Urban rail transit rectifier protection device and method

Abstract

The invention provides an urban rail transit rectifier protection method. The method comprises the following steps: S1, measuring current values of all rectifier diodes of a rectifier; s2, respectively calculating the current maximum value and the current effective value of the current value of each rectifier diode in the time fixed value, and respectively comparing and judging the current maximum value and the current effective value with the current fixed value; and S3, if the judgment result meets the fault judgment condition, controlling the alternating-current side circuit breaker and the direct-current side circuit breaker to trip. The device is characterized in that the device comprises the current transformers and the protector, the protector is connected with the multiple current transformers, the current transformers are used for measuring the current values of the rectifier diodes of the rectifier, and the output of the protector is connected with the alternating current side circuit breaker and the direct current side circuit breaker. According to the invention, the blank of ground fault protection of a secondary side AC ungrounded system of the rectifier transformer is filled.

Description

technical field [0001] The invention belongs to the field of urban rail transit, in particular to a rectifier protection device and method for urban rail transit. Background technique [0002] The urban rail transit traction substation rectifies the power of the medium-voltage AC network through a rectifier to obtain DC power, and supplies power to the traction EMU through the catenary. A typical traction substation includes two medium-voltage AC power sources, two sets of 12-pulse rectifier units, two DC incoming circuit breakers, and four feeder circuit breakers. Two sets of rectifier units are connected in parallel to form an equivalent 24 pulses. The traction substation and the traction network together form the traction power supply system. The traction substation adjacent to the main line implements bilateral power supply to the main line catenary. The rectifier unit is the key link of the traction substation, and faults during operation should be accurately identif...

AI Technical Summary

Problems solved by technology

[0003] The existing rectifier transformer high-voltage side current protection device cannot identify some faults well, specifically: Fault 1: The AC cable from the secondary side of the rectifier transformer to the rectifier has a single-phase ground fault outside the equipment, and the current protection device on the 35kV side cannot Fault identification; Fault 2: An open circuit fault of the rectifier bridge arm occurs inside the rectifier, and the current protection on the 35kV side cannot identify the fault; Fault 3: A short-circuit fault of the rectifier bridge arm occurs inside the rectifier, which is protected by the fuses of each rectifier bridge arm, and the current on the 35kV side Protection implements backup protection, but the protection time is relatively long, and there is a risk of burning the entire device

Therefore, the existing traction power supply system has a relay protection blind zone. Once such a fault occurs, the system will run with a disease, which is very dangerous

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