Suppression assembly for PT open delta winding

Abstract

The suppression assembly comprises a mutual inductor shell, a magnetic screen mutual inductor shell in the mutual inductor shell is structurally designed to comprise an electromagnetic wave reflecting layer and an electromagnetic wave absorbing layer, one side of the mutual inductor shell is provided with an arc-extinguishing and resonance-eliminating mechanism, the arc-extinguishing and resonance-eliminating mechanism comprises a resistor resonance-eliminating piece, a capacitor and an arc-extinguishing cover, and the resistor resonance-eliminating piece is connected with the capacitor and the arc-extinguishing cover. The arc extinguishing chambers are arranged on the periphery of the primary wiring terminal in the mutual inductor shell; according to the suppression assembly for the PT open delta winding, resonance is suppressed through the resistor resonance elimination piece to generate overvoltage, a voltage transformer is prevented from being burnt out, the arc extinguishing cover is arranged on the periphery of the primary wiring terminal in the transformer shell and used for attracting the overvoltage generated by the primary wiring terminal, and the voltage transformer is prevented from being burnt out. And a large amount of energy generated by overvoltage is transmitted and stored into the capacitor through the connecting seat, the cross block, the fixed block I, the lifting telescopic rod and the telescopic guide cylinder which are connected, so that the overvoltage is absorbed, and the voltage transformer is prevented from being burnt due to long-time overvoltage.

Description

Technical Field

[0001] The utility model relates to the technical field of voltage transformers, in particular to a suppression component for a PT open delta winding. Background Art

[0002] PT is also called voltage transformer. Its function is to convert high voltage into 100V low voltage for measurement and protection. The open triangle is used to measure zero-sequence voltage and can be used for phase loss and single-phase grounding detection.

[0003] At present, PT open delta winding is a commonly used measuring device in power systems for measuring voltage and current. However, in actual application, the external electromagnetic magnetic field will interfere with the measurement of the above-mentioned PT open delta winding, and the voltage transformer will often burn out due to overvoltages generated during the opening and closing of the circuit breaker, overvoltages generated during one-way grounding, atmospheric overvoltages during lightning strikes, overvoltages generated by resonance, etc. In order to suppress electromagnetic interference and overvoltage spikes, we have proposed a suppression component for PT open delta winding. Utility Model Content

[0004] The utility model aims to solve the problem in the prior art that the external electromagnetic magnetic field may cause electromagnetic interference to the PT open delta winding measurement and overvoltage may burn the voltage transformer, and proposes a suppression component for the PT open delta winding.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A suppression component for a PT open delta winding, comprising a transformer housing, wherein the structure design of a magnetic shield transformer housing in the transformer housing comprises an electromagnetic wave reflection layer and an electromagnetic wave absorption layer, which are used to suppress the influence of external electromagnetic interference on the winding in the transformer housing;

[0007] An arc extinguishing and harmonic elimination mechanism is arranged on one side of the transformer housing. The arc extinguishing and harmonic elimination mechanism comprises a resistor harmonic elimination component, a capacitor and an arc extinguishing cover. The arc extinguishing cover is arranged at the periphery of the primary terminal in the transformer housing.

[0008] Preferably, an insulating sleeve is provided on the periphery of the primary terminal, and the insulating sleeve is connected to the housing of the magnetic shield transformer.

[0009] Preferably, a telescopic portion is provided between the capacitor and the arc-extinguishing cover, the telescopic portion comprises a telescopic guide cylinder and a lifting telescopic rod, and the lifting telescopic rod is provided in the telescopic guide cylinder.

[0010] Preferably, a fixing part is provided between the telescopic guide cylinder and the lifting and telescopic rod, and the fixing part includes a knob 1, an inner screw hole fixing block and a plurality of tooth grooves, and the plurality of tooth grooves are arranged in a straight line and equidistantly on one side of the lifting and telescopic rod, and the inner screw hole fixing block is connected to the telescopic guide cylinder, and a screw rod 1 is installed on the inner end surface of the knob 1, and the screw rod 1 is installed in the inner screw hole fixing block, and the end of the screw rod 1 is arranged in the tooth groove.

[0011] Preferably, a fixing block 1 is installed at the top of the lifting and telescopic rod, a cross block is installed on the fixing block 1, a screw rod 2 is installed between the fixing block 1 and the cross block, and round blocks and knobs 3 are installed at both ends of the screw rod 2 respectively.

[0012] Preferably, a connecting seat is provided between the cross block and the arc extinguishing cover, a screw rod three is provided between the connecting seat and the cross block, and a knob two is provided at one end of the screw rod three.

[0013] Compared with the prior art, the utility model provides a suppression component for PT open delta winding, which has the following beneficial effects:

[0014] 1. The suppression component for PT open delta winding can effectively suppress the influence of external electromagnetic interference on the winding through the electromagnetic wave reflection layer, the electromagnetic wave absorption layer and the conductive coating, and improve the accuracy of the measurement results of the PT open delta winding in the power system.

[0015] 2. The suppression component for the PT open delta winding is connected in parallel to the two ends of the open delta winding of the voltage transformer through a resistor detuning component to consume the resonant energy, suppress the overvoltage generated by the resonance, and avoid burning the voltage transformer.

[0016] 3. The suppression component for PT open delta winding is arranged at the periphery of the primary terminal in the transformer housing through the arc extinguishing cover, which is used to attract the overvoltage generated by the primary terminal, and transfer the large amount of energy generated by the overvoltage into the capacitor through the connected connecting seat, cross block, fixed block 1, lifting telescopic rod and telescopic guide cylinder, so as to absorb the overvoltage and avoid long-term overvoltage and burning of the voltage transformer. When the voltage in the primary terminal becomes low, several meshes divide the arc into multiple short arcs. Several short arcs increase the heat dissipation area and resistance, so that it can no longer maintain the burning state and extinguish, which is beneficial to protect the primary terminal and winding, so as to avoid the generation of harmonics. Detuning mainly eliminates secondary harmonics and higher harmonics, which is beneficial to the safe operation of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the structure of the suppression assembly for the PT open delta winding proposed by the utility model;

[0018] Figure 2 This is a schematic diagram of the structure of the arc extinguishing and harmonic elimination mechanism in the suppression component for the PT open delta winding proposed by the utility model;

[0019] Figure 3 It is a schematic partial cross-sectional view of the housing of a magnetic shield transformer in a suppression assembly for a PT open delta winding proposed by the utility model.

[0020] In the figure: 1. Magnetic screen transformer housing; 1a. Electromagnetic wave absorption layer; 1b. Electromagnetic wave reflection layer; 2. Insulating sleeve; 3. Resistor detuning component; 4. Capacitor; 5. Telescopic guide cylinder; 6. Knob 1; 7. Internal screw hole fixing block; 8. Lifting telescopic rod; 9. Tooth groove; 10. Fixing block 1; 11. Knob 2; 12. Arc extinguishing cover; 13. Round block; 14. Knob 3; 15. Connecting seat; 16. Cross block. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0022] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0023] Reference Figure 1-3, a suppression component for PT open delta winding, including a PT cabinet, a transformer housing is fixedly installed in the PT cabinet, the transformer housing includes a magnetic shield transformer housing 1, an arc extinguishing and harmonic elimination mechanism is arranged on one side of the transformer housing, the arc extinguishing and harmonic elimination mechanism includes a resistor harmonic elimination component 3, a capacitor 4 and an arc extinguishing cover 12, the structural design of the magnetic shield transformer housing 1 includes an electromagnetic wave reflection layer 1b and an electromagnetic wave absorption layer 1a, which are used to suppress the influence of external electromagnetic interference on the winding in the transformer housing, the electromagnetic wave reflection layer 1b is arranged on the inner side of the magnetic shield transformer housing 1, and specifically adopts a copper film, which is mainly used to reflect the electromagnetic wave generated by the winding inside the magnetic shield transformer housing 1, when the electromagnetic wave encounters the copper film, a part of the energy will be absorbed by the copper film , and multiple reflections occur on the metal surface, and eventually the energy is dissipated. The electromagnetic wave absorption layer 1a is arranged on the outside of the magnetic shield transformer housing 1, and specifically adopts an iron plate with high magnetic permeability and magnetic saturation magnetic field strength, which can effectively absorb and shield external electromagnetic interference. The outer side surface of the iron plate and the inner side surface of the copper film are evenly coated with a layer of conductive coating to protect the surface of the iron plate and the copper film, and the conductive coating material has good conductivity and can effectively absorb and reflect electromagnetic waves. The present application can effectively suppress the influence of external electromagnetic interference on the winding through the electromagnetic wave reflection layer 1b, the electromagnetic wave absorption layer 1a and the conductive coating 1c, and improve the accuracy of the measurement results of the PT open delta winding in the power system.

[0024] It should be introduced that the resistor detuning component 3 is fixedly installed in the PT cabinet by screws. The resistor detuning component 3 in the present application specifically adopts a damping detuning device, which is connected in parallel to the two ends of the open delta winding of the voltage transformer through wires to consume the resonant energy, suppress the overvoltage generated by the resonance, and avoid burning the voltage transformer. Specifically, when the system is operating normally, the damping resistor in the parallel-connected resistor detuning component 3 does not affect the normal operation. When the line voltage is asymmetric, such as single-phase short circuit grounding, broken line and other faults, the neutral point is displaced, making the three-phase voltage asymmetric, which will cause the open delta voltage to increase, the voltage transformer core to saturate, and appear Zero-sequence flux, zero-sequence current flows through the high-voltage winding, and zero-sequence voltage is induced at both ends of the opening angle. Zero-sequence current flows through the parallel damping resistor, consuming the resonant energy to limit and destroy ferromagnetic resonance. The larger the secondary zero-sequence current, the greater the suppression effect. In practical applications, the selection of damping resistors needs to consider the impedance and inductive reactance of the system. If the impedance and inductive reactance of the system are large, a larger damping resistor needs to be selected to effectively consume the resonant energy. Conversely, if the impedance and inductive reactance of the system are small, a smaller damping resistor can be selected. At the same time, in order to ensure the normal operation of the PT, the selection of damping resistors also needs to consider factors such as their power and temperature characteristics.

[0025] In this embodiment, the capacitor 4 is fixedly installed in the PT cabinet, the insulating bushing 2 and the magnetic shield transformer housing 1 are fixedly connected, and a telescopic part is provided between the capacitor 4 and the arc extinguishing cover 12. The telescopic part includes a telescopic guide cylinder 5 and a lifting telescopic rod 8. The lifting telescopic rod 8 is telescopically installed in the telescopic guide cylinder 5.

[0026] In this embodiment, a fixing part is provided between the telescopic guide cylinder 5 and the lifting and telescopic rod 8, and the fixing part includes a knob 6, an inner screw hole fixing block 7 and a plurality of tooth grooves 9. The plurality of tooth grooves 9 are arranged in a straight line and equidistantly on one side of the lifting and telescopic rod 8. The inner screw hole fixing block 7 and the telescopic guide cylinder 5 are fixedly connected. A screw rod 1 is fixedly installed on the inner end surface of the knob 6. The screw rod 1 is threadedly installed in the inner screw hole fixing block 7. The end of the screw rod 1 is telescopically clamped in the tooth groove 9. The knob 6 is manually rotated to drive the screw rod 1 to perform spiral extension and retraction in the inner screw hole fixing block 7, so that the lifting and telescopic rod 8 is locked or telescopically installed in the telescopic guide cylinder 5, so as to achieve the purpose of adjusting the height of the telescopic part.

[0027] In this embodiment, a fixing block 10 is fixedly installed at the top of the lifting telescopic rod 8, a cross block 16 is rotatably installed on the fixing block 10, and the lower end of the cross block 16 and the upper end of the fixing block 10 are matched, contacted and squeezed with each other to increase the friction between the cross block 16 and the fixing block 10, a screw rod 2 is installed between the fixing block 10 and the cross block 16, the screw rod 2 is threadedly connected to the fixing block 10, the screw rod 2 is rotatably connected to the cross block 16, and the head and end of the screw rod 2 are respectively fixedly installed with a round block 13 and a knob 3 14, the round block 13 and one side of the cross block 16 are in contact with each other, and the knob 3 14 is manually rotated to change the rotation of the screw rod 2. The distance between the fixed block 10 and the cross block 16 is adjusted to achieve the effect of adjusting the squeezing force between the fixed block 10 and the cross block 16. A connecting seat 15 is provided between the cross block 16 and the arc extinguishing cover 12. The connecting seat 15 and the arc extinguishing cover 12 are fixedly connected. A screw rod three is provided between the connecting seat 15 and the cross block 16. The end of the screw rod three is fixedly connected with a knob two 11. The screw rod three and the connecting seat 15 are rotatably connected. The screw rod three and the cross block 16 are threadedly connected. The knob two 11 is manually rotated to change the distance between the connecting seat 15 and the cross block 16, thereby achieving the effect of adjusting the squeezing force between the connecting seat 15 and the cross block 16.

[0028] It is further introduced that the lower end of the telescopic guide cylinder 5 is fixedly installed on the upper end of the capacitor 4, and the telescopic guide cylinder 5, the lifting telescopic rod 8, the fixed block 10, the connecting seat 15, the cross block 16 and the arc extinguishing cover 12 are all made of conductive metal. The arc extinguishing cover 12 is close to the outer periphery of the arc extinguishing cover 12, and a plurality of mesh holes are arranged on the outer periphery of the arc extinguishing cover 12. The arc extinguishing cover 12 is arranged on the outer periphery of the primary wiring terminal in the transformer housing to attract the overvoltage generated by the primary wiring terminal, and through the connected connecting seat 15, the cross block 16, the fixed block 10, the lifting telescopic rod 8 and the telescopic guide cylinder 5, the overvoltage is generated. A large amount of energy generated is transferred and stored in capacitor 4 for absorbing overvoltage. When the voltage in the primary terminal becomes low, several mesh holes divide the arc into multiple short arcs. Several short arcs increase the heat dissipation area and resistance, making it impossible for the arc to continue to burn and extinguish, which is beneficial to protecting the primary terminal and winding. This can avoid the generation of harmonics. Detuning mainly eliminates secondary harmonics and higher harmonics, which is beneficial to the safe operation of the circuit. The primary terminal is fixedly installed on the outside of the magnetic shield transformer housing 1, and the outer periphery of the primary terminal is fixedly connected with an insulating sleeve 2.

[0029] In the utility model, firstly, the electromagnetic wave reflecting layer 1b, the electromagnetic wave absorbing layer 1a and the conductive coating 1c can effectively suppress the influence of external electromagnetic interference on the winding, and improve the accuracy of the measurement result of the PT open triangle winding in the power system. Secondly, the resistor detuning component 3 is connected in parallel at both ends of the open triangle winding of the voltage transformer to consume the resonance energy, suppress the overvoltage caused by the resonance, and avoid burning the voltage transformer. Specifically, when the system is operating normally, the damping resistor in the parallel-connected resistor detuning component 3 does not affect the normal operation. When the line voltage is asymmetric, such as single-phase short circuit grounding, line break and other faults, the neutral point is displaced, making the three-phase voltage asymmetric, which will cause the open triangle voltage to increase, the voltage transformer core to saturate, and zero-sequence magnetic flux to appear. The high-voltage winding flows through the zero-sequence current, and the zero-sequence voltage is induced at both ends of the open angle. The parallel-connected damping resistor flows through the zero-sequence current. Sequence current consumes resonant energy to limit and destroy ferromagnetic resonance. The larger the secondary zero-sequence current, the greater the suppression effect. Then, the arc extinguishing cover 12 is arranged on the periphery of the primary terminal in the transformer housing to attract the overvoltage generated by the primary terminal, and through the connected connecting seat 15, cross block 16, fixed block 10, lifting telescopic rod 8 and telescopic guide cylinder 5, a large amount of energy generated by the overvoltage is transferred and stored in the capacitor 4 to absorb the overvoltage and avoid long-term overvoltage and burning of the voltage transformer. When the voltage in the primary terminal becomes low, several meshes divide the arc into multiple short arcs. Several short arcs increase the heat dissipation area and resistance, making it impossible to continue to maintain the burning state and extinguish, which is beneficial to protecting the primary terminal and winding. In this way, the generation of harmonics can be avoided. Detuning mainly eliminates secondary harmonics and higher harmonics, which is beneficial to the safe operation of the circuit.

[0030] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A suppression assembly for a PT open delta winding, comprising a transformer housing, characterized in that: The structure design of the magnetic shield transformer housing (1) in the transformer housing comprises an electromagnetic wave reflection layer (1b) and an electromagnetic wave absorption layer (1a), which are used to suppress the influence of external electromagnetic interference on the winding in the transformer housing; An arc extinguishing and detuning mechanism is provided on one side of the transformer housing. The arc extinguishing and detuning mechanism comprises a resistor detuning component (3), a capacitor (4) and an arc extinguishing cover (12). The arc extinguishing cover (12) is arranged on the periphery of a primary terminal in the transformer housing.

2. The suppression assembly for PT open delta winding according to claim 1, characterized in that: An insulating sleeve (2) is provided on the periphery of the primary wiring terminal, and the insulating sleeve (2) is connected to the magnetic shield transformer housing (1).

3. The suppression assembly for PT open delta winding according to claim 1, characterized in that: A telescopic portion is provided between the capacitor (4) and the arc extinguishing cover (12), the telescopic portion comprising a telescopic guide cylinder (5) and a lifting telescopic rod (8), the lifting telescopic rod (8) being arranged in the telescopic guide cylinder (5).

4. The suppression assembly for PT open delta winding according to claim 3, characterized in that: A fixing part is provided between the telescopic guide cylinder (5) and the lifting telescopic rod (8), and the fixing part comprises a knob (6), an inner screw hole fixing block (7) and a plurality of tooth grooves (9). The plurality of tooth grooves (9) are arranged in a straight line and equidistantly on one side of the lifting telescopic rod (8). The inner screw hole fixing block (7) is connected to the telescopic guide cylinder (5). A screw rod (1) is installed on the inner end surface of the knob (6). The screw rod (1) is installed in the inner screw hole fixing block (7), and the end of the screw rod (1) is arranged in the tooth groove (9).

5. The suppression assembly for PT open delta winding according to claim 3, characterized in that: A fixing block 1 (10) is installed at the top end of the lifting telescopic rod (8), a cross block (16) is installed on the fixing block 1 (10), a screw rod 2 is installed between the fixing block 1 (10) and the cross block (16), and a round block (13) and a knob 3 (14) are installed at the first and second ends of the screw rod 2 respectively.

6. The suppression assembly for PT open delta winding according to claim 5, characterized in that: A connecting seat (15) is provided between the cross block (16) and the arc extinguishing cover (12), a screw rod 3 is provided between the connecting seat (15) and the cross block (16), and a knob 2 (11) is provided at one end of the screw rod 3.

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