Stator for generator, generator and wind generating set
By setting windings with different insulation properties on the ring stator core of the generator and optimizing the stator slot design, the problem of stator winding interlayer discharge is solved, the insulation and reliability are improved, and stable operation under high rated voltages is achieved. Direct grid connection.
Patent Information
- Application Number
- CN202420628784.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-27
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2034-03-27
AI Technical Summary
As the capacity of the generator set increases, the rated voltage of the stator winding increases, resulting in the air between adjacent stator winding outlets being easily broken down, and interlayer discharge occurs, and the prior art is difficult to ensure sufficient insulation margin. .
The winding is set on the annular stator core. By setting the insulation difference of insulating materials in different areas of the out-of-phase and in-phase windings, the design of the stator slot is optimized, the insulation in specific areas is improved, the interlayer discharge is prevented, and the stator and high-voltage switches are prevented. Protective devices are provided between the cabinets.
It effectively improves the insulation of the stator winding, prevents interlayer discharge, enhances the reliability of the stator, allows direct connection to the power grid at high rated voltages, avoids additional transformer settings, and provides protection against abnormal voltages.
Smart Images
Figure CN222147258U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a stator for a generator, a generator and a wind power generator set, in particular to a stator for a generator, a generator and a wind power generator set with improved insulation. Background Art
[0002] As the capacity of generator sets continues to increase, the rated voltage of the stator winding continues to increase. The increase in the voltage of the stator winding can easily cause the air between the outlet wires of adjacent stator windings to be broken down and cause interlayer discharge.
[0003] The interlayer discharge of the stator winding occurs between the outlets of adjacent stator windings in a running high-voltage generator. In order to ensure sufficient insulation margin, there is a sufficient space gap between the outlets of adjacent stator windings. When the potential of the outlet of the stator winding increases due to various reasons, until the potential difference between the two adjacent stator windings is large enough and the field strength generated by the potential exceeds the breakdown field strength of the air gap, the air between the outlets of adjacent stator windings can be easily broken down and develop into interlayer discharge. Utility Model Content
[0004] The utility model provides a stator for a generator, a generator and a wind power generator set to solve the technical problem of low insulation of the existing stator for the generator.
[0005] According to one aspect of the utility model, a stator for a generator is provided, having a winding arranged on an annular stator core, wherein the insulation material of the outgoing wire portion of the half-turn of the winding coil of the winding corresponding to the portion passing through a first stator slot of the annular stator core has higher insulation properties than the insulation material of the other half-turn, wherein the first stator slot is located in the area between the input end and the output end of adjacent out-of-phase windings, and the insulation material of the outgoing wire portion of the half-turn of the winding coil of the winding corresponding to the portion passing through a second stator slot of the annular stator core has lower insulation properties than the insulation material of the other half-turn, wherein the second stator slot is located in the area between the input end and the output end of adjacent in-phase windings.
[0006] According to the utility model, the winding includes an A-phase winding, a B-phase winding and a C-phase winding. For any one of the A-phase winding, the B-phase winding and the C-phase winding, when the center of the phase winding is at the maximum value of the induced magnetic flux, the outgoing wire portion of the phase annular coil of the phase winding close to its input end and the outgoing wire portion of the phase annular coil of the phase winding close to its output end intersect at a first intersection, and the first intersection is the point where the voltage difference is the largest among the intersections of the outgoing wire portions of the phase winding.
[0007] According to the utility model, the winding includes an A-phase winding, a B-phase winding and a C-phase winding, the coil at the input end of the A-phase winding intersects with the coil at the input end of the B-phase winding after 6.5 overlapping windings and 0.5 overlapping windings at a second intersection, the coil at the input end of the C-phase winding intersects with the coil at the input end of the A-phase winding after 6.5 overlapping windings and 0.5 overlapping windings at a third intersection, the coil at the input end of the B-phase winding intersects with the coil at the input end of the C-phase winding after 6.5 overlapping windings and 0.5 overlapping windings at a fourth intersection, wherein the second intersection, the third intersection and the fourth intersection respectively correspond to the maximum points of the potential difference between the A-phase winding and the B-phase winding, the C-phase winding and the A-phase winding, and the B-phase winding and the C-phase winding.
[0008] According to the utility model, the winding includes an A-phase winding, a B-phase winding and a C-phase winding. The coil at the input end of the A-phase winding intersects with the coil at the input end of the B-phase winding after 22.5 overlapping windings and 0.5 overlapping windings at the fifth intersection. The coil at the input end of the C-phase winding intersects with the coil at the input end of the A-phase winding after 22.5 overlapping windings and 0.5 overlapping windings at the sixth intersection. The coil at the input end of the B-phase winding intersects with the coil at the input end of the C-phase winding after 22.5 overlapping windings and 0.5 overlapping windings at the seventh intersection. The fifth intersection, the sixth intersection and the seventh intersection respectively correspond to the minimum points of the potential difference between the A-phase winding and the B-phase winding, the C-phase winding and the A-phase winding, and the B-phase winding and the C-phase winding.
[0009] According to the utility model, the total number of stator slots can be greater than or equal to 60, and the number of parallel branches of the winding can be 1.
[0010] According to another aspect of the present invention, a generator is also provided, comprising a rotor and the above-mentioned stator.
[0011] According to another aspect of the utility model, a wind turbine generator set is also provided, which includes the above-mentioned generator, the cables led out from the stator side of the generator are directly connected to the power grid via the high-voltage switch cabinet, and the cables led out from the rotor side of the generator are connected to the converter cabinet, the switch cabinet, the transformer and the power grid in sequence, wherein a protection device is arranged between the stator of the generator and the high-voltage switch cabinet.
[0012] According to the utility model, the output voltage level of the stator side can be 35kV.
[0013] According to the utility model, the high-voltage switch cabinet can be a vacuum circuit breaker.
[0014] According to the utility model, the protection device may include an RC circuit and a lightning arrester connected in parallel.
[0015] According to the stator for a generator of the utility model, the insulation of the insulating material of the parts of the winding coils of each phase of the stator winding that require high insulation is accurately strengthened according to the potential difference boundaries of the parts of the outgoing wire parts of the stator winding, thereby preventing interlayer discharge between the outgoing wire parts of the stator winding, improving the reliability of the stator winding, and further improving the reliability of the stator.
[0016] According to the generator set of the utility model, since the insulation of the stator winding of the generator is improved, interlayer discharge will not occur between the outgoing wire parts of the stator winding even at a high rated voltage. Therefore, the generator including the stator winding according to the utility model can be directly connected to the power grid without the need to set up a transformer between the generator and the power grid.
[0017] According to the generator set of the utility model, since a protection device is provided between the stator of the generator and the high-voltage switch cabinet, it is possible to further prevent the generator from being damaged due to abnormal voltage. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The above and / or other purposes and advantages of the present invention will become more apparent through the following description of the embodiments in conjunction with the accompanying drawings, in which:
[0019] Figure 1 A schematic diagram of a stator for a generator according to an exemplary embodiment of the present utility model is shown, wherein an input end and an output end of a stator winding are shown;
[0020] Figure 2 Shows Figure 1 A schematic diagram of a planar unfolding of a wound coil of a stator winding;
[0021] Figure 3 Shows Figure 2 Schematic diagram of the decomposition of each phase winding of the stator winding;
[0022] Figure 4 is an equivalent circuit diagram showing a high voltage generator;
[0023] Figure 5 is a schematic diagram of a toroidal coil assembly;
[0024] Figure 6 is a schematic diagram of a wind turbine generator set according to an exemplary embodiment of the present utility model;
[0025] Figure 7 yes Figure 6 Specific structural diagram of the protection device. DETAILED DESCRIPTION
[0026] Now, an exemplary embodiment of the present invention will be described more fully with reference to the accompanying drawings. However, the embodiments of the present invention should not be understood to be limited to the embodiments described herein. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted.
[0027] Figure 1 A schematic diagram of a stator for a generator according to an exemplary embodiment of the present utility model is shown, wherein an input end and an output end of a stator winding are shown; Figure 2 Shows Figure 1 A schematic diagram of a planar unfolding of a wound coil of a stator winding; Figure 3 Shows Figure 2 Schematic diagram of the decomposition of each phase winding of the stator winding.
[0028] Reference Figures 1 to 3 According to an exemplary embodiment of the utility model, a stator for a generator has a winding arranged on an annular stator core 10, wherein the insulation material of the outlet portion of the half-turn of the winding coil of the winding corresponding to the portion passing through the first stator slot of the annular stator core 10 is higher than the insulation material of the other half-turn, wherein the first stator slot is located in the area between the input end and the output end of the adjacent out-of-phase winding, and the insulation material of the outlet portion of the half-turn of the winding coil of the winding corresponding to the portion passing through the second stator slot of the annular stator core is lower than the insulation material of the other half-turn, wherein the second stator slot is located in the area between the input end and the output end of the adjacent in-phase winding.
[0029] Specifically, Figures 1 to 3 As shown, a stator for a generator according to an exemplary embodiment of the utility model includes: the above-mentioned annular stator core 10, including a plurality of slot groups formed along the circumferential direction, each slot group including a continuously arranged A-phase slot group, a B-phase slot group and a C-phase slot group, and the plurality of slot groups including a plurality of stator slots; a stator winding, including an A-phase winding, a B-phase winding and a C-phase winding, wherein the A-phase winding includes an input terminal U and an output terminal X, the B-phase winding includes an input terminal V and an output terminal Y, and the C-phase winding includes an input terminal W and an output terminal Z.
[0030] Among them, in the circumferential direction of the annular stator core 10, the input terminal U, the output terminal Z, the input terminal W, the output terminal Y, the input terminal V and the output terminal X are arranged in sequence to divide the annular stator core 10 into the input terminal U to output terminal Z section, the output terminal Z to input terminal W section, the input terminal W to output terminal Y section, the output terminal Y to input terminal V section, the input terminal V and output terminal X section and the output terminal X to input terminal U section in the circumferential direction.
[0031] Among them, the A-phase winding includes multiple A-phase annular coils, the B-phase winding includes multiple B-phase annular coils, and the C-phase winding includes multiple C-phase annular coils. The insulation material of the half-turn of the A-phase annular coil, the B-phase annular coil, and the C-phase annular coil corresponding to the part of the stator slot passing through the section from the input end U to the output end Z, the section from the input end W to the output end Y, and the section from the input end V to the output end X has higher insulation than the insulation material of the other half-turn of the A-phase annular coil, the B-phase annular coil, and the C-phase annular coil. The insulation material of the half-turn of the A-phase annular coil, the B-phase annular coil, and the C-phase annular coil corresponding to the part of the stator slot passing through the section from the output end Z to the input end W, the section from the output end Y to the input end V, and the section from the output end X to the input end U has lower insulation than the insulation material of the other half-turn of the A-phase annular coil, the B-phase annular coil, and the C-phase annular coil.
[0032] Optionally, the insulation of the insulating material can also be controlled by controlling the thickness of the insulating material. For example, the insulating material of the half-turn of the A-phase annular coil, the B-phase annular coil, and the C-phase annular coil corresponding to the portion passing through the stator slots in the section from the input end U to the output end Z, the section from the input end W to the output end Y, and the section from the input end V to the output end X is thicker than the insulating material of the other half-turn of the A-phase annular coil, the B-phase annular coil, and the C-phase annular coil, and the insulating material of the half-turn of the A-phase annular coil, the B-phase annular coil, and the C-phase annular coil corresponding to the portion passing through the stator slots in the section from the output end Z to the input end W, the section from the output end Y to the input end V, and the section from the output end X to the input end U is thinner than the insulating material of the other half-turn of the A-phase annular coil, the B-phase annular coil, and the C-phase annular coil.
[0033] As the capacity of the generator set increases, the rated voltage of the stator winding increases, which can easily lead to the breakdown of the air between the outlets of adjacent stator windings and interlayer discharge. In order to prevent interlayer discharge between the outlets of the stator windings, it is necessary to optimize the insulation material of the stator windings, especially the insulation material of the outlets. The utility model takes a high-voltage wind turbine, for example, a 35kV doubly-fed wind turbine as an embodiment, and obtains the potential extreme difference boundary between the outlets of the stator windings of the high-voltage wind turbine by calculation, thereby effectively improving the insulation of the stator windings and obtaining a stator for the wind turbine with excellent insulation.
[0034] Table 1 below shows the basic parameters of a 35kV doubly-fed wind turbine generator.
[0035] Table 1
[0036]
[0037] The relationship between the potential at each point of the stator winding and the potential at both ends (i.e., ends) of the stator winding core
[0038] Figure 4 is an equivalent circuit diagram showing a high voltage generator, for example, an equivalent circuit diagram of a 35 kV double-fed wind turbine generator, referring to Figure 4 , the voltage balance equation (1) of the 35 kV doubly-fed wind turbine generator can be obtained.
[0039] (1)
[0040] in, U 1. U 2 are the voltage phasors of the stator and rotor respectively, E is the induced electromotive force phasor of the magnetic field in the air gap, I 1. I 2. I m are the stator current, rotor current and excitation current phasors respectively, r 1, r 2 are the resistances of the stator and rotor respectively, x 1σ , x 2σ and x m They are the leakage reactance and magnetizing reactance of the stator and rotor respectively, j is the imaginary part, and s is the slip rate.
[0041] It can be seen from the above formula that when the stator voltage U 1. When the size is constant, the potential of the stator winding is related to the resistance of the stator winding. r 1 and stator leakage reactance x 1σ When analyzing the potential of the stator winding of a high-voltage double-fed wind turbine generator, the stator current is small and the resistance of the stator winding is r 1 is not too large, the voltage drop caused by the resistance of the stator winding is not large and can be ignored. According to the design of the motor, the stator leakage reactance (except for the motor with 2p=2) generally accounts for a small proportion. Therefore, when analyzing the potential of the stator winding, it can be regarded that the potential of each point of the stator winding is equal to that of the outlet of the stator winding core, that is, E Approximately equal to U 1.
[0042] Calculation of the maximum potential difference between different toroidal coil groups of the same-phase winding
[0043] Taking the A-phase winding as an example, when the center of the A-phase winding is at the maximum value of the induced magnetic flux, its induced electromotive force reaches the maximum peak value. At this time, the outgoing wire portion of the A-phase ring coil near the input terminal U of the A-phase winding intersects with the outgoing wire portion of the A-phase ring coil near the output terminal X at the first intersection O, as shown in FIG. Figure 3As shown, the first intersection O is the point where the voltage difference is the largest among the intersections of the outgoing wires of the A-phase stator winding in theory. Ignoring the impedance of the outgoing wires of the A-phase winding, the potential difference of the first intersection O can be calculated as:
[0044] (2)
[0045] Among them, U N is 35 kV, p is the number of poles, q is the number of slots per pole and per phase. In this exemplary embodiment, p is 4 and q is 6.
[0046] like Figure 3 As shown, the other six intersection points R on both sides of the first intersection point O are the points with the largest potential difference among the intersection points of the outgoing wires between the remaining A-phase annular coil groups. Since none of them are linked with the input terminal U and the output terminal X, the potential difference at each intersection point R is the same according to the principle of potential superposition. The potential difference at this point is calculated to be:
[0047] ……(3)
[0048] U N is 35 kV, p is the number of poles, q is the number of slots per pole and per phase. In this exemplary embodiment, p is 4 and q is 6.
[0049] Calculation of the maximum potential difference between the same toroidal coil groups of the same phase winding
[0050] Figure 5 is a schematic diagram of a toroidal coil group. For example, taking the A-phase toroidal coil group of the A-phase winding as an example, according to the principle of potential superposition, the intersection point P is the point with the largest potential difference in the A-phase toroidal coil group. The potential difference of the intersection point P is calculated as:
[0051] (4)
[0052] U N is 35 kV, p is the number of poles, q is the number of slots per pole and per phase. In this exemplary embodiment, p is 4 and q is 6.
[0053] Calculation of the maximum potential difference between out-of-phase windings
[0054] Compared with the same-phase winding, there is a higher potential difference between the different-phase windings, which causes the oblique electric field between the different-phase windings (the electric field generated in the gap between the winding coils due to the potential difference of the part of the outlet of the adjacent winding coils other than the straight section). In severe cases, corona discharge will continuously corrode the surface of the wire rod, causing hole-shaped defects until the insulation fails. The maximum potential difference between the different-phase windings occurs between the two-phase winding terminals, but there is no intersection between the outlets of the two terminal windings. Assuming that the direction of the potential decrease of the A-phase winding is followed, the intersection of the input end of the first annular coil of the A-phase winding and the outlet of the annular coil of the B-phase winding close to the terminal is found, then this point is judged to be the point with the maximum voltage difference between the different-phase windings.
[0055] In this exemplary embodiment, when the number of parallel branches per phase of the stator winding is equal to 1, the intersection points 1, 2, and 3 of the out-of-phase windings can be obtained (see Figure 2 , including the second intersection 1, the third intersection 2 and the fourth intersection 3) at the peak voltage, the maximum theoretical voltage difference is:
[0056] (5)
[0057] Intersections 1, 2, and 3 correspond to the maximum points of potential difference between the A-phase winding and the B-phase winding, the C-phase winding and the A-phase winding, and the B-phase winding and the C-phase winding, respectively. Taking the potential difference calculation method of intersection 1 as an example, the coil at the input end U of the A-phase winding intersects at intersection 1 after 6.5 lap windings and the coil at the input end V of the B-phase winding intersects at intersection 1 after 0.5 lap windings. Therefore, the potential difference value of intersection 1 is the largest.
[0058] The intersections a, b, c (including the fifth intersection a, the sixth intersection b and the seventh intersection c) correspond to the points of minimum potential difference between the A-phase winding and the B-phase winding, the C-phase winding and the A-phase winding, and the B-phase winding and the C-phase winding, respectively. Taking the potential difference calculation method of the intersection a as an example, the coil at the input end U of the A-phase winding intersects at the intersection a after 22.5 overlaps and the coil at the input end V of the B-phase winding intersects at the intersection a after 0.5 overlaps, so the potential difference at the intersection a is the smallest.
[0059] (6)
[0060] In summary, by analyzing and calculating the maximum potential difference between the in-phase winding and the out-of-phase winding at the outlet of the stator winding, it can be seen that the intersection points of the maximum potential difference of the stator winding are all near the input end of the three-phase winding. Through analysis and calculation, it can be seen that the potential difference of the stator winding is evenly distributed in the circumferential direction of high → low → high, and the maximum peak value of the potential in the distribution interval is 42.28kV→25.8kV.
[0061] The following conclusions can be drawn from the above analysis and calculation: a) The maximum voltage difference between the upper and lower layers of the same-phase winding at the intersection of the adjacent core outlets is much smaller than the maximum voltage difference between the out-of-phase windings. Therefore, when studying the influence of the limit of the electric field size of the stator winding of the high-voltage motor on the insulation, it is necessary to pay attention to the voltage at the intersection of the maximum voltage difference between the out-of-phase windings, and improve the insulation of the weak insulation area; b) Because the number of parallel branches of the high-voltage motor is small or the number of parallel branches is 1, when the resistance of the stator winding and the leakage reactance of the outlet are ignored, the maximum voltage difference between the out-of-phase windings is slightly smaller than the rated voltage peak; c) After analyzing and calculating the potential difference of the stator winding, the area with higher potential difference is distributed at the three-phase incoming line end. It can be found that the distribution law of the potential difference is high → low → high, and it is evenly distributed in the circumferential direction.
[0062] Based on the potential difference boundary between the outgoing wire parts of the stator winding determined by the above analysis of the potential difference at each point of the stator winding of the 35kV doubly fed wind generator, a stator for a wind generator according to the utility model is provided, and the insulation of the stator winding of the stator is improved, thereby avoiding interlayer discharge between the outgoing wire parts of the stator winding and improving the reliability of the stator winding.
[0063] Optionally, the thickness of the insulating material of the winding outlet portion is thicker or the insulation property is better than the insulating material of the winding (i.e., the stator winding) disposed in the stator slot. That is, according to the stator for the generator of the utility model, the insulation property of the stator winding can also be improved by adjusting the thickness or insulation property of the insulating material of the winding portion disposed in the stator slot and the insulating material of the winding outlet portion.
[0064] Optionally, the total number of stator slots is greater than or equal to 60, and the number of parallel branches of the stator winding is 1.
[0065] According to the utility model, a generator is also provided, which comprises a rotor and the above-mentioned stator.
[0066] According to the utility model, a wind turbine generator set is also provided. Figure 6 is a schematic diagram of a wind turbine generator set according to an exemplary embodiment of the present utility model, such as Figure 6 As shown, the wind turbine generator set includes the above-mentioned generator 100, the cables led out from the stator side of the generator 100 are directly connected to the power grid 600 via the high-voltage switch cabinet 200, and the cables led out from the rotor side of the generator 100 are connected to the converter cabinet 400, the switch cabinet 700, the transformer 500 and the power grid 600 in sequence, wherein a protection device 300 is arranged between the stator of the generator 100 and the high-voltage switch cabinet 200.
[0067] Optionally, the stator side output voltage level is 35kV.
[0068] Optionally, the high-voltage switch cabinet 200 is a vacuum circuit breaker.
[0069] Figure 7 yes Figure 6 The specific structure diagram of the protection device is as follows: Figure 7 As shown, optionally, the protection device 300 may include an RC circuit 310 and a lightning arrester 320 connected in parallel.
[0070] According to the stator for a generator of the utility model, the insulation of the insulating material of the parts of the winding coils of each phase of the stator winding that require high insulation is accurately strengthened according to the potential difference boundaries of the parts of the outgoing wire parts of the stator winding, thereby preventing interlayer discharge between the outgoing wire parts of the stator winding, improving the reliability of the stator winding, and further improving the reliability of the stator.
[0071] According to the generator set of the utility model, since the insulation of the stator winding of the generator is improved, interlayer discharge will not occur between the outgoing wire parts of the stator winding even at a high rated voltage. Therefore, the generator including the stator winding according to the utility model can be directly connected to the power grid without the need to set up a transformer between the generator and the power grid.
[0072] According to the generator set of the utility model, since a protection device is provided between the stator of the generator and the high-voltage switch cabinet, it is possible to further prevent the generator from being damaged due to abnormal voltage.
[0073] In the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.
[0074] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.
[0075] For the sake of convenience, directional terms such as front, back, up, down, horizontal, and vertical are used to describe the structure and operation method of the device, but the setting direction of the device is not limited to this. The device can be flipped front to back, upside down, or positioned at other angles.
[0076] The features, structures or characteristics described in the utility model can be combined in one or more embodiments in any suitable manner. In the above description, many specific details are provided to provide a full understanding of the embodiments of the utility model. However, those skilled in the art will appreciate that the technical solution of the utility model can be practiced without one or more of the specific details, or other methods, components, materials, etc. can be adopted. In other cases, known structures, materials or operations are not shown or described in detail to avoid blurring the various aspects of the utility model.
Claims
1. A stator for a generator, having a winding arranged on an annular stator core (10), characterized in that: The insulation material of the lead-out portion of the half-turn of the winding coil of the winding corresponding to the portion passing through the first stator slot of the annular stator core (10) has higher insulation properties than the insulation material of the other half-turn, wherein the first stator slot is located in the area between the input end and the output end of the adjacent out-of-phase winding, and the insulation material of the lead-out portion of the half-turn of the winding coil of the winding corresponding to the portion passing through the second stator slot of the annular stator core (10) has lower insulation properties than the insulation material of the other half-turn, wherein the second stator slot is located in the area between the input end and the output end of the adjacent in-phase winding.
2. The stator for a generator according to claim 1, characterized in that: The winding includes an A-phase winding, a B-phase winding and a C-phase winding. For any one of the A-phase winding, the B-phase winding and the C-phase winding, when the center of the phase winding is at the maximum value of the induced magnetic flux, the outgoing wire portion of the annular coil of the phase winding close to its input end and the outgoing wire portion of the annular coil of the phase winding close to its output end intersect at a first intersection, and the first intersection is the point with the largest voltage difference among the intersections of the outgoing wire portions of the phase winding.
3. The stator for a generator according to claim 1, characterized in that: The winding includes an A-phase winding, a B-phase winding and a C-phase winding. The coil at the input end of the A-phase winding intersects with the coil at the input end of the B-phase winding after 6.5 lap windings and 0.5 lap windings at a second intersection. The coil at the input end of the C-phase winding intersects with the coil at the input end of the A-phase winding after 6.5 lap windings and 0.5 lap windings at a third intersection. The coil at the input end of the B-phase winding intersects with the coil at the input end of the C-phase winding after 6.5 lap windings and 0.5 lap windings at a fourth intersection. The second intersection, the third intersection and the fourth intersection respectively correspond to the maximum points of the potential difference between the A-phase winding and the B-phase winding, the C-phase winding and the A-phase winding, and the B-phase winding and the C-phase winding.
4. The stator for a generator according to claim 1, characterized in that: The winding includes an A-phase winding, a B-phase winding and a C-phase winding. The coil at the input end of the A-phase winding intersects with the coil at the input end of the B-phase winding after 22.5 lap windings and 0.5 lap windings at the fifth intersection. The coil at the input end of the C-phase winding intersects with the coil at the input end of the A-phase winding after 22.5 lap windings and 0.5 lap windings at the sixth intersection. The coil at the input end of the B-phase winding intersects with the coil at the input end of the C-phase winding after 22.5 lap windings and 0.5 lap windings at the seventh intersection. The fifth intersection, the sixth intersection and the seventh intersection respectively correspond to the minimum points of the potential difference between the A-phase winding and the B-phase winding, the C-phase winding and the A-phase winding, and the B-phase winding and the C-phase winding.
5. The stator for a generator according to claim 1, characterized in that: The total number of stator slots is greater than or equal to 60, and the number of parallel branches of the winding is 1.
6. A generator, characterized in that: The generator comprises a rotor and a stator according to any one of claims 1 to 5.
7. A wind turbine generator set, characterized in that: The wind turbine generator set comprises the generator (100) as claimed in claim 6, wherein the cables led out from the stator side of the generator (100) are directly connected to the power grid (600) via the high-voltage switch cabinet (200), and the cables led out from the rotor side of the generator (100) are connected to the converter cabinet (400), the switch cabinet (700), the transformer (500) and the power grid (600) in sequence, wherein a protection device (300) is arranged between the stator of the generator (100) and the high-voltage switch cabinet (200).
8. The wind turbine generator set according to claim 7, characterized in that: The output voltage level on the stator side is 35kV.
9. The wind turbine generator set according to claim 7, characterized in that: The high-voltage switch cabinet (200) is a vacuum circuit breaker.
10. The wind turbine generator set according to claim 7, characterized in that: The protection device (300) comprises an RC circuit (310) and a lightning arrester (320) connected in parallel.