CN112908640A - Saturable reactor of high-voltage direct-current transmission converter valve and manufacturing method thereof - Google Patents

Abstract

The invention relates to a saturable reactor of a high-voltage direct-current transmission converter valve and a manufacturing method thereof, wherein the saturable reactor is externally connected with a thyristor loop and a valve tower cooling loop and comprises a metal winding, a flexible cooling pipeline, an insulating part and an iron core, the flexible cooling pipeline is wound on the outer side of the metal winding, the metal winding and the flexible cooling pipeline are cast in the insulating part together, the flexible cooling pipeline extends out of the insulating part, the iron core is arranged on the outer side of the insulating part, cooling liquid is filled in the flexible cooling pipeline, the flexible cooling pipeline is connected with the valve tower cooling loop, and the metal winding is connected with the thyristor loop. Compared with the prior art, the invention has the advantages of good heat dissipation effect, effective attenuation of vibration conduction, reduction of failure rate of parts and the like.

Description

Saturable reactor of high-voltage direct-current transmission converter valve and manufacturing method thereof

Technical Field

The invention relates to the technical field of high-voltage direct-current transmission protection, in particular to a saturable reactor of a high-voltage direct-current transmission converter valve capable of being installed in a damping and fixing mode and a manufacturing method thereof.

Background

In a high-voltage direct-current transmission converter valve, a saturable reactor is an important component and is generally connected in series with an anode of a thyristor. The saturable reactor plays a role in limiting the change rate of current flowing through the thyristor and bearing main voltage stress when the converter valve receives lightning impulse or steep wave impulse, thereby protecting the thyristor.

At present, the existing converter valve saturable reactor is generally cooled by cooling liquid, and heat brought by resistance loss in a coil and hysteresis loss and eddy current loss in an iron core is taken away. The saturable reactor widely used at present has a structure as shown in fig. 1, and adopts a hollow metal winding, and an insulating material is poured outside the winding and surrounds an iron core at the outside. The cooling circuit passes through the hollow core of the winding. The problems with this type of reactor are mainly twofold:

on the one hand, the heat generated by the iron core is partly conducted to the cooling liquid through the insulation material poured by the winding, and partly diffused outwards through air convection. The insulating material between the hollow winding and the iron core is thick, and the heat conductivity of the insulating material influences the heat dissipation effect of the iron core, so that the temperature of the iron core is high, and the aging of the insulating material is easy to accelerate;

on the other hand, high-frequency mechanical vibration is generated under the action of electromagnetic force in the working state of the reactor, and the vibration may cause the water pipe joint between the hollow winding and an external cooling system to be loosened, so that cooling liquid is leaked.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide the saturable reactor for the high-voltage direct-current transmission converter valve, which has a good heat dissipation effect, effectively weakens vibration conduction and reduces the failure rate of parts, and the manufacturing method thereof.

The purpose of the invention can be realized by the following technical scheme:

a saturable reactor of a high-voltage direct-current transmission converter valve is externally connected with a thyristor loop and a valve tower cooling loop, and comprises a metal winding, a flexible cooling pipeline, an insulating part and an iron core; the flexible cooling pipeline is wound on the outer side of the metal winding; the metal winding and the flexible cooling pipeline are cast in the insulating part together, and the flexible cooling pipeline extends out of the insulating part; the iron core is arranged on the outer side of the insulating part; the flexible cooling pipeline is filled with cooling liquid; the flexible cooling pipeline is connected with the valve tower cooling loop; the metal winding is connected with the thyristor loop.

Preferably, the flexible cooling pipeline is a cooling pipeline made of a flexible high-molecular waterproof insulating material.

Preferably, the insulator is made of epoxy resin.

Preferably, the flexible cooling pipeline is connected with the valve tower cooling circuit through a pipeline joint.

Preferably, the metal winding is electrically connected with the thyristor loop through a metal braided strap.

Preferably, the flexible cooling lines extend beyond the insulating member by more than 20 cm.

Preferably, the cooling liquid is deionized water.

Preferably, the saturable reactor is installed in the converter valve in a damping and fixing mode.

A manufacturing method for the converter valve saturable reactor comprises the following steps:

step 1: respectively manufacturing and molding the metal winding and the flexible cooling pipeline;

step 2: respectively fixing the metal winding and the flexible cooling pipeline in a mode that the winding is arranged inside and the cooling pipeline is arranged outside;

and step 3: directly pouring the metal winding and the flexible cooling pipeline by using an insulating material, wherein the insulating material is poured into an insulating part, and the flexible cooling pipeline extends out of the insulating part during pouring;

and 4, step 4: fixing an iron core outside the insulating part;

and 5: and finishing the manufacture of the converter valve saturable reactor.

Preferably, the length of the flexible cooling pipeline extending out of the insulating part in the step 3 exceeds 20 cm.

Compared with the prior art, the invention has the following beneficial effects:

firstly, the heat dissipation effect is good: the converter valve saturable reactor is arranged with a winding inside and a flexible cooling pipeline outside, and the winding and a cooling liquid pipeline are jointly poured in an insulating material; an iron core is fixed on the outer side of the insulating part; the flexible cooling liquid pipeline is tightly attached to the metal winding in structural design, and simultaneously is close to the iron core as much as possible, so that heat generated by the iron core can be taken away.

Secondly, effectively weakening vibration conduction: the converter valve saturable reactor adopts a flexible cooling pipeline, the flexible cooling pipeline exceeds an insulating part by a certain length and then is connected with a valve tower cooling loop, and in the whole connection mode, except for the connection of a joint and the flexible cooling pipeline, other rigid connection modes are not arranged so as to ensure the flexible connection between the flexible cooling pipeline and the valve tower cooling loop and weaken vibration conduction; meanwhile, the saturable reactor is arranged on the converter valve in a shock absorption mode such as a shock absorber or a spring, so that the shock transmission of the shock to the outside is reduced while the shock amplitude of the reactor is increased, the probability that the reactor and elements in the valve tower break down due to the shock is facilitated, and the problem that the reactor in the prior art is loosened due to the fact that the self shock is transmitted to the connection position between the reactor and an external cooling system through the rigid winding is effectively solved.

Drawings

FIG. 1 is a schematic diagram of a converter valve liquid cooling saturable reactor in the prior art;

FIG. 2 is a schematic structural diagram of a saturable reactor according to the present invention;

FIG. 3 is a side view of a saturable reactor of the present invention;

FIG. 4 is a top view of a saturable reactor of the present invention;

fig. 5 is a schematic view of the cross-sectional structure a-a in fig. 4.

The reference numbers in the figures indicate:

1. metal winding, 2, flexible cooling pipeline, 3, insulating part, 4, iron core.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present invention.

The converter valve saturable reactor designed by the invention is applied to a +/-500 kV direct-current transmission converter valve adopting a liquid cooling system. The direct current transmission converter valve generally needs a saturable reactor in series connection with the anode of each thyristor, and the saturable reactor of the invention is directed to the requirements in the aspect. The saturable reactor is described in detail below:

a saturable reactor of a high-voltage direct-current transmission converter valve is structurally shown in figures 2, 3, 4 and 5, the saturable reactor is externally connected with an existing thyristor loop and a valve tower cooling loop, the saturable reactor comprises a metal winding 1, a flexible cooling pipeline 2, an insulating part 3 and an iron core 4, the flexible cooling pipeline 2 is wound on the outer side of the metal winding 1, the metal winding 1 and the flexible cooling pipeline 2 are jointly poured in the insulating part 3, the flexible cooling pipeline 2 extends out of the insulating part 3, the iron core 4 is arranged on the outer side of the insulating part 3, cooling liquid is filled in the flexible cooling pipeline 2, the flexible cooling pipeline 2 is connected with the valve tower cooling loop, and the metal winding 1 is connected with the thyristor loop. The metal winding 1 also needs to extend out of the insulating part 3, but the metal winding 1 only has insulation requirements, and the air gap also meets the insulation requirements under the condition of linear extension, so that the length can be changed to a certain extent according to external electrical connection, but the distance of the extending part cannot be reduced.

The flexible cooling pipeline 2 is connected with the valve tower cooling loop through the pipeline connector, no other rigid connection is arranged between the connector and the reactor body except for the connection with the flexible cooling pipeline 2, so that the flexible connection between the flexible cooling pipeline 2 and the valve tower cooling pipeline is ensured, and the transmission of vibration to the pipeline connector is reduced by utilizing the flexible cooling pipeline 2. The metal winding 1 does not bear the function of a cooling pipeline in the traditional saturable reactor, has no special requirements on design, and can realize the body function of the metal winding.

The saturable reactor is installed in the converter valve in a damping and fixing mode, such as a damper, a spring and the like, and the metal woven belt meeting the current-carrying requirement is adopted for electrical connection between the metal winding 1 and the thyristor loop.

The fact that the length of the flexible cooling line 2 extending beyond the insulating element 3 exceeds 20cm already ensures good damping, so that the connection to the valve tower cooling circuit is not specifically defined. Since the mass of the reactor body is extremely large compared to the cooling pipe of the protruding portion, vibration approximately regarded as a fixed amplitude acts on the cooling pipe protruding portion. The reaction is carried out by a deflection calculation formula of the simple load lower beam, and the acting force of the cooling pipe and the fixed end of the external cooling loop is inversely proportional to the third power of the extending length, so that the longer the extending length is, the more the vibration transmission is favorably reduced. However, the self weight of the pipeline linearly increases along with the lengthening of the extending part, and in order to ensure that the pipeline is not broken due to self-weight stretching, 20cm is a reasonable length. In practical application, the requirement of shock absorption should be ensured to be met, and meanwhile, the self-weight cannot obviously extend (within 10%). The breaking elongation of the ethylene propylene diene monomer is generally over 100 percent, and if the breaking elongation of the used material is less than 100 percent, the elongation is required to be not more than 10 percent of the breaking elongation in practical use.

The flexible cooling pipeline 2 in this embodiment is made of a flexible polymer waterproof insulating material, specifically EPDM (ethylene propylene diene monomer), and dithiodimorpholine and TMTD are used as a vulcanization system.

The insulating member 3 in this embodiment is made of epoxy resin.

The cooling liquid in the embodiment adopts deionized water, the reactor cooling liquid is deionized water, and the electric conductivity is less than 0.5 mu S/cm at the temperature of 45 ℃. In the case of an operating current of 3000A, the iron loss is about 310W, the copper loss is about 670W, and the total heating power P is 980W, which are obtained from the factory test results and simulation calculation of the reactor with the same current. Setting the average reactor flow a to about 10L/min, for the one adopted

The tube corresponds to a flow rate of about 0.943 m/s. The specific heat capacity of the cooling water is 4.2 multiplied by 103J/(kg DEG C), and the temperature rise of the cooling water after passing through the reactor is about 1.4 ℃, so that effective heat dissipation can be realized. For the reactor with higher working current, the flow rate of the cooling water should meet the condition that the flow rate a is more than or equal to 0.01P (flow unit L/min, power unit W).

The invention also relates to a manufacturing method for the converter valve saturable reactor, which comprises the following steps:

step 1: respectively manufacturing and molding the metal winding and the flexible cooling pipeline;

step 2: respectively fixing the metal winding and the flexible cooling pipeline in a mode that the winding is arranged inside and the cooling pipeline is arranged outside;

and step 3: insulating materials are used for directly pouring the metal winding and the flexible cooling pipeline, the insulating materials are poured into insulating parts, the flexible cooling pipeline extends out of the insulating parts during pouring, and the extending length of the flexible cooling pipeline exceeds 20cm so as to guarantee good damping effect;

and 4, step 4: fixing an iron core outside the insulating part;

and 5: and finishing the manufacture of the converter valve saturable reactor.

While the invention has been described with reference to specific embodiments, the invention is not limited thereto, and various equivalent modifications and substitutions can be easily made by those skilled in the art within the technical scope of the invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (10)

1. A saturable reactor of a high-voltage direct-current transmission converter valve is externally connected with a thyristor loop and a valve tower cooling loop and is characterized by comprising a metal winding (1), a flexible cooling pipeline (2), an insulating part (3) and an iron core (4); the flexible cooling pipeline (2) is wound on the outer side of the metal winding (1); the metal winding (1) and the flexible cooling pipeline (2) are cast in the insulating part (3) together, and the flexible cooling pipeline (2) extends out of the insulating part (3); the iron core (4) is arranged on the outer side of the insulating part (3); the flexible cooling pipeline (2) is filled with cooling liquid; the flexible cooling pipeline (2) is connected with a valve tower cooling loop; the metal winding (1) is connected with the thyristor loop.

2. The saturable reactor for the high-voltage direct current transmission converter valve according to claim 1, wherein the flexible cooling pipeline (2) is a cooling pipeline made of flexible high polymer waterproof insulating material.

3. The saturable reactor for HVDC converter valves according to claim 1, characterized in that the insulator (3) is specifically made of epoxy resin.

4. The saturable reactor for the HVDC converter valve according to claim 1, wherein the flexible cooling pipeline (2) is connected with the valve tower cooling circuit through a pipeline joint.

5. The saturable reactor for the HVDC converter valve according to claim 1, wherein the metal winding (1) is electrically connected with the thyristor loop through a metal braided strap.

6. The saturable reactor for HVDC converter valve according to claim 1, wherein the flexible cooling line (2) extends beyond the insulator (3) by more than 20 cm.

7. The saturable reactor for the HVDC converter valve according to claim 1, wherein the coolant is deionized water.

8. The saturable reactor for the high-voltage direct current transmission converter valve according to claim 1, wherein the saturable reactor is installed in the converter valve in a damping and fixing mode.

9. A manufacturing method for the converter valve saturable reactor as claimed in any one of claims 1-8, characterized in that the manufacturing method comprises:

step 1: respectively manufacturing and molding the metal winding and the flexible cooling pipeline;

step 2: respectively fixing the metal winding and the flexible cooling pipeline in a mode that the winding is arranged inside and the cooling pipeline is arranged outside;

and step 3: directly pouring the metal winding and the flexible cooling pipeline by using an insulating material, wherein the insulating material is poured into an insulating part, and the flexible cooling pipeline extends out of the insulating part during pouring;

and 4, step 4: fixing an iron core outside the insulating part;

and 5: and finishing the manufacture of the converter valve saturable reactor.

10. The manufacturing method of the saturable reactor for the high-voltage direct current transmission converter valve according to claim 9, wherein the length of the flexible cooling line extending out of the insulating member in step 3 exceeds 20 cm.

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