阅读说明：本技术 变压器单个饼式线圈径向变形的测试装置及评估方法 (Testing device and evaluation method for radial deformation of single pancake coil of transformer ) 是由 何智杰 傅炜婷 杨志平 赖伟山 胡镜力 洪文斌 林燕桢 颜城 郑哲艺 孙莹 林瑞 于 2021-08-10 设计创作，主要内容包括：本发明提出一种变压器单个饼式线圈径向变形的测试装置及评估方法,包括M个磁场发生装置和线圈工作电源；单个磁场发生装置由方形开口铁心、励磁绕组、励磁绕组引出线、轴向铁心固定装置、轴向铁心支撑装置和励磁电源构成；磁场发生装置以变压器单个饼式线圈的圆心为圆心,在方形开口铁心的开口处与变压器单个饼式线圈对齐的情况下沿线圈依次等间距排列M个,相邻的不同励磁绕组的励磁绕组引出线依次串联后与励磁电源相连；每个励磁绕组的匝数为可调,用于使变压器单个饼式线圈不同位置的轴向磁场磁感应强度不同；变压器单个饼式线圈在工作时与线圈工作电源相连。其能更为科学和准确的评估变压器单个线圈径向变形程度。(The invention provides a testing device and an evaluation method for radial deformation of a single pancake coil of a transformer, wherein the testing device comprises M magnetic field generating devices and coil working power supplies; the single magnetic field generating device consists of a square open core, an excitation winding outgoing line, an axial core fixing device, an axial core supporting device and an excitation power supply; the magnetic field generating device takes the circle center of a single cake-shaped coil of the transformer as the circle center, M magnetic field generating devices are arranged at equal intervals along the coil in turn under the condition that the opening of the square opening iron core is aligned with the single cake-shaped coil of the transformer, and excitation winding leading-out wires of different adjacent excitation windings are connected in series in sequence and then connected with an excitation power supply; the number of turns of each excitation winding is adjustable, so that the magnetic induction intensities of the axial magnetic fields at different positions of a single pancake coil of the transformer are different; and the single pancake coil of the transformer is connected with a coil working power supply during working. The radial deformation degree of the single coil of the transformer can be more scientifically and accurately evaluated.)

1. A testing device for radial deformation of a single pancake coil of a transformer is characterized by comprising: m magnetic field generating devices and coil working power supplies;

the single magnetic field generating device consists of a square open core, an excitation winding outgoing line, an axial core fixing device, an axial core supporting device and an excitation power supply;

the magnetic field generating device takes the circle center of a single cake-shaped coil of the transformer as the circle center, M magnetic field generating devices are sequentially arranged at equal intervals along the coil under the condition that the opening of the square opening iron core is aligned with the single cake-shaped coil of the transformer, and excitation winding leading-out wires of different adjacent excitation windings are sequentially connected in series and then connected with an excitation power supply;

the number of turns of each excitation winding is adjustable, and the excitation windings are used for enabling the magnetic induction intensities of the axial magnetic fields of different positions of a single pancake coil of the transformer to be different;

the axial iron core fixing device and the axial iron core supporting device are used for fixing and supporting the magnetic field generating device;

and the single pancake coil of the transformer is connected with a coil working power supply during working.

2. The device for testing radial deformation of a single pancake coil of a transformer according to claim 1, wherein: and M is 36.

3. A method for evaluating radial deformation of a single pancake coil of a transformer is characterized by comprising the following steps: a testing device based on the radial deformation of the single pancake coil of the transformer as claimed in claim 1; the method comprises the following steps:

step S1: measuring the inner radius and the outer radius of a single pancake coil of the transformer:

marking positions on a single pancake coil of the transformer at intervals of 360/M degrees of central angles, sequentially marking as the a-th position of the single pancake coil of the transformer, wherein a is 1, 2, 3, … … and M, and measuring the inner radius r (a) and the outer radius R (a) of the single pancake coil of the transformer at the a-th position;

step S2: applying a size of F to a single pancake coil of a transformer_iRadial force of (2):

the excitation power supply is switched on and adjusted to enable the excitation winding to be in the neutral stateEffective value of frequency current is i_e(ii) a Connecting two ends of a lead of a single pancake coil of the transformer to a coil working power supply, but not placing the lead in a magnetic field generating device, adjusting the coil working power supply to enable an effective value of power frequency current in the single pancake coil of the transformer to be I, and disconnecting the power supplies at the two ends of the single pancake coil of the transformer; if necessary, the radial electromagnetic force of the single pancake coil of the transformer under the action of the ith magnetic field generating device on 1/M arc sections is F_iWhen i is 1, 2, 3, … …, M, then i is_eAnd the size of I must satisfy the following formula:

in the formula, the axial height of a single pancake coil of the transformer is recorded as h₁The thickness of the insulating material wrapped on the surface of the single pancake coil winding of the transformer is h₂The length of the center line of the square open core is L, mu_feDenotes the permeability of the core, μ_wPermeability, mu, of the conductor material of a single pancake coil of a transformer_iThe magnetic conductivity of the insulating material of the single pancake coil of the transformer is represented, I represents the effective value of the power frequency alternating current flowing in the single pancake coil of the transformer, and N_iIndicating the number of turns of the excitation winding of the ith magnetic field generating device;

keeping the output setting of a coil working power supply unchanged, putting a single pancake coil of the transformer into a magnetic field generating device, and enabling the ith magnetic field generating device to correspond to the a-th position of the single pancake coil of the transformer; connecting two ends of the single pancake coil of the transformer with a power supply, wherein the alpha position of the winding is F_iAnd is deformed by the radial force;

step S3: sequentially measuring the inner radius r of the a-th position of a single pancake coil of the transformer₁(a) And an outer radius R₁(a)，a＝1、2、3、……、M；

Step S4: calculating the radial deformation evaluation factor K of the a-th position of the single pancake coil of the transformer_a：

In the formula, n represents the position number of a single pancake coil of the transformer;

evaluation factor K from deformation_aAnd judging the radial deformation degree of the single pancake coil of the transformer.

4. The method for evaluating radial deformation of a single pancake coil of a transformer according to claim 3, wherein:

in step S4, K is calculated in the case where a is 1, 2, 3, … …, and M in this order_a(ii) a If 0<K_aLess than or equal to 0.54, the size is F_iThe local radial deformation of the single pancake coil of the transformer at the a-th position meets the requirement under the action of the radial force, if 0.54<K_aLess than or equal to 0.79, the single pancake coil of the transformer is slightly deformed radially at the a position, if at 0.79<K_a2.88, the single pancake coil of the transformer is locally moderately radially deformed at the a position, if K is_a>2.88 the single pancake coil of the transformer is locally severely radially deformed at the a-th position.

5. The method for evaluating radial deformation of a single pancake coil of a transformer according to claim 3, wherein: step S4 is replaced with step S4b or step S5 is added;

wherein, the step S4b or the step S5 specifically includes:

calculating an integral evaluation factor K of radial deformation of a single pancake coil of the transformer:

in the formula, i and j represent the position number of a single cake-shaped coil of the transformer;

and judging the radial deformation degree of the single pancake coil of the transformer according to the deformation overall evaluation factor K.

6. The method for evaluating radial deformation of a single pancake coil of a transformer according to claim 5, wherein:

in step S4b or step S5, if 0<K is less than or equal to 0.98, then the size is F_iThe radial deformation of the single pancake coil of the transformer under the action of the radial force meets the requirement, if 0.98<K is less than or equal to 2.05, the single pancake coil of the transformer is slightly deformed radially, and if the K is less than or equal to 2.05<K is less than or equal to 4, the single pancake coil of the transformer has moderate radial deformation, and if K is less than or equal to 4, the single pancake coil of the transformer has moderate radial deformation>4-transformer single pancake coil severe radial deformation.

Technical Field

The invention relates to the technical field of electrical insulation on-line monitoring and fault diagnosis, in particular to a testing device and an evaluation method for radial deformation of a single pancake coil of a transformer.

Background

The evaluation of the radial force of the current transformer coil is mainly realized by applying mechanical force through a simulation experiment device, the mechanical force is different from the electromagnetic force applied to the transformer coil in the actual operation process, and the applied mechanical force cannot be alternated as in the actual operation of the transformer; in addition, the mechanical force applied to the transformer coil is applied through an external action, so that the damage effect of the coil on the insulating material outside the coil due to the deformation of the coil cannot be reflected more truly; at present, the degree of radial deformation of the coil does not have a specific evaluation factor, and the deformation condition of the winding is generally judged and compared only by visual observation, so that a more objective and scientific evaluation method is lacked. Therefore, a transformer coil radial force simulation experiment device closer to the actual operation condition and an evaluation method of the radial deformation degree of a single transformer coil are needed to assist a transformer designer and an electric power system operation and maintenance worker to master the integral fault resistance of the transformer winding.

Disclosure of Invention

The invention provides a testing device and an evaluation method for radial deformation of a single pancake coil of a transformer, aiming at the defects and shortcomings in the prior art. Through the transformer coil radial force simulation experiment device which is closer to the actual operation condition, the radial deformation degree of a single coil of the transformer is evaluated more scientifically and accurately, and transformer designers and power system operation and maintenance personnel are assisted to master the integral fault resistance of the transformer winding.

The invention specifically adopts the following technical scheme:

a testing device for radial deformation of a single pancake coil of a transformer is characterized by comprising: m magnetic field generating devices and coil working power supplies;

the single magnetic field generating device consists of a square open core, an excitation winding outgoing line, an axial core fixing device, an axial core supporting device and an excitation power supply;

the magnetic field generating device takes the circle center of a single cake-shaped coil of the transformer as the circle center, M magnetic field generating devices are sequentially arranged at equal intervals along the coil under the condition that the opening of the square opening iron core is aligned with the single cake-shaped coil of the transformer, and excitation winding leading-out wires of different adjacent excitation windings are sequentially connected in series and then connected with an excitation power supply;

the number of turns of each excitation winding is adjustable, and the excitation windings are used for enabling the magnetic induction intensities of the axial magnetic fields of different positions of a single pancake coil of the transformer to be different;

the axial iron core fixing device and the axial iron core supporting device are used for fixing and supporting the magnetic field generating device;

and the single pancake coil of the transformer is connected with a coil working power supply during working.

Further, M is 36.

And an evaluation method for radial deformation of a single pancake coil of a transformer, which is characterized by comprising the following steps: the testing device is based on the radial deformation of the single pancake coil of the transformer; the method comprises the following steps:

step S1: measuring the inner radius and the outer radius of a single pancake coil of the transformer:

marking positions on a single pancake coil of the transformer at intervals of 360/M degrees of central angles, sequentially marking as the a-th position of the single pancake coil of the transformer, wherein a is 1, 2, 3, … … and M, and measuring the inner radius r (a) and the outer radius R (a) of the single pancake coil of the transformer at the a-th position;

step S2: applying a size of F to a single pancake coil of a transformer_iRadial force of (2):

the excitation power supply is switched on and adjusted to enable the effective value of the power frequency current in the excitation winding to be i_e(ii) a Connecting two ends of a lead of a single pancake coil of the transformer to a coil working power supply, but not placing the lead in a magnetic field generating device, adjusting the coil working power supply to enable an effective value of power frequency current in the single pancake coil of the transformer to be I, and disconnecting the power supplies at the two ends of the single pancake coil of the transformer; if necessary, the radial electromagnetic force of the single pancake coil of the transformer under the action of the ith magnetic field generating device on 1/M arc sections is F_iWhen i is 1, 2, 3, … …, M, then i is_eAnd the size of I must satisfy the following formula:

in the formula, the axial height of a single pancake coil of the transformer is recorded as h₁The thickness of the insulating material wrapped on the surface of the single pancake coil winding of the transformer is h₂The length of the center line of the square open core is L, mu_feDenotes the permeability of the core, μ_wPermeability, mu, of the conductor material of a single pancake coil of a transformer_iThe magnetic conductivity of the insulating material of the single pancake coil of the transformer is represented, I represents the effective value of the power frequency alternating current flowing in the single pancake coil of the transformer, and N_iIndicating the number of turns of the excitation winding of the ith magnetic field generating device;

keeping the output setting of a coil working power supply unchanged, putting a single pancake coil of the transformer into a magnetic field generating device, and enabling the ith magnetic field generating device to correspond to the a-th position of the single pancake coil of the transformer; connecting two ends of the single pancake coil of the transformer with a power supply, wherein the alpha position of the winding is F_iAnd is deformed by the radial force;

step S3: sequentially measuring the inner radius r of the a-th position of a single pancake coil of the transformer₁(a) And an outer radius R₁(a)，a＝1、2、3、……、M；

Step S4: calculating the radial deformation evaluation factor K of the a-th position of the single pancake coil of the transformer_a：

In the formula, n represents the position number of a single pancake coil of the transformer;

evaluation factor K from deformation_aAnd judging the radial deformation degree of the single pancake coil of the transformer.

Further, in step S4, K when a is 1, 2, 3, … …, and M is calculated in order_a(ii) a If 0<K_aLess than or equal to 0.54, the size is F_iUnder the action of radial force, the single pancake of the transformerThe local radial deformation of the coil at the a-th position is satisfactory if 0.54<K_aLess than or equal to 0.79, the single pancake coil of the transformer is slightly deformed radially at the a position, if at 0.79<K_a2.88, the single pancake coil of the transformer is locally moderately radially deformed at the a position, if K is_a>2.88 the single pancake coil of the transformer is locally severely radially deformed at the a-th position.

Further, step S4 is replaced with step S4b or step S5 is added;

wherein, the step S4b or the step S5 specifically includes:

calculating an integral evaluation factor K of radial deformation of a single pancake coil of the transformer:

in the formula, i and j represent the position number of a single cake-shaped coil of the transformer;

and judging the radial deformation degree of the single pancake coil of the transformer according to the deformation overall evaluation factor K.

Further, in step S4b or step S5, if 0<K is less than or equal to 0.98, then the size is F_iThe radial deformation of the single pancake coil of the transformer under the action of the radial force meets the requirement, if 0.98<K is less than or equal to 2.05, the single pancake coil of the transformer is slightly deformed radially, and if the K is less than or equal to 2.05<K is less than or equal to 4, the single pancake coil of the transformer has moderate radial deformation, and if K is less than or equal to 4, the single pancake coil of the transformer has moderate radial deformation>4-transformer single pancake coil severe radial deformation.

Compared with the prior art, the invention and the preferred scheme thereof have the following beneficial effects:

1. provides a simulation experiment device for radial force of single pancake coil of a transformer

The evaluation of the radial force of the current transformer coil is mainly realized by applying mechanical force through a simulation experiment device, the mechanical force is different from the electromagnetic force applied to the transformer coil in the actual operation process, and the applied mechanical force cannot be alternated as in the actual operation of the transformer; in addition, the mechanical force applied to the transformer coil is applied through an external action, and the damage effect of the coil on the insulating material outside the coil due to the deformation of the coil cannot be reflected more truly.

The radial force simulation experiment device for the single pancake coil of the transformer can be stressed and deformed spontaneously under the action of a coil working power supply and an excitation winding; compared with the current transformer coil radial force evaluation, the method is mainly realized by applying mechanical force through a simulation experiment device, and the deformation process is closer to the coil deformation process of the transformer in actual operation.

2. Provides a method for integrally evaluating the radial deformation of a single pancake coil of a transformer

At present, the degree of radial deformation of the coil does not have a specific evaluation factor, and the deformation condition of the winding is generally judged and compared only by visual observation, so that a more objective and scientific evaluation method is lacked. Therefore, a transformer coil radial force simulation experiment device closer to the actual operation condition and an evaluation method of the radial deformation degree of a single transformer coil are needed to assist a transformer designer and an electric power system operation and maintenance worker to master the integral fault resistance of the transformer winding.

The invention calculates the radial deformation evaluation factor K of the a-th position of the single pancake coil of the transformer_aAnd calculating an overall evaluation factor K of the radial deformation of the single pancake coil of the transformer, and scientifically and reasonably evaluating the radial deformation degree of the single pancake coil of the transformer by combining the given evaluation factor ranges corresponding to the deformation degrees of different windings.

Drawings

The invention is described in further detail below with reference to the following figures and detailed description:

FIG. 1 is a schematic view of a magnetic field generating device according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a simulation experiment platform for radial deformation of a single pancake coil of a transformer, which is composed of 36 magnetic field generators and the single pancake coil of the transformer according to the embodiment of the invention.

Detailed Description

In order to make the features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail as follows:

the scheme for evaluating the radial deformation of the single pancake coil of the transformer provided by the embodiment comprises the following steps:

first step, establishing a simulation experiment device for radial force of single pancake coil of transformer

As shown in fig. 1 and fig. 2, the experimental apparatus for simulating the radial force of the single pancake coil of the transformer provided in this embodiment includes 36 magnetic field generating devices, the single pancake coil 1 of the transformer, and the coil operating power supply 8, where the single magnetic field generating device is composed of a square open core 2, an excitation winding 3, an excitation winding lead-out wire 4, an axial core fixing device 5, an axial core supporting device 6, and an excitation power supply 7.

The magnetic field generating device takes the circle center of a single pancake coil 1 of the transformer as the circle center, 36 magnetic field generating devices are sequentially arranged at equal intervals along the coil under the condition that the opening of the square open iron core 2 is aligned with the single pancake coil 1 of the transformer, and excitation winding leading-out wires 4 of different adjacent excitation windings 3 are sequentially connected in series and then connected with an excitation power supply 7; the number of turns of each excitation winding 3 can be adjusted, so that the magnetic induction intensity of the axial magnetic field of a single pancake coil 1 of the transformer at different positions is different; the axial iron core fixing device 5 and the axial iron core supporting device 6 play a role in fixing and supporting the magnetic field generating device, and the single pancake coil 1 of the transformer is connected with the coil working power supply 8 during working.

Second step, measuring the inner and outer radius of single pancake coil of transformer

The positions are marked on the single pancake coil 1 of the transformer at intervals of ten-degree central angles and are sequentially marked as the a-th position of the single pancake coil 1 of the transformer, wherein a is 1, 2, 3, … … and 36, and the inner radius r (a) and the outer radius r (a) of the single pancake coil 1 of the transformer are measured at the a-th position, and the units are m.

Thirdly, applying a size F to a single pancake coil of the transformer_iRadial force of

The excitation power supply 7 is switched on and adjusted so that the effective value of the power frequency current in the excitation winding is i_eThe unit is A; the two ends of the lead of the single pancake coil 1 of the transformer are connected to the coil working power supply 8, but are not arranged in the magnetic field generating deviceIn the method, a coil working power supply 8 is adjusted to enable the effective value of the working frequency current in the single pancake coil 1 of the transformer to be I, the unit of the working frequency current is A, and the connection of power supplies at two ends of the single pancake coil 1 of the transformer is disconnected; if necessary, the radial electromagnetic force of the single pancake coil 1 of the transformer under the action of the ith magnetic field generating device on 1/36 arc sections is F_iI is 1, 2, 3, … …, 36 and has the unit of N, i_eAnd the size of I must satisfy the following formula:

in the formula, the axial height of a single pancake coil 1 of the transformer is recorded as h₁In the unit of m; the thickness of the insulating material wrapped on the surface of the single pancake coil 1 winding of the transformer is h₂In the unit of m; the length of the central line of the square open core 2 is L, mu_feDenotes the permeability of the core, μ_wPermeability, mu, of the conductor material of a single pancake coil of a transformer_iThe magnetic permeability of the insulating material of the single pancake coil 1 of the transformer is represented, and the unit is H/m; i represents the effective value of the power frequency alternating current flowing in the single pancake coil 1 of the transformer, and the unit is A; n is a radical of_iRepresents the number of turns of the field winding 3 of the i-th magnetic field generating device;

keeping the output setting of a coil working power supply 8 unchanged, putting the single pancake coil 1 of the transformer into a magnetic field generating device, and enabling the ith magnetic field generating device to correspond to the a-th position of the single pancake coil 1 of the transformer; connecting two ends of the single pancake coil 1 of the transformer with a power supply again, wherein the a-th position of the winding is F_iAnd is deformed by the radial force.

Fourthly, sequentially measuring the inner radius r of the a-th position of the single pancake coil of the transformer₁(a) And an outer radius R₁(a)，a＝1、2、3、……、36。

Fifthly, calculating the radial deformation evaluation factor K of the a-th position of the single pancake coil of the transformer_a

In the formula, a corner mark n represents the position number of a single pancake coil 1 of the transformer;

k is calculated when a is 1, 2, 3, … … and 36 in sequence_a(ii) a If 0<K_aLess than or equal to 0.54, the size is F_iThe local radial deformation of the single pancake coil of the transformer at the a-th position meets the requirement under the action of the radial force, if 0.54<K_aLess than or equal to 0.79, the single pancake coil of the transformer is slightly deformed radially at the a position, if at 0.79<K_a2.88, the single pancake coil of the transformer is locally moderately radially deformed at the a position, if K is_a>2.88 the single pancake coil of the transformer is locally severely radially deformed at the a-th position.

Sixthly, calculating the integral evaluation factor K of the radial deformation of the single pancake coil of the transformer

In the formula, corner marks i and j represent the position number of a single pancake coil 1 of the transformer;

if 0<K is less than or equal to 0.98, then the size is F_iThe radial deformation of the single pancake coil of the transformer under the action of the radial force meets the requirement, if 0.98<K is less than or equal to 2.05, the single pancake coil of the transformer is slightly deformed radially, and if the K is less than or equal to 2.05<K is less than or equal to 4, the single pancake coil of the transformer has moderate radial deformation, and if K is less than or equal to 4, the single pancake coil of the transformer has moderate radial deformation>4-transformer single pancake coil severe radial deformation.

The present invention is not limited to the above-mentioned preferred embodiments, and all other various types of testing devices and evaluation methods for radial deformation of single pancake coils of transformers can be obtained from the teaching of the present invention.