Control method for transient energy dissipation system of extra-high voltage alternating-current and direct-current power grid

The invention discloses a control method for a transient energy dissipation system of an extra-high voltage alternating-current and direct-current power grid. If large-power direct current in an extra-high voltage alternating-current and direct-current power grid has faults such as commutation failure or direct-current locking and the like to cause large power drop, a high-speed switch is controlled to switch on and switch off energy consumption impedance to consume system transient energy, and the control method comprises the following steps of: (1) determining direct-current power change characteristics during normal direct-current modulation and direct-current faults; (2) performing rapid energy consumption control according to the direct-current power; (3) under an active impact control method, quitting the transient energy consumption load according to a certain principle; (4) judging whether a control method needs to be switched or not in real time; and (5) under the frequency control method, performing