC through analyzing a topological structure and flexible control characteristics of active power and reactive power of an LCC-MCC series hybrid DC transmission system and output voltage characteristics of the MMC in a locking state, thereby achieving safe and stable operation of the system. The construction cost of an LCC-MCC series hybrid DC transmission topology is the lowest under the same condition; meanwhile, a DC fault is removed by using the LCC; and additional devices, such as a DC circuit breaker and a DC damping circuit do not need to be arranged, so that the economy of the s