Low-voltage electric leakage full-time monitoring device

Abstract

The invention discloses a method for full-time measurement and control of low-voltage electric leakage and timely sending of information or short messages, relates to the technical field of electrical equipment, and can instantly generate short messages and related information to timely remind power supply maintenance personnel to deal with electric leakage of a low-voltage line once electric leakage occurs in the low-voltage line and equipment so as to greatly reduce electric leakage accidents of the low-voltage line. In the attached drawing of the abstract, when any position of the power supply of the transformer leaks electricity, if a power supply line leaks electricity through a street lamp pole, the leakage current flows back to the zero line pile head of the transformer along the leakage current loop (12), so that the current almost the same as the leakage current of the leakage point passes through the grounding down lead (7) of the transformer. When the current reaches a set value or above, a short message and related information are sent out after the current is monitored by the low-voltage electric leakage full-time monitoring device (6). In the scene, step voltages exist between the street lamp pole and the ground and between the transformer grounding down lead and the ground during electric leakage, and potential safety hazards exist.

Description

Technical Field

[0001] This invention relates to the field of electrical equipment technology, and in particular to low-voltage leakage current monitoring and information transmission. Background Technology

[0002] In the field of residential electricity, leakage current is a serious hazard, causing heavy losses and occurring frequently. However, there is currently a lack of a device that can accurately determine whether there is leakage current and transmit information in a timely manner.

[0003] The existing technology has the following defects or problems: Currently, low-voltage lines and equipment lack effective leakage monitoring and timely information transmission devices. Leakage is often detected through the following methods: 1. When a person is electrocuted or injured, or feels an electric shock upon touching a certain location, the power company will investigate. 2. When livestock are electrocuted or injured, the power company will investigate. 3. When leakage occurs in indoor wiring or household appliances, the electricity consumption is recorded in the meter, and abnormally high monthly electricity bills are discovered, prompting an investigation by the power company. 4. When the power company discovers excessive power loss in a transformer area, it is discovered after various investigations.

[0004] The problem to be solved by this invention is to overcome the shortcomings of existing low-voltage line leakage monitoring technology. In the field of civil electricity, once leakage occurs, this device will send a text message and related information to notify the power supply operation and maintenance personnel to investigate and handle the problem. Summary of the Invention

[0005] In civil power distribution transformers, the neutral wire terminal is connected to the transformer casing by a conductor, which is then connected to the grounding electrode by a conductor. This conductor is referred to as the transformer grounding down conductor in this specification and claims. This invention introduces a new device installed inside the low-voltage distribution cabinet of a transformer. It connects to the 220V power supply within the cabinet and passes the transformer grounding down conductor through this device. In the event of a leakage current in the low-voltage lines and equipment supplied by this transformer, it can instantly send SMS messages and related information, providing timely and accurate information to power supply maintenance personnel. This allows for rapid handling of the leakage current and significantly reduces the hazards caused by leakage current in low-voltage lines. Technical solution

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: Research has shown that if a leakage occurs at any point in any of the lines or equipment supplied by a transformer, the transformer's grounding lead will generate a current, almost identical in magnitude to the current at the leakage point. This invention uses a device installed inside the low-voltage distribution cabinet of the distribution transformer to monitor the current in the grounding lead, thereby accurately determining whether there is a leakage in the transformer's power supply area.

[0007] Furthermore, by detecting leakage in low-voltage lines or equipment, the device's internal circuitry is triggered, and an SMS report is immediately sent to the power supply maintenance personnel.

[0008] The beneficial effects of this invention are: The method disclosed in this invention can accurately determine whether there is leakage in the power supply area of ​​the transformer. When leakage is detected, a text message or information is sent in a timely manner. Through the widespread installation of this device, leakage in low-voltage lines and equipment can be detected in a timely manner, which can greatly reduce the occurrence of electric shock accidents to people and animals, as well as the problems of power loss and energy waste caused by leakage.

[0009] The method and device of the present invention, as well as their internal and external structures, and the aforementioned features and advantages, will be disclosed in detail in the following figures and descriptions of the figures, and in their working principle. Attached Figure Description

[0010] The invention will be further described below with reference to the accompanying drawings: Figure 1 These are three views of a low-voltage leakage current monitoring device. Figure 2 This is the internal structure and wiring diagram of a low-voltage leakage current real-time monitoring device. Figure 3 This is a field application scenario diagram of a low-voltage leakage current real-time monitoring device.

[0011] This diagram shows the three-view drawing of a low-voltage leakage current monitoring device. The contents of each icon are as follows: 1. Device housing; 2. Power supply terminals; 3. Pre-drilled holes.

[0012] The device casing is made of insulating plastic and is waterproof. Power supply terminals; used to connect to the 220V power supply from the transformer low-voltage distribution cabinet.

[0013] A perforation is reserved here; a perforation is reserved here to pass through this device. The perforation is the same size as the hole of the current transformer used inside and is aligned with it, so that the transformer grounding lead can pass through this hole.

[0014] Wiring method: 1. Install this device inside the transformer's low-voltage distribution cabinet. 2. Lead the transformer's grounding lead into the device, pass it through the reserved hole, and then connect it to the transformer's grounding electrode. 3. Take a 220V power supply from the transformer's low-voltage distribution cabinet and connect it to the power supply terminal block with a wire.

[0015] 1. Transformer grounding lead; 2. Current transformer; 3. Current control switch; 4. AC contactor; 5. Information transmitter; 6. Connecting wire; 7. Terminal block; 8. Device housing; 9. 220V power supply terminal block.

[0016] Transformer grounding down conductor; the neutral terminal of the distribution transformer is connected to the transformer casing by a conductor and then to the grounding electrode by a conductor. This section of conductor is referred to as the transformer grounding down conductor in this manual.

[0017] 2. Current transformer; ordinary civilian current transformer, with a transformation ratio between 75 / 5 and 200 / 5, has one through hole and two secondary side terminals.

[0018] 3. Current control switch; has one through hole and two terminals (with a normally open switch between the two terminals). A wire passes through the through hole. When current flows through the wire and reaches a predetermined value or higher, the normally open switch closes and the two terminals are connected.

[0019] 4. AC contactor; consisting of one coil and one normally open switch.

[0020] 5. Message transmitter; has two terminals, which send SMS messages and related messages after being powered on.

[0021] 6. Connecting wires; wires used to connect the terminals of various electrical appliances.

[0022] 7. Terminal blocks; the small shapes in the diagram represent the terminals for connecting wires to various devices.

[0023] 8. Device casing; made of insulating plastic, waterproof; 9. 220V power supply terminal block; used to connect to the 220V power supply from the transformer low-voltage distribution cabinet.

[0024] Wiring method: 1. Connect the two secondary side terminals of the current transformer with a wire, which passes through the hole of the current control switch. 2. Connect one terminal of the current control switch to the power supply and the other to the AC contactor coil terminal. 3. Connect one terminal of the AC contactor coil to the current control switch terminal and the other to the power supply. Connect one terminal of the normally open switch to the information transmitter and the other to the power supply. 4. Connect one terminal of the information transmitter to the normally open switch of the AC contactor and the other to the power supply.

[0025] When there is current in the transformer grounding lead and it reaches or exceeds the set value, current flows through the secondary conductor of the current transformer and reaches or exceeds the set value. The normally open current control switch closes, the AC contactor coil is energized, the normally open AC contactor closes, and the information transmitter is energized to send SMS messages and related information.

[0026] 1. 10kV high-voltage power supply line; 2. Power transformer; 3. High-voltage side of transformer; 4. Low-voltage side of transformer; 5. Low-voltage neutral wire terminal; 6. Low-voltage leakage current monitoring device; 7. Transformer grounding lead; 8. Transformer grounding electrode; 9. Earth; 10. 0.4kV low-voltage power supply line; 11. Leakage point; 12. Leakage current loop

[0027] 1. 10kV high-voltage power supply lines; 10kV power supply lines in the power system. Power transformers; civil power supply transformers The high-voltage side of the transformer; the high-voltage windings and terminals of the transformer, etc.

[0028] The low-voltage side of the transformer; the low-voltage windings and terminals of the transformer, etc.

[0029] Low-voltage neutral wire connection terminal; low-voltage neutral wire connection terminal of transformer.

[0030] Low-voltage leakage current real-time monitoring device; the device of this invention.

[0031] Transformer grounding down conductor; Transformer grounding down conductor; The neutral terminal of the distribution transformer is connected to the transformer casing by a conductor and then to the grounding electrode by a conductor. This section of conductor is referred to as the transformer grounding down conductor in this manual. The part shown in blue in the figure is already installed when the transformer is installed.

[0032] Transformer grounding electrode; a concealed structure driven into the ground, a conductor that makes good contact with the ground, and every distribution transformer has one installed.

[0033] Earth; refers to the ground.

[0034] 0.4kV low-voltage power supply line; the 0.4kV low-voltage power supply line supplied by this transformer. Leakage point; a leakage point in this simulation, which can be any location supplied by the transformer.

[0035] Leakage current loop: A schematic diagram of the direction of leakage current flow, shown by the red dashed line path in the diagram.

[0036] When a leakage occurs at any point in the power supply of the operating transformer, such as a leakage through a streetlight pole, the leakage current will flow back to the transformer's neutral terminal along (12, leakage current loop). Therefore, a current almost identical to the leakage current at the leakage point will flow through (7, transformer grounding down conductor). When this current reaches or exceeds a set value, it will be detected by (6, low-voltage leakage real-time monitoring device) and an SMS message and related information will be sent. Note: In this scenario, there is a step voltage between the streetlight pole and the transformer grounding down conductor and the ground during leakage. The magnitude of the voltage is related to the magnitude of the leakage, posing a safety hazard. The step voltage value between the transformer grounding down conductor and the ground can be monitored and measured to determine whether a leakage has occurred in the power distribution.

Claims

1. Protection is a method to determine whether there is leakage in the power supply area of ​​a distribution transformer by monitoring and measuring the current of the grounding lead of the transformer in operation.

2. The protection device detects leakage in the power supply area of ​​a distribution transformer by monitoring and measuring the current of the grounding lead of the transformer in operation and determining that a leakage has occurred. The device will immediately send a text message or related information.

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