A Substation-Oriented Secondary DC Power Loss Discrimination Method

Abstract

The invention relates to a secondary direct-current power source loss discriminating method for substations. The method includes the following steps that: signal acquisition devices and discriminating devices are configured for substations in a regional power grid; the signal acquisition devices and the discriminating devices are both powered by communication power sources in communication cells, wherein the communication power sources are independent from secondary direct-current power sources of the substations; the signal acquisition devices acquire secondary direct-current power outage connection points of the substations and channel abnormal connection points of existing line optical fiber longitudinal protection devices, and transmit the secondary direct-current power outage connection points and the channel abnormal connection points to the discriminating devices through a communication network; and after receiving the secondary direct-current power outage connection points of the substations and the channel abnormal connection points of the existing line optical fiber longitudinal protection devices, the discriminating devices discriminate secondary direct-current power source loss through adopting AND Logic. With the method of the invention adopted, judgment on the secondary direct-current power source loss of the substations can be completed quickly and accurately, and decision-making basis can be provided for subsequent corresponding protection and control strategies, and faults can be isolated quickly, and the safe and stable operation of a system can be ensured.

Description

technical field [0001] The invention relates to a power grid accident discrimination method, in particular to a substation-oriented secondary DC power supply loss discrimination method. Background technique [0002] Loss of secondary DC power supply in power substation - including loss of DC power supply of protection devices and DC power supply of operation circuit - is a serious accident in the operation of substations. After the secondary DC power supply is lost, all protection devices of this substation cannot work, and the main transformer, busbar and all outgoing lines in the substation are out of protection. The remote backup protection delays the action to isolate the fault. Such as figure 1 Substation C in the substation in the substation has lost the secondary DC power supply of the whole station. When the f1 fault occurs on the AC line, the line protection of CB2 cannot operate to remove the fault due to the loss of protection power. CB3 and CB5 of station D de...

AI Technical Summary

Problems solved by technology

After the secondary DC power supply is lost, all protection devices of this substation cannot work, and the main transformer, busbar and all outgoing lines in the substation are out of protection. The remote backup protection delay action to isolate the fault

like figure 1 Substation C in the substation in the substation has lost the secondary DC power supply of the whole station. When the f1 fault occurs on the AC line, the line protection of CB2 cannot operate to remove the fault due to the loss of protection power. CB5 Delayed Removal Faults of Stations CB3 and D

Since the remote backup protection needs to consider the coordination relationship between segments, its action time is relatively slow. In severe cases, its action time may not meet the requirements of system stability, which poses a serious threat to the safe and stable operation of the system.

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