COORDINATION CONTROL METHOD OF MULTI-TERMINAL VSC-HVDC TRANSMISSION SYSTEM

摘要

A coordination control method of a multi-terminal flexible direct current power transmission system. If a direct-current voltage master control station shuts down, a direct-current voltage control slave station takes over direct-current voltage control, and remaining convertor stations keep original control modes. The takeover steps comprise that under the condition that inter-station communications are effective, the master control station sends a shutdown message to the slave station through the inter-station communications, and when the slave station monitors that the direct-current voltage master control station shuts down, the slave station switches a current control mode into a direct-current voltage control mode; and under the condition that inter-station communications fail or inter-station communications are absent, the slave station monitors changes of the direct-current voltage of a system, and when the difference value of a direct-current voltage value and a rated value exceeds a definite threshold value, the slave station switches a current control mode into a direct-current voltage control mode. By means of the method, the direct-current voltage can be effectively controlled, and when the direct-current voltage master control station shuts down due to a fault, the direct-current voltage control slave station can take over the control so that oscillation of the system direct-current voltage is reduced.