Overcurrent protection method and device based on closed-loop running type of power distribution network

Abstract

The invention relates to an overcurrent protection method based on the closed-loop operation mode of the distribution network, which is used for fault discrimination and removal of the overcurrent fault of the protected object in the distribution network adopting the closed-loop operation mode. Two fault currents are measured at both ends, and the phases of the two fault currents are calculated respectively. Based on the phases of the two fault currents, the fault direction at both ends of the protected object is determined, and the location of the overcurrent fault is determined by comparing the fault directions at both ends of the protected object. , and then cut off the overcurrent fault. The invention also relates to an overcurrent protection device, which includes a fault current detection module, a fault discrimination module and a fault removal module. Based on the closed-loop operation mode of the distribution network, the present invention solves the problem of maloperation or refusal to operate in the closed-loop distribution network, and can quickly and reliably perform overcurrent protection, thereby reducing the occurrence of faults in the distribution network in practical applications. The range of power outages caused, and the time of power outages are reduced.

Description

technical field [0001] The invention belongs to the field of distribution automation in the electric power industry, and in particular relates to a method and a device for overcurrent protection applied to a distribution network in a closed-loop operation mode. Background technique [0002] At present, most distribution networks adopt closed-loop design and open-loop operation power supply mode. In order to further improve the reliability of power supply, ensure power quality, reduce line loss and adapt to the actual needs of a large number of decentralized clean power access, distribution network operation structure Major changes need to be implemented, and the closed-loop operation structure is an important technical direction with development prospects. [0003] In the current distribution network, the three-stage current protection method with fixed setting value is adopted, and when the distribution network adopts the closed-loop operation mode, it changes from a single...

AI Technical Summary

Problems solved by technology

[0003] In the current distribution network, the three-stage current protection method with fixed setting value is adopted, and when the distribution network adopts the closed-loop operation mode, it changes from a single power supply radiation network to a ring network, and the distribution network operation mode is more complicated

When a fault occurs in the distribution network, the protection at both ends of the fault section may detect the fault current at the same time, and the magnitude of the fault current is directly related to the operation mode, resulting in the possibility of misoperation or refusal to operate in the three-stage current protection with conventional value setting. question

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