Fault locking method for relay protection in digital substation

Abstract

The invention relates to a fault locking method for relay protection in a digital substation. In the relay protection, a plurality of IED (Intelligent Electronic Device) distributed fault detection elements are integrated with various fault identification criterions to effectively identify faults of a power system; a protection device and intelligent unit double-fault locking mechanism is adopted, wherein a process layer communication CPU (Central Processing Unit) on the protection device only releases GOOSE (Generic Object Oriented Substation Event) trip locking and forwards a GOOSE trip signal to an intelligent unit on the premise that a trip command for protecting the CPU and a fault detection FD open command exist simultaneously; and the intelligent unit only releases locking and trips on the premise that the GOOSE trip command and the FD open command are received simultaneously. On the basis of network information sharing, the fault locking method provided by the invention is integrated with various fault identification criterions to effectively identify the fault of the power system by adopting the plurality of the IED detection elements, and prevents false tripping caused by IED abnormality so as to improve the reliability of the power system.

Description

technical field [0001] The invention belongs to the field of electricity, and relates to a blocking protection method of a relay protection fault detection element for preventing relay protection malfunction in a digital substation. Background technique [0002] The reliability of relay protection devices in high-voltage transmission systems is the guarantee for the safe and stable operation of power systems. In conventional substations, in order to prevent the protection device from malfunctioning due to software and hardware failures, most relay protection devices use the method of driving the starting relay to open and protect the outlet circuit power supply, that is, to block the outlet circuit through hard contacts. The method prevents the protection from malfunctioning. The Chinese patent with the patent number ZL200310110260.6 discloses a relay protection fault detection module, and discloses a corresponding detection method for detecting system disturbances, but thi...

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Problems solved by technology

At present, some manufacturers borrow the traditional blocking mode in the digital substation and adopt the method of adding CPU redundancy in the IED for mutual inspection, that is, the GOOSE trip signal sent by the protection CPU needs to be released after the fault detection signal of the startup CPU is opened, but this The method has the following disadvantages: First, the hardware cost is increased in the IED, which causes many equipment manufacturers to be reluctant to adopt it; second, the locking mechanism is not checked at the last level of the trip exit (generally referred to as an intelligent unit). However, if the smart unit fails to detect, it may malfunction

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