CN114624495A - Passive alternating current micro-current acquisition amplifying device - Google Patents

Abstract

The invention discloses a passive alternating-current micro-current collecting and amplifying device, wherein coil taps which respectively extract N times of turns in a multi-winding insulating coil are respectively connected to leading-out terminals, when N =5 is selected, the leading-out terminals are divided into common terminals 0 and 1N-6N times leading-out terminals, different terminals correspond to different N times amplification factors of the current coil, a discharge display lamp and a discharge tube are respectively connected in parallel between adjacent public terminals 0 and 1N-6N times of leading-out terminals, the discharge display lamp is used for emitting light to remind workers of danger when open circuit discharge occurs, the discharge tube is used for breakdown when open circuit generates overvoltage to protect personnel and equipment safety, an external wiring plug is connected to the leading-out terminals through an experimental wire, the external wiring plug is connected to current terminals in an external current loop, and current calipers with output wires are used for transmitting collected alternating current data to an analyzer for processing. The invention is easy to process, small in volume and convenient to carry; the current loop is connected in series, so that the wiring is simple, the inspection is convenient, the error is not easy to occur, and the occurrence rate of open circuit of the current loop is reduced.

Description

Passive alternating current micro-current acquisition and amplification device

Technical Field

The invention relates to the technical field of electric power, in particular to a passive alternating-current micro-current acquisition and amplification device.

Background

Before the differential relay protection device is put into operation, relay protection workers need to measure load current and check whether a phasor diagram of working voltage is correct or not. For a long time, a large proportion of relay protection and incorrect operation of its automatic devices are caused by reversal of the directional protection polarity or wiring errors. The method is characterized in that the device after power transmission is subjected to electrical parameter testing under the condition of load, which is generally called a hexagonal diagram test, not only is the safety of the primary device for power generation concerned, but also the installation quality of the secondary device is held, and the method plays an important role in safe and stable operation of a power system.

At present, complete voltage and current phasor analysis products exist in the market, and the existing instrument cannot accurately measure the small-load current. When the secondary current value reaches more than 0.15A, the phasor analysis of the voltage and the current can be more accurate. For the current below 0.15A, the current value is small, the measurement result is unstable, a large digital drift phenomenon exists, and the correctness of parameters such as the transformation ratio, the direction and the like cannot be accurately judged. On-site relay protection workers need to wait for a certain load of a line to perform phasor analysis, and sometimes the time for waiting for the load of a user is very long. In order to ensure the safe operation of the equipment after power transmission, even a method with some useless loads is adopted to obtain the load current, so that the risk of load reversing operation is caused, the waiting time is long, and electric energy is wasted. Moreover, as the loop current is increased, the open-circuit voltage is increased, and the safety of human bodies and equipment is extremely easily endangered once the work is carried out.

Disclosure of Invention

The invention aims to provide a passive alternating-current micro-current acquisition and amplification device to solve the technical problem.

In order to achieve the purpose, the invention adopts the following technical scheme:

the passive AC micro-current collecting and amplifying device comprises a multi-winding insulating coil, an extraction terminal and an analyzer, wherein coil taps with N times of turns are respectively extracted from the multi-winding insulating coil and are respectively connected to the extraction terminal, when N =5 is selected, the extraction terminal is divided into a public terminal 0 and a 1N-6N times of extraction terminals, different terminals correspond to different N times of amplification coefficients of a current coil, a discharge display lamp and a discharge tube are respectively connected between the adjacent public terminal 0 and the 1N-6N times of extraction terminals in parallel, the discharge display lamp is used for emitting light to remind workers of danger when in open-circuit discharge, the discharge tube is used for breakdown when overvoltage is generated in open circuit, personal and equipment safety is protected, an external connecting plug is connected to the extraction terminal through an experimental wire, the external connecting plug is connected to the current terminal in an external current loop, and a current caliper with an output wire is used, the AC current data is transmitted to the analyzer for processing.

The amplifying device is arranged in a device shell with a box cover, a box inner lining plate is arranged in the device shell and used for fixing the multi-winding insulating coil and protecting the multi-winding insulating coil, a discharge tube and a leading-out terminal, an anti-collision/grinding outer casing is arranged at an outer leakage part of the multi-winding insulating coil and used for protecting an exposed part of the multi-winding insulating coil from being damaged by collision and friction external force.

The device shell is made of insulating plastics. The multi-winding insulating coil is a coil with taps with different turns in the middle, the number of turns is 20, 5-turn taps and 10-turn taps are respectively led out, and 1 public clamping hole is provided for the current clamp; the diameter of the coil is smaller than the maximum wire diameter of the current clamp which can be clamped by the current clamp by 7.5mm, and the turn-to-turn insulation is larger than 100M omega.

The discharge display lamp adopts a glass discharge tube, and the discharge tube adopts a semiconductor discharge tube, so that interface overvoltage secondary protection is realized; the glass discharge tube realizes the first-level protection of interface overvoltage, and is lightened when the interface voltage of the device is higher than 40V, so as to give an alarm to maintainers; the semiconductor discharge tube realizes the second-level protection of interface overvoltage, breaks down a short circuit when the voltage of the interface of the device is more than 100V, and avoids the damage to personal and equipment safety caused by high voltage generated by the open circuit of a current secondary circuit.

Compared with the prior art, the invention has the following advantages: the invention is suitable for complex environments with strong electromagnetic fields and dense wiring of transformer substations. The invention is easy to process, small in volume and convenient to carry; the current loop is connected in series, so that the wiring is simple, the inspection is convenient, the error is not easy to occur, and the open circuit occurrence rate of the current loop is reduced; for equipment with small load, no load, substation, subway line, larger CT transformation ratio coefficient and the like, under the condition of small load current, the amplification of small current can be realized, the workload is greatly reduced, the power failure time is shortened, and the power transmission efficiency is improved; the power transmission device has obvious effects on saving manpower and material resources and improving power transmission speed. Meanwhile, the direct economic benefit, the social benefit and the enterprise image are greatly improved, and the device has low manufacturing cost and certain application and popularization values.

Drawings

FIG. 1 is a schematic diagram of a single-phase single-winding wire connection according to the present invention;

FIG. 2 is a schematic diagram of a three-phase three-winding type wiring of the present invention;

FIG. 3 is a schematic diagram of the field wiring of the single phase device;

FIG. 4 is a schematic field wiring diagram of a three-phase device;

FIG. 5 is a schematic diagram of the single phase single winding concept of the present invention;

in the figure: 1 multi-winding insulating coil, 2 discharge display lamp, 3 discharge tube, 4 leading-out terminal, 5 external connection plug, 6 test wire, 7 device shell, 8 box cover, 9 current caliper, 10 analyzer, 11 box inner lining board, 12 anti-collision/abrasion outer casing.

Detailed Description

The invention is explained in further detail below with reference to the figures and the specific embodiments.

As shown in the figure, the passive alternating current micro-current acquisition amplifying device comprises a multi-winding insulating coil 1, an extraction terminal 2 and an analyzer 10, wherein coil taps with N times of turns are respectively extracted from the multi-winding insulating coil 1 and are respectively connected to the extraction terminal 4, when N =5 is selected, the extraction terminal 4 is divided into a common terminal 0 and a 1N-6N times of extraction terminals, different terminals correspond to different N times of amplification coefficients of a current coil, a discharge display lamp 2 and a discharge tube 3 are respectively connected between the adjacent common terminal 0 and the 1N-6N times of extraction terminals in parallel, the discharge display lamp 2 is used for lightening the discharge tube to remind a worker of danger when open circuit discharge is carried out, the discharge display lamp 3 is used for breaking down when open circuit generates overvoltage to protect personal and equipment safety, an external wiring plug 5 is connected to the extraction terminal 4 through an experimental wire 6, the external wiring plug 5 is connected to a current terminal in an external current loop, the current clamp 9 with an output line is used for sending collected alternating current data to an analyzer 10 for processing.

The amplifying device is arranged in a device shell 7 with a box cover 8, a box inner lining plate 11 is arranged in the device shell 7, the box inner lining plate 11 is used for fixing a multi-winding insulating coil 1 and protecting the multi-winding insulating coil 1, a discharge tube 3 and a leading-out terminal 4, an anti-collision/grinding outer casing 12 is arranged at the outer leakage part of the multi-winding insulating coil 1, and the anti-collision/grinding outer casing 12 is used for protecting the exposed part of the multi-winding insulating coil 1 from being damaged by collision and friction external force.

The device housing 7 is made of insulating plastic. The multi-winding insulating coil 1 is a coil with taps with different turns in the middle, the number of turns is 20, 5-turn taps and 10-turn taps are respectively led out, and 1 common clamping hole is provided for the current clamp; the diameter of the coil is smaller than the maximum wire diameter of the current clamp which can be clamped by 7.5mm, and the turn-to-turn insulation is larger than 100M omega.

The discharge display lamp 2 adopts a glass discharge tube, and the discharge tube 3 adopts a semiconductor discharge tube, so that interface overvoltage secondary protection is realized; the glass discharge tube realizes the first-level protection of interface overvoltage, and is lightened when the interface voltage of the device is higher than 40V, so as to give an alarm to maintainers; the semiconductor discharge tube realizes the second-level protection of interface overvoltage, breaks down a short circuit when the voltage of the interface of the device is more than 100V, and avoids the damage to personal and equipment safety caused by high voltage generated by the open circuit of a current secondary circuit.

The invention uses the electromagnetic induction principle to enable the collected current to flow through the current caliper 9 for multiple times in the same direction, the magnetic flux generated by the current caliper is amplified by N times, and the analyzer can accurately measure the magnitude and the phase of the micro-current. Even if the secondary current loop is open-circuited by mistake in work, the overvoltage protection element is connected in the device, the overvoltage protection element can discharge when the voltage exceeds 48V, and when overvoltage is generated at a disconnection point due to the disconnection of the loop, the overvoltage indicator emits light to remind a worker to check the loop. Meanwhile, the breakdown insurance can be broken down, and the human body and the equipment are protected from being damaged. The device is designed to be single-phase or three-phase, and can be flexibly used according to the field.

The foregoing is a preferred embodiment of the present invention, and it will be appreciated by those skilled in the art that changes, modifications, substitutions and variations may be made in the embodiments without departing from the principles and spirit of the invention, which is further defined in the appended claims.

Claims (5)

1. passive AC micro-current acquisition and amplification device, it is characterized in that, comprises multi-winding insulating coil, lead-out terminal, analyzer, in the multi-winding insulating coil, the coil taps of N times of turns are extracted respectively and are connected to the lead-out terminal respectively, when selecting N=5, the lead-out terminals are divided into common terminal 0, 1N-6N times lead-out terminals, different terminals correspond to different N-fold magnification factors of the current coil, and are connected in parallel between the adjacent common terminals 0 and 1N-6N times lead-out terminals respectively. Discharge indicator lamp and discharge tube. The discharge indicator lamp is used to emit light when open-circuit discharge is used to remind staff that there is danger. The discharge tube is used to break down when overvoltage is generated in the open circuit to protect the safety of people and equipment. The external wiring plug is connected to the lead-out terminal through the test wire. , The external wiring plug is connected to the current terminal in the external current loop, and the current caliper with the output line is used to send the collected AC current data to the analyzer for processing. 2. The passive AC micro-current collecting and amplifying device as claimed in claim 1, wherein the amplifying device is placed in a device casing with a box cover, and the device casing is provided with a box lining board, and the box lining board is It is used to fix the multi-winding insulating coil, and it is used to protect the multi-winding insulating coil, discharge tube and lead-out terminal. The leakage part of the multi-winding insulating coil is provided with an anti-collision/grinding outer casing, which is used to protect the multi-winding insulation. The exposed part of the coil is not damaged by collision and frictional external force. 3 . The passive AC micro-current collecting and amplifying device according to claim 1 , wherein the device shell is made of insulating plastic. 4 . 4. The passive AC micro-current collecting and amplifying device as claimed in claim 1, wherein the multi-winding insulating coil is a coil with taps with different turns in the middle, and the number of turns is 20. The tap provides a common clamping hole for the current clamp; the coil diameter is smaller than the maximum wire diameter of the current clamp which can be clamped by 7.5mm, and the inter-turn insulation is greater than 100MΩ. 5. The passive AC micro-current collecting and amplifying device according to claim 1, wherein the discharge display lamp adopts a glass discharge tube, and the discharge tube adopts a semiconductor discharge tube, so as to realize secondary overvoltage protection of the interface; The discharge tube realizes the first-level protection of interface overvoltage, and lights up when the device interface voltage is higher than 40V, and alerts the maintenance personnel; the semiconductor discharge tube realizes the second-level protection of interface overvoltage, and when the device interface voltage is greater than 100V Break down and short-circuit to avoid the high voltage generated by the open circuit of the current secondary circuit, which will endanger personal and equipment safety.

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