Non-magnetic stator tooth high-temperature superconducting synchronous phase modifier and determination method

Abstract

According to the non-magnetic stator tooth high-temperature superconducting synchronous phase modifier and the determination method, a plurality of superconducting excitation windings are arranged between a rotor magnet yoke and a superconducting shielding layer along the circumferential array of the rotor magnet yoke, and each superconducting excitation winding is connected with a superconducting excitation winding cooling structure and an excitation winding structure wound by a high-temperature superconducting strip; the superconducting excitation winding cooling structure is arranged on the excitation winding to maintain the excitation winding to operate stably at the set temperature, so that active power loss and temperature rise of the excitation winding are avoided, the superconducting excitation winding has high excitation capacity, the air gap magnetic flux density of the high-temperature superconducting synchronous phase modifier is as high as 1.6 T, and the high-temperature superconducting synchronous phase modifier can be applied to the high-temperature superconducting synchronous phase modifier. Therefore, when the radial sizes are roughly the same, the axial size of the high-temperature superconducting synchronous phase modifier can be greatly reduced, and under the condition of the same power, the axial size of the high-temperature superconducting synchronous phase modifier is about one half of that of an existing synchronous phase modifier, and miniaturization of the synchronous phase modifier is facilitated.

Description

Technical Field

[0001] The invention belongs to the technical field of superconducting motors, and in particular relates to a non-magnetic stator tooth high-temperature superconducting synchronous condenser and a determination method thereof. Background Art

[0002] The integration of a large number of renewable energy sources into the grid has reduced the reliance of electricity supply on traditional fossil energy and the pollution to the natural environment. However, the increasing proportion of renewable energy generation in the power system and the large-scale application of DC transmission have brought serious reactive power imbalance problems to the power grid.

[0003] To solve the above problems, reactive power compensation devices are generally used to adjust the reactive power of the power system. Traditional reactive power compensation devices include capacitors, static VAR generators (SVG), static VAR compensators (SVC) and synchronous condensers. Among them, synchronous condensers have the advantage of smooth and fast reactive power adjustment.

[0004] However, the three-phase AC armature winding and DC excitation winding of conventional synchronous condensers are made of copper conductors, which will inevitably generate a large amount of active power loss during steady-state operation. In addition, the Joule heat generated by the large-scale change of the excitation current in a short period of time will have a serious adverse effect on the insulation of the excitation winding. This makes the maintenance workload of conventional synchronous condensers large and the operating efficiency low, thus limiting their practical application and development.

[0005] In recent years, high-temperature superconducting synchronous condensers have attracted widespread attention in the electric power industry. The excitation windings of high-temperature superconducting synchronous condensers are usually made of second-generation high-temperature superconducting materials, which have a zero resistance effect below the critical temperature. Therefore, compared with conventional synchronous condensers, the excitation windings of high-temperature superconducting synchronous condensers have stronger excitation capabilities and do not produce losses; the current use of ferromagnetic stator teeth directly exposed to high air gap flux density will cause magnetic saturation and tooth harmonic problems, which limits the practical application of existing synchronous condensers. Summary of the invention

[0006] The purpose of the present invention is to provide a non-magnetic stator tooth high-temperature superconducting synchronous condenser and a determination method, so as to overcome the problems of magnetic saturation and tooth harmonics caused by the ferromagnetic stator teeth directly exposed to high air gap flux density in the existing synchronous condenser in the power system with a high proportion of new energy, as well as the problem of limitations in practical application.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows: A non-magnetic stator tooth high-temperature superconducting synchronous condenser comprises a motor shaft, a rotor yoke and a superconducting shielding layer which are coaxially arranged in sequence from the inside to the outside; a plurality of superconducting excitation windings are arrayed along the circumference of the rotor yoke between the rotor yoke and the superconducting shielding layer; each superconducting excitation winding is connected to a superconducting excitation winding cooling structure; an armature winding is arrayed along the circumferential direction on the outer circle of the superconducting shielding layer; the armature winding and the superconducting shielding layer are arranged at intervals; a stator yoke is coaxially arranged on the outer circle of the armature winding; and the motor shaft, the rotor yoke and the stator yoke are connected at the contact surface ends.

[0008] Preferably, the superconducting excitation winding is arranged between the rotor yoke and the superconducting shielding layer through a superconducting excitation winding support structure.

[0009] Preferably, the superconducting excitation winding support structure is made of epoxy resin for impregnating and curing the superconducting excitation winding.

[0010] Preferably, the armature winding is arranged between the superconducting shielding layer and the stator yoke through non-magnetic stator teeth.

[0011] Preferably, each armature winding comprises two winding structure blocks, and the two winding structure blocks are spaced apart in a radial direction of the superconducting shielding layer.

[0012] Preferably, an armature winding cooling structure is provided on the outer rings of the two winding structure blocks.

[0013] Preferably, the rotor yoke and the stator yoke are both formed by laminating non-oriented cold-rolled silicon steel sheets.

[0014] Preferably, the superconducting excitation winding is formed by stacking racetrack-shaped coils made of REBCO high-temperature superconducting tape in an approximately sinusoidal shape.

[0015] A method for determining the distribution of superconducting excitation windings for the above-mentioned non-magnetic stator tooth high-temperature superconducting synchronous condenser comprises the following steps: An equivalent magnetic circuit model of a superconducting synchronous condenser is established, and the no-load excitation ampere-turns of a single magnetic pole are obtained through magnetic circuit calculation. According to the operating characteristics of the superconducting synchronous condenser and the actual current-carrying performance of the superconducting tape, the rated no-load excitation current of the superconducting excitation winding is determined; According to the no-load excitation ampere-turns of a single magnetic pole and the rated no-load excitation current, the total number of winding turns of the six-layer racetrack coil is calculated.

[0016] Preferably, an equivalent magnetic circuit model of a superconducting synchronous condenser is established, the working magnetic flux density of each component of the condenser is given, and the magnetic resistance of each component is determined according to its magnetization characteristics; the no-load excitation ampere-turns of a single magnetic pole of the superconducting synchronous condenser is calculated based on the magnetic resistance and the working magnetic flux density; the curve of the magnetic field at the end of the superconducting excitation winding changing with the excitation current and the curve of the critical current of a single turn of superconducting tape changing with the external magnetic field in the 30K temperature zone are plotted, and the intersection of the two curves is taken as the rated no-load excitation current.

[0017] A two-dimensional rectangular coordinate system is established with the location of the outermost turn of the bottom track-shaped coil as the origin, and the initial coordinates of the outermost turn of the strip are extracted; the position of the outermost turn of the strip is calibrated by mapping it with a sinusoidal function shape approximately in the region [0,π / 2] and multiplying it by the magnification factor; the total number of winding turns of a single magnetic pole is evenly distributed to the six coils and the winding radius of the innermost turn of the strip of the 1st, 2nd, 3rd, 4th, 5th and 6th layers of coils is set to be the same, and the position of the innermost turn of the strip is calibrated; according to the coordinates of the innermost and outermost turns of the strip, the number of windings of each layer of the track-shaped coil is determined.

[0018] Compared with the prior art, the present invention has the following beneficial technical effects: The non-magnetic stator tooth high-temperature superconducting synchronous condenser of the present invention has a plurality of superconducting excitation windings arrayed along the circumference of the rotor yoke between the rotor yoke and the superconducting shielding layer, each superconducting excitation winding is connected to a superconducting excitation winding cooling structure, an excitation winding structure wound with a high-temperature superconducting tape is adopted, and a superconducting excitation winding cooling structure is arranged on the excitation winding to maintain the excitation winding for steady-state operation at a set temperature, thereby avoiding active power loss and temperature rise of the excitation winding. The superconducting excitation winding adopted by the present invention has a strong excitation ability, so that the air gap flux density of the high-temperature superconducting synchronous condenser is as high as 1.6T. Therefore, when the radial dimensions are roughly the same, the axial dimension of the high-temperature superconducting synchronous condenser of the present application can be greatly reduced. Under the condition of the same power, the axial dimension of the high-temperature superconducting synchronous condenser of the present application is about one-half of that of the existing synchronous condenser, which is conducive to the miniaturization of the synchronous condenser.

[0019] Preferably, the armature winding is arranged between the superconducting shielding layer and the stator yoke through non-magnetic stator teeth. The use of non-magnetic stator teeth and a poleless shoe-type superconducting rotor can not only achieve a compact and lightweight structural design, but also reduce the synchronous reactance of the superconducting synchronous phase regulator and increase its reactive regulation speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the structure of a high-temperature superconducting synchronous condenser with non-magnetic stator teeth in an embodiment of the present invention.

[0021] Figure 2 Schematic diagram of the structure of the superconducting excitation winding in an embodiment of the present invention.

[0022] Figure 3 Schematic diagram of the flow of the superconducting excitation winding distribution optimization design method in an embodiment of the present invention.

[0023] In the figure, 1. motor shaft; 2. rotor yoke; 3. superconducting excitation winding; 4. superconducting excitation winding cooling structure; 5. superconducting excitation winding support structure; 6. superconducting shielding layer; 7. air gap; 8. armature winding; 9. armature winding cooling structure; 10. non-magnetic stator teeth; 11. stator yoke; 12. first layer racetrack-type coil; 13. second layer racetrack-type coil; 14. third layer racetrack-type coil; 15. fourth layer racetrack-type coil; 16. fifth layer racetrack-type coil; 17. sixth layer racetrack-type coil. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0025] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings here can usually be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0026] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0027] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0028] like Figure 1 As shown, the present invention provides a non-magnetic stator tooth high-temperature superconducting synchronous condenser, comprising a motor shaft 1, a rotor yoke 2 and a superconducting shielding layer 6 coaxially arranged in sequence from the inside to the outside, a plurality of superconducting excitation windings 3 are arranged along the circumference of the rotor yoke 2 between the rotor yoke 2 and the superconducting shielding layer 6, each superconducting excitation winding 3 is connected to a superconducting excitation winding cooling structure 4, an armature winding 8 is arranged along the circumferential direction of the outer ring of the superconducting shielding layer 6, the armature winding 8 and the superconducting shielding layer 6 are arranged at intervals, a stator yoke 11 is coaxially arranged on the outer ring of the armature winding 8, and the contact surface ends of the motor shaft 1, the rotor yoke 2 and the stator yoke 11 are connected by a dovetail groove; the present application adopts The excitation winding structure is wound with a high-temperature superconducting tape, and a superconducting excitation winding cooling structure is arranged on the excitation winding to maintain the excitation winding in steady-state operation at a set temperature, thereby avoiding active power loss and temperature rise of the excitation winding. The superconducting excitation winding used in the present invention has a strong excitation ability, so that the air gap flux density of the high-temperature superconducting synchronous condenser is as high as 1.6T. Therefore, when the radial dimensions are roughly the same, the axial dimension of the high-temperature superconducting synchronous condenser of the present application can be greatly reduced. Under the condition of the same power, the axial dimension of the high-temperature superconducting synchronous condenser of the present application is about half of that of the existing synchronous condenser, which is conducive to the miniaturization of the synchronous condenser.

[0029] The superconducting excitation winding cooling structure specifically adopts liquid helium as the coolant for cooling. The superconducting excitation winding cooling structure adopts a shell structure made of heat-conducting material. The coil of the superconducting excitation winding 3 is wound on the surface of the shell structure, and the shell structure is tightly connected with the upper and lower surfaces of each layer of the runway-shaped coil; a coolant circulation inlet and outlet are arranged on the shell structure, and the circulation inlet and outlet on the shell structure are connected with an external pump group through a rotor rotating coupling coupler. The external pump group is used as the circulation power of the liquid helium to circulate the liquid helium in the shell structure, so as to maintain the working temperature of the superconducting excitation winding in a conduction cooling manner.

[0030] In the specific implementation of the present application, a shell structure made of stainless steel is adopted, which has a simple structure and good thermal conductivity.

[0031] The non-magnetic stator tooth high-temperature superconducting synchronous condenser of the embodiment of the present invention has a rotor yoke 2 coaxially arranged outside the motor shaft 1, and the superconducting excitation winding 3 is arranged between the rotor yoke 2 and the superconducting shielding layer 6 through the superconducting excitation winding support structure 5. The superconducting excitation winding support structure 5 is coaxially arranged on the outer ring of the rotor yoke 2. In the specific embodiment of the present application, the superconducting excitation winding support structure 5 is made of epoxy resin and is used for impregnating and curing the superconducting excitation winding 3. The superconducting excitation winding cooling structure 4 is connected to the superconducting excitation winding 3. The superconducting excitation winding cooling structure 4 is used to maintain the superconducting excitation winding 3 at a steady-state operating temperature of 30K, thereby forming a poleless boot-type superconducting rotor; the superconducting shielding layer 6 is coaxially arranged outside the superconducting excitation winding support structure 5.

[0032] In a specific implementation of the present application, the motor shaft 1 is made of 304 type high-strength stainless steel, and a fan is arranged at the end of the motor shaft 1 to enhance the convection heat dissipation capacity of the overall non-magnetic stator tooth high-temperature superconducting synchronous phase shifter.

[0033] Example 1 In a specific embodiment of the present application, a non-magnetic stator tooth high-temperature superconducting synchronous condenser is provided, comprising a motor shaft 1, a rotor yoke 2 and a superconducting shielding layer 6 which are coaxially arranged in sequence from the inside to the outside, a plurality of superconducting excitation windings 3 are arranged in a circumferential array along the rotor yoke 2 between the rotor yoke 2 and the superconducting shielding layer 6, each superconducting excitation winding 3 is connected to a superconducting excitation winding cooling structure 4, an armature winding 8 is arranged in a circumferential direction on the outer ring of the superconducting shielding layer 6, the armature winding 8 is arranged between the superconducting shielding layer 6 and the stator yoke 11 through a non-magnetic stator tooth 10, and the superconducting shielding layer 6 is circumferentially wrapped around the outside of the rotor yoke 2; an air gap 7 is provided between the armature winding 8 and the superconducting shielding layer 6. The armature winding 8 is arranged in a circumferential array inside the stator yoke 11; the armature winding 8 is a copper armature winding; as Figure 1 As shown in the partial enlarged view, each armature winding 8 includes two winding structure blocks, and the two winding structure blocks are arranged at intervals along the radial direction of the superconducting shielding layer 6. An armature winding cooling structure 9 is arranged on the outer ring of the two winding structure blocks, and the armature winding cooling structure 9 is passed through a circulating insulating oil to cool the copper armature winding 8; the two winding structure blocks distributed at a short distance in the non-magnetic stator tooth 10 can achieve rapid cooling under the action of the armature winding cooling structure 9, and the stator yoke 11 is coaxially arranged on the outside of the non-magnetic stator tooth 10 and is closely connected through the dovetail groove at the contact surface; the non-magnetic stator tooth 10 is made of epoxy resin. In the specific embodiment of the present application, 72 slots for placing the armature winding are arranged in the non-magnetic stator tooth 10.

[0034] In a specific implementation of the present application, an armature winding cooling structure 9 is provided on the outer ring of the two winding structure blocks. The armature winding cooling structure 9 adopts a frame-type structure. A cooling pipe is provided on the structural wall of the frame-type structure. A coolant for cooling is passed into the cooling pipe. The present application adopts oil circulation cooling for the armature winding. The cooling pipe of the frame-type structure uses circulating insulating oil to cool the armature winding through an external pump group; the frame-type structure serves as the basis of the cooling structure and provides a stable flow channel for the coolant. It has high strength and rigidity and can withstand various mechanical loads during the operation of the motor. The cooling pipes provided in the frame-type structure ensure that the coolant is evenly distributed throughout the armature winding, thereby achieving the best cooling effect.

[0035] In a specific embodiment of the present application, the rotor yoke 2 and the stator yoke 11 are both made of non-oriented cold-rolled silicon steel sheets. The specific preparation process is: select non-oriented cold-rolled silicon steel sheets with high magnetic permeability, low iron loss and good mechanical properties, and the selected non-oriented cold-rolled silicon steel sheets meet specific electromagnetic properties and mechanical strength requirements. The silicon steel sheets are quality inspected to ensure that they are defect-free, have few inclusions and have a smooth surface. Then, according to the design size and shape of the rotor yoke, the silicon steel sheets are accurately cut, and the cut silicon steel sheets are stacked in a predetermined direction and order; during the stacking process, it is necessary to ensure that the silicon steel sheets are arranged neatly and tightly, and avoid misalignment or warping. Then use a special clamping device or tool to press the stacked silicon steel sheets. The purpose of pressing is to ensure close contact between the silicon steel sheets to reduce magnetic resistance and leakage, and to improve the overall strength and stability of the yoke. While pressing, use a suitable fixing method such as welding, bolting, etc. to fix the silicon steel sheets together to form a complete rotor yoke.

[0036] In the specific embodiment of the present application, the rotor yoke 2 and the stator yoke 11 are both formed by laminating DW315-50 non-oriented cold-rolled silicon steel sheets with a thickness of 0.5 mm.

[0037] In one embodiment, the rotor of the superconducting synchronous condenser is provided with four superconducting excitation windings 3, and the rotor speed is 1500rpm; the superconducting excitation winding is a racetrack-shaped coil wound with REBCO high-temperature superconducting tape, which is stacked in an approximately sinusoidal shape. The six-layer coil is arranged on the superconducting excitation winding 3, and the six-layer racetrack-shaped coil is radially stacked in an approximately sinusoidal shape to form a single excitation pole. The racetrack-shaped coil is wound with REBCO high-temperature superconducting tape and is equipped with a superconducting excitation winding cooling structure; the racetrack-shaped coil used in the present application is a directional coil, and its shape is similar to a runway. The design of this coil increases the length of the straight part and reduces the length of the curved part, so it has unique advantages in application.

[0038] Example 2 In a specific embodiment of the present application, a non-magnetic stator tooth high-temperature superconducting synchronous condenser with a six-layer racetrack coil is provided, comprising a motor shaft 1, a rotor yoke 2 and a superconducting shielding layer 6 coaxially arranged in sequence from the inside to the outside, a plurality of superconducting excitation windings 3 are arranged along the circumference of the rotor yoke 2 between the rotor yoke 2 and the superconducting shielding layer 6, each superconducting excitation winding 3 is connected to a superconducting excitation winding cooling structure 4, an armature winding 8 is arranged along the circumferential direction on the outer ring of the superconducting shielding layer 6, the armature winding 8 is arranged at intervals between the armature winding 8 and the superconducting shielding layer 6, a stator yoke 11 is coaxially arranged on the outer ring of the armature winding 8, and the motor shaft 1 The contact surface ends of the rotor yoke 2 and the stator yoke 11 are connected by dovetail grooves; the superconducting excitation winding includes a first layer of racetrack-shaped coil 12, a second layer of racetrack-shaped coil 13, a third layer of racetrack-shaped coil 14, a fourth layer of racetrack-shaped coil 15, a fifth layer of racetrack-shaped coil 16 and a sixth layer of racetrack-shaped coil 17 which are coaxially arranged, and the inner circle winding radius of the first layer of racetrack-shaped coil 12 and the second layer of racetrack-shaped coil 13 is the same, the inner circle winding radius of the third layer of racetrack-shaped coil 14 and the fourth layer of racetrack-shaped coil 15 is the same, and the inner circle winding radius of the fourth layer of racetrack-shaped coil 15 and the fifth layer of racetrack-shaped coil 16 is the same.

[0039] In one embodiment, the superconducting excitation winding is equipped with a superconducting excitation winding cooling structure, and cold helium gas is passed through the superconducting excitation winding to maintain the superconducting excitation winding at a steady-state temperature of 30K.

[0040] In one embodiment, a superconducting shielding layer is made of 6063 aluminum alloy, which can effectively shield high-order harmonics from the stator side and slow down the rising speed of the short-circuit pulse magnetic field at the superconducting excitation winding.

[0041] In one embodiment, a cross-sectional area of ​​2.5 mm is used. 2 The copper armature winding made of Litz fine copper wire can reduce the eddy current loss caused by the armature winding being directly exposed to the high air gap magnetic field.

[0042] In one embodiment, the copper armature winding is equipped with an armature winding cooling structure, and insulating oil flows through the armature winding cooling structure. The current density of the copper armature winding can reach up to 10A / mm 2 .

[0043] In one embodiment, the non-magnetic stator teeth are made of epoxy resin and are tightly connected to the stator yoke via dovetail grooves at the contact surface.

[0044] In one embodiment, the rated no-load excitation current of the superconducting synchronous condenser is 349A, and the no-load air gap flux density is as high as 1.6T.

[0045] like Figure 3As shown, in another embodiment of the present application, a method for determining the distribution of superconducting excitation windings for a non-magnetic stator tooth high-temperature superconducting synchronous condenser is provided, wherein the non-magnetic stator tooth high-temperature superconducting synchronous condenser comprises a motor shaft 1, a rotor yoke 2 and a superconducting shielding layer 6 coaxially arranged in sequence from the inside to the outside, a plurality of superconducting excitation windings 3 are arranged along the circumference of the rotor yoke 2 between the rotor yoke 2 and the superconducting shielding layer 6, each superconducting excitation winding 3 is connected to a superconducting excitation winding cooling structure 4, an armature winding 8 is arranged along the circumferential direction on the outer ring of the superconducting shielding layer 6, the armature winding 8 is arranged at intervals with the superconducting shielding layer 6, a stator yoke 11 is coaxially arranged on the outer ring of the armature winding 8, and the contact surface ends of the motor shaft 1, the rotor yoke 2 and the stator yoke 11 are connected by a dovetail groove. Specifically, the following steps are included: S1, establish an equivalent magnetic circuit model of the superconducting synchronous condenser, and obtain the no-load excitation ampere-turns of a single magnetic pole through magnetic circuit calculation; Specifically, an equivalent magnetic circuit model of a superconducting synchronous condenser is established, the working magnetic flux density of each component of the condenser is given, and the magnetic resistance of each component is determined according to its magnetization characteristics; the no-load excitation ampere-turns of a single magnetic pole of the superconducting synchronous condenser is calculated based on the magnetic resistance and the working magnetic flux density.

[0046] S2, according to the operating characteristics of the superconducting synchronous condenser and the actual current-carrying performance of the superconducting tape, determine the rated no-load excitation current of the superconducting excitation winding; Calculation steps for rated no-load excitation current: According to the influence of the magnetic field at the end of the racetrack coil on the current-carrying capacity of the superconducting tape, plot the curve of the magnetic field at the end of the superconducting excitation winding changing with the excitation current and the curve of the critical current of a single turn of superconducting tape changing with the external magnetic field in the 30K temperature zone. Take the intersection of the two curves as the rated no-load excitation current.

[0047] S3, according to the no-load excitation ampere-turns of a single magnetic pole and the rated no-load excitation current, the total number of winding turns of the six-layer racetrack type coil is calculated, and the superconducting excitation winding is manufactured according to the total number of winding turns of the coil.

[0048] The calculation steps of the number of turns of the six-layer racetrack coil are as follows: a two-dimensional rectangular coordinate system is established with the location of the outermost turn of the bottom layer of the racetrack coil as the origin, and the initial coordinates of the outermost turn are extracted; the position of the outermost turn is calibrated by mapping it with a sinusoidal function shape in the region of [0,π / 2] and multiplying it by the magnification factor; the total number of turns of a single magnetic pole is evenly distributed to the six coils and the winding radius of the innermost turn of the 1st, 2nd, 3rd, 4th, 5th and 6th layers of coils is set to be the same, and the position of the innermost turn is calibrated; the number of turns of each layer of the racetrack coil is determined according to the coordinates of the innermost and outermost turns.

[0049] In a specific embodiment of the present application, along the radial direction of the motor shaft 1, from the outside to the inside, there are the first layer of racetrack-shaped coils 12, the second layer of racetrack-shaped coils 13, the third layer of racetrack-shaped coils 14, the fourth layer of racetrack-shaped coils 15, the fifth layer of racetrack-shaped coils 16 and the sixth layer of racetrack-shaped coils 17; the winding radius of the first layer of racetrack-shaped coils 12 and the second layer of racetrack-shaped coils 13, the third layer of racetrack-shaped coils 14 and the fourth layer of racetrack-shaped coils 15, the fifth layer of racetrack-shaped coils 16 and the sixth layer of racetrack-shaped coils 17 are set to be the same.

[0050] The number of winding turns of the first racetrack coil 12, the second racetrack coil 13, the third racetrack coil 14, the fourth racetrack coil 15, the fifth racetrack coil 16 and the sixth racetrack coil 17 are changed so that they are radially stacked in an approximately sinusoidal shape.

[0051] In a specific embodiment of the present application, the armature winding 8 includes three phases, namely, phase A, phase B and phase C, and is equipped with an armature winding cooling structure, in which flowing insulating oil flows, and the armature winding is immersed in the insulating oil of the cooling structure.

[0052] The synchronous condenser used in the prior art uses copper conductors to make the excitation winding, which is easy to cause large steady-state current loss and high temperature of the excitation winding when actually adjusting reactive power, which will reduce the operating efficiency and have a serious adverse effect on the inter-turn insulation of the excitation winding. The non-magnetic stator tooth high-temperature superconducting synchronous condenser structure proposed in the present invention uses REBCO high-temperature superconducting tape to wind the excitation winding, and is equipped with a superconducting excitation winding cooling structure. The superconducting excitation winding is cooled to a steady-state operating temperature of 30K by circulating cold helium. A poleless boot-type superconducting rotor is used, and the racetrack-type coil is impregnated and cured with epoxy resin and radially stacked in an approximately sinusoidal shape to form the excitation poles of the rotor. The armature winding is double-layered and short-distance distributed in the 72 slots of the non-magnetic stator teeth, and is equipped with an armature winding cooling structure to increase the current density. After forced oil circulation cooling, its maximum current density during steady-state operation is close to 10A / mm 2 The stator yoke and rotor yoke are both made of 0.5mm thick DW315-50 silicon steel sheets laminated together to reduce the iron loss of the yoke.

[0053] The present invention adopts a poleless shoe-type superconducting rotor structure, eliminates the rotor pole shoe, retains only the rotor yoke, and uses epoxy resin to impregnate and solidify the superconducting excitation winding, thereby reducing the weight of the superconducting synchronous condenser.

[0054] Furthermore, the present invention radially stacks the racetrack-shaped coils in a nearly sinusoidal shape, which can improve the air gap magnetic flux density distribution of the superconducting synchronous phase regulator, making it closer to a sine, thereby reducing the induced electromotive force harmonics of the armature winding.

[0055] The present invention adopts non-magnetic stator teeth and uses epoxy resin to make the stator teeth, which can effectively avoid the tooth harmonics and magnetic saturation problems caused by conventional ferromagnetic stator teeth.

[0056] The present invention adopts non-oriented cold-rolled silicon steel laminations with a thickness of 0.5 mm to manufacture the stator yoke and the rotor yoke, which can reduce the iron loss of the yoke and improve the operating efficiency of the superconducting synchronous phase shifter.

[0057] The present invention adopts a large physical air gap structure, which can reduce the synchronous reactance of the superconducting synchronous condenser to 1 / 3 of that of the conventional synchronous condenser, and significantly improves the reactive power regulation speed of the superconducting synchronous condenser.

[0058] The present invention adopts a single Litz thin copper wire with a diameter of about 1-1.5 mm to twist the armature winding, which can effectively reduce the eddy current loss of the copper armature winding under a high-frequency field.

[0059] The present invention adopts forced oil circulation to cool the copper armature winding. The maximum current density of the copper armature winding during steady-state operation is close to 10A / mm 2 .

[0060] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and disclosure of the invention. This application is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the following claims.

[0061] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

[0062] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A non-magnetic stator teeth high temperature superconducting synchronous condenser, characterized in that: The invention comprises a motor shaft (1), a rotor yoke (2) and a superconducting shielding layer (6) which are coaxially arranged in sequence from the inside to the outside; a plurality of superconducting excitation windings (3) are arranged in an array along the circumference of the rotor yoke (2) between the rotor yoke (2) and the superconducting shielding layer (6); each superconducting excitation winding (3) is connected to a superconducting excitation winding cooling structure (4); an armature winding (8) is arranged in an array along the circumferential direction on the outer ring of the superconducting shielding layer (6); the armature winding (8) and the superconducting shielding layer (6) are arranged at intervals; a stator yoke (11) is coaxially arranged on the outer ring of the armature winding (8); and the motor shaft (1), the rotor yoke (2) and the stator yoke (11) are connected at contact surface ends.

2. A non-magnetic stator tooth high temperature superconducting synchronous condenser according to claim 1, characterized in that: The superconducting excitation winding (3) is arranged between the rotor yoke (2) and the superconducting shielding layer (6) via a superconducting excitation winding support structure (5).

3. A non-magnetic stator tooth high temperature superconducting synchronous condenser according to claim 2, characterized in that: The superconducting excitation winding support structure (5) is made of epoxy resin and is used for impregnating and curing the superconducting excitation winding (3).

4. The non-magnetic stator teeth high temperature superconducting synchronous condenser according to claim 1, characterized in that: The armature winding (8) is arranged between the superconducting shielding layer (6) and the stator yoke (11) via non-magnetic stator teeth (10).

5. The non-magnetic stator teeth high temperature superconducting synchronous condenser according to claim 1, characterized in that: Each armature winding (8) comprises two winding structure blocks, and the two winding structure blocks are arranged at intervals along the radial direction of the superconducting shielding layer (6).

6. A non-magnetic stator tooth high temperature superconducting synchronous condenser according to claim 5, characterized in that: An armature winding cooling structure (9) is arranged on the outer rings of the two winding structure blocks.

7. The non-magnetic stator teeth high temperature superconducting synchronous condenser according to claim 1, characterized in that: The rotor yoke (2) and the stator yoke (11) are both made of non-oriented cold-rolled silicon steel sheets laminated together.

8. The non-magnetic stator teeth high temperature superconducting synchronous condenser according to claim 1, characterized in that: The superconducting excitation winding is made of racetrack-shaped coils wound with REBCO high-temperature superconducting tapes and stacked in an approximately sinusoidal shape.

9. A method for determining the distribution of superconducting excitation windings for a non-magnetic stator tooth high temperature superconducting synchronous condenser according to any one of claims 1 to 8, characterized in that: The following steps are involved: An equivalent magnetic circuit model of a superconducting synchronous condenser is established, and the no-load excitation ampere-turns of a single magnetic pole are obtained through magnetic circuit calculation. According to the operating characteristics of the superconducting synchronous condenser and the actual current-carrying performance of the superconducting tape, the rated no-load excitation current of the superconducting excitation winding is determined; According to the no-load excitation ampere-turns of a single magnetic pole and the rated no-load excitation current, the total number of winding turns of the six-layer racetrack coil is calculated.

10. The method for determining the distribution of superconducting excitation windings according to claim 9, characterized in that: The curve of the magnetic field at the end of the superconducting excitation winding changing with the excitation current and the curve of the critical current of a single turn of superconducting tape changing with the external magnetic field in the 30K temperature range are plotted, and the intersection of the two curves is taken as the rated no-load excitation current.

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