An integrated leakage transformer with current and voltage detection

Abstract

The application discloses a kind of integrated leakage transformer with current voltage detection, including framework, leakage induction coil, multiple for connecting main detection circuit electric conductor and multiple respectively for detecting the voltage and current of main detection circuit voltage induction coil and current induction coil, multiple electric conductor, voltage induction coil and current induction coil are all assembled on framework to form compact setting, electric conductor is threaded through current induction coil and leakage induction coil, voltage induction coil is connected electric conductor by load unit to form voltage input loop and form induced voltage, leakage induction coil is used to external leakage detection circuit, to form compact integrated leakage transformer, and can detect leakage current, also consider detecting the voltage and current of main detection circuit, and effectively improve the precision of leakage detection, also effectively reduce the occupied space of leakage transformer, to be able to install in narrow, compact installation space.

Description

Technical Field

[0001] This invention relates to the field of current transformer technology, and in particular to an integrated leakage current transformer with current and voltage detection. Background Technology

[0002] To ensure electrical safety, all electrical equipment used in the power system must undergo leakage current detection. Leakage current refers to the conduction current that flows through a conductor when it comes into contact with the circuit of an electrical device. If the leakage current is too large, it will cause electrical safety accidents.

[0003] Traditional leakage current transformers are used to detect leakage current in leakage detection circuits. The leakage current detection method is as follows: the leakage detection circuit is electrically connected to one winding of a toroidal magnetic core, and positive and negative pulse signals are applied to the other winding of the toroidal magnetic core respectively. Then, the residual current in the leakage detection circuit is calculated using the magnetic modulation principle. This residual current is the leakage current.

[0004] Monitoring the current and voltage of the main detection circuit usually requires separate voltage transformers and current transformers. If traditional leakage current transformers, voltage transformers and current transformers are simply used together, the detection mechanism in the power system will have a complex structure and occupy a large volume, making it impossible to install in a small and compact installation space. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides an integrated leakage current transformer with current and voltage detection capabilities. This transformer can not only detect the leakage current of the leakage current detection circuit but also detect the voltage and current of the main detection circuit, achieving a compact structure and small footprint.

[0006] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0007] An integrated leakage current transformer with current and voltage detection includes a frame and a leakage current induction coil mounted at the bottom of the frame. It also includes a current and voltage detection unit and multiple conductors for connecting to a main detection circuit. The current and voltage detection unit includes multiple voltage induction coils for detecting the voltage of the main detection circuit and multiple current induction coils for detecting the current of the main detection circuit. The conductors, voltage induction coils, and current induction coils are all mounted around the frame in a compact arrangement. The current induction coil has a first winding. The conductors pass through the current induction coil and the leakage current induction coil. The first winding and the conductors cooperate to form a pair. The voltage sensing coil has a second winding and a third winding. The second winding is connected to the conductor through a load unit to form a voltage input circuit. The voltage of the voltage input circuit corresponds to the voltage of the main detection circuit. The third winding cooperates with the second winding to induce a voltage corresponding to the voltage of the voltage input circuit. The leakage current sensing coil has a fourth winding and a fifth winding. The fourth winding is used to connect an external leakage current detection circuit. The first winding, the third winding, and the fifth winding are all used to connect an external voltage and current testing unit.

[0008] Furthermore, the conductor is a U-shaped metal needle.

[0009] Furthermore, the skeleton has a skeleton body and multiple mounting frames surrounding the skeleton body. Both the mounting frames and the skeleton body are provided with mounting channels that cooperate with the conductors. The conductors are inserted one by one into the mounting channels of the mounting frames, and then the two ends of the conductors pass through the mounting channels of the skeleton body and the bottom of the skeleton body in sequence. The current sensing coil is sleeved on the mounting frame.

[0010] Furthermore, multiple mounting frames are evenly spaced on the main frame.

[0011] Furthermore, the outer peripheral surface of the frame body is provided with a plurality of first mounting slots for accommodating the voltage sensing coil; each first mounting slot is located between two adjacent mounting frames.

[0012] Furthermore, a second mounting groove for accommodating the voltage sensing coil is provided on the top of the main frame body.

[0013] Furthermore, it also includes a shielding component; the frame body has multiple mounting through holes that cooperate with the load unit; the shielding component includes a shielding cover and a shielding sheet, the bottom of the frame body is provided with a concave bottom groove, the shielding cover is assembled in the bottom groove, the leakage current induction coil is assembled in the shielding cover, and the shielding sheet covers the shielding cover.

[0014] Furthermore, it also includes a housing, and the skeleton is assembled inside the housing; the inner wall of the housing is provided with a first limiting boss that cooperates with the current sensing coil and a second limiting boss that cooperates with the voltage sensing coil.

[0015] Furthermore, the current sensing coil has a first magnetic core, and the first winding is wound on the first magnetic core; the voltage sensing coil has a second magnetic core, and the second winding and the third winding are both wound on the second magnetic core; the leakage current sensing coil has a third magnetic core, and the fourth winding and the fifth winding are both wound on the third magnetic core; the load unit is a resistor.

[0016] Furthermore, the main detection circuit is a three-phase four-wire system, with three voltage sensing coils and three current sensing coils; the number of conductors is four, with three conductors connected to the three-phase power of the main detection circuit and the other conductor connected to the neutral wire of the main detection circuit.

[0017] The technical solution provided by this invention has the following beneficial effects:

[0018] By assembling multiple conductors, voltage sensing coils, and current sensing coils around the frame to form a compact leakage current transformer, and then using a current-voltage detection unit to detect the voltage and current of the main detection circuit, it is possible not only to detect the leakage current of the leakage current detection circuit, but also to detect the voltage and current of the main detection circuit, thus forming an integrated transformer. This effectively improves the accuracy of leakage current detection and reduces the space occupied by the leakage current transformer, allowing it to be installed in a small and compact installation space. Attached Figure Description

[0019] Figure 1 The diagram shown is a structural schematic of an integrated leakage current transformer with current and voltage detection without a housing in the embodiment.

[0020] Figure 2 The diagram shown is a schematic of an integrated leakage current transformer with current and voltage detection, equipped with a housing, in an embodiment.

[0021] Figure 3 The figure shown is a cross-sectional view of an integrated leakage current transformer with current and voltage detection, equipped with a housing, in an embodiment.

[0022] Figure 4 The diagram shown is a circuit connection diagram of an integrated leakage current transformer with current and voltage detection in the embodiment.

[0023] Figure 5 The diagram shown is a schematic of the conductor in the embodiment;

[0024] Figure 6 The image shown is a first-view schematic diagram of the skeleton in the embodiment;

[0025] Figure 7 The diagram shown is a second-view illustration of the skeleton in the embodiment.

[0026] Figure 8 The diagram shown is a schematic representation of the outer casing in the embodiment. Detailed Implementation

[0027] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention, primarily used to illustrate the embodiments and to explain the operating principles of the embodiments in conjunction with the relevant descriptions in the specification. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention. Components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0028] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0029] Reference Figures 1 to 4As shown, this embodiment provides an integrated leakage current transformer (hereinafter referred to as the transformer) with current and voltage detection. The transformer includes a frame 3 and a leakage current induction coil 4 mounted on the bottom of the frame 3. It also includes a current and voltage detection unit and four conductors 5 for connecting to the main detection circuit 1. The current and voltage detection unit includes three voltage induction coils 6 for detecting the voltage of the main detection circuit 1 and three current induction coils 7 for detecting the current of the main detection circuit 1. The four conductors 5, three voltage induction coils 6, and three current induction coils 7 are all mounted around the frame 3 to form a compact arrangement. The current induction coil 7 has a first winding. The conductors 5 pass through the current induction coil 7 and the leakage current induction coil 4. The first winding and the conductors 5 are connected to the main detection circuit 1. The first winding is coordinated with the conductor 5 to form an induced current corresponding to the current flowing through the conductor 5. The current flowing through the conductor 5 is the current of the main detection circuit 1. The voltage sensing coil 6 has a second winding and a third winding. The second winding is connected to the conductor 5 through a load unit 9 to form a voltage input circuit. The voltage of the voltage input circuit corresponds to the voltage of the main detection circuit 1. The third winding is coordinated with the second winding to induce an induced voltage corresponding to the voltage of the voltage input circuit. The leakage current sensing coil 4 has a fourth winding and a fifth winding. The fourth winding is used to connect to the external leakage current detection circuit 2. The first winding, the third winding, and the fifth winding are all used to connect to the external voltage and current testing unit.

[0030] In this embodiment, the voltage and current testing unit belongs to the prior art, such as an integrated circuit unit containing a dedicated chip for testing the current of the main detection circuit 1, a dedicated chip for testing the voltage of the main detection circuit 1, and a dedicated chip for testing leakage current.

[0031] The transformer also includes an output terminal 10 for electrically connecting the voltage and current testing unit. The output terminal 10 is mounted on one side of the frame 3, and the output terminal of the current and voltage detection unit (such as the third winding and the fifth winding) and the first winding of the leakage current induction coil 4 are electrically connected to the input terminal of the voltage and current testing unit through the output terminal 10, so as to transmit the current signal and voltage signal corresponding to the main detection circuit 1 and the leakage current signal corresponding to the leakage current detection circuit 2 to the voltage and current testing unit for testing to obtain the corresponding test values.

[0032] The main detection circuit 1 is a three-phase four-wire system, in which three conductors 5 are respectively connected to the three phases of the main detection circuit 1 (i.e., phase A, phase B and phase C), and the other conductor 5 is connected to the neutral line N of the main detection circuit 1.

[0033] The input signal sources for the leakage current induction coil 4 include the leakage current detection circuit 2 externally connected to the fourth winding and the main detection circuit 1 connected to the conductor 5 passing through the leakage current induction coil 4.

[0034] When no leakage current occurs in the main detection circuit 1, since it is a zero-sequence current (i.e., the vector sum of the three-phase currents is zero), the fifth winding of the leakage current induction coil 4 does not generate a corresponding induction signal.

[0035] When AC leakage current occurs in the main detection circuit 1, the fifth winding of the leakage current induction coil 4 can generate a corresponding induction signal.

[0036] Furthermore, when leakage current occurs in the leakage detection circuit 2, the fifth winding of the leakage induction coil 4 can also generate a corresponding induction signal.

[0037] By assembling multiple conductors 5, voltage sensing coils 6, and current sensing coils 7 around the frame 3 to form a compact current transformer, and then using a current-voltage detection unit for detecting the voltage and current of the main detection circuit 1, not only can the leakage current of the leakage detection circuit 2 be detected, but the voltage and current of the main detection circuit 1 can also be detected, thus forming an integrated current transformer. This effectively improves the accuracy of leakage detection and reduces the space occupied by the current transformer, allowing it to be installed in a small and compact installation space.

[0038] Of course, in other embodiments, the number of conductors 5 can also be two, and the number of voltage sensing coils 6 and current sensing coils 7 can each be one.

[0039] In another preferred embodiment, such as Figure 5 The conductor 5 shown is a U-shaped metal needle.

[0040] More specifically, the frame 3 has a frame body 37 and four mounting frames 31 surrounding the frame body 37. Both the mounting frames 31 and the frame body 37 are provided with mounting channels for the conductors 5. The conductors 5 are inserted into the mounting channels of the mounting frames 31 one by one. Then, the two ends of the conductors 5 pass through the mounting channels of the frame body 37 and the bottom of the frame body 37 in sequence. The current sensing coil 7 is sleeved on the mounting frame 31, and the four mounting frames 31 are evenly spaced on the frame body 37, that is, the included angle between every two adjacent mounting frames 31 is 90 degrees.

[0041] In this specific embodiment, the current sensing coil 7 has a ring-shaped first magnetic core, and the first winding is wound on the first magnetic core; the voltage sensing coil 6 has a ring-shaped second magnetic core, and the second winding and the third winding are both wound on the second magnetic core; the leakage current sensing coil 4 has a ring-shaped third magnetic core, and the fourth winding and the fifth winding are both wound on the third magnetic core.

[0042] Specifically, the current sensing coil 7 is a 1703N coil, the voltage sensing coil 6 is a 1303P coil, and the leakage current sensing coil 4 is a 2303P coil. Furthermore, the first winding of the current sensing coil 7 has 2000 turns, the second and third windings of the voltage sensing coil 6 each have 1000 turns, and the fourth and fifth windings of the leakage current sensing coil 4 each have 75 turns.

[0043] The mounting frame 31 includes a detachable outer frame and an inner frame, each having a mounting groove.

[0044] like Figure 6 and Figure 7 As shown, the main skeleton 37 includes an upper skeleton and a lower skeleton connected to each other. Four outer frame parts and the upper skeleton are integrally connected to form a first skeleton, and four inner frame parts and the lower skeleton are integrally connected to form a second skeleton.

[0045] When the first frame is detachably assembled onto the second frame, the mounting grooves of the outer frame of the first frame and the inner frame of the second frame are connected to form the mounting channel of the mounting frame 31.

[0046] like Figure 1 As shown, firstly, three current sensing coils 7 are sequentially inserted into the corresponding U-shaped conductors 5. Then, the two ends of the conductors 5 are inserted into the mounting grooves and mounting channels of the second frame. After that, the first frame is placed on the second frame so that both the conductors 5 and the current sensing coils 7 are fixed by the frame 3 and are not easy to loosen.

[0047] When the conductor 5 passes through the first magnetic core of the current sensing coil 7, the conductor 5 and the current sensing coil 7 form a magnetic induction to generate a corresponding induction signal (such as the first winding generating an induced current corresponding to the current flowing through the conductor 5).

[0048] The current transformer also includes a shielding assembly 11, which includes a shielding cover and a shielding sheet. The bottom of the second frame (i.e., the bottom of the frame body 37 or the bottom of the frame 3) is provided with a recessed bottom groove 34. The shielding cover is installed in the bottom groove 34. The leakage current induction coil 4 is installed in the shielding cover and fixed together with potting compound. Then the shielding sheet covers the shielding cover to form an enclosure for the leakage current induction coil 4, so as to prevent the leakage current induction coil 4 from being affected by external electromagnetic interference and to ensure the balance of the leakage current induction coil 4, thereby reducing the probability of the current transformer malfunction and further ensuring the stability of the current transformer's test accuracy.

[0049] More specifically, the outer periphery of the frame body 37 is provided with two first mounting slots 32 for accommodating voltage sensing coils 6, each first mounting slot 32 is located between two adjacent mounting frames 31, and the top of the frame body 37 is provided with a second mounting slot 33 for accommodating voltage sensing coils 6.

[0050] Two voltage sensing coils 6 are installed one-to-one in two first mounting slots 32 on the outer periphery of the frame body 37, and the third voltage sensing coil 6 is installed in a second mounting slot 33 on the top of the frame body 37. This allows the three voltage sensing coils 6 to be fixed to the frame 3 in an embedded manner, so as to avoid the voltage sensing coils 6 occupying extra volume and thus reduce the space occupied by the transformer.

[0051] In another preferred embodiment, such as Figure 6 The skeleton body 37 shown has multiple mounting through holes 35 for mounting load units 9.

[0052] The frame body 37 has a through hole at its center that penetrates the upper and lower surfaces. Some of the through holes 35 are located on the inner wall of the through hole in the frame body 37, while the other part of the through holes 35 are located on the mounting frame 31. The through holes near the mounting frame 31 are respectively connected to the mounting channels of the corresponding mounting frame 31.

[0053] In another preferred embodiment, the load unit 9 is a resistor, and each current sensing coil 7 is equipped with a resistor.

[0054] In specific implementation, such as Figure 1 As shown, the four mounting frames 31 are arranged in clockwise order as the first mounting frame, the second mounting frame, the third mounting frame, and the fourth mounting frame. The first mounting frame and the third mounting frame are arranged symmetrically as one group, and the second mounting frame and the fourth mounting frame are arranged symmetrically as another group.

[0055] The four conductors 5 are respectively a first conductor mounted on the first mounting frame, a second conductor mounted on the second mounting frame, a third conductor mounted on the third mounting frame, and a fourth conductor mounted on the fourth mounting frame. The first conductor, the second conductor, and the third conductor are electrically connected to the three-phase power of the main detection circuit 1, and the fourth conductor is electrically connected to the neutral line N of the main detection circuit 1.

[0056] The three current sensing coils 7 are a first current sensing coil, a second current sensing coil, and a third current sensing coil. The first current sensing coil is sleeved on the first mounting frame, the second current sensing coil is sleeved on the second mounting frame, and the third current sensing coil is sleeved on the third mounting frame.

[0057] The three voltage sensing coils 6 are a first voltage sensing coil, a second voltage sensing coil, and a third voltage sensing coil. The first voltage sensing coil is assembled in a first mounting groove 32 located between the third mounting frame and the fourth mounting frame. The second voltage sensing coil is assembled in the first mounting groove 32 located between the first mounting frame and the fourth mounting frame. The third voltage sensing coil is assembled in a second mounting groove 33 located at the top of the frame body 37.

[0058] The three resistors are a first resistor, a second resistor, and a third resistor. The first resistor and the second resistor are sequentially mounted on the mounting through holes of the third mounting frame and the first mounting frame, and the third resistor is mounted on the mounting through hole in the through hole of the frame body 37.

[0059] One end of the first resistor is inserted into the mounting through hole of the third mounting frame until it abuts against the outer wall of the third conductor inside the third mounting frame to form an electrical connection. The other end is electrically connected to the first end of the second winding of the first voltage sensing coil through a wire. The second end of the second winding of the first voltage sensing coil is electrically connected to the fourth conductor (i.e., the neutral wire end) through a wire.

[0060] One end of the second resistor is inserted into the mounting through hole of the first mounting frame until it abuts against the outer wall of the first conductor inside the first mounting frame to form an electrical connection. The other end is electrically connected to the first end of the second winding of the second voltage sensing coil through a wire. The second end of the second winding of the second voltage sensing coil is electrically connected to the fourth conductor through a wire.

[0061] One end of the third resistor is inserted obliquely into the mounting through hole in the through hole of the frame body 37 until it abuts against the outer wall of the second conductor in the second mounting frame to form a stable electrical connection or contact. The other end passes downward through the through hole of the frame body 37 and is electrically connected to the first end of the second winding of the third voltage sensing coil through a wire. The second end of the second winding of the third voltage sensing coil is electrically connected to the fourth conductor through a wire.

[0062] In a further preferred embodiment, such as Figure 8 As shown, the current transformer also includes a housing 8, and a frame 3 is assembled inside the housing 8. The inner wall of the housing 8 is provided with a first limiting boss 81 that cooperates with the current sensing coil 7 and a second limiting boss 82 that cooperates with the voltage sensing coil 6.

[0063] The first limiting boss 81 abuts against the top of the outer ring of the current sensing coil 7 to further restrict the installation position of the current sensing coil 7 and ensure that the current sensing coil 7 is not easily moved.

[0064] The second limiting boss 82 abuts against the top of the outer ring of the voltage sensing coil 6 to further restrict the installation position of the voltage sensing coil 6 and ensure that the voltage sensing coil 6 is not easily moved.

[0065] Furthermore, the output terminal 10 includes a first output terminal, a second output terminal, and a third output terminal. The fifth winding of the leakage current induction coil 4 is electrically connected to the first output terminal via a wire, and then an external voltage and current testing unit is connected to the first output terminal.

[0066] The lead wires of the second output terminal are equipped with insulating sleeves for easy wiring. The current sensing coil 7 is electrically connected to the second output terminal through the lead wires with insulating sleeves, and then connected to an external voltage and current testing unit through the second output terminal.

[0067] The lead wires of the third output terminal are also equipped with insulating sleeves to facilitate wiring. The voltage sensing coils 6 are all electrically connected to the third output terminal through the lead wires, and then the voltage and current testing unit is connected to the third output terminal.

[0068] Of course, in other embodiments, the structure of the output terminal 10 is not limited to this, and the specific structure of the output terminal 10 is determined according to the terminal definition of the circuit schematic of the actual product.

[0069] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. An integrated leakage current transformer with current and voltage detection, comprising a frame and a leakage current induction coil mounted at the bottom of the frame, characterized in that: It also includes a current and voltage detection unit and multiple conductors for connecting to the main detection circuit; The current and voltage detection unit includes multiple voltage sensing coils for detecting the voltage of the main detection circuit and multiple current sensing coils for detecting the current of the main detection circuit. Multiple conductors, voltage sensing coils, and current sensing coils are all mounted around the frame to form a compact arrangement; The current sensing coil has a first winding, and the conductor passes through the current sensing coil and the leakage current sensing coil. The first winding and the conductor cooperate to form an induced current corresponding to the current flowing through the conductor. The current flowing through the conductor is the current of the main detection circuit. The voltage sensing coil has a second winding and a third winding. The second winding is connected to the conductor through a load unit of the voltage sensing coil to form a voltage input circuit. The voltage of the voltage input circuit corresponds to the voltage of the main detection circuit. The third winding cooperates with the second winding to induce a voltage corresponding to the voltage of the voltage input circuit. The leakage current induction coil has a fourth winding and a fifth winding, the fourth winding being used for connecting an external leakage current detection circuit; The first winding, the third winding, and the fifth winding are all used for connecting an external voltage and current testing unit; The current sensing coil has a first magnetic core, and the first winding is wound on the first magnetic core; the voltage sensing coil has a second magnetic core, and the second winding and the third winding are both wound on the second magnetic core; the leakage current sensing coil has a third magnetic core, and the fourth winding and the fifth winding are both wound on the third magnetic core; the load unit is a resistor; The main detection circuit is a three-phase four-wire system, with three voltage sensing coils and three current sensing coils. There are four conductors, three of which are connected to the three-phase power of the main detection circuit, and the other conductor is connected to the neutral wire of the main detection circuit.

2. The integrated leakage current transformer with current and voltage detection according to claim 1, characterized in that: The conductor is a U-shaped metal needle.

3. The integrated leakage current transformer with current and voltage detection according to claim 1, characterized in that: The skeleton has a skeleton body and multiple mounting frames surrounding the skeleton body. Both the mounting frames and the skeleton body are provided with mounting channels for the conductors. The conductors are inserted one by one into the mounting channels of the mounting frames, and then the two ends of the conductors pass through the mounting channels of the skeleton body and the bottom of the skeleton body in sequence. The current sensing coil is sleeved on the mounting frame.

4. The integrated leakage current transformer with current and voltage detection according to claim 3, characterized in that: Multiple mounting frames are evenly spaced on the main frame.

5. The integrated leakage current transformer with current and voltage detection according to claim 3, characterized in that: The outer peripheral surface of the frame body is provided with a plurality of first mounting slots for accommodating the voltage sensing coil; each first mounting slot is located between two adjacent mounting frames.

6. The integrated leakage current transformer with current and voltage detection according to claim 5, characterized in that: The top of the main frame body is provided with a second mounting groove to accommodate the voltage sensing coil.

7. The integrated leakage current transformer with current and voltage detection according to claim 3, characterized in that: It also includes a shielding component; the frame body has multiple mounting through holes that cooperate with the load unit; the shielding component includes a shielding cover and a shielding sheet, the bottom of the frame body is provided with a concave bottom groove, the shielding cover is assembled in the bottom groove, the leakage current induction coil is assembled in the shielding cover, and the shielding sheet covers the shielding cover.

8. The integrated leakage current transformer with current and voltage detection according to claim 1, characterized in that: It also includes a housing, and the frame is assembled inside the housing; the inner wall of the housing is provided with a first limiting boss that cooperates with the current sensing coil and a second limiting boss that cooperates with the voltage sensing coil.

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