Transformer with leakage current limiting function

Abstract

The present invention relates to a transformer equipped with a leakage current limiting function, wherein current leaking from a phase voltage line of a three-phase or single-phase alternating current (AC) power system electrically connected to the primary coil or / and secondary coil of the transformer can be collected through a leakage current collecting coil spring mounted on the phase voltage line.

Description

Technology Field

[0001] The present invention relates to leakage current limiting technology, and in particular to a transformer equipped with a leakage current limiting function. Background Technology

[0002] A transformer is a device that converts alternating current (AC) voltage, and there is a wide variety of types, ranging from large transformers for power transmission and reception facilities to small and medium-sized transformers for household use and electronic devices.

[0003] If a transformer gets wet and comes into contact with the human body through the water, the current leaking from the transformer flows through the water and the human body to the ground, which is the grounding surface, and may cause an electric shock accident to the human body.

[0004] Electric shock is a phenomenon in which the human body reacts when the current flowing from a power source through the human body to the ground surface exceeds a certain level. Generally, if the flowing current is 15mA or more, it causes convulsions, and if it is 50mA or more, it leads to death.

[0005] The primary cause of death is cardiac arrest, in which the heart stops functioning as the electric current flowing through it damages the nerves. The risk of electric shock is related to the body's resistance at the time of current application, which depends significantly on the condition of the skin.

[0006] Korean Registered Patent No. 10-1625493 (published May 30, 2016), previously filed by the applicant of the present invention, describes that leakage current decreases as the difference in the area ratio between two flat-plate conductors increases. This technology prevents electric shock by limiting leakage current using the difference in area between the conductor electrodes.

[0007] The inventors have researched a technology that can efficiently prevent electric shock to the human body by collecting leakage current from a phase voltage line of a three-phase or single-phase alternating current (AC) power system electrically connected to the primary coil or / and secondary coil of a transformer through a leakage current collecting coil spring mounted on the phase voltage line. Prior art literature

[0008] Republic of Korea Registered Patent No. 10-1625493 (Published May 30, 2016) The problem to be solved

[0009] The present invention aims to provide a transformer equipped with a leakage current limiting function capable of capturing current leaking from a phase voltage line of a three-phase or single-phase alternating current (AC) power system electrically connected to the primary side coil or / and secondary side coil of the transformer through a leakage current capturing coil spring mounted on the phase voltage line. means of solving the problem

[0010] According to one aspect of the present invention for achieving the above-mentioned purpose, a transformer having a leakage current limiting function comprises: a primary coil to which an input side phase voltage line of a three-phase or single-phase AC power system and an input side neutral line of a three-phase or single-phase AC power system are each connected at both ends; a secondary coil to which an output side phase voltage line of a three-phase or single-phase AC power system and an output side neutral line of a three-phase or single-phase AC power system are each connected at both ends; a core on which the primary coil and the secondary coil are wound; and a leakage current capturing coil spring mounted on at least one of the input side phase voltage line and the output side phase voltage line to capture leakage current leaking from the phase voltage line.

[0011] According to an additional aspect of the present invention, a transformer having a leakage current limiting function may further include a neutral line area expansion patch mounted on at least one of a primary coil end connected to an input neutral line or a secondary coil end connected to an output neutral line to capture current leaking from the primary coil or the secondary coil.

[0012] According to an additional aspect of the present invention, a transformer equipped with a leakage current limiting function may further include an insulating tubular case that houses a coil spring for collecting leakage current inside and conceals it so that it is not exposed to the outside.

[0013] According to an additional aspect of the present invention, a coil spring for collecting leakage current can be implemented to be electrically connected to or disconnected from the neutral wire.

[0014] According to an additional aspect of the present invention, the cross-sectional area of ​​the neutral line area expansion patch may be 4 to 100,000 times the cross-sectional area of ​​the neutral line.

[0015] According to an additional aspect of the present invention, the neutral line area expansion patch can be implemented as a conductor comprising a material mixed with graphite and copper (Cu).

[0016] According to an additional aspect of the present invention, a transformer having a leakage current limiting function may further include an insulating enclosure that houses a primary coil, a secondary coil, and a core inside and protects the interior from the external environment. Effects of the invention

[0017] The present invention has the effect of efficiently preventing electric shock to the human body by capturing current leaking from a phase voltage line of a three-phase or single-phase alternating current (AC) power system electrically connected to the primary side coil or / and secondary side coil of a transformer through a leakage current capturing coil spring mounted on the phase voltage line. Brief explanation of the drawing

[0018] FIG. 1 is a diagram illustrating the configuration of an embodiment of a transformer equipped with a leakage current limiting function according to the present invention, illustrating a three-phase transformer applied to a three-phase alternating current (AC) power system. FIG. 2 is a diagram illustrating the configuration of an embodiment of a transformer equipped with a leakage current limiting function according to the present invention, illustrating a single-phase transformer applied to a single-phase alternating current (AC) power system. Specific details for implementing the invention

[0019] The foregoing and additional aspects are embodied through embodiments described with reference to the attached drawings. It is understood that the components of each embodiment may be combined in various ways within the embodiment or with components of other embodiments, unless otherwise stated or contradicted. Based on the principle that the inventor may appropriately define the concepts of terms to best describe his invention, the terms used in this specification and claims shall be interpreted in a meaning and concept consistent with the description or proposed technical idea.

[0020] Blocks referred to as 'circuits' in this specification may be composed of hardware such as dedicated semiconductors, gate arrays, FPGAs, or parts thereof. One or more blocks may be implemented as a single piece of hardware. As another example, these blocks may be implemented in software as an information processing device in which a computing element executes program instructions stored in a memory element. Multiple blocks may be implemented as part of a program executed on the same computing element.

[0021] As another example, these blocks may be implemented in a hybrid form where part of the individual circuit is hardware and part is software. Additionally, in the software implementation, the computational elements may include digital signal processors, dedicated computational processors, artificial intelligence processing engines, dedicated AI processors, and graphics processors, or a combination thereof to the extent possible.

[0022] Hereinafter, the present invention will be described in detail through preferred embodiments described with reference to the attached drawings so that those skilled in the art can easily understand and reproduce it. Although specific embodiments are illustrated in the drawings and detailed descriptions are provided, this is not intended to limit the various embodiments of the present invention to a specific form.

[0023] In describing the present invention, if it is determined that a detailed description of related known functions or configurations could unnecessarily obscure the essence of the embodiments of the present invention, such detailed description will be omitted.

[0024] When it is stated that one component is "connected" or "joined" to another component, it should be understood that while it may be directly connected or joined to that other component, there may also be other components in between.

[0025] On the other hand, when it is stated that one component is "directly connected" or "directly coupled" to another component, it should be understood that no other component exists in between.

[0026] FIG. 1 is a diagram illustrating the configuration of an embodiment of a transformer equipped with a leakage current limiting function according to the present invention, illustrating a three-phase transformer applied to a three-phase alternating current (AC) power system.

[0027] FIG. 2 is a diagram illustrating the configuration of an embodiment of a transformer equipped with a leakage current limiting function according to the present invention, illustrating a single-phase transformer applied to a single-phase alternating current (AC) power system.

[0028] As illustrated in FIGS. 1 and 2, a transformer (100) having a leakage current limiting function according to this embodiment includes a primary coil (110), a secondary coil (120), a core (130), and a coil spring (140) for collecting leakage current.

[0029] The primary coil (110) is connected at both ends to the input side phase voltage line (210) of a three-phase or single-phase AC power system and the input side neutral line (310) of a three-phase or single-phase AC power system, respectively.

[0030] The secondary coil (120) is connected at both ends to the output side phase voltage line (220) of a three-phase or single-phase AC power system and the output side neutral line (320) of a three-phase or single-phase AC power system, respectively.

[0031] The core (130) is wound with a primary coil (110) and a secondary coil (120). At this time, the core (130) may be an EI core in the form of stacked silicon steel plates in the shape of an E and an I, a toroidal core in the form of a donut (ring), or a ferrite core made of a ferrite alloy material, but is not limited thereto.

[0032] According to the Ampere-Maxwell law (the fourth equation of Maxwell's equations), a magnetic field is formed inside a core (130) with high permeability in which the primary coil (110) is wound by the current flowing in the primary coil (110), and according to Faraday's law, a change in magnetic flux occurs in the core (130), causing current to flow in the secondary coil (120) wound in the core (130), thereby transforming the alternating current (AC).

[0033] The voltage being transformed varies depending on the winding ratio of the primary coil (110) and the secondary coil (120) wound on the core (130). When the number of turns (turns) of the primary coil (110) is denoted as Np and the number of turns (turns) of the secondary coil (120) is denoted as Ns, the current relationship is as follows. In the equation below, p represents the primary side and s represents the secondary side.

[0034]

[0035] A coil spring (140) for collecting leakage current is made of a conductive material and is mounted on at least one of an input-side phase voltage line (210) and an output-side phase voltage line (220) to collect leakage current leaking from the phase voltage lines (210) and (220).

[0036] At this time, the leakage current capture coil spring (140) can be implemented to be electrically connected to or disconnected from the neutral wire (310)(320). The leakage current capture effect is superior when the leakage current capture coil spring (140) is electrically connected to the neutral wire compared to when it is not connected.

[0037] Table 1 below shows the experimental results of comparing the leakage current flowing in the water with a transformer without a leakage current capture coil spring (140) and a transformer with a leakage current capture coil spring (140) installed, each submerged in water (tap water) in a water tank, with the water not grounded.

[0038] With 220V / 60Hz commercial power connected to the primary coil (110) of the transformer and a 120W incandescent lamp connected as a load to the secondary coil (120) of the transformer, the current leaking into the water from the transformer (Experiment A of Table 1) without the leakage current collecting coil spring (140) installed was measured to be approximately 3mA.

[0039] Meanwhile, in a transformer (Experiment B of Table 1) in which a 220V / 60Hz commercial power supply is connected to the primary side coil (110) of the transformer and a 120W incandescent lamp is connected as a load to the secondary side coil (120) of the transformer, a leakage current collecting coil spring (140) is mounted on the phase voltage line and the leakage current collecting coil spring (140) is electrically connected to the neutral line, the current leaking and flowing through the water was measured to be approximately 1.2mA.

[0040] Meanwhile, with a commercial power supply of 220V / 60Hz connected to the primary side coil (110) of the transformer and a 120W incandescent lamp connected as a load to the secondary side coil (120) of the transformer, a leakage current collecting coil spring (140) is mounted on the phase voltage line, and the leakage current collecting coil spring (140) is electrically disconnected from the neutral line. In the transformer (Experiment C of Table 1), the current flowing through the water due to leakage was measured to be approximately 2mA.

[0041] experiment A B C leakage current 3mA 1.2mA 2mA

[0042] As can be seen from the experimental results, when a leakage current capture coil spring (140) is mounted on the upper voltage line, the leakage current is captured by the leakage current capture coil spring (140) mounted on the upper voltage line, and the leakage current flowing through water is reduced, thereby limiting the leakage current flowing to the human body.

[0043] In addition, when the leakage current collecting coil spring (140) mounted on the upper voltage line is electrically connected to the neutral line, the leakage current flowing through the water is further reduced compared to the case where the leakage current collecting coil spring (140) is not electrically connected to the neutral line, and it can be seen that the leakage current flowing to the human body is further restricted.

[0044] By implementing it in this way, the present invention can collect current leaking from a phase voltage line of a three-phase or single-phase AC power system electrically connected to the primary coil or / and secondary coil of a transformer through a leakage current collecting coil spring mounted on the phase voltage line, thereby effectively preventing electric shock to the human body.

[0045] Meanwhile, according to an additional aspect of the present invention, a transformer (100) having a leakage current limiting function may further include a neutral line area expansion patch (150). The neutral line area expansion patch (150) is mounted on at least one of the end of the primary coil (110) connected to the input neutral line (310) or the end of the secondary coil (120) connected to the output neutral line (320), and captures current leaking from the primary coil (110) or the secondary coil (120).

[0046] At this time, the neutral line area expansion patch (150) can be implemented as a conductor containing a material mixed with graphite and copper (Cu), so that it has excellent thermal conductivity and a low coefficient of thermal expansion, making it advantageous for deformation.

[0047] Meanwhile, the cross-sectional area (150) of the neutral line area expansion patch (150) can be implemented to be 4 to 100,000 times the cross-sectional area of ​​the neutral line (310)(320). By the neutral line area expansion patch (150), the area of ​​the neutral line (310)(320) is expanded, and the area of ​​the neutral line (310)(320) becomes larger than that of the phase voltage line (210)(220).

[0048] In the first place, the number of people who visited the site was 100.25. The same was the case of the 12th day of the 20th month, and the number of people who visited the site of the 2nd day of the 2nd month

[0049] The reason is that, as described in the prior art, such as in Korean Registered Patent No. 10-1404806, the larger the area of ​​the flat-shaped conductor connected to the (-) terminal (corresponding to the neutral wire of the present invention) compared to the flat-shaped conductor connected to the (+) terminal of the power source (corresponding to the phase voltage of the present invention), the smaller the leakage current leaking into the human body becomes.

[0050] Meanwhile, according to an additional aspect of the present invention, a transformer (100) equipped with a leakage current limiting function may further include an insulating tubular case (160). The insulating tubular case (160) houses a coil spring (140) for collecting leakage current inside and conceals it so that it is not exposed to the outside. For example, the insulating tubular case (160) may be cylindrical or polygonal.

[0051] Since an electric shock accident may occur if the leakage current collecting coil spring (140) is exposed to the outside and the human body comes into direct contact with the leakage current collecting coil spring (140), the leakage current collecting coil spring (140) is housed inside an insulating tubular case (160) case (180) so that the leakage current collecting coil spring (140) is not exposed to the outside, thereby preventing electric shock to the human body.

[0052] Meanwhile, according to an additional aspect of the present invention, a transformer (100) equipped with a leakage current limiting function may further include an insulator enclosure (170). The insulator enclosure (170) houses a primary coil (110), a secondary coil (120), and a core (130) inside to protect the interior from the external environment.

[0053] For example, the insulator housing (170) may be implemented as a back housing and a front door, and the front door may be coupled to the back housing while the primary coil (110), the secondary coil (120), and the core (130) are housed inside the back housing, but is not limited thereto.

[0054] By implementing it in this way, the present invention can protect the interior from the external environment by housing and concealing the primary coil (110), the secondary coil (120), and the core (130) inside the insulator enclosure (170).

[0055] As explained above, the present invention can collect leakage current from a phase voltage line of a three-phase or single-phase alternating current (AC) power system electrically connected to the primary coil or / and secondary coil of a transformer through a leakage current collecting coil spring mounted on the phase voltage line, thereby effectively preventing electric shock to the human body.

[0056] The various embodiments disclosed in this specification and drawings are provided merely as specific examples to aid understanding and are not intended to limit the scope of the various embodiments of the invention.

[0057] Accordingly, the scope of the various embodiments of the present invention should be interpreted as including all modifications or variations derived based on the technical concept of the various embodiments of the present invention, in addition to the embodiments described herein. Industrial applicability

[0058] The present invention is industrially available in the field of transformer-related technology and the field of application technology. Explanation of the symbols

[0059] 100: Transformer equipped with leakage current limiting function 110: Primary coil 120: Secondary coil 130 : Core 140: Coil spring for capturing leakage current 150: Neutral wire area expansion patch 160: Insulated cylindrical case 170 : Insulator enclosure 210, 220: Phase voltage line 310, 320: Neutral wire

Claims

Claim 1 A transformer having a leakage current limiting function comprising: a primary coil to which an input phase voltage line of a three-phase or single-phase AC power system and an input neutral line of a three-phase or single-phase AC power system are each connected at both ends; a secondary coil to which an output phase voltage line of a three-phase or single-phase AC power system and an output neutral line of a three-phase or single-phase AC power system are each connected at both ends; a core on which the primary coil and the secondary coil are wound; and a leakage current capturing coil spring mounted on at least one of the input phase voltage line and the output phase voltage line to capture leakage current leaking from the phase voltage line. Claim 2 A transformer having a leakage current limiting function according to claim 1, further comprising: a neutral line area expansion patch mounted on at least one of a primary coil end connected to an input neutral line or a secondary coil end connected to an output neutral line, for capturing current leaking from the primary coil or the secondary coil. Claim 3 A transformer having a leakage current limiting function according to claim 1, further comprising: an insulating tubular case that houses a coil spring for collecting leakage current inside and conceals it so as not to be exposed to the outside. Claim 4 In claim 1, a coil spring for capturing leakage current; a transformer having a leakage current limiting function that is electrically connected to or disconnected from the neutral line. Claim 5 In claim 2, a transformer having a leakage current limiting function in which the cross-sectional area of ​​the neutral line area expansion patch is 4 to 100,000 times the cross-sectional area of ​​the neutral line. Claim 6 In claim 2, the neutral line area expansion patch is a transformer having a leakage current limiting function implemented with a conductor comprising a material mixed of graphite and copper (Cu). Claim 7 A transformer having a leakage current limiting function according to any one of claims 1 to 6, further comprising: an insulating enclosure that houses a primary coil, a secondary coil, and a core inside and protects the interior from the external environment.

Images