WO2019147212A1

WO2019147212A1 - Stator for linear electric submersible pump unit and method for producing same

Info

Publication number: WO2019147212A1
Application number: PCT/UA2018/000073
Authority: WO
Inventors: Дмитрий Валерьевич ХАЧАТУРОВ
Original assignee: Дмитрий Валерьевич ХАЧАТУРОВ
Priority date: 2018-01-25
Filing date: 2018-07-11
Publication date: 2019-08-01

Abstract

The claimed invention relates to the field of electrical engineering, particularly to designing linear motors that can be used in electric submersible pump units in the oil industry. The essence of the claimed technical solution consists in the fact that structural elements of a stator are made of a material having a relative thermal expansion equal to the thermal expansion of elements of the moving part of a linear motor. Sections of the stator are in the form of a frame structure that is made from C-shaped ferromagnetic transverse elements (spacers) having radial protrusions. Said elements are connected by sectional and inter-sectional guides that are axially mounted and are capable of providing a constant pole pitch value and precisely positioning stator elements relative to one another.

Description

DESCRIPTION

Linear electric submersible pump stator

installation and method of its manufacture

The invention relates to the field of electrical engineering, in particular, to the design of linear electric motors used in electric submersible pumping installations in the oil industry.

The principle of operation of the known linear electric submersible pumping units is based on the reciprocating movement of the movable part of the linear motor connected to the plunger of the pump unit, under the influence of a traveling electromagnetic field created in the stator winding of the electric motor.

Mainly the stator is made in the form of a set of circular inductors installed around the guide moving part of a linear electric motor. Such a constructive implementation requires reliable fixation of the coils ensuring their constant and accurate positioning, both relative to each other and relative to the elements of the moving part of the linear electric motor, thus ensuring a constant pole separation of the stator and uniform distribution of magnetic induction in the linear electric motor.

Also, one of the main requirements for the operation of electric motors is to increase the efficiency, smoothness of movement and efficiency. This result is achieved through the use of combined windings, at the moment the most famous winding of this type is "Slavyanka". This winding scheme implies a parallel connection of two three-phase windings into a star and a triangle. Thanks to the combined windings, the parameters of the engines are significantly improved, in particular, energy efficiency is increased, and the use of expensive electrical materials is reduced.

In the claimed invention, an embodiment of a sectional frame stator of a linear electric motor is presented with implemented principles for constructing "low-speed" electric machines in combination with the use of a combined winding with all its advantages.

From the application for the invention US2016372994A1 from 12.22.2016 IPC NC 41/02 known stator submersible pump installation, which contains the reference core in the form of a hollow element made in the form of a guide movable part of a linear actuator, with at least one coil inductance installed outside the core fixed by a layer of heat shrinkable material. In this case, the design provides for the presence of a friction layer of heat shrinkable material between the core and at least one inductance coil. Also, the structure may provide for annular inserts between the inductors.

The disadvantages of the described technical solution include the method of fixing the inductance coils by means of heat-shrinkable material, which does not ensure sufficient accuracy of positioning the stator coils relative to each other, and can also lead to a change in the position of the coils during operation under the influence of significant temperatures. From the patent for utility model RU 113090 dated 01/27/2012, a synchronous rotating electric machine with combined windings is known, which includes a six-phase winding consisting of two three-phase combined windings connected respectively to a star and a triangle with a ratio of the numbers of turns of a triangle and a star equal to l / 3, with each phase having an equal number of teeth, coils of different phases are laid in different grooves so that the resulting magnetic flux induction vectors of each of the adjacent phases form an angle between themselves 30 e. degrees Odd phases are connected into a star, and even - into a triangle or vice versa, and the conclusions of their phases, separated from each other by 30 el. degrees are interconnected and form the connection points of the phases.

Also from the application for US invention US20130038144A1 dated 02/14/2013, the stator of the motor of a submersible pumping unit is known, which contains many coils and spacers between them, wound from one conductor of a certain length, with alternating three specified sets of coils with different current directions. The ends of the stator winding are connected to the star at the end of the last set of coils. The number of coils in each set is a multiple of three. Also according to the described invention, each set of coils contains a plurality of coils forming adjacent pairs, one of the pair of coils being wound in the opposite direction with respect to the other of the coils of the pair. The engine described in this embodiment of the invention is low-speed, since, according to the description, the number of pairs of stator poles exceeds the number of pairs of poles of the movable part (slider).

The disadvantages of the described technical solution include the fact that when the windings are connected to a star or a triangle, the magnetic field of the winding is not sinusoidal and has a stepped form of the curve magnetomotive force (MDS), when powered from a source of sinusoidal voltage, which leads to the modulation of the slider pull and causes unwanted acoustic noise and vibration of the engine due to electromagnetic forces. Based on the constructive implementation, the disadvantages of the described technical solution include the use of fastening elements installed between the stator sections, which can affect the accuracy of the positioning of the stator elements, as well as the implementation of the stator with comb elements significantly increases the metal structure and complicates the manufacturing technology.

The technical problem to which the invention is directed, is to improve the operational characteristics of a linear valve motor with a stable traction force with accurate positioning of the stator structural elements regardless of thermal expansion and mechanical load.

The technical result obtained from the implementation of the claimed invention is to increase the traction force, increase the output torque of the motor, ensuring the sinusoidal curve of the magnetomotive force (MDS), as well as improving the accuracy of positioning the stator design elements relative to the moving part of the motor regardless of the relative thermal expansion and mechanical stress. Also the implementation of the technical solution helps to reduce the number of structural elements, improving the manufacturability.

The essence of the proposed technical solution is that the structural elements of the stator are made of a material with a relative temperature expansion equal to the temperature expansion of the elements of the moving part of a linear electric motor. Stator sections made in the form of a frame structure formed from C-shaped transverse ferromagnetic elements (spacers) with radial protrusions. These elements are connected by sectional and intersectional guides mounted in the axial direction and made with the possibility of providing a constant value of pole division and precise positioning of the stator elements relative to each other.

Sectional and intersectional guides are made in the form of perforated plate strips installed in engagement with the radial protrusions of C-shaped transverse ferromagnetic elements (spacers) with fixation by means of periodically installed locking elements. C-shaped supporting elements (spacers) are made with a transverse slit, which is made with a gradual transition along the arc and during the formation of the stator sections forms a longitudinal groove for laying the connected ends of the coils.

According to a preferred embodiment, the stator winding contains a set of coils placed between the C-shaped transverse elements (spacers) of the stator sections, combined into groups with an equal number of coils. Coils are placed in groups, taking into account alternating changes in the direction of the current within one group. The stator winding is a part of the magnetic system, in which the number of stator teeth differs from the number of magnetic poles of the moving part of the linear actuator by a multiple of two, forming the resulting magnetic field with the number of magnetic poles of the stator equal to the number of magnetic poles of the moving part. Coils in groups are arranged in pairs with alternating connections in a star and a triangle, forming in each pair an angle between the magnetic flux induction vectors 90 el. degrees, however, groups of coils related to one phase are shifted relative to the groups of coils belonging to other phases by 120 e. degrees

Also according to a preferred embodiment of the invention, the stator winding is nine-phase with the same number of teeth per phase and consists of three three-phase windings, connected in parallel two of which are connected in a star and one in a triangle.

In the coil group, at least two coils represent one phase and form one pole, one of the indicated pair of coils is connected to a star, and the second to a triangle with similar coils of other phases, each pair of coils in the group having reverse polarity with respect to previous.

A method of manufacturing a stator in accordance with the claimed design consists in that the stator is made of sections, the structural elements of which are made of a material with a relative temperature expansion equal to the temperature expansion of the elements of the moving part of a linear electric motor. The stator sections are made in the form of a frame structure formed from C-shaped transverse ferromagnetic elements with radial protrusions, as well as sectional and intersection guides. Between C-shaped transverse elements, a set of coils is installed, which are combined into groups arranged with regard to alternating changes in the direction of the current within one group. Coils in groups form in pairs with alternating connections in a star and a triangle, forming in each pair the angle between the magnetic flux induction vectors 90 el. degrees Groups of coils belonging to the same phase are shifted relative to the groups of coils belonging to other phases by 120 el. degrees

b Also, according to a preferred embodiment, the stator winding is made of three three-phase windings connected in parallel, two of which are connected in a star and one in a triangle.

The essence of the proposed technical solution is explained, but not limited to the following graphic materials:

figure 1 - linear electric submersible pumping unit;

figure 2 - stator linear electrophoreses pumping unit, General view; fig.Z - stator electric submersible pumping unit in the section;

4 is a C-shaped ferromagnetic insert (option 1);

5 is a C-shaped ferromagnetic insert (option 2);

6 is a diagram of a stator winding of an electro-submersible pumping installation;

Fig.7 - the curve of the magnetomotive force (MFS) in a nonmagnetic gap.

The claimed invention is implemented in the design of a linear electrophoreses pump installation of modular design, which contains ground 1 (figure 1) and submersible 2 parts. The ground part is presented in the form of a control unit 3, made in the form of a three-phase high-frequency inverter-regulator and an output transformer connected to a linear valve motor 4 by a cable line 5. The load part 2 (figure 1) contains a linear valve motor 4 including a stator 6 (figure .2) which is made of a set of sections 7. Sections 7 of the stator are formed from around the hollow guide 8 (FIG. 3) for the movable part 9 of the linear electric motor (slider), annular support elements made x a C-shaped cross-ferromagnetic elements (spacers) 10 separating the coil 11 forming the winding to the number of magnetic poles p> 10. The stator winding includes a spatially combined composition of three-phase interdependent parts (windings) assembled into a star and a triangle. According to a preferred embodiment of the invention, the structural elements of the stator are made of a material with a relative temperature expansion equal to the temperature expansion of the elements of the moving part of a linear electric motor. This embodiment allows for accurate positioning of the stator elements relative to the moving part of the linear motor (slider), so that the total temperature expansion does not affect the ratio of the geometric dimensions of the stator and slider elements, ensuring the stability of the traction force over a wide temperature range.

Section 7 of the stator is made in the form of a frame structure formed from C-shaped transverse ferromagnetic elements (spacers) 10 with radial protrusions 12, as well as sectional 13 and intersectional 14 guides mounted around the circumference of the stator in the axial direction. Guides 13,14 are made with the possibility of providing a constant value of pole division and accurate positioning of the stator elements relative to each other. According to the described implementation variant, the guides 13,14 are presented in the form of plate-like perforated elements installed in engagement with radial protrusions 12 C-shaped transverse ferromagnetic elements (spacers) 10, fixed by means of periodically installed locking elements 15. These locking elements are easily removable and made with the possibility of quick installation, by installing over the guides 13,14 entering into engagement with the teeth on the radial protrusions 12. Depending on the implementation of the intersectional The first guides 14 can be realized, both in the form of separately installed perforated plates (FIG. 1), and in the form of sectional guides 13, mounted between adjacent sections (not shown in the pictures). Embodiments of the C-shaped support elements (spacers) 10 shown in (Fig. 4,5). According to one of possible implementation options, C-shaped transverse ferromagnetic spacers 10 (FIG. 4) are made with a transverse slit 16, with a gradual transition along the arc and forming stator sections form a longitudinal groove for laying the connected ends of the coils 1 1.

Each section of the stator contains at least one group 17; 17 _P (figure 2), formed from a pair of coils 11; 11 _p , separated by a ferromagnetic spacer 10; 10 _P. At least one of the pair of coils 11 of at least one group 17 of the first section 7, relating to one of the phases, is connected to the coils 11 _n in the corresponding group 17 _{n of the} following section 7 _P , relating to the other phases, by connecting a star or a triangle, providing alternation and spatial phase shift of the supply voltage.

According to the method of implementation of the proposed technical solution, the stator winding (FIG. 6) is made of three three-phase windings, connected in parallel two of which are connected to a star (shown in the diagram by a solid line in the form of trapezoids with different line widths for each phase) and one in a triangle ( the diagram is shown by a dashed line in the form of rectangles, with different thickness of lines for each phase).

The stator winding contains a set of coils 11 placed between C-shaped transverse elements 10 sections 7 of the stator and grouped into groups 17 with an equal number of coils placed with regard to alternating changes in the direction of current within one group. The described winding and slider (in Fig. 6, shown as alternatingly arranged magnets with poles "S", "N") form a magnetic system in which the number of stator teeth differs from the number of magnetic poles of the moving part of a linear electric motor by a multiple of two, forming resulting magnetic field with the number of stator magnetic poles equal to the number of magnetic poles of the movable part. Coils in groups arranged in pairs with alternating connections in a star and a triangle. In each pair of coils, the angle between the magnetic flux induction vectors is 90 el. degrees, while the groups of coils belonging to one phase are shifted relative to the groups of coils belonging to other phases by 120 el. degrees

According to one possible embodiment of the winding in a group of coils, at least two coils represent one phase and form one pole, with one of the specified pair of coils connected in a star, and the second in a triangle with similar coils of other phases. Also, each pair of coils in a group has reverse polarity with respect to the previous pair.

It is also possible to connect the coils into a winding, in which one part of the set of coils forms groups connected into a star, and the second into a triangle displaced in space relative to each other by 90 el. degrees

Performing a motor stator with a winding (FIG. 6) according to the described invention allows to obtain a linear motor with the number of pole pairs on a slider 2p = 38 with the number of slots on the stator z = 36 or z = 72.

The operation of a linear motor with a stator of the claimed design can be described as follows.

Due to the fact that at one point in time, the direction vector of the magnetic field generated by the current flowing through one phase of the stator winding coincides with the magnetic field vector of the slider, and in the other two, the resulting vector is parallel to the slider axis ( in the axial direction), while on the slider force begins to act, seeking to bring it into a stable position. This, in turn, leads to the creation of a driving moment, since the slider is positioned relative to the stator in such a way that the sum of the magnetic field vectors in the radial direction is even zero.

A sinusoidal current flows in the stator winding, the phases connected in a star are arranged in space 120 ° relative to each other, the phases connected in a triangle are similar. In this case, the windings connected in a triangle are offset relative to the windings connected in a star by half the slot division with z = 36 or by one slot division with z = 72.

The displacement of the windings connected in a star relative to the windings connected in a triangle leads to the creation of a pulsating magnetic field in each tooth, while the summing vector of the maximum magnetic flux moves sequentially along the teeth of the stator. The magnetic field created by the permanent magnets of the slider is carried along by the magnetic field vector, which is created by the stator winding, creating a driving moment acting on the moving part of the electric motor.

With the help of a control (controller), the voltage is applied to the stator windings so that the magnetic field vector of the stator is always equal to the magnetic field vector of the slider. With the help of pulse width modulation (PWM), the controller controls the current flowing through the stator windings of the motor, i.e. the magnetic field vector of the stator, and thus adjusts the moment acting on the slider. The control is implemented in such a way as to create and maintain a running magnetic field in the gap between the stator and the slider, which carries the slider. Implementation of the claimed invention with the use of a combined winding of an electric motor contributes to the achievement of this technical result, providing an increase in tractive effort with an increase in the output torque of the electric motor. It is also possible to achieve the sinusoidal curve of the magnetomotive force (MSS), as shown in (Fig.7), which ensures maximum smoothness of the moving part of the electric motor (slider) and increases its resource. Execution of the stator in the form of a frame sectional construction provides manufacturability of the assembly and contributes to improving the accuracy of positioning the stator structural elements relative to the elements of the moving part of the electric motor regardless of the relative temperature expansion and mechanical stress.

The claimed technical solution provides for various options and alternative forms of implementation. A specific embodiment is disclosed in the description and shown by means of the above graphic materials. The described embodiment of the invention is not limited to the specific form disclosed and may cover all possible versions, equivalents and alternatives, within the essential features disclosed in the claims.

Claims

Claims Stator of a linear electro-immersion pumping installation and method of its manufacture

1. A linear electrophorege pumping unit stator consisting of a plurality of sections that contain, mounted around a hollow guide for a moving linear actuator, annular support elements dividing a set of coils forming a winding with a number of magnetic poles p> 10, including a spatially combined three-phase composition interdependent parts (windings) assembled into a star and a triangle, characterized in that the structural elements of the stator are made of a material with a relative temperature expansion by irradiation equal to the temperature expansion of the moving part of the linear actuator, and the stator sections are made in the form of a frame structure formed from C-shaped transverse ferromagnetic elements (spacers) with radial protrusions, as well as sectional and intersectional guides mounted in the axial direction, made with the possibility of providing the magnitude of pole division and precise positioning of the stator elements relative to each other.

2. The stator of the linear electric submersible pumping installation according to claim 1 is characterized in that the sectional and intersectional guides are made in the form of plate-like perforated elements mounted in engagement with the radial protrusions of the C-shaped transverse ferromagnetic elements (spacers) with fixation by means of periodically fixed locking elements, at the same time C-shaped supporting elements (spacers) are made with a transverse slot, with a gradual transition along the arc and during the formation of the stator sections, they form a longitudinal groove for laying the connected ends of the coils.

3. The stator of a linear electric submersible pumping installation is different in that the stator winding is made of a set of coils grouped together and is part of a magnetic system, in which the number of stator teeth differs from the number of magnetic poles of the moving part of a linear electric motor by a factor of two, forming the resulting magnetic the field with the number of magnetic poles of the stator is equal to the number of magnetic poles of the movable part, with the coils in groups arranged in pairs with alternating connections in a star and a triangle, the image yu in each pair the angle between the magnetic flux induction vectors 90 el. degrees, while the groups of coils belonging to the same phase are shifted relative to the groups of coils belonging to other phases by 120 e. degrees

4. The linear electric submersible pumping unit stator according to claims 1; 3 differs in that the stator winding is nine-phase and consists of three three-phase windings, connected in parallel two of which are connected in a star and one in a triangle.

5. The stator of the linear electric submersible pumping installation according to item 3 is different in that in a group of coils, at least two coils represent one phase and form one pole, one of the specified pair of coils is connected to a star, and the second to a triangle with similar coils other phases, each pair of coils in the group has a reverse polarity with respect to the previous one.

6. A method of manufacturing a stator, a linear electro-immersion pumping installation, is characterized in that the stator is formed from sections, the structural elements of which are made of a material with a relative temperature expansion equal to the temperature the expansion of the moving part of the linear motor, and the stator sections are in the form of a frame structure formed from C-shaped transverse ferromagnetic elements (spacers) with radial protrusions, as well as sectional and intersection guides, between the C-shaped transverse elements set a set of coils, which are combined into groups placed with regard to alternating changes in the direction of the current within one group, and the coils in the groups are formed in pairs with alternating connections in a star and tr a square, forming in each pair an angle between the magnetic flux induction vectors 90 el. degrees, while groups of coils belonging to one phase are shifted relative to groups of coils belonging to other phases by 120 e. degrees

7. A method of manufacturing a stator, a linear electro-immersion pumping installation according to claim 6, characterized in that the stator winding is formed from three three-phase windings, connected in parallel two of which are connected in a star and one in a triangle.