High-capacity flexible DC converter valve surplus power overvoltage suppression method and system

• Main Authors: CHEN QICHEN, ZHENG KUAN, FAN LINZHEN, XU YING, ZHANG YIMING, TENG SHANGFU, LI MING, CHEN SIQI, YONG ZHI, ZHAO ZHENG, LI TAN, GANG MINGZE
• Format: Patent
• Language: Chinese; English
• Published: 10.11.2023
• Subjects: CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERATION

The invention relates to a high-capacity flexible DC converter valve surplus power overvoltage suppression method and system, and the method comprises the steps: carrying out the global simulation scanning of all types of AC system faults, and dividing the AC system faults into three grades according to the simulation result and the adopted measures: a slight fault, a medium fault and a severe fault; for a slight fault, no hardware or control additional strategy is needed, and fault ride-through is realized by depending on the overvoltage endurance capability of the equipment; for a medium fault, after the fault is identified, the transmitting end quickly reduces the transmitted direct current power to realize fault ride-through; for a serious fault, after the fault is identified, a receiving end quickly enters a power quick cut-off mode, and transmission of surplus power on a direct current side is quickly blocked. The over-voltage level of the converter valve can be effectively reduced when the receiving en