CN112103060A - Multi-stage excitation high-voltage proportion standard device - Google Patents

Abstract

The invention discloses a multi-stage excitation high-voltage proportion standard device and a preparation method thereof. The device includes: a main reference voltage device, the main reference voltage device comprising: a first Core1, a second Core2, and a third Core 3; wherein the second Core2 is located within the first Core; the third Core3 is positioned outside the first Core; a winding N2e wound around the first Core1 on a first side; a winding N1e wound around the first Core1 and the second Core2 at the same time on a first side; a winding N2 wound around the first Core1, the second Core2, and the third Core at the same time on a second side opposite to the first side; and a winding N1 wound outside the winding N2. The device has a high level of use voltage and accuracy.

Description

Multistage excitation high voltage proportional standard device

technical field

The invention belongs to the technical field of electric power measurement standard equipment, and in particular relates to a multi-stage excitation high-voltage proportional standard device.

Background technique

There are two types of voltage transformers: field use and laboratory use. Field voltage transformers are called power voltage transformers; laboratory voltage transformers are used to calibrate field voltage transformers, which are called standard voltage transformers. The accuracy of standard voltage transformers is at least one or two levels higher than that of field voltage transformers. In addition, standard voltage transformers also have many accuracy classes. At present, the standard voltage transformer with the highest accuracy is called "power frequency voltage proportional standard device".

With the engineering application of UHV transmission technology, the accurate measurement of UHV grid voltage has become a key technical problem that needs to be studied and solved urgently. Since the insulation problem in the high voltage field and other various electrical parameters are affected and restricted by the high voltage, the current maximum working voltage of the two-stage electromagnetic power frequency voltage ratio standard is 10KV.

SUMMARY OF THE INVENTION

In view of the above problems, the present invention provides a multi-stage excitation high-voltage proportional standard device and a manufacturing method thereof, so as to solve the problems of low operating voltage and low accuracy of the current voltage proportional standard device.

In a first aspect, the present invention provides a multi-stage excitation high-voltage proportional standard device, comprising:

The main standard voltage device, the main standard voltage device includes:

The first core Core1, the second core Core2 and the third core Core3; among them,

the second iron core Core2 is located in the first iron core;

the third iron core Core3 is located outside the first iron core;

On the first side, the winding N2e wound on the first core Core1;

On the first side, winding N1e on the first iron core Core1 and the second iron core Core2 at the same time;

On the second side opposite to the first side, winding N2 of the first core Core1, the second core Core2 and the third core at the same time;

The winding N1 is wound outside the winding N2.

Further, it also includes:

Auxiliary standard voltage device, the auxiliary standard voltage device includes:

winding N1a and winding N2a;

Wherein, the winding N1e, the winding N1a and the winding N1 are connected in parallel;

The winding N2e is connected in series with the winding N2a.

further,

The winding N1e, the winding N1a and the winding N1 have the same number of turns;

The winding N2e, the winding N2a and the winding N2 have the same number of turns.

further,

When the rated voltage of the standard device is 500/√3kV,

The first iron core Core1 has an annular closed contour and is made of silicon steel;

The second core Core2 has an annular closed contour and is made of permalloy 1J85;

The third iron core Core3 has an annular closed contour and is made of permalloy 1J85.

further,

In the winding N1, the layer width on the side away from the first iron core Core1 is gradually smaller than the layer width on the side close to the first iron core Core1;

In the winding N1e, the layer width on the side away from the first iron core Core1 is gradually smaller than the layer width on the side away from the first iron core Core1.

further,

The auxiliary standard voltage device further includes: a fourth iron core Core4;

The first iron core Core1, the second iron core Core2, the third iron core Core3 and the fourth iron core Core4 are respectively connected to the ground point.

further,

When the winding N1a is connected to a standard high voltage source, and the winding N2 is connected to a standard voltage test instrument,

According to the voltage waveform obtained by the standard voltage test instrument and the voltage waveform provided by the standard high-voltage source, it is determined that the accuracy level of the standard device is 0.002.

In a second aspect, the present invention provides a method for manufacturing a multi-stage excitation high-voltage proportional standard device, comprising:

Obtain the first core Core1, the second core Core2 and the third core Core3 with preset material, cross-sectional shape, cross-sectional area and magnetic density respectively;

Obtain wires with pre-set materials, cross-sectional shapes and cross-sectional areas;

A winding N2e with the number of turns Y2 is wound around the first side of the first core Core1 with a wire;

Place the second core Core2 in the first core Core1;

On the first side, a winding N1e with a number of turns Y1 is wound around the first core Core1 and the second core Core2 with wires;

Set the third core Core3 outside the first core Core1;

On the second side opposite to the first side, the first core Core1, the second core Core2 and the third core Core3 are wound with wires to form a winding N2 with a number of turns Y2;

The winding N1 with the number of turns Y1 is wound around the winding N2 with a wire.

further,

When winding the winding N1, the layer width on the side away from the first iron core Core1 is gradually smaller than the layer width on the side close to the first iron core Core1;

When winding the winding N1e, the layer width on the side away from the first iron core Core1 is gradually smaller than the layer width on the side close to the first iron core Core1.

Further, it also includes:

Obtain an auxiliary standard voltage device, the auxiliary standard voltage device includes: a fourth iron core Core4, a winding N1a, and a winding N2a;

Connect winding N1e, winding N1, and winding N1a in parallel;

Connect winding N2a in series with winding N2e;

Connect the first core Core1, the second core Core2, the third core Core3 and the fourth core Core4 to the grounding point respectively;

The head and end of the reserved winding N1a are respectively connected with the standard high voltage source;

The head and end of the reserved winding N2 are respectively connected with the standard voltage test instrument.

The multi-stage excitation high-voltage proportional standard device provided by the invention has a structure of four iron cores and six windings, and realizes high-voltage excitation and low-voltage excitation respectively, thereby improving the use voltage level of the voltage proportional standard device, reducing the excitation current and improving the voltage ratio. Accuracy level of a standard device.

Description of drawings

Exemplary embodiments of the present invention may be more fully understood by reference to the following drawings:

1 is a schematic diagram of the composition of a multi-stage excitation high-voltage proportional standard device according to an embodiment of the present invention;

2 is a schematic diagram of a multi-stage excitation principle of a multi-stage excitation high-voltage proportional standard device according to an embodiment of the present invention;

3 is an equivalent circuit diagram of a multi-stage excitation high-voltage proportional standard device according to an embodiment of the present invention;

4 is a schematic diagram of a usage scenario of a multi-stage excitation high-voltage proportional standard device according to an embodiment of the present invention;

5 is a schematic structural diagram of a two-stage voltage transformer for high-voltage excitation in the prior art;

Fig. 6 is the principle circuit of two-stage voltage transformer of high voltage excitation in the prior art;

Fig. 7 is the principle circuit of two-stage voltage transformer of low-voltage excitation in the prior art;

FIG. 8 is a principle circuit of a three-stage voltage transformer with high excitation in the prior art.

Detailed ways

Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, however, the present invention may be embodied in many different forms and is not limited to the embodiments described herein, which are provided for this thorough and complete disclosure invention, and fully convey the scope of the invention to those skilled in the art. The terms used in the exemplary embodiments shown in the drawings are not intended to limit the invention. In the drawings, the same elements/elements are given the same reference numerals.

Unless otherwise defined, terms (including scientific and technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is to be understood that terms defined in commonly used dictionaries should be construed as having meanings consistent with the context in the related art, and should not be construed as idealized or overly formal meanings.

At present, there are three main types of power frequency voltage ratio standards commonly used in the world: resistive type, capacitive type and electromagnetic type. Resistive and capacitive standard devices are greatly affected by temperature, and their stability is not as good as electromagnetic standard devices. The electromagnetic power frequency voltage proportional standard has the advantages of simple principle, convenient use, stability and reliability. In the electromagnetic structure, the two-stage standard transformer has high accuracy and good stability, and is the most widely used.

(1) The origin of the double-stage transformer

The two-stage principle was first proposed by H.B. Brooks in 1922 and applied to two-stage current transformers. Compared with the single-stage iron core current transformer, the accuracy has been greatly improved.

With the help of the reciprocity theorem, in 1964 CUTKOSKY.R.D first proposed the concept of two-stage voltage transformer. And based on this concept, the voltage ratio required by the direct-reading audio device is designed and realized. But he did not elaborate and analyze the basic principle of the two-stage voltage transformer in detail.

In 1968, T.A.Deacon of the British National Physical Laboratory (NPL) comprehensively analyzed the basic principle and structure of the two-stage voltage transformer, and its basic schematic diagram and principle circuit are shown in Figures 5 and 6 respectively.

Compared with the common single-stage voltage transformer, the error of the two-stage voltage transformer is about the product of the errors of the two single-stage transformers, so the accuracy level is greatly improved. Based on this principle, T.A.Deacon developed a low-voltage two-stage voltage transformer to verify the feasibility of the theory. However, because the first-level windings have to pass through the second-level windings, the insulation between the windings is difficult to design. At present, the maximum operating voltage of the dual-level voltage transformers at home and abroad is 10kV.

Since the highest voltage level of the two-stage voltage transformer with high-voltage excitation is only 10kV, in order to develop the two-stage voltage transformer above 10kV, a low-voltage excitation structure is adopted. The low-voltage excitation structure was first proposed by experts such as Peng Shixiong from the North China Electric Power Academy, and a 35kV proportional standard device was successfully developed. In recent years, China Metrology Institute has achieved 110kV/√3kV.

The principle circuit diagram of the two-stage voltage transformer with low-voltage excitation structure is shown in Figure 7. The dashed frame 1 is the two-stage main standard device, I and II are the silicon steel sheet and the permalloy iron core respectively, W1 and W2 are the proportional primary and secondary windings, and W3 is the low-voltage excitation winding. The dotted frame 2 is a transformer for auxiliary excitation with the same voltage, W4 and W5 are the primary and secondary proportional windings, respectively, and W3=W5, W1=W4.

In order to further improve the accuracy, one more stage is added on the basis of the two-stage, and the schematic diagram of the three-stage high-voltage excitation three-stage voltage proportional standard device using the three-stage structure is shown in the figure. Core1 and W1 high-voltage excitation winding form the first-stage voltage transformer, Core2 and W2 form the second-stage voltage transformer, and core3, W3, W4, W5 form the third-stage voltage transformer. In the three-stage voltage proportional standard device, the first and second-stage excitation windings W1 and W2 are both high-voltage windings, which are high-voltage excitation structures. Therefore, as with the high-voltage excitation dual-stage structure, due to the limitation of insulation, the current use voltage level disclosed in the literature is only 1kV.

The principle diagram of the multi-stage excitation high-voltage proportional standard device according to the embodiment of the present invention is shown in FIG. 2 . The multi-stage excitation high-voltage proportional standard device includes:

the main standard voltage device P ₀ of the left part and the auxiliary standard voltage device _Pe of the right part;

The main standard voltage device P ₀ is provided with a first core Core1, a second core Core2 and a third core Core3;

The main standard voltage device P ₀ is also provided with a high-voltage proportional winding N1, a high-voltage excitation winding N1e, a low-voltage excitation winding N2e, and a low-voltage proportional winding N2;

The auxiliary standard voltage device _Pe is provided with a fourth core Core4, a winding N2a and a winding N1a;

Among them, the high-voltage proportional winding N1 and the high-voltage excitation winding N1e are connected in parallel with the winding N1a;

The winding N2a is connected in series with the low-voltage excitation winding N2e;

Winding N1a is also used for connection with standard high voltage source;

Winding N2 is also used for connection with standard voltage measuring instruments.

Specifically, the three windings on the primary side (that is, the high-voltage side): the number of turns of the winding N1, the winding N1e, and the winding N1a are the same, which is the first number of turns Y1; The head ends are respectively connected to the power supply ends of the standard high voltage source, and the ends of their respective taps are respectively connected to the grounding points of the standard high voltage source, so that each winding is connected in parallel with both ends of the high precision standard high voltage source. Among them, the voltage between the two ends of the standard high-voltage source is recorded as U1.

The number of turns of the three windings on the secondary side (ie, the low-voltage side): winding N2, winding N2e, and winding N2a are also the same, which is the second number of turns Y2. The winding N2a is the source US ' of the low-voltage excitation winding _N2e ; the winding N2a is connected in series with the low-voltage excitation winding N2e. In a specific implementation, the head and end of the winding N2a are connected end-to-end with the head and end of the low-voltage excitation winding N2e to form a loop.

Winding N2 is also used to connect a standard voltage measuring instrument, and the voltage between its two ends is recorded as U2.

According to the relationship between the multi-stage excitation structure and the number of winding turns, theoretically, U2 should be equal to U1; but there is actually a deviation, and the accuracy level of the multi-stage excitation high-voltage proportional standard device is determined by comparing the deviation between U2 and U1.

As shown in Figures 2 and 3, the main standard voltage device P ₀ is provided with multi-stage excitation, wherein the first-stage excitation consists of the first core Core1, the low-voltage excitation winding N2e and the auxiliary standard device Pe;

The second-stage excitation consists of the second core Core2 and the high-voltage excitation winding N1e;

The third-stage excitation consists of the third core Core3, the high-voltage proportional winding N1, and the low-voltage proportional winding N2.

Specifically, in the multi-stage excitation high-voltage proportional standard device,

The low-voltage excitation winding N2e is the excitation of the iron core Core1, and its excitation current is I _oe ;

The high-voltage excitation winding N1e is the excitation of the iron core Core2, and its excitation current is I ₀₂ ;

The high-voltage winding N1 is the core Core3 excitation, and its excitation current is I ₀₃ ;

The high-voltage excitation winding N1a is the excitation of the iron core Core4, and its excitation current is I ₀₁ ;

And there is I ₀₃ <<I ₀₂ <<I ₀₁ ; wherein, I ₀₁ is the sum of the excitation current I _0S and the load current I _0e '.

As shown in FIG. 1 , at the lower end, the magnetic flux direction in the first iron core Core1 , the magnetic flux direction in the second iron core Core2 , and the magnetic flux direction in the third iron core Core3 are the same.

During winding, in order to ensure that the windings wound on the side of the same iron core have the same magnetic flux direction in the iron core, and the windings wound on different sides of the same iron core have the same magnetic flux direction in the iron core. , it is necessary to determine the opposite winding direction of the windings according to the series or parallel relationship between the windings, such as clockwise winding or counterclockwise winding.

Therefore, the multi-stage excitation high-voltage proportional standard device combines the two methods of high-voltage excitation and low-voltage excitation, so it has high operating voltage and good stability.

After the accuracy level is verified, further, as shown in FIG. 4 , the multi-level high-voltage excitation standard device of this embodiment (in FIG. 4 , the first entity from the left side) is used as a standard device to connect to the device. The verification circuit calibrates the 500kV series auxiliary voltage transformer under test (in Figure 4, the second entity from the left). In Figure 4, from the left, the third and fourth entities are series resonant power supplies, which are standard high voltage sources. The accuracy level of the voltage transformer under test is determined by comparing the error between the measurement value of the standard device and the measurement value of the voltage transformer under test.

In the cross-sectional view from a top view as shown in FIG. 1 , the structure of the main standard voltage device P ₀ in this embodiment is as follows:

The first iron core Core1, the second iron core Core2 and the third iron core Core3 are all rounded rectangular annular iron cores;

The second core Core2 is located in the first core Core1, and the second core Core2 and the first core Core1 are eccentrically arranged with respect to the axis A;

The first iron core Core1, the second iron core Core2 and the third iron core Core3 are all arranged symmetrically with respect to the axis B;

The low-voltage excitation winding N2e is wound on the upper side of the first core Core1;

The high-voltage excitation winding N1e is wound on the upper side of the first iron core Core1 and the upper side of the second iron core Core2;

The cross section of the high-voltage excitation winding N1e is an isosceles trapezoid, with a long side on the side close to the first iron core Core1, and a short side on the other side/end away from the upper side of the first iron core Core1.

The third core Core3 is located outside the first core Core1 and the second core Core2;

The winding N2 is wound on the lower side of the first iron core Core1, the lower side of the second iron core Core2 and the upper side of the third iron core Core3;

The winding N1 is wound on the lower side of the first iron core Core1, the lower side of the second iron core Core2, the upper side of the third iron core Core3 and the winding N2.

The cross section of the winding N1 is an isosceles trapezoid, with a long side on the side close to the iron core and a short side on the other side away from the iron core.

Different from the current general structure in which the high-voltage winding N1e is surrounded by the high-voltage winding N1, on the whole, in the standard device of this embodiment, the high-voltage excitation winding N1e at the upper end and the high-voltage proportional winding N1 at the opposite lower end are The space is basically symmetrical. The two high-voltage windings of the multi-stage excitation are basically symmetrical with respect to the center line A, that is, the structural form arranged on both sides of the device cleverly solves the insulation problem between the two high-voltage windings. The low-voltage windings N2 and N2e nested in the high-voltage winding N1 and the high-voltage winding N1e respectively are low-voltage windings, and the insulation problem does not need to be considered. Therefore, the standard device of this embodiment has a high operating voltage and good stability.

In FIG. 1 , the third iron core and the first iron core respectively have gaps of different sizes on the four sides thereof. In the specific implementation, since the insulation problem between the iron cores is solved, two adjacent iron cores can be arranged as close as possible, so that the gap between the two is as small as possible;

Similarly, since the insulation problem between adjacent windings has been solved, two adjacent windings can be placed as close as possible so that the gap between them is as small as possible. In this way, on the one hand, the compactness of the structure of the multi-stage excitation assembly can be improved, on the other hand, the length of the wires used in each winding can be reduced, and the size of each iron core can also be reduced, thereby saving raw materials.

It should be understood that each rounded rectangular annular iron core may also be a closed racetrack-shaped annular iron core (that is, two horseshoe-shaped after being spliced at the opening) or a circular annular annular iron core.

The auxiliary standard voltage device Pe is a conventional voltage transformer, and the structure in the prior art is directly adopted without additional special design.

During the specific implementation, the relative positional relationship between the main standard voltage device and the auxiliary standard voltage device is not limited; it is only necessary to connect the head end and the end of the two windings of the auxiliary standard voltage device to the corresponding main standard voltage according to the circuit connection relationship specified above. The head and end of the windings of the device are connected.

When measuring its test accuracy, the high-voltage proportional winding N1a of the auxiliary standard voltage device is connected to the high-voltage source (not shown in Figure 2) under test; the low-voltage proportional winding N2 of the main standard voltage device is connected to the high-precision voltage measuring instrument (Figure 2). 2) connection; by comparing the waveform of the measured high-voltage source with the voltage waveform obtained by the high-precision voltage measuring instrument, determine the voltage amplitude and phase accuracy respectively.

The accuracy level is the most important technical parameter of the voltage proportional standard device. Below, in conjunction with Fig. 3, the error of the multi-stage excitation voltage proportional standard device is theoretically deduced and analyzed, so as to determine its accuracy level. The variables in Figure 3 and their physical meanings are listed in Table 1 below:

Table 1 Variables and their physical meanings

1), the first-level error

和负载电流

因此第一级误差由励磁误差

和负载误差

组成。According to Figure 3, the first stage current I ₀₁ contains the excitation current

and load current

Therefore the first order error is determined by the excitation error

and load error

composition.

为According to the definition of voltage transformer error, the first-stage excitation error

for

以及

可以得到:considering

as well as

You can get:

可以表示为：load error

It can be expressed as:

In formula (4),

2), second-level error

等于第一级电压互感器在绕组N1a的阻抗

绕组N2a的阻抗(折算到一次侧)

和绕组N2e的阻抗(折算到一次侧)上的总压降：The primary side voltage of the second stage

equal to the impedance of the first-stage voltage transformer in winding N1a

Impedance of winding N2a (converted to primary side)

and the total voltage drop across the impedance of winding N2e (reduced to the primary side):

则有because

then there are

Then the excitation error of the second stage is obtained

3), the multi-level error

等于绕组N1e的阻抗

上的压降：The primary side voltage of the first stage

equal to the impedance of winding N1e

Pressure drop over:

可表示为：Then the excitation error of the multi-stage

can be expressed as:

4), the overall error

可表示为：As a whole, the total error of the multi-level voltage proportional standard device

can be expressed as:

To sum up, formula (8) can be further expressed as:

Comparing formulas (2), (4), (6), (7), (9), we can get

That is, the total error of the multi-stage standard device is equal to the product of the excitation error of each stage.

For example, if the excitation errors in the first, second and multi-stages are all 1%, the total error is 1%×1%×1%=1×10 ⁻⁶ , so that the error can be greatly reduced.

与第一级的励磁误差

数量级相当；这里在预估整体误差时，对其忽略不计，得到的总误差的量级保持不变。It should be understood that, at this time, the load error of the first stage

Excitation error with the first stage

The order of magnitude is comparable; here, when estimating the overall error, it is ignored, and the magnitude of the resulting overall error remains the same.

When designing a 500/√3kV multi-stage excitation voltage proportional standard device with a transformation ratio of 5000, as shown in Figure 1 and Figure 2, in line with the above-mentioned multi-stage excitation principle and structure, the following steps are included:

(1) Parameter calculation

The first iron core is a silicon steel sheet with a large magnetic flux.

First of all, when the rated voltage U _N is 500/√3kV, the working magnetic density B of the first iron core is 1.0T.

Under the premise that the working magnetic density is determined, the larger the turn potential is, the larger the cross-sectional area of the iron core is, and the excitation error caused by the increase of the excitation admittance also increases. However, if the turn potential is too small, more turns are required for the windings wound on the iron core. At this time, the internal impedance of the primary winding will increase, and the excitation error will also increase.

After comprehensively considering various factors such as the shape and area of the cross section of the iron core, the error performance and the number of turns of the primary winding, the turn potential and the corresponding number of turns are determined.

Specifically, 500kV takes a turn potential of about 2V/turn; and the number of turns is determined according to the turn potential.

这时，二次绕组的匝数为30匝，为一次匝数除以变比5000。Specifically, the number of turns of the primary winding of the first iron core is selected as N ₁ =N _1e =150000, then the turn potential is:

At this time, the number of turns of the secondary winding is 30 turns, which is the number of primary turns divided by the transformation ratio 5000.

Further, according to the turn potential formula e _t =4.44fBSk×10 ^-4 , where,

k is the lamination coefficient of the iron core, which is taken as 0.99;

f is the power frequency voltage frequency, which is 50Hz;

B is the working magnetic density;

S is the cross-sectional area of the core lamination;

The cross-sectional shape of the first iron core is determined to be circular, and the cross-sectional area of the first iron core is calculated as S=87.36 cm ² .

The second iron core is selected from permalloy 1J85, and the rated magnetic flux is 0.45T; the cross-sectional shape of the second iron core is determined to be square, and the cross-sectional area of the second iron core is calculated as S=6cm ² .

The third iron core is selected from permalloy 1J85, and the rated magnetic flux is 0.1T; the cross-sectional shape of the third iron core is determined to be square, and the cross-sectional area of the third iron core is calculated as S=1.6cm ² .

The fourth iron core is selected from the same material, rated magnetic flux, shape and cross-sectional area as the first iron core.

Table 2 Core parameters

Core1 Core2 Core3 Core4 Core material Silicon steel sheet Permalloy 1J85 Permalloy 1J85 Silicon steel sheet Section shape round square square round Cross-sectional area 87.36cm² 6cm² 1.6cm² 87.36cm² Rated magnetic density 1.0T 0.45T 0.1T 1.0T

Permalloy refers to an iron-nickel alloy with a large initial magnetic permeability. The biggest feature of permalloy is that it has high magnetic permeability in weak magnetic field, and their saturation magnetic induction is generally between 0.6 and 1.0T. The initial permeability refers to the permeability at "no load", and the permeability under different conditions (different magnetic fields, different frequencies and different temperatures) is generally smaller than the initial permeability.

The manufacturing process of the standard device of this embodiment is as follows:

1), preparation:

Customized 3 cores with preset material, cross-sectional shape, cross-sectional area and rated magnetic density respectively;

Prepare wires with preset material, cross-sectional shape and cross-sectional area respectively;

Obtain the auxiliary standard excitation device, which has a preset transformation ratio of 5000 and a working voltage level of 500/√3kV, including the fourth core Core4, winding N1a, and winding N2a;

2), winding

The first-stage low-voltage excitation winding N2e is wound around the first side of the iron core Core1 to obtain the first-stage low-voltage excitation winding N2e with the number of turns Y2;

Embed the iron core Core2 in the iron core Core1;

The second-stage high-voltage excitation winding N1e is wound around the first side of the iron core Core1 and the first side of the iron core Core2 to obtain a high-voltage excitation winding N1e with a number of turns Y1, wherein the first side of the iron core Core1 and the iron core Core2 The first side of the core is adjacent; that is, the second-stage high-voltage excitation winding N1e is simultaneously wound on the first side of the core Core1 and the first side of the core Core2;

Fix the iron core Core3 on the outer side of the iron core Core1;

The multi-stage low-voltage proportional winding N2 is wound around the second side of the iron core Core1, the second side of the iron core Core2 and the first side of the iron core Core3, and the multi-stage low-voltage proportional winding N2 with the number of turns Y2 is obtained, wherein , the second side and the first side of the core Core1 are opposite sides, the second side and the first side of the core Core2 are opposite sides, and the first side of the core Core3 is adjacent to the second side of the core Core1 ; That is, the multi-stage low-voltage proportional winding N2 is simultaneously wound on the second side of the core Core1, the second side of the core Core2 and the first side of the core Core3;

The multi-stage high-voltage proportional winding N1 is wound around the second side of the core Core1, the second side of the core Core2, the first side of the core Core3, and the multi-stage low-voltage proportional winding N2, and the number of turns is Y1. The multi-stage high-voltage proportional winding N1, that is, the high-voltage proportional winding N1 is simultaneously wound on the second side of the core Core1, the second side of the core Core2, the first side of the core Core3, and the multi-stage low-voltage proportional winding N2.

Specifically, as shown in FIG. 1 , the windings gradually decrease in number of turns and layer width from the inside to the outside. At the same time, the closer to the core, the lower the voltage on the winding; the farther from the core, the higher the voltage on the winding; therefore, by controlling the number of turns or width, a sufficiently safe insulation distance is achieved.

3) Wiring

Connect the second-stage high-voltage excitation winding N1e, the high-voltage proportional winding N1, and the winding N1a in parallel;

Connect the winding N2a in series with the first-stage low-voltage excitation winding N2e;

And reserve the head and end of winding N1a to connect with standard high voltage source respectively;

And reserve the head and end of the multi-stage low-voltage proportional winding N2 to be connected to the standard voltage test instrument respectively.

The iron core Core1, the iron core Core2, the iron core Core3 and the iron core Core4 are respectively grounded for equipotential grounding.

Compared with the traditional structure, the iron core Core3 is located on the lower side, and the high-voltage excitation winding N1e and the high-voltage proportional winding N1 are of upper and lower symmetrical structures, which together solve the long-standing problem that the two-stage voltage proportional standard device is difficult to apply at voltage levels above 10kV.

As shown in FIG. 4 , the multi-stage excitation voltage proportional standard device of this embodiment is respectively connected to a standard high-voltage source and a standard voltage test instrument to perform error calibration on them.

Table 3 lists the final error calibration results. The accuracy level of the multi-stage excitation voltage proportional standard device is 0.002. With reference to the current 500/√3kV voltage proportional standard device, which is the highest domestic level of 0.005, the multi-level excitation voltage proportional standard device has improved an accuracy level.

Table 3 Error calibration results

The present invention has been described above with reference to a few embodiments. However, as is known to those skilled in the art, other embodiments than the above disclosed invention are equally within the scope of the invention, as defined by the appended patent claims.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a//the [means, component, etc.]" are open to interpretation as at least one instance of a means, component, etc., unless expressly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.

Claims (10)

1. a multistage excitation high voltage proportional standard device, is characterized in that, comprises: The main standard voltage device, the main standard voltage device includes: The first core Core1, the second core Core2 and the third core Core3; among them, the second iron core Core2 is located in the first iron core; the third iron core Core3 is located outside the first iron core; On the first side, the winding N2e wound on the first core Core1; On the first side, winding N1e on the first iron core Core1 and the second iron core Core2 at the same time; On the second side opposite to the first side, winding N2 of the first core Core1, the second core Core2 and the third core at the same time; The winding N1 is wound outside the winding N2. 2. The standard device according to claim 1, further comprising: Auxiliary standard voltage device, the auxiliary standard voltage device includes: winding N1a and winding N2a; Wherein, the winding N1e, the winding N1a and the winding N1 are connected in parallel; The winding N2e is connected in series with the winding N2a. . 3. The standard device according to claim 2, characterized in that, The winding N1e, the winding N1a and the winding N1 have the same number of turns; The winding N2e, the winding N2a and the winding N2 have the same number of turns. 4. The standard device according to claim 3, characterized in that, When the rated voltage of the standard device is 500/√3kV, The first iron core Core1 has an annular closed contour and is made of silicon steel; The second core Core2 has an annular closed contour and is made of permalloy 1J85; The third iron core Core3 has an annular closed contour and is made of permalloy 1J85. 5. The standard device according to claim 4, characterized in that, In the winding N1, the layer width on the side away from the first iron core Core1 is gradually smaller than the layer width on the side close to the first iron core Core1; In the winding N1e, the layer width on the side away from the first iron core Core1 is gradually smaller than the layer width on the side away from the first iron core Core1. 6. The standard device according to claim 5, characterized in that, The auxiliary standard voltage device further includes: a fourth iron core Core4; The first iron core Core1, the second iron core Core2, the third iron core Core3 and the fourth iron core Core4 are respectively connected to the ground point. 7. The standard device according to any one of claims 1 to 6, characterized in that, When the winding N1a is connected to a standard high voltage source, and the winding N2 is connected to a standard voltage test instrument, According to the voltage waveform obtained by the standard voltage test instrument and the voltage waveform provided by the standard high-voltage source, it is determined that the accuracy level of the standard device is 0.002. 8. A method for making a multi-stage excitation high-voltage proportional standard device, characterized in that, comprising: Obtain the first core Core1, the second core Core2 and the third core Core3 with preset material, cross-sectional shape, cross-sectional area and magnetic density respectively; Obtain wires with pre-set materials, cross-sectional shapes and cross-sectional areas; A winding N2e with the number of turns Y2 is wound around the first side of the first core Core1 with a wire; Place the second core Core2 in the first core Core1; On the first side, a winding N1e with a number of turns Y1 is wound around the first core Core1 and the second core Core2 with wires; Set the third core Core3 outside the first core Core1; On the second side opposite to the first side, the first core Core1, the second core Core2 and the third core Core3 are wound with wires to form a winding N2 with a number of turns Y2; The winding N1 with the number of turns Y1 is wound around the winding N2 with a wire. 9. The manufacturing method according to claim 8, characterized in that, When winding the winding N1, the layer width on the side away from the first iron core Core1 is gradually smaller than the layer width on the side close to the first iron core Core1; When winding the winding N1e, the layer width on the side away from the first iron core Core1 is gradually smaller than the layer width on the side close to the first iron core Core1. 10. The manufacturing method according to claim 8, further comprising: Obtain an auxiliary standard voltage device, the auxiliary standard voltage device includes: a fourth iron core Core4, a winding N1a, and a winding N2a; Connect winding N1e, winding N1, and winding N1a in parallel; Connect winding N2a in series with winding N2e; Connect the first core Core1, the second core Core2, the third core Core3 and the fourth core Core4 to the grounding point respectively; The head and end of the reserved winding N1a are respectively connected with the standard high voltage source; The head and end of the reserved winding N2 are respectively connected with the standard voltage test instrument.

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