CN103384062B - Isolation control system of grid power distribution fault detection - Google Patents

Abstract

The invention discloses a distribution network fault detection and isolation control system, which comprises an opening and closing switch, a voltage detection module, a zero-sequence voltage acquisition module, a fault current acquisition module and a controller. The zero-sequence voltage acquisition module installed in each distribution network section of the present invention detects the zero-sequence voltage in the section. When there is a zero-sequence voltage exceeding the limit value, it indicates that there is a single-phase grounding in the section. The controller can accurately open and close the switch of the section based on the zero-sequence voltage data, thereby realizing the isolation of the single-phase ground fault section; the present invention further introduces the fault current as a criterion, when the distribution network section When no fault current is detected, it can be determined that there is no fault in this section. When the substation recloses, it does not need to go through the closing delay confirmation, and directly controls the switch to close, so as to reduce the power outage time of the non-faulty section.

Description

Distribution Network Fault Detection and Isolation Control System

technical field

The invention relates to distribution network technology, in particular to feeder automation fault isolation technology.

Background technique

Existing distribution network fault detection methods generally use voltage as the fault criterion. When a certain phase of the three-phase voltage is abnormal, it is judged that the distribution network is faulty. At this time, the substation trips. After the substation is reclosed, the terminals are closed step by step after a delay. When the substation trips again, the distribution network section can be judged. for the faulty section. The above scheme cannot achieve fault isolation for the section with a single-phase ground fault; for the section without a fault, the secondary reclosing of the substation needs to be closed with a delay to increase the power outage time of the non-faulty section. Therefore, the prior art has the problems of protecting the blind zone and increasing the power failure time of the non-fault zone.

Contents of the invention

In view of the above problems, the present invention provides a distribution network fault detection and isolation control system that can realize the single-phase ground fault isolation function and effectively reduce the power failure time of non-fault sections.

The technical scheme that the present invention adopts for solving its technical problem is:

Distribution network fault detection and isolation control system, including: an opening and closing switch set in each distribution network section to control the opening and closing of the distribution network section; set in each distribution network section to detect three-phase voltage A voltage detection module of different size; a zero-sequence voltage acquisition module for collecting zero-sequence voltage data in each distribution network section; a fault current acquisition module for collecting fault current data in each distribution network section; And, the controller used to control the action of the opening and closing switch, the output terminals of the voltage detection module, the zero-sequence voltage acquisition module, and the fault current acquisition module are connected to the controller, and the control terminal of the opening and closing switch is connected to the controller; the distribution network When the opening and closing switches in the section are in the closing state, after the zero-sequence voltage acquisition module detects a zero-sequence voltage greater than the preset value, the controller controls the opening and closing switches of the distribution network section to open to realize this Isolation of the distribution network section; when the opening and closing switch in the distribution network section is in the closing state, the fault current acquisition module does not detect the fault current, and the opening and closing of the distribution network section when the distribution network is reclosed for the second time The switch does not need to be confirmed by a delay, and directly controls its opening and closing switch to close.

The zero-sequence voltage acquisition module is a voltage transformer or an electronic voltage sensor with a zero-sequence voltage detection function.

The beneficial effects of the present invention are: the zero-sequence voltage acquisition module set in each distribution network section of the present invention detects the zero-sequence voltage in the section, and when there is a zero-sequence voltage exceeding the limit value, it indicates that the section In the case of single-phase grounding, the controller can accurately open the opening and closing switches of the section based on the zero-sequence voltage data, thereby realizing the isolation of the single-phase grounding fault section; the present invention further introduces fault current as a judgment According to the data, when the fault current is not detected in the distribution network section, it can be determined that there is no fault in the section. When the substation recloses, it does not need to go through the closing delay confirmation, and directly controls the switch to close, so as to reduce the power failure of the non-faulty section. time.

Description of drawings

Further explanation is carried out below in conjunction with accompanying drawing and specific embodiment:

Fig. 1 is a schematic diagram of the system composition of the present invention.

detailed description

The distribution network fault detection and isolation control system of the present invention is used to control the opening and closing conditions of different sections in the distribution network to realize fault isolation.

As shown in Figure 1, the control system includes an opening and closing switch 1 arranged in each distribution network section for controlling the opening and closing of the distribution network section, and an opening and closing switch 1 arranged in each distribution network section for detecting three-phase Voltage detection module for voltage size 2. Zero-sequence voltage acquisition module for collecting zero-sequence voltage data in each distribution network section 3. Fault current for collecting fault current data in each distribution network section The acquisition module 4 and the controller 5 for controlling the action of the opening and closing switches. The output ends of the voltage detection module 2 , the zero-sequence voltage acquisition module 3 , and the fault current acquisition module 4 are connected to the controller 5 , and the control end of the opening and closing switch 1 is connected to the controller 5 . The above-mentioned voltage detection module 2 , zero-sequence voltage acquisition module 3 , fault current acquisition module 4 and opening and closing switch 1 are generally arranged in a single power distribution terminal and exist as an integral structure. The power distribution terminal can realize data interaction with the controller 5 through different communication methods. The zero-sequence voltage acquisition module 3 in the present invention is preferably implemented by a voltage transformer SPS or an electronic voltage sensor EVT with a zero-sequence voltage detection function.

The working principle of the present invention is as follows: when the opening and closing switch in the distribution network section is in the closing state, after the zero-sequence voltage acquisition module detects a zero-sequence voltage greater than the preset value, the controller controls the distribution network section The opening and closing switch is opened to realize the isolation of the distribution network section; when the opening and closing switch in the distribution network section is in the closing state, the fault current acquisition module does not detect the fault current, and the secondary reclosing of the distribution network is for The opening and closing switch of the distribution network section does not need to be confirmed by delay, and directly controls the closing of the opening and closing switch to reduce the power failure time of the non-fault section.

The embodiments of the present invention are not limited by the above-mentioned examples, as long as they achieve the technical effect of the present invention by basically the same means, they should all belong to the protection scope of the present invention.

Claims (2)

1. Distribution network fault detection and isolation control system, characterized in that the system is used for single-phase ground faults, including: An opening and closing switch is set in each distribution network section to control the opening and closing of the distribution network section; A voltage detection module for detecting the magnitude of the three-phase voltage is set in each distribution network section; A zero-sequence voltage acquisition module for collecting zero-sequence voltage data is set in each distribution network section; setting a fault current collection module for collecting fault current data in each distribution network section; and, A controller for controlling the action of the opening and closing switch, the output terminals of the voltage detection module, the zero-sequence voltage acquisition module, and the fault current acquisition module are connected to the controller, and the control terminal of the opening and closing switch is connected to the controller; When the opening and closing switch in the distribution network section is in the closing state, after the zero-sequence voltage acquisition module detects a zero-sequence voltage greater than the preset value, the controller controls the opening and closing switch of the distribution network section to open. Realize the isolation of the distribution network section; When the opening and closing switch in the distribution network section is in the closing state, the fault current acquisition module does not detect the fault current, and the opening and closing switch of the distribution network section does not need to be confirmed by delay when the distribution network is reclosed for the second time , directly control the opening and closing switch to close. 2. The distribution network fault detection and isolation control system according to claim 1, wherein the zero-sequence voltage acquisition module is a voltage transformer or an electronic voltage sensor with a zero-sequence voltage detection function.