360-slot and 28-pole symmetrical eight-branch three-phase wave winding connection method

Abstract

The invention discloses a 360-slot and 28-pole symmetrical eight-branch winding connection method, and relates to the field of alternating current windings. The invention aims to solve the problem that an existing 360-slot 28-pole motor does not have symmetrical eight branches. All the slots are sequenced according to the electrical angle sequence, the winding is divided into six phase belts A, Z, B, X, C and Y according to the electrical angle, each phase belt occupies the electrical angle of 60 degrees, and the three-phase symmetry is ensured. The motor is divided into two unit motors according to the electrical angle coincidence condition, four branches are formed in each unit motor, and bars between long jumper wires in corresponding branch windings are exchanged between the two unit motors, so that the number of jumper points is reduced, a wiring scheme available for engineering is obtained, and the motor is a three-phase symmetrical eight-branch winding.

Description

Technical Field

[0001] The present invention belongs to the field of AC windings, and in particular relates to a connection method for a 360-slot, 28-pole, symmetrical, eight-branch three-phase wave winding. Background Art

[0002] The stator winding is an important component for realizing electromechanical energy conversion, and directly affects the various performances of the motor. According to the traditional AC motor winding theory, the number of parallel branches of the stator winding a must be a factor of the number of motor poles 2p, that is, 2p / a is an integer. Therefore, for a twenty-eight-pole motor, there is no 8-branch design. However, for large-capacity generators, such as hydro-turbine generators above 700MW, it is more appropriate to design the stator winding into 8 branches. On the one hand, the stator slot current can be controlled within the design experience range of air-cooled units, and on the other hand, the stator voltage can be reduced, reducing the difficulty of stator winding insulation design.

[0003] In the prior art, all slots are divided into six phase belts of A, Z, B, X, C, and Y according to the slot potential angle. Each phase belt occupies a phase belt width of 60 degrees, among which A, B, and C phase belts are called positive phase belts, and X, Y, and Z phase belts are called negative phase belts. One positive and one negative form a phase winding, that is, the A phase belt and the X phase belt constitute the A phase winding, the B phase belt and the Y phase belt constitute the B phase winding, and the C phase belt and the Y phase belt constitute the C phase winding. The potential vectors of each phase winding differ by 120 degrees to form a three-phase symmetrical winding. Each phase winding uses a pole-phase group or a unit motor (0.5 unit motor when the fractional slot denominator is an odd number) as the minimum unit of the branch. The number of branch minimum units is at most equal to the number of motor poles. The branch minimum units are combined in series and parallel to form each branch. The synthetic potential vector of each branch is required to be equal in size and phase, that is, the branch minimum units contained in each branch are required to be equal. At this time, the number of branches that can be formed must be a factor of the number of poles.

[0004] For a twenty-eight-pole motor, there are at most 28 branch minimum units. The number of symmetrical branches that can be formed by these branch minimum units through series and parallel connection is: 1, 2, 4, 7, 18, 28. It can be seen that there is no 8-branch solution. If it is connected into 8 branches according to the traditional method, then the number of branch minimum units contained in each branch is not equal, the amplitude and phase of the synthetic potential of each branch are evenly distributed, and each branch is asymmetrical. There must be branch circulation between the branches, which will cause heating of the stator winding and increased vibration of the unit. Summary of the invention

[0005] The present invention aims to solve the above-mentioned problems existing in the prior art and provides a method for connecting a three-phase wave winding with 360 slots, 28 poles and symmetrical eight branches. The present invention uses wire rods as the smallest unit for forming branches, and each branch is connected by the same number of wire rods. The synthetic potential amplitudes and phases of the eight branches are equal, the branch windings are symmetrical, and there is no circulating current between the branches.

[0006] A connection method for a three-hundred-sixty-slot, twenty-eight-pole, eight-branch symmetrical three-phase wave winding, the connection method specifically comprising:

[0007] S1. All slots are numbered from 1 to 360 in sequence, with slot 1 as the reference position, i.e., 0 degrees, the electrical angles of all slots are calculated, and the slot numbers are rearranged in ascending order of electrical angles to form an electrical angle sequence. For a 360-slot 28-pole motor, the electrical angles overlap in pairs, and all slots can be divided into two completely identical parts. The first part contains slot numbers from 1 to 180, which is called unit motor 1, and the second part contains slot numbers from 181 to 360, which is called unit motor 2;

[0008] S2. Divide all slots into six phase bands of A, Z, B, X, C, and Y according to the electrical angle sequence. The slot number in the electrical angle interval [0, 60) is the A phase band, and so on. The slot number in the interval [60, 120) is the Z phase band, the slot number in the interval [120, 180) is the B phase band, the slot number in the interval [180, 240) is the X phase band, the slot number in the interval [240, 300) is the C phase band, and the slot number in the interval [300, 360) is the Y phase band. The slots of the same electrical angle of the two unit motors are divided into the same phase band. Among them, the A, B, and C phase bands are called positive phase bands, and the X, Y, and Z phase bands are called negative phase bands. One positive and one negative form a phase winding, that is, the A phase band and the X phase band form the A phase winding, the B phase band and the Y phase band form the B phase winding, and the C phase band and the Y phase band form the C phase winding. The amplitude of the potential vector of the three-phase winding of A, B, and C is equal, and the phase difference is 120 degrees.

[0009] S3, according to the electrical angle sequence, the phase slots in the unit motor 1 are divided into odd slots and even slots, the first branch of the A, B, and C phase windings is composed of the upper wire rods of the positive phase with odd slots and the lower wire rods of the negative phase with even slots, the second branch is composed of the lower wire rods of the positive phase with odd slots and the upper wire rods of the negative phase with even slots, the third branch is composed of the upper wire rods of the positive phase with even slots and the lower wire rods of the negative phase with odd slots, and the fourth branch is composed of the lower wire rods of the positive phase with even slots and the upper wire rods of the negative phase with odd slots;

[0010] Similarly, each phase slot in the unit motor 2 is divided into odd-numbered slots and even-numbered slots. The 5th branch of the A, B, and C phase windings is composed of the upper wire rods of the positive phase with odd-numbered slots and the lower wire rods of the negative phase with even-numbered slots, the 6th branch is composed of the lower wire rods of the positive phase with odd-numbered slots and the upper wire rods of the negative phase with even-numbered slots, the 7th branch is composed of the upper wire rods of the positive phase with even-numbered slots and the lower wire rods of the negative phase with odd-numbered slots, and the 8th branch is composed of the lower wire rods of the positive phase with even-numbered slots and the upper wire rods of the negative phase with odd-numbered slots; in this way, a three-phase symmetrical 8-branch winding is formed.

[0011] During actual wiring, the electrical angle sequence is followed, starting from the first wire rod, and connected in sequence in an up-to-down manner. If necessary, jumper connection is required. Each branch contains 3 jumper points, and there are 72 jumper points in total for three-phase eight branches. The jumper connection is achieved using short copper rings.

[0012] Furthermore, in order to reduce the jumper points and obtain an engineering feasible solution, the wire rods between the longer jumper wires in the corresponding branch windings can be interchanged between unit motor 1 and unit motor 2, so that the jumper points in each branch are reduced to 1, and there are 24 jumper points in total for three-phase eight branches, and the jumper wire length is 30 slots.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] (1) The present invention provides a twenty-eight-pole symmetrical eight-branch winding, which can improve the design rationality of large generators, especially hydro-turbine generators above 700MW. The stator slot current can be controlled within the design experience range of air-cooled units, which is also beneficial to reducing the stator voltage, reducing the difficulty of stator winding insulation design, and reducing the risk of corona at the stator end.

[0015] (2) The eight branches in the present invention satisfy the requirements of equal potential amplitude and phase, symmetrical branch windings, and no circulating current between the branches after parallel connection. Compared with the asymmetric eight branches, the problems of stator winding heating and increased unit vibration caused by branch circulating current are avoided, thereby improving the stability of motor operation.

[0016] (3) The type of wire rods of the present invention is the same as that of conventional branch windings. Each branch contains a jumper point, and the jumper is realized by a short copper ring. The length of the jumper line is Z / (2*m*a)=30, which is equivalent to the length of the inter-pole connecting line of the conventional stacked winding, and does not complicate the manufacturing and installation process of the winding. Z is the number of stator slots, m is the number of phases, and a is the number of branches. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the electrical angle sequence and phase band division of the present invention.

[0018] Figure 2 Schematic diagram of the connection of 72 jumper points of the present invention

[0019] Figure 3 Schematic diagram of 24 jumper connection points of the present invention DETAILED DESCRIPTION

[0020] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than 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 belong to the scope of protection of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0021] Specific implementation method 1: A 360-slot, 28-pole, symmetrical, eight-branch three-phase wave winding connection method described in this implementation is specifically as follows:

[0022] S1. All slots are numbered from 1 to 360 in sequence, with slot 1 as the reference position, i.e., 0 degrees, the electrical angles of all slots are calculated, and the slot numbers are rearranged in ascending order of electrical angles to form an electrical angle sequence. For a 360-slot 28-pole motor, the electrical angles overlap in pairs, and all slots can be divided into two completely identical parts. The first part contains slot numbers from 1 to 180, which is called unit motor 1, and the second part contains slot numbers from 181 to 360, which is called unit motor 2;

[0023] S2. Divide all slots into six phase bands of A, Z, B, X, C, and Y according to the electrical angle sequence. The slot number in the electrical angle interval [0, 60) is the A phase band, and so on. The slot number in the interval [60, 120) is the Z phase band, the slot number in the interval [120, 180) is the B phase band, the slot number in the interval [180, 240) is the X phase band, the slot number in the interval [240, 300) is the C phase band, and the slot number in the interval [300, 360) is the Y phase band. The slots of the same electrical angle of the two unit motors are divided into the same phase band. Among them, the A, B, and C phase bands are called positive phase bands, and the X, Y, and Z phase bands are called negative phase bands. One positive and one negative form a phase winding, that is, the A phase band and the X phase band form the A phase winding, the B phase band and the Y phase band form the B phase winding, and the C phase band and the Y phase band form the C phase winding. The amplitude of the potential vector of the three-phase winding of A, B, and C is equal, and the phase difference is 120 degrees.

[0024] S3, according to the electrical angle sequence, the phase slots in the unit motor 1 are divided into odd slots and even slots, the first branch of the A, B, and C phase windings is composed of the upper wire rods of the positive phase with odd slots and the lower wire rods of the negative phase with even slots, the second branch is composed of the lower wire rods of the positive phase with odd slots and the upper wire rods of the negative phase with even slots, the third branch is composed of the upper wire rods of the positive phase with even slots and the lower wire rods of the negative phase with odd slots, and the fourth branch is composed of the lower wire rods of the positive phase with even slots and the upper wire rods of the negative phase with odd slots;

[0025] Similarly, each phase slot in the unit motor 2 is divided into odd-numbered slots and even-numbered slots. The 5th branch of the A, B, and C phase windings is composed of the upper wire rods of the positive phase with odd-numbered slots and the lower wire rods of the negative phase with even-numbered slots, the 6th branch is composed of the lower wire rods of the positive phase with odd-numbered slots and the upper wire rods of the negative phase with even-numbered slots, the 7th branch is composed of the upper wire rods of the positive phase with even-numbered slots and the lower wire rods of the negative phase with odd-numbered slots, and the 8th branch is composed of the lower wire rods of the positive phase with even-numbered slots and the upper wire rods of the negative phase with odd-numbered slots; in this way, a three-phase symmetrical 8-branch winding is formed.

[0026] During actual wiring, the electrical angle sequence is followed, starting from the first wire rod, and connected in sequence in an up-to-down manner. If necessary, jumper connection is required. Each branch contains 3 jumper points, and there are 72 jumper points in total for three-phase eight branches. The jumper connection is achieved using short copper rings.

[0027] Furthermore, in order to reduce the jumper points and obtain an engineering feasible solution, the wire rods between the longer jumper wires in the corresponding branch windings can be interchanged between unit motor 1 and unit motor 2, so that the jumper points in each branch are reduced to 1, and there are 24 jumper points in total for three-phase eight branches, and the jumper wire length is 30 slots.

[0028] In the present invention, all slots in each unit motor are divided into six phase belts of A, Z, B, X, C and Y in order of electrical angle. Each phase belt occupies an electrical angle of 60 degrees, and one phase winding is formed by one positive and one negative, that is, the A phase belt and the X phase belt form the A phase winding, the B phase belt and the Y phase belt form the B phase winding, and the C phase belt and the Y phase belt form the C phase winding. The amplitude of the potential of each phase winding is equal, and the phase difference is 120 degrees, thereby ensuring three-phase symmetry.

[0029] The present invention divides each phase slot into odd slots and even slots in the unit motor according to the electrical angle sequence, and the synthetic potential vector of the upper layer of the positive phase odd slot is: The synthetic potential angle of the upper layer of the bars in the positive phase with even slots is Then the synthetic potential angle of the lower layer of the odd-numbered slots in the negative phase is The synthetic potential angle of the lower layer of the even-numbered slots in the negative phase is Available That is, the amplitude of the synthetic potential vector of the combination is equal and the phase is the same, and the two branches formed in this way are symmetrical to each other; further, the electrical positions of the upper and lower layers of wire bars in each slot are equal, that is, the four branches of each phase in each unit motor are symmetrical to each other; further, the electrical angles of the slots contained in unit motor 1 and unit motor 2 coincide, so that the eight branches of each phase are symmetrical to each other.

[0030] Specific implementation method 2: refer to Figures 1 to 3 Specifically describe this embodiment, a 360-slot, 28-pole, symmetrical, eight-branch three-phase wave winding connection method described in this embodiment:

[0031] S1, such as Figure 1 As shown, all slots are numbered from 1 to 360 in sequence, with slot 1 as the reference position, i.e. 0 degrees, and the electrical angles of all slots are calculated according to the following formula, and the slot numbers are rearranged in order from small to large electrical angles to form an electrical angle sequence:

[0032]

[0033] Among them, i is the slot number, α p is the electrical angle between slots of the motor;

[0034] For a 360-slot 28-pole motor, the electrical angles overlap in pairs, and all slots can be divided into two completely identical parts. The first part contains slot numbers 1 to 180, called unit motor 1, and the second part contains slot numbers 181 to 360, called unit motor 2.

[0035] S2, such as Figure 1 As shown, all slots are divided into six phase bands of A, Z, B, X, C, and Y according to the electrical angle sequence. The slot number in the electrical angle interval [0, 60) is the A phase band, and so on, the interval [60, 120) is the Z phase band, the interval [120, 180) is the B phase band, the interval [180, 240) is the X phase band, the interval [240, 300) is the C phase band, and the interval [300, 360) is the Y phase band. The slots of the same electrical angle of the two unit motors are divided into the same phase band. Among them, the A, B, and C phase bands are called positive phase bands, and the X, Y, and Z phase bands are called negative phase bands. One positive and one negative form a phase winding, that is, the A phase band and the X phase band form the A phase winding, the B phase band and the Y phase band form the B phase winding, and the C phase band and the Y phase band form the C phase winding. The amplitude of the potential vector of the three-phase winding of A, B, and C is equal, and the phase difference is 120 degrees.

[0036] S3, such as Figure 2 As shown, each phase slot in the unit motor 1 is divided into odd slots and even slots, the first branch of the A, B, and C phase windings is composed of the upper wire rods with odd slots of the positive phase and the lower wire rods with even slots of the negative phase, the second branch is composed of the lower wire rods with odd slots of the positive phase and the upper wire rods with even slots of the negative phase, the third branch is composed of the upper wire rods with even slots of the positive phase and the lower wire rods with odd slots of the negative phase, and the fourth branch is composed of the lower wire rods with even slots of the positive phase and the upper wire rods with odd slots of the negative phase, and they are connected in the order of top to bottom. Specifically, the upper wire rods are those without "'", the lower wire rods are those with "'", "-" indicates equidistant connection, and "^" indicates jumper connection:

[0037] The connection path of the first branch of phase A is: 1-14'-27-40'-53-66'-79-92'-105-118'-131-144'-157-170'^3-16'-29-42'-55-68'-81-94'-107-120'-133-146'-159-172'^5-18'^1. Open any position to make a line end to form the first branch winding of phase A; phase A The connection path of the second branch is: 1'-14-27'-40-53'-66-79'-92-105'-118-131'-144-157'-170^3'-16-29'-42-55'-68-81'-94-107'-120-133'-146-159'-172^5'-18^1', open any position to make a line end, and form the second branch winding of phase A; phase A The 3-branch connection path is: 91-104'-117-130'-143-156'-169^2'-15-28'-41-54'-67-80'-93-106'-119-132'-145-158'-171^4'-17-30'-43-56'-69-82'-95-108'^91, open any position to make a line end, and form the third branch winding of phase A; phase A The connection path of the 4th branch is: 91'-104-117'-130-143'-156-169'^2-15'-28-41'-54-67'-80-93'-106-119'-132-145'-158-171'^4-17'-30-43'-56-69'-82-95'-108^91', open any position to make a line end, and form the 4th branch winding of phase A;

[0038] The connection path of the first branch of phase B is: 31-44'-57-70'-83-96'-109-122'-135-148'-161-174'^7-20'-33-46'-59-72'-85-98'-111-124'-137-150'-163-176'^9-22'-35-48'^31. Open any position to make a line end to form the first branch winding of phase B; phase B The connection path of the second branch is: 31'-44-57'-70-83'-96-109'-122-135'-148-161'-174^7'-20-33'-46-59'-72-85'-98-111'-124-137'-150-163'-176^9'-22-35'-48^31', open any position to make a line end, and form the second branch winding of phase B; phase B first The connection path of the 3 branches is: 121-134'-147-160'-173^6'-19-32'-45-58'-71-84'-97-110'-123-136'-149-162'-175^8'-21-34'-47-60'-73-86'-99-112'-125-138'^121. Open any position to make a line end to form the third branch winding of phase B; phase B The connection path of the fourth branch is: 121'-134-147'-160-173'^6-19'-32-45'-58-71'-84-97'-110-123'-136-149'-162-175'^8-21'-34-47'-60-73'-86-99'-112-125'-138^121', open any position to make a line end, and form the fourth branch winding of phase B;

[0039] The connection path of the first branch of phase C is: 61-74'-87-100'-113-126'-139-152'-165-178'^11-24'-37-50'-63-76'-89-102'-115-128'-141-154'-167-180'^13-26'-39-52'-65-78'^61. Open any position to make a line end to form the first branch winding of phase C; The connection path of the second branch of phase C is: 61'-74-87'-100-113'-126-139'-152-165'-178^11'-24-37'-50-63'-76-89'-102-115'-128-141'-154-167'-180^13'-26-39'-52-65'-78^61'. Open any position to make a line end to form the second branch winding of phase C. ; The connection path of the third branch of phase C is: 121-134'-147-160'-173^6'-19-32'-45-58'-71-84'-97-110'-123-136'-149-162'-175^8'-21-34'-47-60'-73-86'-99-112'-125-138'^121, open any position to make a line end, and form the third branch winding of phase C; The connection path of the fourth branch of phase C is: 121'-134-147'-160-173'^6-19'-32-45'-58-71'-84-97'-110-123'-136-149'-162-175'^8-21'-34-47'-60-73'-86-99'-112-125'-138^121'. Open any position to make a line end to form the fourth branch winding of phase C;

[0040] Similarly, the slots of each phase in the unit motor 2 are divided into odd slots and even slots, the 5th branch of the A, B, and C phase windings are composed of the upper wire rods of the positive phase with odd slots and the lower wire rods of the negative phase with even positions, the 6th branch is composed of the lower wire rods of the positive phase with odd slots and the upper wire rods of the negative phase with even positions, the 7th branch is composed of the upper wire rods of the positive phase with even slots and the lower wire rods of the negative phase with odd positions, and the 8th branch is composed of the lower wire rods of the positive phase with even slots and the upper wire rods of the negative phase with odd positions, and they are connected in the order of top to bottom. Specifically, the upper wire rods are those without "'", the lower wire rods are those with "'", "-" indicates equidistant connection, and "^" indicates jumper connection:

[0041] The connection path of the 5th branch of phase A is: 181-194'-207-220'-233-246'-259-272'-285-298'-311-324'-337-350'^183-196'-209-222'-235-248'-261-274'-287-300'-313-326'-339-352'^185-198'^181, open any position to make a line end, and form the 5th branch winding of phase A; The connection path of the sixth branch of phase A is: 181'-194-207'-220-233'-246-259'-272-285'-298-311'-324-337'-350^183'-196-209'-222-235'-248-261'-274-287'-300-313'-326-339'-352^185'-198^181', open any position to make a line end, and form the sixth branch winding of phase A; The connection path of the 7th branch of phase A is: 271-284'-297-310'-323-336'-349^182'-195-208'-221-234'-247-260'-273-286'-299-312'-325-338'-351^184'-197-210'-223-236'-249-262'-275-288'-271. Open any position to make a line end to form the 7th branch winding of phase A. The connection path of the 8th branch of phase A is: 271'-284-297'-310-323'-336-349'^182-195'-208-221'-234-247'-260-273'-286-299'-312-325'-338-351'^184-197'-210-223'-236-249'-262-275'-288-271'. Open any position to make a line end to form the 8th branch winding of phase A.

[0042] The connection path of the 5th branch of phase B is: 211-224'-237-250'-263-276'-289-302'-315-328'-341-354'^187-200'-213-226'-239-252'-265-278'-291-304'-317-330'-343-356'^189-202'-215-228'^211, open any position to make a line end, and form the 5th branch winding of phase B; The connection path of the sixth branch of phase B is: 211'-224-237'-250-263'-276-289'-302-315'-328-341'-354^187'-200-213'-226-239'-252-265'-278-291'-304-317'-330-343'-356^189'-202-215'-228^211'. Open any position to make a line end to form the sixth branch winding of phase B. The connection path of the 7th branch of phase B is: 301-314'-327-340'-353^186'-199-212'-225-238'-251-264'-277-290'-303-316'-329-342'-355^188'-201-214'-227-240'-253-266'-279-292'-305-318'-301. Open any position to make a line end to form the 7th branch winding of phase B. The connection path of the 8th branch of phase B is: 301'-314-327'-340-353'^186-199'-212-225'-238-251'-264-277'-290-303'-316-329'-342-355'^188-201'-214-227'-240-253'-266-279'-292-305'-318-301'. Open any position to make a line end to form the 8th branch winding of phase B.

[0043] The connection path of the 5th branch of phase C is: 241-254'-267-280'-293-306'-319-332'-345-358'^191-204'-217-230'-243-256'-269-282'-295-308'-321-334'-347-360'^193-206'-219-232'-245-258'^241, open any position to make a line end, and form the 5th branch winding of phase C; The connection path of the sixth branch of phase C is: 241'-254-267'-280-293'-306-319'-332-345'-358^191'-204-217'-230-243'-256-269'-282-295'-308-321'-334-347'-360^193'-206-219'-232-245'-258^241'. Open any position to make a line end to form the sixth branch winding of phase C. The connection path of the 7th branch of phase C is: 331-344'-357^190'-203-216'-229-242'-255-268'-281-294'-307-320'-333-346'-359^192'-205-218'-231-244'-257-270'-283-296'-309-322'-335-348'^331. Open any position to make a line end to form the 7th branch winding of phase C; The connection path of the 8th branch of phase C is: 331'-344-357'^190-203'-216-229'-242-255'-268-281'-294-307'-320-333'-346-359'^192-205'-218-231'-244-257'-270-283'-296-309'-322-335'-348^331'. Open any position to make a line end to form the 8th branch winding of phase C.

[0044] like Figure 3 As shown, further, in order to reduce the jumper points and obtain an engineering solution, between unit motor 1 and unit motor 2, the wire rods between the two longer jumper wires in the corresponding branch windings are interchanged, specifically: the 1st branch is interchanged with the 5th branch, that is, the 2nd branch is interchanged with the 6th branch, that is, the 3rd branch is interchanged with the 7th branch, that is, the 4th branch is interchanged with the 8th branch, so that the jumper point of each branch is reduced to 1, and the three-phase eight-branch has a total of 24 jumper points, and the jumper wire length is 30 slots. The specific connection is as follows:

[0045] The connection path of the first branch of phase A is: 1-14'-27-40'-53-66'-79-92'-105-118'-131-144'-157-170'-183-196'-209-222'-235-248'-261-274'-287-300'-313-326'-339-352'-5-18'^1, open any position to make a line end, and form the first branch winding of phase A; the connection path of the second branch of phase A is: 1'-14-27'-40-53'-66-79'-92-105'-118-131'-144-157'-170-183'-196-209'-222- 235'-248-261'-274-287'-300-313'-326-339'-352-5'-18^1', open any position to make a line end, forming the second branch winding of phase A; the connection path of the third branch of phase A is: 91-104'-117-130'-143-156'-169-182'-195-208'-221-234'-247-260'-273-286'-299-312'-325-338'-351-4'-17-30'-43-56'-69-82'-95-108'^91, open any position to make a line end, forming the third branch winding of phase A; the fourth branch of phase A is: The connection path of the A-phase 4 branch winding is: 91'-104-117'-130-143'-156-169'-182-195'-208-221'-234-247'-260-273'-286-299'-312-325'-338-351'-4-17'-30-43'-56-69'-82-95'-108^91', open any position to make a line end, and form the A-phase 4 branch winding; the connection path of the A-phase 5 branch is: 181-194'-207-220'-233-246'-259-272'-285-298'-311-324'-337-350'-3-16'-29-4 2'-55-68'-81-94'-107-120'-133-146'-159-172'-185-198'^181, open any position to make a line end, forming the fifth branch winding of phase A; the connection path of the sixth branch of phase A is: 181'-194-207'-220-233'-246-259'-272-285'-298-311'-324-337'-350-3'-16-29'-42-55'-68-81'-94-107'-120-133'-146-159'-172-185'-198^181', open any position to make a line end, forming the sixth branch winding of phase A;The connection path of the 7th branch of phase A is: 271-284'-297-310'-323-336'-349-2'-15-28'-41-54'-67-80'-93-106'-119-132'-145-158'-171-184'-197-210'-223-236'-249-262'-275-288'-271. Open any position to make a line end to form the 7th branch winding of phase A. The connection path of the 8th branch of phase A is: 271'-284-297'-310-323'-336-349'-2-15'-28-41'-54-67'-80-93'-106-119'-132-145'-158-171'-184-197'-210-223'-236-249'-262-275'-288-271'. Open any position to make a line end to form the 8th branch winding of phase A.

[0046] The connection path of the first branch of phase B is: 31-44'-57-70'-83-96'-109-122'-135-148'-161-174'-187-200'-213-226'-239-252'-265-278'-291-304'-317-330'-343-356'-9-22'-35-48'^31, open any position to make a line end, and form the first branch winding of phase B; the connection path of the second branch of phase B is: 31'-44-57'-70-83'-96-109'-122-135'-148-161'-174-187'-200-213'-226-239'-2 52-265'-278-291'-304-317'-330-343'-356-9'-22-35'-48^31', open any position to make a line end, forming the second branch winding of phase B; the connection path of the third branch of phase B is: 121-134'-147-160'-173-186'-199-212'-225-238'-251-264'-277-290'-303-316'-329-342'-355-8'-21-34'-47-60'-73-86'-99-112'-125-138'^121, open any position to make a line end, forming the third branch winding of phase B; The connection path of the 4 branches is: 121'-134-147'-160-173'-186-199'-212-225'-238-251'-264-277'-290-303'-316-329'-342-355'-8-21'-34-47'-60-73'-86-99'-112-125'-138^121', open any position to make a line end, and form the fourth branch winding of phase B; the connection path of the fifth branch of phase B is: 211-224'-237-250'-263-276'-289-302'-315-328'-341-354'-7-20'-33-46'-59-7 2'-85-98'-111-124'-137-150'-163-176'-189-202'-215-228'^211, open any position to make a line end, forming the fifth branch winding of phase B; the connection path of the sixth branch of phase B is: 211'-224-237'-250-263'-276-289'-302-315'-328-341'-354-7'-20-33'-46-59'-72-85'-98-111'-124-137'-150-163'-176-189'-202-215'-228^211', open any position to make a line end, forming the sixth branch winding of phase B;The connection path of the 7th branch of phase B is: 301-314'-327-340'-353-6'-19-32'-45-58'-71-84'-97-110'-123-136'-149-162'-175-188'-201-214'-227-240'-253-266'-279-292'-305-318'-301. Open any position to make a line end to form the 7th branch winding of phase B. The connection path of the 8th branch of phase B is: 301'-314-327'-340-353'-6-19'-32-45'-58-71'-84-97'-110-123'-136-149'-162-175'-188-201'-214-227'-240-253'-266-279'-292-305'-318-301'. Open any position to make a line end to form the 8th branch winding of phase B.

[0047] The connection path of the first branch of phase C is: 61-74'-87-100'-113-126'-139-152'-165-178'^191-204'-217-230'-243-256'-269-282'-295-308'-321-334'-347-360'^13-26'-39-52'-65-78'^61, open any position to make a line end, and form the first branch winding of phase C; the connection path of the second branch of phase C is: 61'-74-87'-100-113'-126-139'-152-165'-178^191'-204-217'-230-243'-256-269' -282-295'-308-321'-334-347'-360^13'-26-39'-52-65'-78^61', open any position to make a line end, forming the second branch winding of phase C; the connection path of the third branch of phase C is: 151-164'-177^190'-203-216'-229-242'-255-268'-281-294'-307-320'-333-346'-359^12'-25-38'-51-64'-77-90'-103-116'-129-142'-155-168'^151, open any position to make a line end, forming the third branch winding of phase C; The connection path of the 4 branches is: 151'-164-177'^190-203'-216-229'-242-255'-268-281'-294-307'-320-333'-346-359'^12-25'-38-51'-64-77'-90-103'-116-129'-142-155'-168^151', open any position to make a line end, and form the C phase 4 branch winding; the connection path of the C phase 5 branch is: 241-254'-267-280'-293-306'-319-332'-345-358'^11-24'-37-50'-63-76'-89-102 '-115-128'-141-154'-167-180'^193-206'-219-232'-245-258'^241, open any position to make a line end, forming the fifth branch winding of phase C; the connection path of the sixth branch of phase C is: 241'-254-267'-280-293'-306-319'-332-345'-358^11'-24-37'-50-63'-76-89'-102-115'-128-141'-154-167'-180^193'-206-219'-232-245'-258^241', open any position to make a line end, forming the sixth branch winding of phase C;The connection path of the 7th branch of phase C is: 331-344'-357^10'-23-36'-49-62'-75-88'-101-114'-127-140'-153-166'-179^192'-205-218'-231-244'-257-270'-283-296'-309-322'-335-348'^331, open any position to make a line end, and form the 7th branch winding of phase C; the connection path of the 8th branch of phase C is: 331'-344-357'^10-23'-36-49'-62-75'-88-101'-114-127'-140-153'-166-179';

[0048] ^192-205'-218-231'-244-257'-270-283'-296-309'-322-335'-348^331', open any position to make the line end, and form the 8th branch winding of phase C.

[0049] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, it should be clear to those skilled in the art that the technical solutions described in the above embodiments may be modified, or some or all of the technical features therein may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A connection method for a 360-slot, 28-pole, symmetrical, eight-branch, double-layer, three-phase wave winding, characterized in that: The wave winding can be obtained by the following steps: S1. All slots are numbered from 1 to 360 in sequence, with slot 1 as the reference position, i.e., 0 degrees, the electrical angles of all slots are calculated, and the slot numbers are rearranged in ascending order of electrical angles to form an electrical angle sequence. For a 360-slot 28-pole motor, the electrical angles overlap in pairs, and all slots can be divided into two completely identical parts. The first part contains slot numbers from 1 to 180, which is called unit motor 1, and the second part contains slot numbers from 181 to 360, which is called unit motor 2; S2. Divide all the slots into six phase bands of A, Z, B, X, C and Y according to the electrical angle sequence. The slot number in the electrical angle interval of [0, 60) is the A phase band, and so on. The slot number in the interval of [60, 120) is the Z phase band, the slot number in the interval of [120, 180) is the B phase band, the slot number in the interval of [180, 240) is the X phase band, the slot number in the interval of [240, 300) is the C phase band, and the slot number in the interval of [300, 360) is the Y phase band. The slots of the same electrical angle of the two unit motors are divided into the same phase band, among which the A, B and C phase bands are called positive phase bands, and the X, Y and Z phase bands are called negative phase bands. One positive and one negative form a phase winding, that is, the A phase band and the X phase band form the A phase winding, the B phase band and the Y phase band form the B phase winding, and the C phase band and the Y phase band form the C phase winding. The amplitude of the potential vector of the A, B and C three-phase windings is equal, and the phase difference is 120 degrees; S3, according to the electrical angle sequence, the phase slots in the unit motor 1 are divided into odd slots and even slots, the first branch of the A, B, and C phase windings is composed of the upper wire rods of the positive phase with odd slots and the lower wire rods of the negative phase with even slots, the second branch is composed of the lower wire rods of the positive phase with odd slots and the upper wire rods of the negative phase with even slots, the third branch is composed of the upper wire rods of the positive phase with even slots and the lower wire rods of the negative phase with odd slots, and the fourth branch is composed of the lower wire rods of the positive phase with even slots and the upper wire rods of the negative phase with odd slots; Similarly, each phase slot in the unit motor 2 is divided into odd-numbered slots and even-numbered slots. The 5th branch of the A, B, and C phase windings is composed of the upper wire rods of the positive phase with odd-numbered slots and the lower wire rods of the negative phase with even-numbered slots. The 6th branch is composed of the lower wire rods of the positive phase with odd-numbered slots and the upper wire rods of the negative phase with even-numbered slots. The 7th branch is composed of the upper wire rods of the positive phase with even-numbered slots and the lower wire rods of the negative phase with odd-numbered slots. The 8th branch is composed of the lower wire rods of the positive phase with even-numbered slots and the upper wire rods of the negative phase with odd-numbered slots, forming a three-phase symmetrical 8-branch winding.

2. A method for connecting a three-hundred-sixty-slot, twenty-eight-pole, symmetrical eight-branch double-layer three-phase wave winding as claimed in claim 1, characterized in that: In S3, according to the electrical angle sequence, starting from the first wire rod, the wires are connected in sequence in an up-down order. If necessary, jumper connection is required. Each branch contains 3 jumper points, and there are 72 jumper points in total for three-phase eight branches. The jumper connection is achieved by using short copper rings.

3. A method for connecting a three-hundred-sixty-slot, twenty-eight-pole, symmetrical eight-branch double-layer three-phase wave winding as claimed in claim 1, characterized in that: In S3, in order to reduce the number of jumper points, the wire rods between the longer jumper wires in the corresponding branch windings can be interchanged between unit motor 1 and unit motor 2, so that the jumper point of each branch is reduced to 1, and there are 24 jumper points in total for three-phase eight branches, and the jumper wire length is 30 slots.

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