CN204595140U - A kind of interior distribution device ground connection audible-visual annunciator - Google Patents

Abstract

The utility model provides an acousto-optic alarm for the grounding of an indoor power distribution device, which includes a voltage transformer. One is a star-connected winding, and the other is a zero-sequence winding. Voltage relays are connected at both ends of the zero-sequence winding, and a contact switch of the voltage relay is connected in series with an alarm. This technical solution can automatically warn the on-site personnel at the first time to prohibit entering or evacuating the power distribution device that may be grounded when a single-phase ground fault occurs in the neutral point not directly grounded system, so as to prevent personal electric shock accidents.

Description

An audible and visual alarm for grounding of indoor power distribution equipment

technical field

The utility model relates to the field of power supply, in particular to an acousto-optic alarm for grounding of an indoor power distribution device.

Background technique

When a single-phase ground fault occurs in a system where the neutral point is not directly grounded, the ground fault point may be on each outgoing line on the power distribution device (this section of busbar), or on the equipment in the high-voltage room of this section of busbar. It will take about 5 minutes for the monitoring attendant to notify the operation and maintenance attendant through screening, analysis and judgment. If it is a composite fault, the required judgment time will be longer; then the operation and maintenance attendant will notify the on-site maintenance, operation and maintenance inspection, and professional inspection team , infrastructure maintenance and other personnel, so that the maximum time from the grounding to the notification to the on-site personnel can reach more than ten minutes. A device that alerts on-site personnel that they are prohibited from entering or evacuating grounded electrical distribution installations, which is a safety hazard.

Invention content:

The technical problem to be solved by the utility model is to provide a grounding sound and light alarm for indoor power distribution devices, which can send out early warning information at the first time to prevent personal electric shock accidents, and can start the image monitoring system in real time, so that the on-duty staff can comprehensively Master the situation of on-site equipment and personnel.

The utility model adopts following technical scheme to realize the object of the invention:

An audible and visual alarm for grounding of an indoor power distribution device, including a voltage transformer, characterized in that: the voltage transformer is connected to the high-voltage bus through a handcart, and the voltage transformer has two secondary windings, one of which is a star The other is a zero-sequence winding, the two ends of the zero-sequence winding are connected with a voltage relay, and the contact switch of the voltage relay is connected in series with an alarm.

As a further limitation of the technical solution, the zero-sequence reporting winding is connected to a controller, and the controller is connected to a camera and a wireless transmitting module.

As a further limitation to this technical solution, the controller adopts AT89S52 single-chip microcomputer, and the wireless transmitting module adopts transmitting chip PT2262.

As a further limitation of the technical solution, the starting voltage of the voltage relay is 30V.

As a further limitation to the technical solution, the working voltage of the alarm is 24V DC.

As a further limitation of the technical solution, the alarm is installed on the voltage transformer cabinet door of the bus.

As a further limitation of the technical solution, the contact switch of the voltage relay is a normally open contact.

As a further limitation of the technical solution, the alarm is an audible and visual alarm.

As a further limitation of the technical solution, the camera is installed on the top of the voltage transformer cabinet.

Compared with the prior art, the utility model has the advantages and positive effects: the technical solution can automatically warn the on-site personnel to prohibit entry or evacuation at the first time when a single-phase ground fault occurs in the neutral point not directly grounded system The power distribution device that may be grounded can prevent personal electric shock accidents; the wiring is simple, the action is reliable, and the alarm is instantaneous. The start of the device is started by the moving contact of the voltage relay, and the alarm can be connected, so the wiring is simple and the action is reliable. It can act as an alarm instantaneously to warn the on-site personnel to prohibit entering or immediately evacuate the possible grounding place, so as to prevent personal electric shock accidents. The alarm can return immediately after the grounding disappears; the cost is low, the installation is convenient, and there is no need to power off the high-voltage equipment during installation; the alarm is installed on the PT cabinet door of each section of the busbar, and can intuitively and clearly inform the field personnel of the busbar that has failed. As an auxiliary device for monitoring the grounding fault of the indoor power distribution device, the camera can intuitively check whether the grounding fault is caused by rain leakage in the power distribution room, water ingress from unclosed doors and windows, or entry of small animals due to lax closing of doors and windows, and whether the grounding causes a fire, etc. The situation is transmitted to the monitoring center, so that the duty officer can make correct judgment and processing.

Description of drawings

Fig. 1 is the schematic circuit diagram of the grounding sound and light alarm of the indoor power distribution device of the present invention.

Fig. 2 is a block diagram of the grounding image monitoring principle of the indoor power distribution device of the present invention.

In Figure 1, 1. Zero-sequence winding, 2. Switch handcart, 3. Star connection winding, 4. Alarm, KV, voltage relay.

Detailed ways:

Below in conjunction with embodiment, further illustrate the utility model.

Referring to Fig. 1 and Fig. 2, the utility model includes a voltage transformer, and the voltage transformer is connected to a high-voltage bus (not shown in the figure) through a voltage transformer switch handcart, and the voltage transformer has two secondary windings , one is a star connection winding 3, and the other is a zero-sequence winding 1, the two ends of the zero-sequence winding 1 are connected to a voltage relay KV, and the contact switch of the voltage relay is connected to an alarm 4 in series.

The zero-sequence winding 1 is connected to the controller, and the controller is connected to the camera and the wireless transmission module. When the voltage transformer senses the voltage signal of the zero-sequence winding 1, the controller sends a remote alarm signal through the wireless transmission module, and the camera shoots The on-site images are sent to the remote monitoring center, so that the on-duty personnel of the monitoring center can further understand the situation of personnel and equipment on the site, and also serve as a backup of the sound and light alarm, so that the on-duty personnel can make correct judgments and processing.

The controller adopts AT89S52 single-chip microcomputer, and the wireless transmitting module adopts transmitting chip PT2262.

The operating voltage of the alarm 4 is 24V.

The alarm 4 is installed on the voltage transformer cabinet door of the busbar.

The contact switch of the voltage relay is a normally open contact.

The alarm 4 is an audible and visual alarm. The recording content of the voice warning is "the equipment has a ground fault, please do not approach; the on-site personnel keep their feet together and evacuate 4 meters away from the equipment."

This technical solution is applicable to the indoor power distribution device of the power system or the user's high-voltage electrical equipment, and the neutral point is not directly grounded. When the above-mentioned power distribution device has a single-phase ground fault, it can instantly send out an alarm voice and flash the alarm light to inform the scene Maintenance, inspection, operation and other personnel should leave the place that may be grounded in a timely and correct manner to ensure personal safety and prevent personal accidents caused by contact with electric shock and step voltage electric shock.

Article 5.2.4 of the "State Grid Corporation Electricity Safety Work Regulations" (substation part) stipulates that when high-voltage equipment is grounded, indoor personnel should be 4 meters away from the fault point, and outdoor workers should be 8 meters away from the fault point. Insulated boots should be worn when entering the above range, and insulated gloves should be worn when touching the equipment shell and structure.

When a single-phase ground fault occurs in the neutral point non-directly grounded system, the ground fault point may be on each outgoing line on the power distribution device (this section of busbar), or it may be the supporting porcelain bottle, switch handcart and busbar of this section of busbar Insulation failure of high-voltage indoor equipment such as voltage transformers, main transformer bridges, and outgoing cable heads. That is to say, the ground fault point may be on the distribution line or in the power distribution room (high voltage room). After the State Grid Corporation of China implemented three episodes and five majors, the control personnel will monitor the operation of the power grid; when a single-phase ground fault occurs in the system, the monitoring duty officer will monitor dozens of "device abnormalities", "voltage limit", "bus grounding" Screening, analysis and judgment of monitoring information to determine whether it is system grounding or voltage transformer fuse or system resonance, and then report to dispatch and notify the operation and maintenance attendant, it takes about 5 minutes, if system grounding plus resonance, or system grounding causes insurance Composite faults such as fuses require longer judgment time; then the operation and maintenance attendant will notify the on-site maintenance, operation and maintenance inspection, and professional inspection team personnel, so that the maximum time from the start of grounding to the notification to the on-site personnel can reach more than ten minutes , there is no device on site that can directly remind and warn people on site to evacuate or prohibit them from entering the site; even if the control personnel, operation and maintenance personnel on duty determine that the fault point is on the line by pulling the road or other technical means, the non-fault phase of the equipment in the power distribution room Withstand line voltage, up to nearly 2 hours, the on-site personnel are not easy to get close to the equipment, so the on-site personnel must be informed at the first time when the ground fault occurs, but the reality is that the on-site personnel cannot be notified immediately; this situation may It is a safety hazard that threatens the personal safety of on-site personnel.

Claims (8)

1. A grounding audible and visual alarm for indoor power distribution equipment, including a voltage transformer, is characterized in that: the voltage transformer is connected with the high-voltage bus through a switch handcart, and the voltage transformer has two secondary windings, one It is a star-connected winding, and the other is a zero-sequence winding. The two ends of the zero-sequence winding are connected in parallel with a voltage relay, and the contact switch of the voltage relay is connected in series with an alarm. 2. The sound and light alarm for grounding of indoor power distribution device according to claim 1, characterized in that: the zero-sequence winding is connected to a controller, and the controller is connected to a camera and a wireless transmitting module. 3. The sound and light alarm for grounding of indoor power distribution device according to claim 2, characterized in that: said controller adopts AT89S52 single-chip microcomputer, and said wireless transmitting module adopts transmitting chip PT2262. 4. The grounding audible and visual alarm for indoor power distribution device according to claim 2, characterized in that: the starting voltage of the voltage relay is 30V. 5. The sound and light alarm for grounding of indoor power distribution device according to claim 1, characterized in that: the working voltage of the alarm is DC 24V. 6. The grounding audible and visual alarm device for indoor power distribution device according to claim 1, characterized in that: the alarm device is installed on the voltage transformer cabinet door of the bus bar. 7. The grounding audible and visual alarm for the indoor power distribution device according to claim 1, characterized in that: the contact switch of the voltage relay is a normally open contact. 8. The grounding audible and visual alarm for indoor power distribution equipment according to claim 1, characterized in that: the alarm is an audible and visual alarm.