Testing device for partial discharge measurement of double-body phase-shifting transformer
By combining a series transformer and an excitation transformer, along with auxiliary tools such as a metal conductive sleeve and an adhesive layer, the problem of partial discharge measurement under high-voltage conditions of phase-shifting transformers was solved, achieving efficient and accurate partial discharge measurement and a simplified wiring process.
Patent Information
- Application Number
- CN202423255618.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-28
- Publication Date
- 2026-02-10
- Estimated Expiration
- 2034-12-28
AI Technical Summary
Partial discharge measurement of phase-shifting transformers is difficult to achieve in high-voltage environments, especially due to their complex outgoing line structure and multiple monitoring terminals, making it difficult for existing technologies to perform partial discharge measurement efficiently.
A combination structure of series transformer and excitation transformer is adopted. Partial discharge measurement is performed by applying a low excitation voltage through the low-voltage winding. The wires are easily connected by the auxiliary tool of metal conductive sleeve and adhesive layer, which simplifies the wiring process.
It enables convenient partial discharge measurement of phase-shifting transformers under high-voltage conditions, improves connection efficiency and measurement accuracy, and simplifies the operation process.
Smart Images
Figure CN223897574U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of power transformer testing technology, specifically relating to a test device for partial discharge measurement of a dual-body phase-shifting transformer. Background Technology
[0002] A power system is a system for the production and consumption of electrical energy, consisting of power plants, transmission lines, distribution lines, and loads. During steady-state operation, the voltage and power distribution at each node of the power grid is called the power flow distribution. Changes in the impedance and phase angle of parallel loads in the power grid branches will lead to changes in the steady-state power flow, thus affecting the reliable and stable output of electrical energy. Therefore, power systems introduce power flow control equipment—phase-shifting transformers—to adjust the power flow distribution by changing the phase angle. However, phase-shifting transformers have many windings, complex outgoing line structures, and a wide range of winding voltage distribution. The induced voltage test with partial discharge measurement is particularly challenging during acceptance testing due to its high boost voltage, numerous partial discharge monitoring terminals, and the significant challenges in test circuit design and voltage monitoring. Utility Model Content
[0003] The purpose of this invention is to provide a test device for partial discharge measurement using a dual-body phase-shifting transformer with a simple structure and reasonable design, in order to solve the above-mentioned problems and solve the test problems caused by high voltage.
[0004] This utility model achieves the above objectives through the following technical solutions:
[0005] A test device for partial discharge measurement of a dual-body phase-shifting transformer includes a series transformer T1 and an excitation transformer T2. The series transformer T1 and the excitation transformer T2 are connected to each other, and the high-voltage winding of the excitation transformer T2 is connected in series in the middle of the high-voltage winding of the series transformer T1. The three phases lead out a high-voltage neutral point, and the low-voltage winding of the series transformer T1 is corner-connected and externally connected to the phase-shifting winding of the excitation transformer T2.
[0006] As a further optimization of this utility model, the series transformer T1 and the excitation transformer T2 are connected by an auxiliary tool;
[0007] The auxiliary tool includes a metal conductive sleeve, an insulating layer, and an adhesive layer. The metal conductive sleeve has a circular sleeve structure. Adhesive layers are fixedly provided at both ends of the metal conductive sleeve. An insulating layer is fixedly applied to the outer surface of both the adhesive layer and the metal conductive sleeve. Small teeth are fixedly provided at the inner circle of the adhesive layer.
[0008] As a further optimization of this utility model, multiple small teeth are provided, and the tips of the multiple small teeth are all distributed towards the middle part of the metal conductive sleeve.
[0009] As a further optimization of this utility model, the end of the adhesive layer away from the metal conductive sleeve has a larger opening.
[0010] As a further optimization of this utility model, the inner wall of the metal conductive sleeve is also provided with an exhaust groove, which is distributed along the length direction of the metal conductive sleeve.
[0011] The beneficial effects of this utility model are as follows: This utility model applies a lower excitation voltage to the low-voltage winding of the series transformer by temporarily leading out the test terminals, thereby completing the partial discharge test of the complex double-body phase-shifting transformer. It can easily handle the power supply line and complete the measurement of the partial discharge test of the high-voltage six terminals.
[0012] The metal conductive sleeve is a conductive structure that ensures a conductive connection between two wires. In this invention, an adhesive layer is provided to allow the wires to be inserted smoothly, replacing the conventional wiring method and simplifying the operation.
[0013] The adhesive layer has a certain degree of stickiness and can be elastically deformed. It is usually made of plastic film. When the ends of two wires are inserted into the metal conductive sleeve at the same time, the inner wall of the adhesive layer can be heated with fire to melt it to a certain extent. Then, the outer ring of the adhesive layer can be manually squeezed to adhere the adhesive layer to the outer ring surface of the wire, which can play a role in sealing and waterproofing, and also realize the quick connection between the two wires, improving the connection efficiency. Attached Figure Description
[0014] Figure 1 This is the test circuit diagram used for partial discharge testing of the dual-body phase-shifting transformer of this utility model;
[0015] Figure 2 This is a schematic diagram of the series transformer T1 and excitation transformer T2 of this utility model;
[0016] Figure 3 This is a schematic diagram of the auxiliary tool structure of this utility model;
[0017] Figure 4 This is a structural diagram of the auxiliary tool of this utility model during use;
[0018] Figure 5 This is a schematic diagram of the structure of the auxiliary tool of this utility model after connecting two wires.
[0019] In the diagram: 1. Metal conductive sleeve; 2. Insulating layer; 3. Adhesive layer; 4. Small teeth; 5. Wire; 21. Folded part; 51. Wire sheath. Detailed Implementation
[0020] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.
[0021] This invention proposes a test device for measuring partial discharge in a dual-body phase-shifting transformer.
[0022] The technical solution of this utility model is as follows: Test terminals are led out from the low-voltage side of the series transformer. The voltage of the low-voltage winding at the corresponding tap is calculated based on the turn voltage of the high-voltage winding of the series transformer. Since the number of turns in the phase-adjusting winding of the excitation transformer is relatively small, the voltage is low. The method of using low-voltage winding excitation for partial discharge measurement allows for flexible selection of appropriate power application methods to complete the partial discharge measurement test, thereby optimizing the circuit and simultaneously assessing the partial discharge of each high-voltage terminal.
[0023] Working principle: (Reference) Figure 1 As shown, this dual-body phase-shifting transformer consists of a series transformer T1 and an excitation transformer T2 connected together. The high-voltage winding of the series transformer is connected in series with the high-voltage winding of the excitation transformer at its midpoint, with a high-voltage neutral point drawn from all three phases. The low-voltage winding of the series transformer is delta-connected and externally connected to the phase-shifting winding of the excitation transformer. By calculating the voltage of the corresponding tapped low-voltage winding of the series transformer, the excitation-side voltage for the partial discharge test is determined. This voltage is relatively low, and the wiring is simple and convenient.
[0024] The voltage applied to the low-voltage winding of the series transformer in the partial discharge measurement circuit is calculated using the following formula: (Induction multiple K)
[0025]
[0026] Note:U H θ is the rated high voltage of the series transformer; θ is the half-phase shift angle of the phase-shifting transformer.
[0027] N H N represents the number of turns in the high-voltage coil of a series transformer. L This refers to the number of turns in the low-voltage coil of a series transformer.
[0028] 2) Connect the wires according to the test circuit diagram, and perform voltage correction on the high-voltage terminal S and low-voltage terminals EF, G, and H of the series transformer of the test object. Check whether the voltage of the high-voltage terminal and the low-voltage terminal matches the calculated value, and perform partial discharge measurement according to the standard procedure.
[0029] For example:
[0030] Calculate the high-voltage turn voltage of the series winding of the phase-shifting transformer:
[0031] Parameters of the tested phase-shifting phase change: Rated voltage Ur: 115kV
[0032] Number of coil turns: Series transformer high-voltage winding: 190, low-voltage winding: 219
[0033] Series transformer turn voltage:
[0034] 2) Calculate the voltage applied to the low-voltage winding for the partial discharge test:
[0035] Low-voltage winding excitation side voltage: 1.58 × 489.4 / 1000 × 219 = 16.93 kV
[0036] High-voltage side voltage:
[0037] 3) Voltage correction: When the potential of the S side to ground is 100kV, the potential between EF, G, and H is 9.3kV, which is consistent with the calculated tap voltage value.
[0038] In summary, when performing partial discharge measurements on double-body phase-shifting transformers with voltage levels of 110kV and below, selecting an appropriate power application method based on the existing test equipment and power supply in the laboratory can optimize the circuit and make the test method more flexible.
[0039] refer to Figure 3 As shown in the figure, this utility model also proposes an auxiliary tool for facilitating the connection of series transformer T1 and excitation transformer T2, specifically including: a metal conductive sleeve 1, an insulating layer 2 and an adhesive layer 3. The metal conductive sleeve 1 has a circular sleeve structure. Adhesive layers 3 are fixedly provided at both ends of the metal conductive sleeve 1. The end of the adhesive layer 3 away from the metal conductive sleeve 1 has a large opening. The outer surface of both the adhesive layer 3 and the metal conductive sleeve 1 is fixedly covered with an insulating layer 2. Small teeth 4 are fixedly provided at the inner circle of the adhesive layer 3. Multiple small teeth 4 are provided, and the tips of the multiple small teeth 4 are all distributed towards the middle part of the metal conductive sleeve 1.
[0040] like Figure 4 As shown, when using the auxiliary tool, part of the wire sheath 51 at the end of the wire 5 on the series transformer T1 and the excitation transformer T2 is peeled off. The part of the wire sheath 51 that has been peeled off extends from the adhesive layer 3 into the interior of the metal conductive sleeve 1, and the ends of the two wires 5 extend from the adhesive layers 3 at both ends of the metal conductive sleeve 1 until the ends of the two wires 5 are attached or attached to the inner wall of the metal conductive sleeve 1.
[0041] The metal conductive sleeve 1 is a conductive structure that can ensure the conductive connection between the two wires 5. In this utility model, the wires 5 can be smoothly inserted by setting an adhesive layer 3, which replaces the conventional wiring method and is simple to operate.
[0042] Furthermore, the adhesive layer 3 has a certain degree of stickiness and can be elastically deformed. It is usually made of plastic film. When the ends of the two wires 5 are simultaneously inserted into the metal conductive sleeve 1, the inner wall of the adhesive layer 3 can be heated with fire to melt the inner wall of the adhesive layer 3 to a certain extent. Then, the outer ring of the adhesive layer 3 can be manually squeezed to adhere the adhesive layer 3 to the outer ring surface of the wires 5, which plays a role in sealing and waterproofing, and realizes the rapid connection between the two wires 5, improving the connection efficiency.
[0043] Furthermore, when the adhesive layer 3 is bonded to the outer ring of the conductor 5, it engages with the conductor sheath 51 of the outer ring of the conductor 5 through the small teeth 4, achieving further engagement and fixation, making the connection less likely to detach and resulting in high connection strength.
[0044] It should be noted that, as Figure 4 As shown, only the outer section of the wire 5 extending into the metal conductive sleeve 1 is stripped of its outer sheath 51, while the section of the wire 5 inside the adhesive layer 3 is retained for subsequent connection.
[0045] It should also be noted that the small teeth 4 can be set on the folded part 21, which is the insulating layer 2 of the outer ring of the adhesive layer 3. Setting the small teeth 4 on the folded part 21 avoids the problem of the small teeth 4 detaching due to subsequent baking of the inner wall of the adhesive layer 3.
[0046] like Figure 5 The diagram shown is a final schematic of the metal conductive sleeve 1 connected between two wires 5.
[0047] like Figure 3 As shown, an exhaust groove 11 is also provided on the inner wall of the metal conductive sleeve 1. The exhaust groove 11 is distributed along the length direction of the metal conductive sleeve 1. When the wire 5 is inserted into the metal conductive sleeve 1, excess gas can be discharged through the exhaust groove 11, which avoids the problem of too much air inside the metal conductive sleeve 1 and also enables the two wires 5 to be connected smoothly.
[0048] The embodiments described above are merely examples of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.
Claims
1. A test apparatus for partial discharge measurement using a dual-body phase-shifting transformer, comprising a series transformer T1 and an excitation transformer T2, characterized in that, The series transformer T1 and the excitation transformer T2 are connected to each other, and the high voltage winding of the series transformer T1 is connected in series with the high voltage winding of the excitation transformer T2 in the middle. The three phases lead out the high voltage neutral point, and the low voltage winding of the series transformer T1 is connected to the phase adjustment winding of the excitation transformer T2.
2. The test apparatus for partial discharge measurement of a dual-body phase-shifting transformer according to claim 1, characterized in that: The series transformer T1 and the excitation transformer T2 are connected by an auxiliary tool; The auxiliary tool includes a metal conductive sleeve (1), an insulating layer (2) and an adhesive layer (3). The metal conductive sleeve (1) is a circular sleeve structure. Adhesive layers (3) are fixedly provided at both ends of the metal conductive sleeve (1). The outer surface of the adhesive layer (3) and the outer ring of the metal conductive sleeve (1) are fixedly covered with an insulating layer (2). Small teeth (4) are fixedly provided at the inner ring of the adhesive layer (3).
3. The test apparatus for partial discharge measurement of a dual-body phase-shifting transformer according to claim 2, characterized in that: The small teeth (4) are provided in multiple ways, and the tips of the multiple small teeth (4) are all distributed towards the middle part of the metal conductive sleeve (1).
4. The test apparatus for partial discharge measurement of a dual-body phase-shifting transformer according to claim 2, characterized in that: The adhesive layer (3) has a large opening at the end furthest from the metal conductive sleeve (1).
5. The test apparatus for partial discharge measurement of a dual-body phase-shifting transformer according to claim 2, characterized in that: The inner wall of the metal conductive sleeve (1) is also provided with an exhaust groove (11), which is distributed along the length of the metal conductive sleeve (1).