Current transformer and three-phase four-wire current detection device

Abstract

The embodiment of the invention provides a current transformer and a three-phase four-wire current detection device, and relates to the technical field of current detection. The current transformer comprises an electromagnetic relay and a first current warning device; the first current warning device comprises a poke rod, a warning piece and an elastic component arranged on the base. The warning piece is located between the poke rod and the elastic component and connected with one end of the elastic component and one end of the poke rod, and the other end of the poke rod is connected to the electromagnetic relay. The electromagnetic relay is used for being connected with a wire to be detected and controlling the poke rod to move according to the current of the wire to be detected so as to change the telescopic state of the elastic component and the relative position of the warning piece. According to the invention, whether the three phases of the line are balanced or not can be judged more intuitively and accurately.

Description

Technical Field

[0001] This application relates to the technical field of current detection, and particularly to a current transformer and a three-phase four-wire current detection device. Background Art

[0002] In a low-voltage three-phase four-wire system, due to factors such as uneven three-phase loads and random electricity consumption, a three-phase imbalance will occur. When the three-phase imbalance degree is large, it will not only affect the power transmission efficiency, increase the line loss, but also cause damage to electrical equipment and even may lead to safety accidents.

[0003] To ensure the stable operation of the power system, it is necessary to judge the three-phase imbalance degree in order to adjust the load in a timely manner. In the prior art, a handheld clamp ammeter or a current transformer with a fault indicator light is usually used for current detection to determine the three-phase balance situation of the three-phase four-wire system. When detecting the current, maintenance personnel need to set up a ladder to climb high for installation and measurement, and the maintenance personnel need to be close to view the current or light state displayed by it to determine the fault state.

[0004] However, in the above solution, the repeated high-altitude measurement operations will not only increase the falling risk of maintenance personnel, but also the light signal is not obvious enough. Especially during the day, it will be impossible to accurately judge the light intensity of the indicator light, so it is impossible to accurately judge whether the three phases of the line are balanced and impossible to know the power system fault in time. Summary of the Invention

[0005] Embodiments of this application provide a current transformer and a three-phase four-wire current detection device to achieve the effect of more intuitively and accurately judging whether the three phases of the line are balanced.

[0006] In a first aspect, embodiments of this application provide a current transformer, and the current transformer includes an electromagnetic relay and a first current warning device; wherein,

[0007] The first current warning device includes a toggle rod, a warning member, and an elastic member disposed on the base; the warning member is located between the toggle rod and the elastic member, and is respectively connected to the elastic member and one end of the toggle rod, and the other end of the toggle rod is connected to the electromagnetic relay;

[0008] The electromagnetic relay is used to be connected to the measured wire, and control the movement of the toggle rod according to the magnitude of the current in the measured wire, so as to change the telescopic state of the elastic member and the relative position of the warning member.

[0009] In a possible implementation, the warning member includes an identification rod and an identification plate, and the identification rod and the identification plate are of an integral structure; the identification rod is located between the toggle rod and the elastic member, and is respectively connected to the elastic member and one end of the toggle rod.

[0010] In a possible implementation, the first current warning device further includes a zero-adjustment and correction member, and the zero-adjustment and correction member is connected between the elastic member and the warning member; the zero-adjustment and correction member is used to correct the elastic member so that when the current transformer is in a non-use state, the warning member is in an initial position.

[0011] In a possible implementation, the first current warning device further includes a scale identification member arranged in parallel with the elastic member on the base; when the toggle rod moves, the scale position pointed to by the warning member changes accordingly.

[0012] In a possible implementation, the electromagnetic relay includes an electromagnet, an armature, a spring, and an iron core;

[0013] The electromagnet is connected to the iron core, the electromagnet is arranged on the fixed frame of the electromagnetic relay, one end of the spring is connected to the fixed frame, the other end of the spring is connected to the armature, and the armature is further connected to the other end of the toggle rod;

[0014] The iron core is used to connect the wire to be measured; the electromagnet is used to generate a corresponding magnetic field according to the current of the wire to be measured so as to change the telescopic state of the spring; the armature is used to control the movement of the toggle rod according to the telescopic state of the spring so as to change the telescopic state of the elastic member and the relative position of the warning member.

[0015] In a possible implementation, the electromagnetic relay further includes a current-limiting resistor, and the electromagnet is connected to the iron core through the current-limiting resistor.

[0016] In a possible implementation, a fixed buckle is arranged on the iron core, and the fixed buckle is used to fix the wire to be measured.

[0017] In a possible implementation, the current transformer further includes a second current warning device, and the second current warning device includes a first power supply and a first alarm, and the positive pole of the first power supply is connected to the positive pole of the first alarm;

[0018] The electromagnetic relay is further used to control the negative pole of the first power supply and the negative pole of the first alarm to become in a connected state when it is determined that the current of the wire to be measured is in a first preset interval.

[0019] In a possible implementation manner, the current transformer further includes a third current warning device, and the third current warning device includes a second power supply and a second alarm. The positive pole of the second power supply is connected to the positive pole of the second alarm;

[0020] The electromagnetic relay is further configured to control the negative pole of the second power supply and the negative pole of the second alarm to become a connected state when it is determined that the current of the measured wire is in a second preset range.

[0021] In a possible implementation manner, the first alarm includes at least one of a buzzer, a horn, a lighting member, a wireless transmitter, and a smoke generator; the second alarm includes at least one of a buzzer, a horn, a lighting member, a wireless transmitter, and a smoke generator.

[0022] In a second aspect, an embodiment of the present application provides a three-phase four-wire current detection device, and the three-phase four-wire current detection device includes four current transformers as described in the first aspect above and / or various possible current transformers of the first aspect; wherein, the current transformers are installed side by side in the same direction so that the toggle rod moves in the same spatial direction.

[0023] In the current transformer and the three-phase four-wire current detection device provided by the embodiments of the present application, the current transformer includes an electromagnetic relay and a first current warning device; wherein, the first current warning device includes a toggle rod, a warning member, and an elastic member disposed on the base; the warning member is located between the toggle rod and the elastic member and is respectively connected to the elastic member and one end of the toggle rod, and the other end of the toggle rod is connected to the electromagnetic relay; the electromagnetic relay is configured to be connected to the measured wire and control the movement of the toggle rod according to the magnitude of the current of the measured wire so as to change the telescopic state of the elastic member and the relative position of the warning member. On the one hand, the magnitude of the current can be very intuitively determined through the distance moved by the warning member, so as to judge the three-phase balance state and fault state of the line, and solve the problem that it is impossible to accurately identify the light intensity due to light problems, and thus it is impossible to accurately judge whether the three phases of the line are balanced or whether there is a fault; on the other hand, the current transformer of the embodiment of the present application can be installed once and used continuously. After installing the current transformer of the embodiment of the present application, the moving position of the warning member can be observed on the ground without climbing to check, reducing the falling risk and improving the use safety. Description of the Drawings

[0024] The drawings here are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present application and used together with the specification to explain the principles of the present application.

[0025] Figure 1 It is a schematic structural diagram of a current transformer provided by an embodiment of the present application;

[0026] Figure 2 This is a schematic structural diagram of another current transformer provided by an embodiment of the present application;

[0027] Figure 3 This is a schematic structural diagram of yet another current transformer provided by an embodiment of the present application;

[0028] Figure 4 This is an application scenario diagram of a three-phase four-wire current detection device provided by an embodiment of the present application.

[0029] Explanation of reference numerals:

[0030] 100 - Current transformer; 10 - Electromagnetic relay; 11 - Electromagnet; 12 - Armature; 13 - Spring; 14 - Iron core; 15 - Current-limiting resistor; 16 - Fixed buckle; 17 - First contact; 18 - Second contact; 20 - First current warning device; 21 - Toggle lever; 22 - Warning member; 221 - Identification rod; 222 - Identification plate; 23 - Base; 24 - Elastic member; 25 - Zero-adjustment and correction member; 26 - Scale identification member; 30 - Conductive wire under test; 40 - Second current warning device; 41 - First power supply; 42 - First alarm; 50 - Third current warning device; 51 - Second power supply; 52 - Second alarm.

[0031] Through the above-mentioned drawings, specific embodiments of the present application have been shown, and there will be more detailed descriptions hereinafter. These drawings and textual descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. Detailed implementation manners

[0032] Here, exemplary embodiments will be described in detail, and their examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numerals in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0033] In the description of the embodiments of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation on the embodiments of the present application.

[0034] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the embodiments of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0035] In the embodiments of the present application, unless otherwise clearly defined and limited, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or communicable with each other; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0036] In the embodiments of the present application, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0037] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0038] In a low-voltage three-phase four-wire system, due to factors such as the unevenness of three-phase loads and the randomness of power consumption, the situation of three-phase imbalance will occur. When the degree of three-phase imbalance is relatively large, it will not only affect the transmission efficiency of electric energy, increase the line loss, but also cause damage to power equipment and even may lead to safety accidents.

[0039] In order to ensure the stable operation of the three-phase four-wire power system, it is necessary to judge the degree of three-phase imbalance and adjust the load of the unbalanced three phases. At present, usually by monitoring the magnitude of the current in the three-phase circuit to judge the weight of the load.

[0040] In one example, a clamp ammeter is used to measure the three-phase current of the line one by one to judge which phase has a heavier / lighter load. Then, the load of the three phases is redistributed to make the current of each phase close to the same, ensuring that the three-phase load of the line is within the balanced range. Since the position of the low-voltage overhead line is usually relatively high, in this solution, the grid operation and maintenance personnel need to hold a clamp ammeter and climb a ladder to measure. In the case of complex low-voltage alley lines and branch lines, detecting the three-phase current of the line section by section and phase by phase is not only time-consuming and laborious, but also the repeated climbing measurements will increase the risk of falling for the operation and maintenance personnel.

[0041] In another example, a current transformer with a fault indicator light is used for current detection. When the three-phase load is within the balanced range, the indicator light of the current transformer will remain constantly on. When the current of any one phase exceeds the balanced limit range, the corresponding indicator light will go out. In this way, the maintenance personnel can quickly judge which phase the faulty line is specifically located in, improving the efficiency of fault troubleshooting. However, in this solution, when the light signal is not obvious, especially during the day, it will be impossible to accurately judge the light intensity of the indicator light. When the sunlight is stronger, it is even impossible to accurately judge whether the indicator light is on, and naturally it is impossible to accurately judge whether the three phases of the line are balanced or whether there is a fault.

[0042] To solve the above technical problems, an embodiment of the present application provides a current transformer, which configures a warning member as a judgment basis, and judges the magnitude of the current by the moving distance of the warning member. On the one hand, through the moving distance of the visible object, the magnitude of the current can be very intuitively determined, so as to judge the three-phase balance state and fault state of the line, and solve the problem that the light intensity cannot be accurately identified due to light problems, so that the three-phase of the line cannot be accurately judged Whether it is balanced or whether there is a fault; on the other hand, the current transformer of the embodiment of the present application can be installed once and used continuously. After installing the current transformer of the embodiment of the present application, the moving position of the warning member can be observed on the ground without climbing high to check, reducing the risk of falling.

[0043] The following uses specific embodiments to describe in detail the technical solutions of the present application and how the technical solutions of the present application solve the above technical problems. These specific embodiments below can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0044] Exemplarily, Figure 1 is a schematic structural diagram of a current transformer provided by an embodiment of the present application. As Figure 1 shown, the current transformer 100 provided by the embodiment of the present application includes an electromagnetic relay 10 and a first current warning device 20. Among them, the first current warning device 20 includes a toggle rod 21, a warning member 22, and an elastic member 24 disposed on the base 23; the warning member 22 is located between the toggle rod 21 and the elastic member 24, and is respectively connected to the elastic member 24 and one end of the toggle rod 21, and the other end of the toggle rod 21 is connected to the electromagnetic relay 10. The electromagnetic relay 10 is used to connect to the measured wire 30, and controls the movement of the toggle rod 21 according to the magnitude of the current in the measured wire 30, so as to change the telescopic state of the elastic member 24 and the relative position of the warning member 22.

[0045] Exemplarily, when the current in the measured wire 30 is under normal current conditions, the electromagnetic relay 10 does not act, the toggle rod 21 remains stationary, the elastic member 24 is in an initial state, and the position of the warning member 22 does not change significantly. When the current in the measured wire 30 exceeds a certain limit value, the electromagnetic relay 10 is activated, generates a magnetic field to push the toggle rod 21 to move, and the movement of the toggle rod 21 changes the telescopic state of the elastic member 24 and pushes the warning member 22 to move to a visible or perceivable position. According to the relative position where the warning member 22 moves, the magnitude of the current in the measured wire 30 can be known. The larger the current, the greater the distance the warning member 22 moves, and the smaller the current, the smaller the distance the warning member 22 moves.

[0046] Optionally, the elastic component 24 can be any one of a spring, a rubber pad, a gas spring, a metal bellows, a polyurethane elastomer, etc., and the embodiment of the present application is not limited. Among them, the spring has the advantages of strong bearing capacity, large elastic deformation range, and applicability to a variety of load conditions; the rubber pad has the advantages of good shock absorption and sound insulation effects, and easy installation; the gas spring has the advantages of strong bearing capacity and adjustable elasticity; the metal bellows has the advantages of high temperature resistance and corrosion resistance; the polyurethane elastomer has the advantages of wear resistance, oil resistance, and good elasticity. In practical applications, a suitable elastic material can be selected according to the environment in which the measured wire 30 is located.

[0047] When the current transformer provided in the embodiment of the present application is used to simultaneously measure the current of phase A, phase B, phase C, and phase N (also known as zero phase) in a three-phase four-wire system, the current distribution and load conditions of each phase in the line can be known according to the relative position of the warning piece in each corresponding current transformer after the movement, thereby determining whether the three phases of the line are in a balanced state. If the relative positions of the warning pieces in each corresponding current transformer after the movement are substantially the same, it can be considered that the line is in a three-phase balanced state; and if the difference between the relative positions of the warning pieces in each corresponding current transformer after the movement exceeds a preset range, it can be considered that the line is in a three-phase unbalanced state.

[0048] The warning member 22 is a component with an obvious identification function, and the operation and maintenance personnel can still clearly see the distance moved by the warning member at a high place at a relatively long distance (such as on the ground). Figure 1 As shown, the warning member 22 includes an identification rod 221 and an identification plate 222, wherein the identification rod 221 and the identification plate 222 are an integrated structure; the identification rod 221 is located between the toggle rod 21 and the elastic component 24, and is respectively connected to one end of the elastic component 24 and the toggle rod 21.

[0049] For example, Figure 1 As shown, when the toggle rod 21 is pushed by the magnetic field generated by the electromagnetic relay 10 and moves downward, the identification rod 221 will move downward with the toggle rod 21 to compress the elastic component 24, and the identification plate 222 integrally connected to the identification rod 221 will also move downward with the identification rod 22. According to the relative position of the identification rod 221 and the identification plate 222, the current of the measured wire can be known.

[0050] Understandably, when the current transformer provided in the embodiment of the present application is used to measure the current of a circuit, the identifier on the identifier plate 222 can be set according to actual requirements. For example, when measuring the current of phase A, "A" can be written on the identifier plate 222; when measuring the current of phase B, "B" can be written on the identifier plate 222; when measuring the current of phase C, "C" can be written on the identifier plate 222; when measuring the current of phase N, "N" can be written on the identifier plate 222. Of course, other methods can also be used for distinction, such as using different colors for identification, for example, using yellow to represent phase A, using green to represent phase B, using red to represent phase C, using blue to represent phase N, etc. The embodiment of the present application does not make any restrictions.

[0051] Exemplarily, in the embodiment of the present application, the electromagnetic relay 10 is an electromechanical component that uses the current in the measured wire 30 to generate an electromagnetic force to control the movement of the toggle lever 21. The embodiment of the present application does not limit the specific structure of the electromagnetic relay 10.

[0052] Optionally, in a possible embodiment, as Figure 1 shown, the electromagnetic relay 10 includes an electromagnet 11, an armature 12, a spring 13, and an iron core 14. Among them, the electromagnet 11 is connected to the iron core 14. The electromagnet 11 is arranged on the fixed frame of the electromagnetic relay 10. One end of the spring 13 is connected to the fixed frame, and the other end of the spring 13 is connected to the armature 12. The armature 12 is also connected to the other end of the toggle lever 21. The iron core 14 is used to connect the measured wire 30. The electromagnet 11 is used to generate a corresponding magnetic field according to the current in the measured wire 30 to change the telescopic state of the spring 13. The armature 12 is used to control the movement of the toggle lever 21 according to the telescopic state of the spring 13 to change the telescopic state of the elastic member 24 and the relative position of the warning member 22.

[0053] Exemplarily, by reasonably setting the components in the electromagnetic relay 10, such as the coil of the electromagnet 11 and the elasticity of the spring 13, the electromagnetic relay 10 can be realized: when the current in the measured wire 30 is within the normal range, the electromagnet 11 does not generate enough magnetic field, the armature 12 remains stationary under the action of the spring 13, the toggle lever 21 does not move, and the elastic member 24 and the warning member 22 remain in the initial position. When the current in the measured wire 30 exceeds the preset threshold, the electromagnet 11 is energized and generates a magnetic field. This magnetic field attracts the armature 12, causing it to overcome the restoring force of the spring 13 and move towards the electromagnet 11. The movement of the armature 12 will drive the movement of the toggle lever 21, which will not only change the telescopic state of the elastic member 24 but also push the warning member 22 to move into a visible or perceivable position, thereby providing a warning of abnormal current.

[0054] The current transformer 100 provided by the embodiment of the present application includes an electromagnetic relay 10 and a first current warning device 20; wherein, the first current warning device 20 includes a toggle lever 21, a warning member 22, and an elastic member 24 disposed on a base 23; the warning member 22 is located between the toggle lever 21 and the elastic member 24, and is respectively connected to the elastic member 24 and one end of the toggle lever 21, and the other end of the toggle lever 21 is connected to the electromagnetic relay 10; the electromagnetic relay 10 is used to be connected to a measured wire 30, and control the movement of the toggle lever 21 according to the magnitude of the current in the measured wire 30, so as to change the telescopic state of the elastic member 24 and the relative position of the warning member 22. On the one hand, the magnitude of the current can be very intuitively determined by the distance that the warning member moves, so as to judge the three-phase balance state and fault state of the line, solving the problem that the light intensity cannot be accurately identified due to light problems, and thus the three-phase of the line cannot be accurately judged whether it is balanced or whether there is a fault; on the other hand, the current transformer of the embodiment of the present application can be installed once and used continuously. After installing the current transformer of the embodiment of the present application, the moving position of the warning member can be observed on the ground without climbing to check, reducing the falling risk and improving the use safety.

[0055] Exemplarily, Figure 2 is a schematic structural diagram of another current transformer provided by the embodiment of the present application. In Figure 1 On the basis of the current transformer 100 shown, optionally, in some possible embodiments, as Figure 2 shown, the first current warning device 20 may further include a zero-adjustment and correction component 25, and the zero-adjustment and correction component 25 is connected between the elastic member 24 and the warning member 22; the zero-adjustment and correction component 25 is used to correct the elastic member 24, so that when the current transformer 100 is in a non-use state, the warning member 22 is located at the initial position.

[0056] Exemplarily, the zero-adjustment and correction component 25 may be any one of an adjustment screw, a gasket, an adjustment nut, a spring seat, an adjustment rod, a hydraulic or pneumatic regulator, an electronic regulator, etc., and the embodiment of the present application does not make a limitation. The adjustment screw can change the initial length or tension of the spring by rotating the screw, the initial compression amount of the spring can be adjusted by increasing or decreasing the number or thickness of the gaskets, the tension or length of the spring can also be changed by rotating the nut, the initial state of the spring can be changed by adjusting the position of the spring seat, the tension or length of the spring can be changed by moving the adjustment rod, the tension of the spring can be changed by adjusting the hydraulic or pneumatic pressure, and the tension of the spring can be adjusted by controlling a motor or an electromagnetic device through an electronic signal. In practical applications, a suitable zero-adjustment and correction component 25 can be selected according to the characteristics of the selected elastic member 24.

[0057] It is understandable that during long-term use, the initial position of the elastic component 24 may change, and therefore, it needs to be corrected regularly so that when the current transformer 100 is not in use, the warning member 22 is located at the initial position.

[0058] It should be noted that the non-use state of the current transformer 100 refers to a state in which the electromagnet 11 does not generate a sufficient magnetic field, the armature 12 remains stationary under the action of the spring 13, and the toggle rod 21 does not move.

[0059] By periodically performing zero adjustment and correction on the elastic component 24 through the zero adjustment and correction component 25, the measurement accuracy of the current transformer 100 can be ensured, so as to more accurately determine the current magnitude and accurately judge the three-phase balance state and fault state of the line.

[0060] exist Figure 1 Based on the current transformer 100 shown in FIG. 1 , optionally, in a possible embodiment, as shown in FIG. Figure 2 As shown, the first current warning device 20 may further include a scale identification member 26 disposed on the base 23 in parallel with the elastic member 24; when the toggle rod 21 moves, the scale position of the warning member 22 pointing to the scale identification member 26 changes accordingly.

[0061] For example, when the current transformer 100 is not in use, the warning piece 22 points to the zero scale line of the scale identification piece 26. When the toggle rod 21 is pushed downward by the magnetic field generated by the electromagnetic relay 10, the warning piece 22 moves downward with the toggle rod 21, so that the scale position of the warning piece 22 pointing to the scale identification piece 26 will change accordingly. According to the scale position indicated by the warning piece 22, combined with the corresponding relationship between the preset scale and the current, the operation and maintenance personnel can know the current size in the measured wire 30 more clearly.

[0062] Through the correspondence between the scale in the scale identification part 26 and the current, the current size of the measured conductor can be quantified, which is convenient for operation and maintenance personnel to judge the three-phase balance state and fault state in the line more quickly and accurately.

[0063] exist Figure 1 Based on the current transformer 100 shown in FIG. 1 , optionally, in a possible embodiment, as shown in FIG. Figure 2 As shown, the electromagnetic relay 10 may further include a current limiting resistor 15 , and the electromagnet 11 is connected to the iron core 14 via the current limiting resistor 15 .

[0064] Among them, the current-limiting resistor 15 is an important protection component, mainly used to control the magnitude of the current passing through the coil of the electromagnet 11. In the embodiment of the present application, the electromagnet 11 is connected to the iron core 14 through the current-limiting resistor 15. This connection method means that the current must pass through the current-limiting resistor 15 before entering the coil of the electromagnet 11. The purpose of this design is to limit and regulate the current before it enters the coil of the electromagnet 11, so as to ensure that the electromagnet 11 operates within a safe and efficient working range.

[0065] Exemplarily, the measured wire 30 serves as a power source to provide current. According to different usage scenarios, the magnitude of the current in the measured wire 30 is different. In order to improve the safety and reliability of the electromagnetic relay 10, the embodiment of the present application can also add a current-limiting resistor 15 in the electromagnetic relay 10. Among them, by limiting the current through the current-limiting resistor 15, it is possible to prevent the coil from overheating or being damaged due to excessive current, and it can also help maintain the stability of the current when the power supply voltage fluctuates, ensure the normal operation of the electromagnetic relay 10, and reduce unnecessary energy consumption, thereby improving the overall efficiency of the system.

[0066] In Figure 1 Based on the current transformer 100 shown, optionally, in a possible embodiment, as Figure 2 shown, a fixed buckle 16 can also be provided on the iron core 14, and the fixed buckle 16 is used to fix the measured wire 30.

[0067] Exemplarily, the fixed buckle 16 is a mechanical component installed on the iron core 14 and can be made of metal or durable plastic. By using the fixed buckle 16, the measured wire 30 can be firmly fixed on the iron core 14, which helps to ensure that the wire does not move or fall off during the operation of the device, thereby guaranteeing the measurement accuracy and the stability of the device; in addition, the fixed buckle 16 can also help reduce the stress on the wire when it is subjected to external force or vibration, reducing the risk of wire breakage or poor contact; further, by using the fixed buckle 16, the installation and maintenance of the wire become more simple and fast. The buckle design allows for quick installation and disassembly of the wire, reducing the time and complexity of device maintenance.

[0068] The design solution of the present application to provide the fixed buckle 16 on the iron core 14 enhances the reliability and measurement accuracy of the device by providing a stable wire fixing structure, and also simplifies the installation and maintenance process.

[0069] In Figure 1 Based on the current transformer 100 shown, optionally, in a possible embodiment, as Figure 2As shown, the current transformer 100 may also include a second current warning device 40, wherein the second current warning device 40 includes a first power supply 41 and a first alarm 42, and the positive pole of the first power supply 41 is connected to the positive pole of the first alarm 42; the electromagnetic relay 10 is also used to control the negative pole of the first power supply 41 and the negative pole of the first alarm 42 to become connected when it is determined that the current of the measured conductor 30 is in the first preset interval.

[0070] Illustratively, the greater the current in the measured wire 30, the stronger the magnetic field generated by the electromagnet 11, the greater the force for the armature 12 to move downward, and thus the greater the force for the push rod 21 to move downward, the greater the compression force on the elastic component 24, and the greater the displacement of the warning member 22.

[0071] It is understandable that the current in the measured wire 30 may be too large or too small. In order to better complete the fault judgment, the current transformer 100 of the embodiment of the present application may also include a second current warning device 40, and when it is determined that the current of the measured wire 30 is in the first preset interval, the second current warning device 40 is controlled to issue an alarm.

[0072] Among them, the first preset interval can be an interval with a relatively small current value, or an interval with a relatively large current value. The embodiment of the present application does not limit the specific range of the first preset interval. When it is determined that the current of the measured wire 30 is in the first preset interval, the electromagnetic relay 10 controls the negative pole of the first power supply 41 and the negative pole of the first alarm 42 to become connected, so that the first alarm 42 sounds an alarm. The first power supply 41 is a power source that provides power to the first alarm 42, which can be a battery or other forms of power. The first alarm 42 is a device for issuing an alarm signal. When the alarm is activated, it emits warning signals such as sound and light.

[0073] Optionally, the first alarm 42 may include at least one of a buzzer, a speaker, a lighting component, a wireless transmitter, and a smoke generator. Among them, the buzzer can emit a single frequency sound, which can be used for a simple prompt tone. The speaker can play complex audio signals, such as music, voice, etc. The lighting component can be an LED indicator light, indicating different states through different colors or flashing modes. The wireless transmitter can send an alarm signal to a remote device. The smoke generator can generate smoke or fog, and can generate different amounts of smoke or fog according to the current size of the measured wire. In actual applications, one or more alarms can be selected according to actual needs and equipment costs so that operation and maintenance personnel can know the fault status more quickly.

[0074] For example, Figure 3 A schematic diagram of the structure of another current transformer provided in an embodiment of the present application. Figure 1 and Figure 2Based on the current transformer 100 shown, optionally, in a possible embodiment, as Figure 3 shown, the current transformer 100 may further include a third current warning device 50, where the third current warning device 50 includes a second power supply 51 and a second alarm 52, and the positive pole of the second power supply 51 is connected to the positive pole of the second alarm 52; the electromagnetic relay 10 is further configured to control the negative pole of the second power supply 51 and the negative pole of the second alarm 52 to become in a connected state when it is determined that the current in the measured wire 30 is in a second preset interval.

[0075] Exemplarily, multiple alarm devices may also be set up to issue alarms in different current intervals respectively. For example, the first preset interval may be set as the interval with a relatively small current value, and the second preset interval may be set as the interval with a relatively large current value. The specific ranges of the first preset interval and the second preset interval are not limited in the embodiments of the present application. When it is determined that the current in the measured wire 30 is in the first preset interval, the electromagnetic relay 10 controls the negative pole of the first power supply 41 and the negative pole of the first alarm 42 to become in a connected state, so that the first alarm 42 issues an alarm; when it is determined that the current in the measured wire 30 is in the second preset interval, the electromagnetic relay 10 controls the negative pole of the second power supply 51 and the negative pole of the second alarm 52 to become in a connected state, so that the second alarm 52 issues an alarm; when it is determined that the current in the measured wire 30 is in an interval other than the first preset interval and the second preset interval, the negative pole of the first power supply 41 and the negative pole of the first alarm 42, and the negative pole of the second power supply 51 and the negative pole of the second alarm 52 are all in a non-connected state, and no alarm is made.

[0076] Optionally, the second alarm 52 may also include at least one of a buzzer, a horn, a lighting element, a wireless transmitter, and a smoke generator, etc., which is not limited in the embodiments of the present application.

[0077] Optionally, in order to control the connection states of the negative pole of the first power supply 41 and the negative pole of the first alarm 42, and the negative pole of the second power supply 51 and the negative pole of the second alarm 52, the electromagnetic relay may further be provided with a first contact 17 and a second contact 18, which are respectively used to control the closing and opening of the second current warning device 40 and the third current warning device 50.

[0078] Through the first current warning device 20, the second current warning device 40, and the third current warning device 50, the present application realizes the detection of the three-phase current of the line through multi-channel judgment elements and multi-sensory judgment channels, and it is convenient to detect the three-phase imbalance and fault states of the line in any environment, whether it is day or night.

[0079] The embodiment of the present application further provides a three-phase four-wire current detection device, which includes four current transformers in the above embodiments; wherein, the four current transformers are installed side by side in the same direction, so that the toggle rod moves in the same spatial direction.

[0080] Exemplarily, Figure 4 is an application scenario diagram of a three-phase four-wire current detection device provided by an embodiment of the present application. As Figure 4 shown, on a newly built or existing three-phase four-wire low-voltage overhead wire, current transformers can be successively installed side by side on the A-phase, B-phase, C-phase, and N-phase wires, and their warning components are controlled to be on the same starting line, and the toggle rod moves in the same spatial direction. In this way, when judging the three-phase balance state and fault state of the line, by comparing the relative positions of the warning components, it can be quickly determined which lines are three-phase unbalanced. For branches with large three-phase imbalance, it can also be quickly identified which phase has a heavy load and which phase has a light load, so as to facilitate grid operation and maintenance personnel to adjust the three-phase load in time.

[0081] Since the present application judges the three-phase balance state and fault state of the line by the distance moved by the warning component, the current magnitude can be very intuitively determined, solving the problem that the light intensity cannot be accurately identified due to light problems, and thus it is impossible to accurately judge whether the three phases of the line are balanced or whether there is a fault; in addition, the current transformer of the embodiment of the present application can be installed once and used continuously. After installing the current transformer of the embodiment of the present application, the moving position of the warning component can be observed on the ground without climbing high to check, reducing the risk of falling and improving the use safety.

[0082] Finally, it should be noted that: After considering the specification and practicing the invention disclosed herein, those skilled in the art will easily think of other implementation schemes of the present invention. The present invention aims to cover any variations, uses or adaptive changes of the present invention, which follow the general principles of the present invention and include the common general knowledge or conventional technical means in the technical field not disclosed in the present invention. It is not limited to the precise structure already described and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present invention is only limited by the appended claims.

Claims

1. A current transformer, characterized in that: The current transformer includes an electromagnetic relay and a first current warning device; wherein, The first current warning device includes a toggle rod, a warning member, and an elastic member arranged on a base; the warning member is located between the toggle rod and the elastic member, and is respectively connected to the elastic member and one end of the toggle rod, and the other end of the toggle rod is connected to the electromagnetic relay; The electromagnetic relay is used to be connected to the measured wire, and controls the movement of the toggle rod according to the current of the measured wire, so as to change the telescopic state of the elastic component and the relative position of the warning member.

2. The current transformer according to claim 1, characterized in that: The warning member comprises an identification rod and an identification plate, wherein the identification rod and the identification plate are in an integrated structure; the identification rod is located between the toggle rod and the elastic component, and is respectively connected to one end of the elastic component and the toggle rod.

3. The current transformer according to claim 1, characterized in that: The first current warning device also includes a zero adjustment correction component, which is connected between the elastic component and the warning member; the zero adjustment correction component is used to correct the elastic component so that when the current transformer is in a non-use state, the warning member is located at an initial position.

4. The current transformer according to claim 1, characterized in that: The first current warning device also includes a scale identification member arranged on the base in parallel with the elastic member; when the toggle rod moves, the scale position of the warning member pointing to the scale identification member changes accordingly.

5. The current transformer according to any one of claims 1 to 4, characterized in that: The electromagnetic relay comprises an electromagnet, an armature, a spring and an iron core; The electromagnet is connected to the iron core, and the electromagnet is arranged on the fixed frame of the electromagnetic relay, one end of the spring is connected to the fixed frame, the other end of the spring is connected to the armature, and the armature is also connected to the other end of the toggle rod; The iron core is used to connect the measured wire; the electromagnet is used to generate a corresponding magnetic field according to the current of the measured wire to change the expansion and contraction state of the spring; The armature is used to control the movement of the toggle rod according to the telescopic state of the spring, so as to change the telescopic state of the elastic component and the relative position of the warning member.

6. The current transformer according to claim 5, characterized in that: The electromagnetic relay further comprises a current limiting resistor, and the electromagnet is connected to the iron core via the current limiting resistor.

7. The current transformer according to claim 5, characterized in that: The iron core is provided with a fixing buckle, and the fixing buckle is used to fix the measured wire.

8. The current transformer according to any one of claims 1 to 4, characterized in that: The current transformer further includes a second current warning device, the second current warning device includes a first power supply and a first alarm, and the positive electrode of the first power supply is connected to the positive electrode of the first alarm; The electromagnetic relay is also used to control the negative electrode of the first power supply and the negative electrode of the first alarm to become connected when it is determined that the current of the measured wire is in a first preset interval.

9. The current transformer according to claim 8, characterized in that: The current transformer further includes a third current warning device, the third current warning device includes a second power supply and a second alarm, and the positive electrode of the second power supply is connected to the positive electrode of the second alarm; The electromagnetic relay is further used to control the negative electrode of the second power supply and the negative electrode of the second alarm to become connected when it is determined that the current of the measured wire is in a second preset interval.

10. A three-phase four-wire current detection device, characterized in that: The three-phase four-wire current detection device comprises four current transformers as described in any one of claims 1 to 9; wherein the current transformers are installed in parallel in the same direction so that the toggle rods move in the same spatial direction.

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