Voltage mutual inductance device with cable plug type independent power supply

Abstract

The utility model belongs to the technical field of voltage mutual inductance, and particularly relates to a voltage mutual inductance device with a cable plug type independent power supply. A voltage transformer for a power supply comprises an independent voltage iron core and an independent power supply primary coil wound on the independent voltage iron core; a phase iron core, a B phase iron core, a C phase iron core, and an A phase primary coil, a B phase primary coil and a C phase primary coil respectively wound on the A phase iron core, the B phase iron core and the C phase iron core are physically separated, the five transformers form a 5PT integrated structure through epoxy resin, and ferromagnetic resonance is effectively inhibited by combining iron core material optimization and anti-resonance design. Compact design is achieved, and narrow spaces such as a ring main unit are adapted. And the safety is improved. Magnetic field interference is avoided and metering precision is ensured.

Description

Technical Field

[0001] This invention belongs to the field of voltage transformer technology, specifically relating to a voltage transformer device with an independent power supply and a cable plug. Background Technology

[0002] Voltage transformers are primarily used to measure high voltages while protecting measuring instruments and operators from high-voltage hazards. Their working principle is mainly based on that of a transformer, utilizing electromagnetic induction to convert high voltage to low voltage. When the voltage on a high-voltage line changes, the voltage transformer proportionally converts it into a low-voltage signal for use by measuring instruments and protection devices. A typical three-phase voltage transformer distribution network precision metering system includes a distribution network, transformer modules, data acquisition modules, data processing modules, analysis modules, and alarm display modules. It monitors the transformer modules in real time by monitoring voltage, determines their operating status based on the monitoring data, and re-determines the operating parameters of the transformer modules if their operating status is found to be unqualified, thus accurately detecting the distribution network voltage and improving the monitoring efficiency of the distribution network.

[0003] Existing voltage transformers, such as the 4PT structure, integrate the power supply winding and metering winding onto the same core. This design, when supplying power to intelligent terminals or operating mechanisms, causes significant errors in the metering winding due to magnetic field coupling, severely impacting the accuracy of the metering device. Furthermore, traditional transformers are bulky, making them difficult to fit into compact spaces such as ring main units, and pose a risk of ferroresonance, affecting system stability. While existing technologies partially alleviate these problems through common-mode rejection and other means, they fail to fundamentally solve the interference problem between the power supply and metering windings, and lack optimized designs for small-volume, high-safety scenarios. Summary of the Invention

[0004] This invention addresses the problems of significant errors caused by magnetic field coupling in existing voltage transformers, which severely affect the accuracy of metering devices, as well as their large size, poor stability, and low safety. It proposes a voltage transformer with an independent power supply and a cable plug, comprising: an A-phase core, a B-phase core, a C-phase core, and an O-phase core, on which primary coils for phases A, B, C, and O are wound respectively; the two ends of the O-phase primary coil are connected to O-connection wires and N-connection wires respectively; the axes of the A-phase core, B-phase core, and C-phase core are parallel to each other; the axis of the O-phase core is perpendicular to the axis of the A-phase core.

[0005] The device further includes: an independent power supply voltage transformer, which includes: an independent voltage core and an independent power supply primary coil wound on it; the axis of the independent voltage core is perpendicular to the axis of the A-phase core; the axis of the independent voltage core is parallel to the axis of the O-phase core.

[0006] The primary terminals of the A-phase primary coil, the B-phase primary coil, and the C-phase primary coil are respectively connected to the A-phase fuse, the B-phase fuse, and the C-phase fuse;

[0007] The O-phase primary coil's O-phase primary terminal and N-phase primary terminal are respectively connected to the O-phase terminal and the N-phase terminal; the independent power supply primary coil's two ends are respectively connected to the independent power supply B connection wire and the independent power supply C connection wire; the A-phase primary coil, B-phase primary coil, and C-phase primary coil are respectively connected to the A connection wire, the B connection wire, and the C connection wire; the O-phase terminal and the N-phase terminal are respectively connected to the O connection wire and the N connection wire.

[0008] The independent power supply primary coil is sealed and connected to a cable plug.

[0009] According to the voltage transformer device with cable plug type independent power supply described above, the independent power supply voltage transformer adopts V-type connection method.

[0010] According to the voltage transformer device with cable plug type independent power supply described above, the overall structure of the device is encapsulated by epoxy resin casting, and the outer surface is sprayed with conductive paint and grounded.

[0011] According to the voltage transformer device with cable plug type independent power supply described above, the O-phase terminal and N-phase terminal are silver-plated copper terminals.

[0012] According to the voltage transformer device with cable plug type independent power supply described above, the A-phase fuse, B-phase fuse and C-phase fuse are high-voltage current-limiting type fuses.

[0013] According to the voltage transformer device with cable plug type independent power supply described above, the epoxy resin has an insulation class of H and a temperature resistance range of -30℃ to 180℃.

[0014] According to the voltage transformer device with cable plug type independent power supply described above, the grounding resistance of the conductive paint is ≤0.1Ω.

[0015] According to the voltage transformer device with cable plug type independent power supply described above, the cable plug is connected to the primary coil of the independent power supply using a silicone rubber sealing structure.

[0016] According to the voltage transformer device with cable plug type independent power supply described above, the device is suitable for ambient temperature: -30℃~40℃, altitude ≤1000m, and load power factor. The operating conditions.

[0017] According to the voltage transformer device with cable plug type independent power supply described above, the device is used in ring main unit or gas-insulated switchgear to realize the dual functions of accurate metering of distribution network and power supply of intelligent terminal.

[0018] The beneficial effects of the present invention are as follows:

[0019] 1. This invention separates the independent power supply from the metering: the voltage transformer for power supply (independent voltage core and independent primary coil wound on it) is physically separated from the metering transformer (A-phase core, B-phase core, C-phase core and A-phase primary coil, B-phase primary coil, C-phase primary coil wound on it respectively), to avoid magnetic field interference and ensure metering accuracy.

[0020] 2. This invention integrates five current transformers (three-phase metering + independent power supply dual windings) into a single unit using epoxy resin, forming a 5PT integrated structure, achieving a compact design suitable for small spaces such as ring main units.

[0021] 3. This invention uses an independent power transformer with V-connection, combined with optimized core material and anti-resonance design, to effectively suppress ferroresonance.

[0022] 4. The present invention uses internal epoxy resin casting to enhance insulation and external conductive paint spraying to achieve reliable grounding, thus optimizing the process and improving safety.

[0023] 5. This invention simplifies the installation process and reduces operation and maintenance costs through standardized terminal block and fuse design, modular connection. Attached Figure Description

[0024] Figure 1 This is a top view and a cross-sectional view of a voltage transformer device with a cable plug-type independent power supply according to the present invention.

[0025] Figure 2 This is a cross-sectional view of the right view of a structural schematic diagram of a voltage transformer device with a cable plug-type independent power supply according to the present invention.

[0026] Figure 3 This is a cross-sectional view of the left view of a structural schematic diagram of a voltage transformer device with a cable plug-type independent power supply according to the present invention.

[0027] Figure 4 This is a wiring diagram of a voltage transformer device with a cable plug-type independent power supply according to the present invention.

[0028] In the diagram: 1-Phase A core, 2-Phase B core, 3-Phase C core, 4-Phase A primary coil, 5-Phase B primary coil, 6-Phase C primary coil, 7-Phase O core, 8-Phase O primary coil, 9-Independent voltage core, 10-Independent power supply primary coil, 11-Phase A fuse, 12-Phase B fuse, 13-Phase C fuse, 14-Phase O terminal, 15-Phase N terminal, 16-A connection wiring, 17-B connection wiring, 18-C connection wiring, 19-O connection wiring, 20-N connection wiring, 21-Independent power supply C connection wiring, 22-Independent power supply B connection wiring, AA phase primary coil start terminal, AO-A phase primary coil end, BB phase primary coil start terminal, BO-B phase primary coil end, CC phase primary coil start terminal, CO-C phase primary coil end, OO phase primary coil start terminal, NO phase primary coil end. Detailed Implementation

[0029] Preferred Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0031] like Figures 1 to 3 As shown: In this embodiment, a voltage transformer device with a cable plug-type independent power supply includes: an A-phase core 1, a B-phase core 2, a C-phase core 3, and an O-phase core 7, on which an A-phase primary coil 4, a B-phase primary coil 5, a C-phase primary coil 6, and an O-phase primary coil 8 are wound respectively; the two ends of the O-phase primary coil 8 are respectively connected to an O-connection wire 19 and an N-connection wire 20; the axes of the A-phase core 1, B-phase core 2, and C-phase core 3 are parallel to each other; the axis of the O-phase core 7 is perpendicular to the axis of the A-phase core 1.

[0032] The device further includes: an independent power supply voltage transformer, which includes: an independent voltage core 9 and an independent power supply primary coil 10 wound on it; the axis of the independent voltage core 9 is perpendicular to the axis of the A-phase core 1; the axis of the independent voltage core 9 is parallel to the axis of the O-phase core 7.

[0033] The primary terminals of phase A primary coil 4, phase B primary coil 5 and phase C primary coil 6 are respectively connected to phase A fuse 11, phase B fuse 12 and phase C fuse 13.

[0034] The O-phase primary coil 8 has its O-phase primary terminal and N-phase primary terminal connected to O-phase terminal 14 and N-phase terminal 15, respectively; the independent power supply primary coil 10 has its two ends connected to independent power supply B connection wire 21 and independent power supply C connection wire 22, respectively; the A-phase primary coil 4, B-phase primary coil 5, and C-phase primary coil 6 have A connection wire 16, B connection wire 17, and C connection wire 18, respectively; the O-phase terminal 14 and N-phase terminal 15 have O connection wire 19 and N connection wire 20, respectively.

[0035] The independent power supply primary coil 10 is sealed and connected to a cable plug.

[0036] The independent power supply voltage transformer adopts a V-type connection. The overall structure of the device is encapsulated by epoxy resin casting, and the outer surface is coated with conductive paint and grounded.

[0037] Phase O terminal 14 and Phase N terminal 15 are silver-plated copper terminals. Phase A fuse 11, Phase B fuse 12, and Phase C fuse 13 are high-voltage current-limiting fuses. The epoxy resin insulation class is H, with a temperature range of -30℃ to 180℃. The grounding resistance of the conductive paint is ≤0.1Ω.

[0038] The cable plug is connected to the primary coil 10 of the independent power supply using a silicone rubber sealing structure.

[0039] The device is suitable for ambient temperatures of -30℃ to 40℃, altitudes ≤1000m, and load power factors of [missing information]. (Lag) operating conditions. The device is used in ring main units or gas-insulated switchgear to achieve the dual functions of accurate metering of the distribution network and power supply to intelligent terminals.

[0040] like Figures 1 to 4 As shown, an embodiment of a voltage transformer with a cable plug-type independent power supply includes a three-phase metering unit and an independent power supply unit. The three-phase metering unit consists of an A-phase core 1, a B-phase core 2, a C-phase core 3, and corresponding A-phase primary coils 4, B-phase primary coils 5, and C-phase primary coils 6. The primary terminals of A-phase primary coils 4, B-phase primary coils 5, and C-phase primary coils 6 are respectively connected to A-phase fuses 11, B-phase fuses 12, and C-phase fuses 13. The O-phase core 7 is connected to the O-phase primary coil 8 via the O-phase terminal 14, and the N-phase terminal 15 is connected to the system neutral wire. The independent power supply voltage transformer consists of an independent voltage core 9 and a primary coil 10. The independent power supply voltage transformer uses a V-type connection and is connected to the B-phase primary coil's starting terminal (B terminal) and the B-phase primary coil's ending terminal (BO terminal) via independent power supply B connection wire 21 and independent power supply C connection wire 22, providing a stable power supply.

[0041] All iron cores and coils are vacuum-cast and cured with epoxy resin to form an integral insulation structure, and then coated with conductive paint and grounded via copper tape. The cable plug adopts the American 200A standard interface, which is crimped with a silicone rubber sealing ring to ensure dust and water resistance.

[0042] The power supply and metering windings are designed independently to avoid mutual interference, and the metering error is ≤0.2%.

[0043] The independent power supply voltage transformer adopts a V-type connection method combined with the annealing process of all iron cores, which improves the resonance suppression efficiency by 60%.

[0044] The PT integrated package reduces the size by 40% compared to traditional products and is suitable for ring main unit installation.

[0045] The epoxy resin insulation layer has a withstand voltage of ≥35kV, and the conductive paint grounding resistance is ≤0.1Ω, meeting the IP67 protection level.

[0046] Taking a 10kV distribution network ring main unit as an example, actual measurements show that under the conditions of a load power factor of 0.8 and an ambient temperature of -20℃, the metering accuracy is stable at level 0.2, the independent power supply output fluctuation is <2%, and the ferroresonance occurrence rate is reduced to below 0.5%, which fully meets the design requirements.

[0047] The parameters for this embodiment are shown in Table 1 below:

[0048] Table 1. Parameters of a voltage transformer device with a cable plug-type independent power supply according to this embodiment.

[0049] Terminal markings Accuracy level Rated output (VA) 1a 1b (100V) Level 0.2 10VA 1a 1c (100V) Class of 2002 10VA 1b 1c (100V) Class of 2002 10VA 2a 2b (220V) Level 0.5 10VA 2a 2c (220V) Level 0.5 10VA 2b 2c (220V) Level 0.5 10VA da dn1(100 / 3v) 3P level 100VA dn1 dn2(100 / 3v) 3P level 100VA DN2 DN3 (100 / 3V) 3P level 100VA dn3 dn(100 / 3v) 3P level 100VA bc(220v) Level 3 500VA

[0050] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A voltage transformation device with a cable plug type independent power supply, characterized by, It comprises: A-phase iron core (1), B-phase iron core (2), C-phase iron core (3) and O-phase iron core (7), on which A-phase primary coil (4), B-phase primary coil (5), C-phase primary coil (6) and O-phase primary coil (8) are wound respectively; the two ends of O-phase primary coil (8) are connected with O-phase connecting wire (19) and N-phase connecting wire (20) respectively; the axes of A-phase iron core (1), B-phase iron core (2) and C-phase iron core (3) are parallel to each other; the axis of O-phase iron core (7) is perpendicular to the axis of A-phase iron core (1); The device further comprises: independent power supply voltage transformer, which comprises: independent voltage iron core (9) and independent power supply primary coil (10) wound thereon; the axis of independent voltage iron core (9) is perpendicular to the axis of A-phase iron core (1); the axis of independent voltage iron core (9) is parallel to the axis of O-phase iron core (7); The primary terminals of A-phase primary coil (4), B-phase primary coil (5) and C-phase primary coil (6) are connected with A-phase fuse (11), B-phase fuse (12) and C-phase fuse (13) respectively; The O-phase primary terminal and N-phase primary terminal of O-phase primary coil (8) are connected with O-phase terminal post (14) and N-phase terminal post (15) respectively; the two ends of independent power supply primary coil (10) are connected with independent power supply B-phase connecting wire (21) and independent power supply C-phase connecting wire (22) respectively; A-phase connecting wire (16), B-phase connecting wire (17) and C-phase connecting wire (18) are connected on A-phase primary coil (4), B-phase primary coil (5) and C-phase primary coil (6) respectively; O-phase connecting wire (19) and N-phase connecting wire (20) are connected on O-phase terminal post (14) and N-phase terminal post (15) respectively; The independent power supply primary coil (10) is sealingly connected with a cable plug.

2. A voltage transformation device with a separate power supply in the form of a plug-in cable according to claim 1, characterized in that: The independent power supply voltage transformer adopts V-type wiring mode.

3. A voltage transformation device with a cable plug type independent power supply according to claim 2, characterized in that: The overall structure of the device is encapsulated by epoxy resin, and the outer surface is sprayed with conductive paint and grounded.

4. A voltage transformation device with a cable plug type independent power supply according to claim 3, characterized in that: The O-phase terminal post (14) and N-phase terminal post (15) are copper-plated silver terminals.

5. A voltage transformation device with a cable plug type independent power supply according to claim 4, characterized in that: The A-phase fuse (11), B-phase fuse (12) and C-phase fuse (13) are high-voltage current-limiting fuses.

6. A voltage transformation device with a separate power supply in the form of a plug-in cable according to claim 5, characterized in that: The insulation level of the epoxy resin is H level, and the temperature resistance range is -30℃ to 180℃.

7. A voltage transformation device with a separate power supply in the form of a plug-in cable according to claim 6, characterized in that: The grounding resistance of the conductive paint is ≤0.1Ω.

8. A voltage transformation device with a cable plug type independent power supply according to claim 7, characterized in that: The cable plug and the independent power supply primary coil (10) are connected by a silicon rubber sealing structure.

9. A voltage transformation device with a cable plug type independent power supply according to claim 8, characterized in that: The device is suitable for environmental temperature: -30℃ ~ 40℃, altitude ≤1000m, load power factor cosφ = 0.8 working condition.

10. A voltage transformation device with a cable plug type independent power supply according to claim 9, characterized in that: The device is used in ring network cabinet or gas-filled cabinet to realize the double functions of precise metering and intelligent terminal power supply for distribution network.

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