Three-phase four-wire power supply system zero-line breaking alarm positioning device and method

Abstract

The invention discloses a three-phase four-wire power supply system zero-line breaking alarm positioning device. The positioning device comprises a zero-line breaking alarm element and a zero-line breaking positioning element; the zero-line breaking alarm element comprises a ground capacitor C, a voltage measurement element, and a line breaking alarm; the ground capacitor C is arranged at the tailend of the zero-line and grounded; the voltage measurement element and the ground capacitor C are connected in parallel to measure a voltage value of the ground capacitor C; the line breaking alarm is connected with the voltage measurement element; when a measurement value of the voltage measurement element exceeds a set value, the line breaking alarm gives out an alarm; the zero-line breaking positioning element comprises a current measurement element, a rectification voltage-limiting circuit, and an indicator light; the current measurement element is connected with the rectification voltage-limiting circuit, the rectification voltage-limiting circuit is connected with the indicator light, and the current measurement element is serially connected among contacts of various station equipment on the zero-line. The positioning device can accurately make reaction and give out an alarm when the zero-line breaking fault occurs, and the line breaking region can be accurately positioned whenthe zero-line breaking fault occurs.

Description

technical field [0001] The invention relates to a three-phase four-wire system power supply system zero line disconnection alarm positioning device and method, and belongs to the technical field of electric power equipment. Background technique [0002] The normal operation of the substation AC system is crucial to the stability of the substation. The three-phase four-wire connection mode is the usual power supply mode of the station power system, and the disconnection fault detection of the neutral line is very important for the reliable and stable operation of the station equipment, and the disconnection fault of the neutral line is the most difficult fault to find in the substation one. When the neutral line of the station power supply system of the substation is disconnected, the neutral point displacement voltage on the side of the station power supply system will shift, which may cause a large number of station equipment to burn out. According to the daily working co...

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Problems solved by technology

[0003] 1. There is no professional system detection method: the existing substation does not install a specific device for detecting zero line disconnection. When the zero line disconnection occurs in the system, the system cannot accurately respond to the disconnection fault, resulting in the long-term operation of some equipment in the disconnected line. overvoltage or undervoltage condition

On-site operation personnel and maintenance personnel mainly judge the zero line disconnection fault indirectly by checking the operation status of the station equipment. The accuracy is related to the work experience and work skills of the staff, which cannot meet the requirements of on-site work.

[0004] 2. Unable to detect the fault in time: the zero line disconnection fault can only be found through indirect methods, so when the zero line disconnection occurs in the system, there is no fault signal, and it can only be discovered when the operation and maintenance personnel inspect the equipment; because the fault cannot be found and eliminated in time Line failure, some equipment works in overvoltage state for a long time, reducing the life of equipment; some equipment runs in undervoltage state, reducing its reliability

Due to the failure of the equipment in the station to operate normally, the safety of the substation is endangered, and the possible consequences are very dangerous

[0005] 3. Unable to accurately locate the disconnection location: Due to the complex wiring method of the substation station system, when the zero line disconnection occurs, the disconnection point cannot be found intuitively. It is necessary to speculate on the fault point according to the voltage and current conditions of the station equipment, and increase maintenance Construction difficulty and maintenance time reduce equipment reliability

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