A full-line quick-acting protection method for single-ended electrical quantities using choke coils to construct line boundaries

Abstract

Disclosed is a single-ended electrical quantity-based fast full-circuit protection method using a choke to construct a circuit boundary. In the method, a circuit boundary is constructed by installing a choke on a circuit according to topology types of various power supply systems, and then protection determination data is constructed from differences in electrical quantity differences of a circuit region under protection or during an internal or an external failure, thereby realizing fast full-circuit protection based on single-ended electrical quantities. The present invention adopts a choke to construct a boundary of a circuit, and then achieves single-ended quantity-based fast full-circuit protection for a circuit having no boundary elements. The method of the present invention effectively overcomes the problem of poor protection sensitivity of operational frequency quantities in an alternating current circuit containing multiple inverters, and also meets a requirement of fast protection operations for direct current circuits. The invention does not require additional protection when applied to a power distribution network, so as to achieve fast determination of an internal or external failure of a protection region simply by using single-ended electrical quantities, thereby effectively solving the relay protection problem of a power grid containing multiple inverters.

Description

technical field [0001] The invention belongs to the technical field of electric power system relay protection, and in particular relates to a single-end electric quantity full-line rapid protection method using a choke coil to construct a line boundary. Background technique [0002] With the large-scale access of wind turbines and photovoltaic power sources and the large-scale application of DC power transmission and distribution, the power system presents a form with multiple converters. For the AC system, the ability of the inverter to provide short-circuit current effectively reduces the protection sensitivity; for the DC system, the vulnerability of the converter requires the protection to quickly remove the fault. At the same time, for the distribution network, the access of distributed power sources makes it a multi-source power supply system. The bidirectional flow of short-circuit current makes it difficult to cooperate with current protection. Communication is requi...

AI Technical Summary

Problems solved by technology

For the AC system, the ability of the inverter to provide short-circuit current effectively reduces the protection sensitivity; for the DC system, the vulnerability of the converter requires the protection to quickly remove the fault

At the same time, for the distribution network, the access of distributed power sources makes it a multi-source power supply system. The bidirectional flow of short-circuit current makes it difficult to cooperate with current protection. Communication is required when using double-ended differential protection and longitudinal protection. , high cost, unable to be used on a large scale

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