A relay protection device for a large rectifier unit

Abstract

The invention relates to a relay protection system, in particular to a relay protection device of a large-scale rectifier unit. The relay protection device of the large-scale rectifier unit comprises the rectifier unit, an alternating current circuit breaker, an direct current disconnecting switch, wherein three groups of alternating current transformers are arranged at the alternating-current side of the rectifier unit, direct current sensors and countercurrent sensors are arranged at the direct-current side of the rectifier unit, a protective device is arranged among the alternating current transformers, the direct current sensors and the countercurrent sensors, the protective device can collect three groups of signals of the alternating current transformers and four groups of signals of the direct current sensors and the countercurrent sensors. The relay protection device of the large-scale rectifier unit has the advantages that the current is collected respectively through the alternating-current side and the direct-current side of the rectifier unit and the range of protection is free from dead zone.

Description

technical field [0001] The invention relates to a relay protection system, in particular to a relay protection system for a large-scale rectifier unit, and belongs to the technical field of relay protection for DC power supply rectifiers. Background technique [0002] The high-current rectification system is mainly a general term for equipment that provides DC power for electrolysis processes such as chemical industry and metallurgy. Among them, the electrolytic aluminum production system is a typical large-capacity DC power load, and the DC power supply device that supplies power to it is usually a rectification system composed of multiple sets of rectifier units connected in parallel. At least one of them is a spare rectifier unit. Each set of silicon rectification equipment is mainly composed of a voltage regulating rectifier transformer, a silicon rectifier cabinet, a DC isolating switch, a DC sensor, a pure water cooling device, and a secondary protection system. Among ...

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Problems solved by technology

The rectifier unit protection generally adopts a microcomputer protection device, but it can only use its 2-stage current protection function. At the same time, because the impedance of the voltage regulating rectifier transformer varies from 10% to 600%, the sensitivity of the current protection cannot meet the requirements.

Generally, it is necessary to cancel the setting of the rectifier unit accident button. In abnormal situations, manual opening is sometimes required. The reliability of power supply and equipment safety cannot be guaranteed, and at the same time, it threatens the safety of the power grid.

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