OVERVOLTAGE PROTECTION DEVICE AND PROTECTION METHOD FOR ALTERNATING-CURRENT SIDE OF FLEXIBLE DIRECT-CURRENT POWER TRANSMISSION SYSTEM

摘要

An overvoltage protection device and protection method for an alternating-current side of a flexible direct-current power transmission system. A protection device (7) is connected to the two sides of a grounding resistor (6) at the side of a converter transformer valve in parallel and used for acting to draw away a fault current when a fault occurs in an alternating-current line I (4) or a direct-current line (8) and causes the overvoltage of the alternating-current line or when a valve base controller detects that a short-circuit fault occurs in the alternating-current line I (4), so as to suppress an overvoltage level of the alternating-current line I (4), and protect a valve body (9) of a converter valve. The protection device has rapid action, strong through-flow energy, and large absorbed energy, and can quickly protect the valve body so as to guarantee the secure and stable operation of the flexible direct-current power transmission system.