CN106328349B - A kind of biquadratic winding double-stage voltage transformer - Google Patents

Abstract

The invention discloses a dual-secondary winding double-stage voltage transformer, which comprises a first-stage iron core, a second-stage iron core, a primary winding N ₁ , a secondary winding N ₂ , a secondary winding N ₃ , and an excitation winding; It is characterized in that: the excitation winding N _L is wound on the _first -stage iron core, the primary winding N1, the secondary winding _N2 , and the secondary winding N3 are wound on the first _- stage iron core and the second-stage iron core, and the two The secondary winding _N2 is the secondary winding with the ground potential as the reference potential, and the secondary winding N3 is the secondary winding with the high voltage potential _of the primary voltage as the reference potential; While meeting the requirements of potential measurement, another secondary conversion quantity takes the high voltage potential of the primary voltage as the reference potential measurement requirement.

Description

A double-secondary winding double-stage voltage transformer

technical field

The invention relates to a double-secondary winding double-stage voltage transformer, which belongs to the technical field of electric power monitoring and measurement.

Background technique

The double-stage voltage transformer is shown in Figure 1. It has an excitation winding and a primary winding, which can meet the requirements of a secondary voltage measurement with the ground potential as the reference potential. When the secondary voltage measurement is required, ordinary double-stage voltage transformers cannot meet the requirements.

Contents of the invention

The problem to be solved by the present invention is to provide a double-secondary winding double-stage voltage transformer. The double-stage voltage transformer has an excitation winding, a primary winding and two secondary windings, wherein, N _L is the excitation winding, N ₁ is the primary winding, N ₂ is the secondary winding with the ground potential as the reference potential, and N ₃ is the secondary winding with the high voltage potential of the primary voltage as the reference potential. When a secondary transformation is satisfied, the ground potential is used as the reference potential for measurement At the same time, it meets the measurement requirements of another secondary conversion quantity with the high voltage potential of the primary voltage as the reference potential.

The present invention is realized by adopting the following technical solutions. A double-secondary winding double-stage voltage transformer, including a first-stage iron core and a second-stage iron core, an excitation winding N _L wound on the first-stage iron core, a primary winding N ₁ and a secondary winding N ₂ , _The secondary winding N3 is wound on the first-level iron core and the second-level iron core.

More specifically, the secondary winding _N2 is a secondary winding with the ground potential as the reference potential, and the secondary winding N3 is the secondary winding with the high voltage potential _of the primary voltage as the reference potential.

More particularly, the high potential end _{AL of the excitation winding N L is connected to the high potential end A of the primary winding N 1, and the low potential end X L of the excitation} winding N _L is connected to the low potential end X of the primary winding N ₁ ; _The polarity terminal 2n of the secondary winding N3 is connected to the high potential terminal _A of the primary winding N1, and the nonpolar terminal _2a of the secondary winding N3 is set on the side of the high potential terminal _A of the primary winding N1.

More specifically, the insulation distance between the non-polar end _2a of the secondary winding N3 and the low potential end X _of the primary winding N1 should not be less _than the high potential end _A of the primary winding N1 and the low potential end of the primary winding N1 X distance.

More particularly, the insulation distance between the non-polar end _2a of the secondary winding N3 and the high potential end _A of the primary winding N1 should not be less than 2mm.

More specifically, the A terminal is drawn from the high potential end _{A of} the primary winding N1, the X terminal is drawn from the low potential end X of the primary winding N1, and the 1a terminal is drawn from the non-polar end 1a of the secondary winding _N2 . The polarity end 1n of the secondary winding _N2 leads to the 1n terminal, and the nonpolarity end _2a of the secondary winding N3 leads to the 2a terminal.

The secondary loads of the secondary winding N ₂ and the secondary winding N ₃ of the double-secondary winding double-stage voltage transformer of the present invention are no-load.

The beneficial effect of the present invention is that, on the basis of the common double-stage voltage transformer, the 2a terminal of a secondary winding N ₃ is added on the appearance, and when the primary winding N ₁ is wound, the secondary winding N ₃ and the primary winding N ₁ is wound in series, the polarity end 2n of the secondary winding N ₃ is connected to the high potential end A of the primary winding N ₁ , and is drawn to the A terminal of the double-secondary winding double-stage voltage transformer, which is the primary winding The high potential terminal A of N ₁ is also the polar terminal 2n of the secondary winding N ₃ ; that is, the problem of measuring the secondary voltage of the secondary winding N ₃ with the high voltage potential of the primary voltage as the reference potential is solved, and two Insulation problems between secondary windings; one can simultaneously measure the secondary voltage with the ground potential as the reference potential and the other with the high-voltage potential of the primary voltage as the reference potential. The method is simple, economical, scientific, practical and operable , Low cost and other advantages.

Description of drawings

Figure 1 is a schematic diagram of an ordinary two-stage voltage transformer;

Figure 2 is a wiring diagram of a common double-stage voltage transformer winding;

Fig. 3 is an equivalent circuit diagram of a common double-stage voltage transformer;

Figure 4 is the main schematic diagram of the appearance of a common two-stage voltage transformer;

Fig. 5 is a top view of an ordinary double-stage voltage transformer;

Fig. 6 is a schematic diagram of a double-secondary winding double-stage voltage transformer;

Fig. 7 is a wiring diagram of double-secondary winding double-stage voltage transformer winding;

Fig. 8 is an equivalent circuit diagram of a double-secondary winding double-stage voltage transformer;

Fig. 9 is the main schematic diagram of the shape of the double-secondary winding double-stage voltage transformer;

Fig. 10 is a top view of the appearance of a dual-stage voltage transformer with dual secondary windings;

Symbols in the figure:

1----first-line iron core, 2----second-level iron core;

N _L ---- excitation winding;

N ₁ - primary winding;

N ₂ , N ₃ ---- secondary winding;

A ---- the high potential end of the primary winding, X ---- the low potential end of the primary winding;

A _L ---- the high potential end of the excitation winding, X _L ---- the low potential end of the excitation winding;

1a--the non-polar end of the secondary winding _N2 , 1n--the polar end of the secondary winding _N2 ;

2a---the non-polar end of the secondary winding N ₃ , 2n---the polar end of the secondary winding N ₃ ;

----Primary voltage vector;

----Secondary winding N ₂ voltage vector;

----Secondary winding N ₃ voltage vector;

----Excitation winding N _L current vector;

----Primary winding N ₁ current vector;

----The primary induced potential vector of the first stage transformer;

---- N ₁ winding induced potential vector on the two iron cores;

Z _L ---- the internal impedance of the N _L winding;

Z ₁ ---- the internal impedance of N ₁ winding;

Z′ ₂ ---- converted to the internal impedance of the primary N ₂ winding;

Z′ ₃ ---- converted to the internal impedance of the N ₃ winding;

Y _ml ---- the excitation admittance of the first stage transformer;

Y _m2 ---- the excitation admittance of the second stage transformer;

---- Converted to primary _N2 winding voltage vector;

---- Converted to the primary N ₃ winding voltage vector.

Detailed ways

The specific implementation steps of the present invention will be further described below in conjunction with the accompanying drawings.

The double-secondary winding double-stage voltage transformer is shown in Figure 6. The double-secondary winding double-stage voltage transformer is based on the basic principle of the conventional double-stage voltage transformer (see Figure 1-5), and considers the manufacturing process and insulation Technical factors, another secondary winding N ₃ is wound on the iron core of the original primary winding N ₁ and secondary winding N ₂ , the winding position, insulation treatment and output mode of the secondary winding N ₂ etc. are unchanged (see Figure ₇ ); the insulation treatment and output mode _of the primary winding N1 are all unchanged, the present invention requires the secondary winding N3 to be connected in series with the primary winding N1, and the secondary winding _N3 is wound _first and then the winding The polarity end 2n of the primary winding N ₁ and the secondary winding N ₃ is connected to the high potential end A of the primary winding N ₁ to solve the problem that the secondary winding N ₃ takes the high voltage potential of the primary voltage as the reference potential; according to the double-stage voltage mutual inductance The basic principle of the transformer, the primary voltage of the excitation winding N _L and the primary winding N ₁ are equal, the number of turns of the winding is equal, the excitation winding N _L is wound on the first-stage iron core, the primary winding N ₁ and the secondary winding N ₂ , the secondary _The secondary winding N3 is wound on the first-level iron core and the second-level iron core.

In the present invention, the high potential end _{AL of the excitation winding N L is connected to the high potential end A of the primary winding N 1, and the low potential end X L of the excitation} winding N _L is connected to the low potential end X of the primary winding N ₁ ; the present invention requires _The polar terminal 2n of the secondary winding N3 is connected to the high potential terminal _A of the primary winding N1, and the non-polar terminal _2a of the secondary winding N3 is set on the side of the high potential terminal _A of the primary winding N1 (see Fig. 7 ), the insulation distance between the non-polar end _2a of the secondary winding N3 and the low potential end X of the primary winding N should not be less _than the distance between the high potential end _A of the primary winding N1 and the low potential end X of the primary winding N1; The potential difference between the non-polar terminal 2a of the secondary winding N ₃ and the high potential terminal A of the primary winding N ₁ is the secondary voltage. According to JJG314-2010 "Verification Regulations for Voltage Transformers for Measurement", the rated secondary voltage of the voltage transformer is The maximum voltage is 100V, therefore, the insulation distance between the non-polar end _2a of the secondary winding N3 and the high potential end _A of the primary winding N1 should not be less than 2mm.

The present invention requires that the secondary loads of the secondary winding _N2 and the secondary winding N3 _of the double-secondary winding double-stage voltage transformer be no-load.

After adding a secondary proportional winding to the evaluation of the influence of the double-stage voltage transformer error, the equivalent circuit diagram of the ordinary double-stage voltage transformer is shown in Figure 3. From the basic principle of the voltage transformer, its no-load error is:

For the derivation, see "Voltage Ratio Standard", Shanxi Science and Technology Press, edited by Zhao Xiumin; Zhao Yitao, P24～P25;

Compare the equivalent circuit diagram of double-secondary winding double-stage voltage transformers as shown in Figure 8. The error of voltage transformers is composed of no-load error and load error superposition. The error of the transformer is only the no-load error, and its error characteristics remain consistent with the common double-stage voltage transformer.

Calculation of winding turns:

In the formula:

N is the number of winding turns; U _n is the rated primary voltage; e is the turn potential of the winding; T is 1 turn.

Take the rated primary voltage 10kV as an example:

Example 1

1. Maintain the basic principle, manufacturing process, and design technical methods of ordinary double-stage voltage transformers of the same level:

2. Use the same insulating material, iron core and wire as the ordinary double-stage voltage transformer of the same level;

3. The calculation, winding method and winding position of excitation winding, original primary winding and secondary winding remain unchanged;

4. The positions of the original primary winding and secondary winding outside the double-stage voltage transformer remain unchanged;

5. The shape of the original ordinary double-stage voltage transformer of the same level is basically unchanged, and a 2a terminal is added next to the A terminal (see Figure 7, Figure 9, Figure 10), and the non-polar end 2a of the secondary winding N ₃ is connected to the primary winding The insulation distance _of the low potential end X of N1 should not be less than the distance between the high potential end _{A of} the primary winding N1 and the low potential end X of the primary winding N1, the non-polar end _2a of the secondary winding N3 and the primary winding N The insulation distance between the high potential terminals A of ₁ should not be less than 2mm.

6. The primary voltage of the excitation winding N _L and the primary winding N ₁ are equal, and the number of turns of the winding is equal;

7. The excitation winding N _L is wound on the first-stage iron core, the high potential end A _L of the excitation winding N _L is connected to the high potential end A of the primary winding N ₁ , and the low potential end X _L of the excitation winding N _L is connected to the primary _The low potential terminal X of winding N1 is connected;

8. When winding the primary winding N1 (see Figure ₇ , Figure 9, and Figure ₁₀ ), the secondary winding N3 and the primary winding N1 are wound in series on the _first -level iron core and the second-level iron core, _The polarity terminal 2n of the secondary winding N3 is connected to the high potential terminal _A of the primary winding N1, and leads to the A terminal of the double secondary winding double-stage voltage transformer, which is the high potential _of the primary winding N1 Terminal _A is also the polarity terminal 2n of the secondary winding N3;

9. The 2a terminal of the secondary winding N ₃ is led to the 2a terminal of the double-secondary winding double-stage voltage transformer;

10. The X terminal of the primary winding N ₁ is led to the X terminal of the double secondary winding double stage voltage transformer;

11. Wind the secondary winding N ₂ at the position where the ordinary double-stage voltage transformer of the same level originally wound the secondary winding N ₂ , and the non-polar end 1a of the secondary winding N ₂ leads to the double-secondary winding double-stage voltage mutual inductance The 1a terminal of the transformer, the polarity terminal 1n of the secondary winding N ₂ leads to the 1n terminal of the double secondary winding double-stage voltage transformer;

The content that is not described in detail in the specification of the present invention belongs to the well-known technology of those skilled in the art. The dual-secondary winding double-stage voltage transformer is used to replace the ordinary double-stage voltage transformer. While meeting the requirements of a secondary voltage measurement with the ground potential as the reference potential, it also meets the secondary voltage with the high-voltage potential of the primary voltage as the reference potential. Secondary voltage measurement requirements.

Claims (5)

1. A dual-secondary winding double-stage voltage transformer, comprising a first-level iron core, a second-level iron core, a primary winding N ₁ , a secondary winding N ₂ , a secondary winding N ₃ , and an excitation winding; it is characterized in that : The excitation winding N _L is wound on the first-stage iron core, the primary winding N ₁ , the secondary winding N ₂ , and the secondary winding N ₃ are wound on the first-stage iron core and the second-stage iron core; the excitation winding N The high potential end A _L of _L is connected to the high potential end A of the primary winding N ₁ , the low potential end X _L of the excitation winding N _L is connected to the low potential end X of the primary winding N ₁ ; the polarity end of the secondary winding N ₃ 2n is connected to the high potential end _A of the primary winding N1, and the non-polar end _2a of the secondary winding N3 is set on the side of the high potential end A of the primary winding N1 _{; A} is drawn from the high potential end A of the primary winding N1 Terminals, the X terminal is drawn from the low potential end X of the primary winding N ₁ , the 1a terminal is drawn from the non-polar end 1a of the secondary winding N ₂ , the 1n terminal is drawn from the polarity end 1n of the secondary winding N ₂ , and the 1n terminal is drawn from the secondary winding N 2 The non-polar end _2a of the winding N3 leads to the terminal 2a; the secondary winding _N2 is a secondary winding with the ground potential as the reference potential, and the secondary winding N3 is the secondary winding with the high voltage potential _of the primary voltage as the reference potential. winding. 2. The double-secondary winding double-stage voltage transformer according to claim 1, characterized in that: the insulation distance between the non-polar end _2a of the secondary winding N3 and the low _- potential end X of the primary winding N1 should not be less than The distance between the high potential end _{A of} the primary winding N1 and the low potential end X of the primary winding N1. 3. The double-secondary winding double-stage voltage transformer according to claim 2, characterized in that: the insulation distance between the non-polar end _2a of the secondary winding N3 and the high potential end _A of the primary winding N1 should not less than 2mm. 4. The double-secondary winding double-stage voltage transformer according to claim 1, characterized in that: the secondary loads _of the secondary winding _N2 and the secondary winding N3 are no-load. 5. The double-secondary winding double-stage voltage transformer according to claim 1, characterized in that: the primary voltage of the excitation winding N _L and the primary winding N ₁ are equal, and the number of turns of the windings is equal.