Method and system capable of separating and measuring alternating current copper loss and iron loss of motor

Abstract

The invention provides a method and a system capable of separating and measuring alternating current copper loss and iron loss of a motor. The method comprises the following steps of: manufacturing a part of stator bodies of an N-line motor and a 2N-line motor in each slot as test objects; testing total loss data and external circuit characteristic parameters of partial stators of the N line and the 2N line of each slot under load operation; obtaining a difference value of alternating current copper loss; correcting a simulation model of the alternating current copper loss of the motor by using the obtained alternating current copper loss difference value, and outputting the alternating current copper loss of the motor of each slot N line and each slot 2N line under different rotating speeds and different torques; carrying out no-load test by using an unpunched magnetic rotor to obtain no-load loss; according to the total loss, the copper loss and the no-load loss obtained by testing the N-line stator and the 2N-line stator, the iron core loss is obtained; and correcting the iron core loss simulation model of the motor by using the obtained iron core loss value, and outputting the iron core loss of each slot of N-line and 2N-line motors at different rotating speeds and different torques. According to the invention, separation and calculation of AC copper loss and iron core loss of the motor can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of motor loss testing, in particular to a partial stator testing device for separating and measuring AC copper loss and iron loss, and in particular to a method and system for separating and measuring AC copper loss and iron loss of a motor. Background Art

[0002] As new energy vehicle motors develop towards higher speeds, the synchronous growth of electromagnetic fundamental frequency has led to an increase in winding AC copper loss and core loss, posing a challenge to the accuracy of motor efficiency design and thermal analysis. The AC copper loss inside the motor is generated under a complex magnetic field background, with both spatial harmonic components and time domain high-frequency harmonic interference. In addition, the alternating magnetic field not only generates AC copper loss, but also core loss in the magnetic circuit. These two losses are coupled with each other and are difficult to separate and measure directly.

[0003] In order to accurately and effectively analyze the efficiency and thermal management of the motor, it is necessary to obtain the changing rules of AC copper loss and core loss. However, when testing the whole machine, especially when using flat wire windings, winding is difficult, costly, and the test cycle is long, so a new device is needed to improve the test efficiency and accuracy. Summary of the invention

[0004] In view of the defects in the prior art, the present invention provides a method and system for separating and measuring the AC copper loss and iron loss of a motor.

[0005] According to a method and system for separating and measuring AC copper loss and iron loss of a motor provided by the present invention, the scheme is as follows:

[0006] In a first aspect, a method for separating and measuring AC copper loss and iron loss of a motor is provided, the method comprising: a motor rotor and two partial stator bodies having the same shape as the complete stator of the motor to be measured, each partial stator body comprising at least one number of slots corresponding to the number of pole pairs, symmetrically arranged on both sides of the rotor, assuming that each slot of the motor to be measured has N winding wires, and the measurement method comprises:

[0007] Step S101: manufacturing a partial stator body of an N-wire motor and a 2N-wire motor in each slot, that is, a partial stator body of an N-wire motor and a 2N-wire motor as a test object, and the total copper conductor cross-section in the slots of the two motors is the same;

[0008] Step S102: testing the total loss data and external circuit characteristic parameters of the stator body of the N-line motor and the 2N-line motor under load operation, and the speed and current at each test point are kept consistent;

[0009] Step S103: Obtain the difference in AC copper loss according to the difference in total loss under equal current test of the stator body of the N-wire motor and the 2N-wire motor or the difference in winding equivalent resistance in the external circuit characteristics;

[0010] Step S104: using the acquired AC copper loss difference to correct the AC copper loss simulation model of the N-wire motor and the 2N-wire motor, and outputting the AC copper loss of the N-wire motor and the 2N-wire motor at different speeds and torques;

[0011] Step S105: using an unpunched rotor to perform a no-load test on a portion of the stator body of the N-wire motor and the 2N-wire motor to obtain a no-load loss;

[0012] Step S106: according to the total loss, copper loss and no-load loss obtained by testing the stator body of the N-wire motor and the 2N-wire motor, the core loss of the stator body of the N-wire motor and the 2N-wire motor at different test points is obtained;

[0013] Step S107: Use the obtained core loss value to correct the core loss simulation model of the N-wire motor and the 2N-wire motor, and output the core loss of the N-wire and 2N-wire motors at different speeds and torques.

[0014] Preferably, in terms of speed control, the armature magnetic field of a portion of the stator body rotates at the same speed as the rotor magnetic field;

[0015] The synchronous rotation angles of the armature magnetic field and the rotor magnetic field between the partial stator bodies of the N-line motor and the 2N-line motor at each test point are consistent.

[0016] Preferably, the step S102 comprises: obtaining the total loss of the two devices under test according to the difference between the power input power and the output power of the motor under test by installing torque and speed sensors between the towing motor and the motor under test;

[0017] The motor input active power is obtained from the input current and input voltage:

[0018] P0=U0I0cosφ

[0019] Among them, P0 is the motor input active power, U0 is the input voltage, I0 is the input current, and φ is the phase angle between the input voltage and the input current;

[0020] According to the torque and speed sensors installed between the towing motor and the motor under test, the output power of the motor under test is obtained by the following formula:

[0021]

[0022] Among them, P m is the motor output power, T is the torque, and n is the speed (r / min);

[0023] Based on the input active power and output power, the total loss of the test device is obtained:

[0024] P=P0-Pm

[0025] Among them, P is the total loss of the motor, P0 is the input active power of the motor, and P m is the output power.

[0026] Preferably, step S103 includes: while keeping the rotation speed and current of the two motors consistent, obtaining the difference ΔP of the AC copper loss at each rotation speed and current value by the difference of the total loss of part of the stator body of the N-wire motor and the 2N-wire motor. e .

[0027] Preferably, the step S103 further comprises: obtaining the equivalent resistance difference ΔR of the partial stator windings of the N-wire motor and the 2N-wire motor according to the magnitude of the terminal voltage and its phase with the current through the external circuit characteristics of the partial stator bodies of the N-wire motor and the 2N-wire motor while keeping the rotation speed and current of the two motors consistent, and also calculating the difference ΔP of the AC copper loss at each rotation speed and current value according to the following formula: e :

[0028] ΔP e =nI 2 ΔR

[0029] Where ΔP e is the AC copper loss difference, n is the number of motor phases, and I is the effective current.

[0030] Preferably, step S105 comprises: replacing the rotor with a non-magnetized rotor, driving the rotor with a towing motor, and measuring the no-load loss at various speeds and current values ​​according to the torque and speed sensors, that is, the sum of the wind friction loss, the bearing loss and the stray loss:

[0031]

[0032] Among them, P f is the no-load loss, T1 is the torque, and n1 is the speed (rpm).

[0033] Preferably, step S106 comprises: obtaining the core loss by subtracting the no-load loss and the AC copper loss of the winding from the total loss of the partial stator and the full rotor structure:

[0034] P Fe =PP e -P f

[0035] Among them, P Fe is the motor core loss, P is the total motor loss, P e is the motor AC copper loss, P f It is the no-load loss of the motor.

[0036] In a second aspect, a system capable of separating and measuring AC copper loss and iron loss of a motor is provided, the system comprising: a motor rotor, two opposed partial stator bodies, a rotating shaft, a winding retaining ring, a rectangular conductor, a partial stator body fixture, and a pair of motors;

[0037] The pair of drag motors are connected to the rotating shaft, and the motor rotor is located between some stator body clamps and rotates around the rotating shaft;

[0038] The two partial stator bodies are symmetrically arranged on both sides of the motor rotor;

[0039] The winding retaining rings are arranged at two ends of the motor rotor; the rectangular wire is wound around the part of the stator body.

[0040] Preferably, the contour features of the two partial stator bodies are consistent with the shape of the motor to be measured, and each partial stator body comprises at least one number of slots corresponding to the number of pole pairs;

[0041] A torque speed sensor is arranged between the motor rotor and the towing motor;

[0042] The rectangular wires of the two partial stator bodies arranged symmetrically are wound in opposite directions.

[0043] Particularly preferably, the two partial stator bodies are symmetrically arranged on both sides of the complete motor rotor, the original air gap length is ensured between the motor rotor, and the partial stator body fixture is made of non-magnetic material.

[0044] Particularly preferably, the test device consisting of two partial stator bodies and a motor rotor is used to test two-phase, three-phase and multi-phase windings.

[0045] Particularly preferably, during the test, the motor rotor is connected to a pair of towing motors, and the pair of towing motors generates a load force or a driving force under no-load.

[0046] Preferably, the partial stator body is respectively wound with N-wire and 2N-wire conductors per slot to form an N-wire motor and a 2N-wire motor; during the winding, opposite winding is performed between the two stator bodies, and the shape of the winding conductor is such that the N-wire and 2N-wire motors have the same width, the height of the N-wire winding conductor is twice that of the 2N-wire winding conductor, and the total copper cross-section of the conductor in each slot is kept equal to that of the 2N-wire winding conductor;

[0047] The 2N line winding uses two wires wound in parallel on the connecting line, that is, the current passing through the single wire of the N line motor and the double wires of the 2N line motor are consistent, and the average current density is consistent.

[0048] Particularly preferably, the speed control is performed so that the magnetic field of a part of the stator body and the magnetic field of the rotor have the same rotation speed.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] The present invention restores the electromagnetic environment inside the motor through the structure of opposing partial stator bodies and complete rotors, and can perform opposite cross windings, avoiding the problem that the short sides of rectangular wires are difficult to bend, greatly reducing the testing difficulty, cost and cycle, and realizing the separation and calculation of the motor's AC copper loss and core loss through the difference in AC copper loss between the four-wire motor and the eight-wire motor.

[0051] Other beneficial effects of the present invention will be explained in the specific implementation manner through the introduction of specific technical features and technical solutions. Through the introduction of these technical features and technical solutions, those skilled in the art should be able to understand the beneficial technical effects brought about by the technical features and technical solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0053] Figure 1 The diagram is a step-by-step diagram of the separation and measurement method of the AC copper loss and core loss of the motor;

[0054] Figure 2 This is a physical picture of the stator body test device of the motor;

[0055] Figure 3 This is a physical picture of the stator body of the motor;

[0056] Figure 4 This is a physical picture of the motor shaft;

[0057] Figure 5 This is a physical picture of the motor rotor;

[0058] Figure 6 This is a physical picture of the winding retaining ring;

[0059] Figure 7 This is a physical picture of the stator body fixture of the motor;

[0060] Figure 8 This is a physical picture of the motor no-load test device;

[0061] Figure 9a-9b This is a physical diagram of the wires of the motor with N wires per slot and the motor with 2N wires per slot;

[0062] Figures 10a to 10b This is the schematic diagram of the windings of the original eight-wire motor and the original four-wire motor;

[0063] Fig.11 This is a schematic diagram of the winding connection method of the original eight-wire motor;

[0064] Fig.12 It is a schematic diagram of the connection method of the eight-wire motor winding of the present invention.

[0065] Figure numerals: 1. motor rotor; 2. part of stator body; 3. rotating shaft; 4. winding retaining ring; 5. rectangular wire; 6. part of stator body fixture. DETAILED DESCRIPTION

[0066] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0067] Embodiment 1:

[0068] The embodiment of the present invention provides a system for separating and measuring the AC copper loss and iron loss of a motor, referring to Figure 1 and Figure 2 As shown, the system specifically includes: a motor rotor 1, two opposite partial stator bodies 2, a rotating shaft 3, a winding retaining ring 4, a rectangular wire 5, a partial stator body fixture 6 and a pair of motors; Figure 3 , 4 , 5, 6, and 7 respectively show the specific structures of a portion of the stator body 2, the rotating shaft 3, the motor rotor 1, the winding retaining ring 4, and a portion of the stator body fixture 6.

[0069] The towing motor is connected to the rotating shaft 3, and the motor rotor 1 is located between the partial stator body clamps 6 and rotates around the rotating shaft 3;

[0070] The two partial stator bodies 2 are symmetrically arranged on both sides of the motor rotor 1;

[0071] The winding retaining rings 4 are arranged at both ends of the motor rotor 1 to guide the winding of the rectangular wire 5 to avoid interference with the motor rotor 1 during testing; the rectangular wire 5 is wound around a portion of the stator body 2 .

[0072] Reference Figure 3 As shown, the contour features of the two partial stator bodies 2 are consistent with the shape of the motor being tested, and each partial stator body 2 includes at least one number of slots corresponding to the number of pole pairs;

[0073] A torque speed sensor is arranged between the motor rotor 1 and the towing motor.

[0074] Reference Figure 2 As shown, two partial stator bodies 2 are symmetrically arranged on both sides of the complete motor rotor 1, and the original air gap length is guaranteed between the motor rotor 1. The rectangular wires 5 of the two symmetrically arranged partial stator bodies 2 are wound in opposite directions. The partial stator body fixture 6 is made of non-magnetic materials, such as aluminum, organic materials, etc.

[0075] The test device consisting of two partial stator bodies 2 and a motor rotor 1 is used to test two-phase, three-phase and multi-phase windings.

[0076] During the test, the motor rotor 1 is connected to the towing motor, and the towing motor generates a load force or a driving force under no-load.

[0077] Part of the stator body 2 is respectively wound with N wires and 2N wires conductors in each slot to form an N wire motor and a 2N wire motor; during winding, opposite winding is performed between the two stator bodies, and the shape of the winding conductor is such that the N wire and 2N wire motors have the same width, the height of the N wire winding conductor is twice that of the 2N wire winding conductor, and the total copper cross-section of the conductor in each slot remains equal.

[0078] When speed control is performed, the rotation speed of the magnetic field of the part of the stator body 2 should be consistent with that of the rotor magnetic field. If id = 0, it is necessary to ensure that during the operation of the motor, the rotor magnetic field and the magnetic field of the part of the stator body 2 maintain an electrical angle of 90 degrees; the 2N line winding uses two wires in parallel on the connection line, that is, the current flowing through the single wire of the N-wire motor and the double wire of the 2N-wire motor are consistent, and the average current density is consistent.

[0079] The present invention also provides a method for separating and measuring the AC copper loss and iron loss of a motor, referring to Figure 1 As shown, a partial stator test device for separating and measuring AC copper loss and iron loss is used. The partial stator test device for separating and measuring AC copper loss and iron loss of a motor comprises at least a complete motor rotor 1 and two partial stator bodies that are consistent with the shape of the complete stator of the motor under test, each partial stator body comprises at least one number of slots corresponding to the number of pole pairs, and is symmetrically arranged on both sides of the rotor. It is assumed that each slot of the motor under test has N winding wires. The method specifically comprises:

[0080] Step S101: manufacturing a partial stator body of a motor with N wires and 2N wires (two wires wound in parallel) in each slot, that is, a partial stator body of an N wire motor and a 2N wire motor as a test object, and the total copper conductor cross-section in the slots of the two motors is the same;

[0081] Step S102: testing the total loss data and external circuit characteristic parameters of the stator body of the N-line motor and the 2N-line motor under load operation, and keeping the rotation speed and current consistent at each test point.

[0082] In speed control, the armature magnetic field of part of the stator body rotates at the same speed as the rotor magnetic field.

[0083] In speed control, the synchronous rotation angle of the armature magnetic field and the rotor magnetic field between the N-line motor and the partial stator body of the 2N-line motor at each test point is consistent. For example, when id=0, it is necessary to ensure that the rotor magnetic field and the partial stator body magnetic field maintain an equal electrical angle of 90 degrees during the operation of the N-line motor and the 2N-line motor. For another example, under weak magnetic operation, the rotor magnetic field of the N-line motor and the 2N-line motor maintain the same weak magnetic angle with the armature magnetic field of the partial stator body.

[0084] In step S102, the total loss of the two devices under test is obtained according to the difference between the power input power and the output power of the motor under test by installing torque and speed sensors between the towing motor and the motor under test;

[0085] Specifically, for the stator of the N-wire motor part and the stator of the 2N-wire motor part, equal current and equal speed load tests are performed at different working points respectively while keeping the speed n and the current I consistent.

[0086] The motor input active power is obtained from the input current and input voltage according to the following formula:

[0087] P0=U0I0 cosφ

[0088] Among them, P0 is the motor input active power, U0 is the input voltage, I0 is the input current, and φ is the phase angle between the input voltage and the input current;

[0089] According to the torque and speed sensors installed between the towing motor and the motor under test, the output power of the motor under test is obtained by the following formula:

[0090]

[0091] Among them, P m is the motor output power, T is the torque, and n is the speed (r / min);

[0092] Based on the input active power and output power, the total loss of the test device is obtained:

[0093] P=P0-P m

[0094] Among them, P is the total loss of the motor, P0 is the input active power of the motor, and P m is the output power.

[0095] Step S103: Obtain the difference in AC copper loss according to the difference in total loss under equal current test of partial stator bodies of the N-wire motor and the 2N-wire motor or the difference in winding equivalent resistance in external circuit characteristics.

[0096] The step S103 includes: while keeping the rotation speed and current of the two motors consistent, obtaining the difference ΔP of the AC copper loss at each rotation speed and current value by the difference of the total loss of part of the stator body of the N-wire motor and the 2N-wire motor. e ;

[0097] Step S103 can also obtain the equivalent resistance difference ΔR of the partial stator winding of the N-wire motor and the 2N-wire motor according to the external circuit characteristics of the partial stator body of the N-wire motor and the 2N-wire motor, while keeping the rotation speed and current of the two motors consistent, according to the magnitude of the terminal voltage and its phase with the current, and can also calculate the difference ΔP of the AC copper loss at each rotation speed and current value according to the following formula: e :

[0098] ΔP e =nI 2 ΔR

[0099] Where n is the number of motor phases and I is the effective value of current.

[0100] Step S104: using the acquired AC copper loss difference to correct the AC copper loss simulation model of the N-wire motor and the 2N-wire motor, and outputting the AC copper loss of the N-wire motor and the 2N-wire motor at different speeds and torques.

[0101] Step S105: Refer to Figure 8 and Figure 9a-9b As shown, a no-load test is performed on part of the stator body of the N-line motor and the 2N-line motor using an unpunched rotor to obtain the no-load loss, namely, the wind friction loss, bearing loss and other stray losses.

[0102] The step S105 includes: replacing the rotor with a non-magnetized rotor, driving the rotor with a towing motor, and measuring the no-load loss at various speeds and current values ​​according to the torque and speed sensors, that is, the sum of the wind friction loss, bearing loss and stray loss:

[0103]

[0104] Among them, P f is the no-load loss, T1 is the torque, and n1 is the speed (rpm).

[0105] Step S106: according to the total loss, copper loss and no-load loss obtained from the test of the N-wire motor and the 2N-wire motor, the core loss of the N-wire motor and the 2N-wire motor at different test points of the stator body is obtained.

[0106] The step S106 includes: subtracting the no-load loss and the AC copper loss of the winding from the total loss of the partial stator and the full rotor structure to obtain the core loss:

[0107] P Fe=PP e -P f

[0108] Among them, P Fe is the motor core loss, P is the total motor loss, P e is the motor AC copper loss, P f It is the no-load loss of the motor.

[0109] Step S107: Use the obtained core loss value to correct the core loss simulation model of the N-wire motor and the 2N-wire motor, and output the core loss of the N-wire and 2N-wire motors at different speeds and torques.

[0110] Embodiment 2:

[0111] This embodiment further describes the present invention based on the above-mentioned embodiment.

[0112] The following description takes N=4, that is, a motor with four wires per slot and a motor with eight wires per slot using a partial stator body as examples, referred to as a four-wire motor and an eight-wire motor.

[0113] like Figure 2 As shown, two partial stator bodies are arranged symmetrically, and the original air gap length of the motor is maintained between the two partial stator bodies, and opposite windings are performed between the two partial stator bodies.

[0114] like Figures 10a to 10b As shown in the figure, it is a schematic diagram of the original winding under two pole pairs of a four-wire motor and an eight-wire motor. The number of slots per phase of each pole is 1, that is, the number of parallel slots is 1, and the windings on the left and right sides are named "A1+, B1-, C1+, A1-, B1+, C1-" phases and "A2+, B2-, C2+, A2-, B2+, C2-" phases. The arrangement of each phase of the winding of the four-wire motor is the same as that of the above-mentioned eight-wire motor.

[0115] like Fig.11 The figure shows the wiring diagram of the original winding of the eight-wire motor. When winding, connect in sequence according to "A1+~A1-, B1-~B1+, C1+~C1-, A2+~A2-, B2-~B2+, C2+~C2-". The connection method of the winding of the four-wire motor is the same as that of the eight-wire motor.

[0116] The eight-wire motor winding method used in the present invention is as follows Fig.12 As shown, the opposite windings are cross-connected, wherein "A1+~A2-, B1-~B2+, C1+~C2-, A1-~A2+, B1+~B2-, C1-~C2+" are connected in sequence. The connection method of each winding of the four-wire motor is consistent with the above-mentioned eight-wire motor.

[0117] like Figure 9a-9b , Figures 10a to 10bAs shown in the figure, the wires of the four-wire motor and the eight-wire motor are of equal width in shape, the conductor height of the four-wire motor winding is twice that of the eight-wire motor winding conductor, and the total cross-section of the copper conductor in each slot is equal. The eight-wire motor uses two wires in parallel to keep its average current density consistent with that of the four-wire motor. Figure 9a It is an eight-wire (2N-wire) motor winding conductor. Figure 9b It is the four-wire (N-wire) motor winding conductor.

[0118] The method for separating and measuring AC copper loss and core loss of a motor provided by the present invention is applicable to permanent magnet synchronous motors, asynchronous AC motors, radial magnetic field motors and axial magnetic field motors. When N=4, the method comprises:

[0119] S101, preparing partial stator bodies of a four-wire motor and an eight-wire motor as test objects, wherein the total copper conductor cross-sections in the slots of the two motors are the same.

[0120] S102, testing the total stator loss data and external circuit characteristic parameters of the 4-wire and 8-wire (2-wire parallel winding) parts in each slot under load operation, and keeping the speed and current consistent at each test point.

[0121] Among them, when controlling the speed, the magnetic field of part of the stator body should be kept consistent with the rotation speed of the rotor magnetic field. It is necessary to ensure that during the operation of the motor, the rotor magnetic field and the magnetic field of part of the stator body maintain an electrical angle of 90 degrees, and the electrical angle is adjusted by the phase difference; the 8-wire winding adopts 2-wire parallel winding on the connecting line, that is, the current passing through the single wire of the four-wire motor and the double wire of the eight-wire motor are consistent, and the average current density is consistent; at a fixed speed n and current I, the corresponding terminal voltage data of the four-wire motor and the eight-wire motor are obtained respectively.

[0122] According to the following formula, the motor input active power P0 is obtained from the input current I0, input voltage U0 and phase difference angle φ:

[0123] P0=U0I0 cosφ

[0124] According to the torque and speed sensor installed between the towing motor and the motor under test, the torque T and speed n are measured, and the output power P of the motor under test is obtained by the following formula: m :

[0125]

[0126] According to the input active power P0 and output power P m , get the total loss P of the motor:

[0127] P=P0-Pm

[0128] S103, calculating the difference between the total loss of part of the stator body of the four-wire motor and the eight-wire motor, and obtaining the AC copper loss difference ΔP e .

[0129] In addition, the equivalent resistance difference ΔR of the stator windings of the four-wire and eight-wire motor parts can be derived based on the input voltage amplitude and its phase angle with the input current obtained under equal current, equal speed and equal load tests of the four-wire motor part stator and the eight-wire motor part stator at different working points. According to the effective value of the current I and the number of motor phases n, the difference in AC copper loss at various speeds and current values ​​can be calculated by the following formula:

[0130] ΔP e =nI 2 ΔR

[0131] S104, using the obtained AC copper loss difference to correct the AC copper loss simulation model of the motor, and outputting the AC copper consumption of the whole four-wire motor and the eight-wire motor at different speeds and different torques.

[0132] Among them, the AC copper loss model calculation is implemented in the finite element electromagnetic simulation software.

[0133] S105, use a rotor without magnetization to perform a no-load test to obtain wind friction loss, bearing loss and other stray losses at the same speed.

[0134] Among them, during the no-load test, the original rotor is replaced with an unmagnetized rotor, and the rotor is driven by the towing motor. According to the torque T1 and speed n1 (r / min) measured by the torque and speed sensor, the no-load loss is calculated, that is, the sum of wind friction loss, bearing loss and stray loss P1:

[0135]

[0136] S106, the core loss is obtained based on the total loss, copper loss and no-load loss obtained from the stator test of the four-wire and eight-wire motors.

[0137] Among them, according to the total loss P, no-load loss P f And the corresponding winding copper loss P e , the core loss P is calculated by the following formula Fe :

[0138] P Fe =PP e -P f

[0139] S107, using the obtained core loss value to correct the core loss simulation model of the motor, and outputting the core losses of the four-wire motor and the eight-wire motor at different speeds and torques.

[0140] Among them, the core loss model calculation is implemented in the finite element electromagnetic simulation software.

[0141] The embodiments of the present invention provide a method and system for separating and measuring the AC copper loss and iron loss of a motor. The electromagnetic environment inside the motor is restored through the structure of opposing partial stator bodies and complete rotors. At the same time, opposite cross windings can be performed, avoiding the problem that the short sides of rectangular wires are difficult to bend, greatly reducing the testing difficulty, cost and cycle. The AC copper loss and core loss of the motor can be separated and calculated through the difference in AC copper loss between a four-wire motor and an eight-wire motor.

[0142] Those skilled in the art know that, in addition to realizing the system and its various devices, modules, and units provided by the present invention in a purely computer-readable program code, it is entirely possible to realize the same functions in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system and its various devices, modules, and units provided by the present invention can be considered as a hardware component, and the devices, modules, and units included therein for realizing various functions can also be regarded as structures within the hardware component; the devices, modules, and units for realizing various functions can also be regarded as both software modules for realizing the method and structures within the hardware component.

[0143] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A method for separating and measuring AC copper loss and iron loss of a motor, characterized in that: include: The motor rotor and two partial stator bodies that are consistent with the shape of the complete stator of the motor under test, each partial stator body contains at least one slot number corresponding to the number of pole pairs, and are symmetrically arranged on both sides of the rotor. Assuming that each slot of the motor under test has N winding wires, the measurement method includes: Step S101: manufacturing a partial stator body of an N-wire motor and a 2N-wire motor in each slot, that is, a partial stator body of an N-wire motor and a 2N-wire motor as a test object, and the total copper conductor cross-section in the slots of the two motors is the same; Step S102: testing the total loss data and external circuit characteristic parameters of the stator body of the N-line motor and the 2N-line motor under load operation, and the speed and current at each test point are kept consistent; Step S103: Obtain the difference in AC copper loss according to the difference in total loss under equal current test of the stator body of the N-wire motor and the 2N-wire motor or the difference in winding equivalent resistance in the external circuit characteristics; Step S104: using the acquired AC copper loss difference to correct the AC copper loss simulation model of the N-wire motor and the 2N-wire motor, and outputting the AC copper loss of the N-wire motor and the 2N-wire motor at different speeds and torques; Step S105: using an unpunched rotor to perform a no-load test on a portion of the stator body of the N-wire motor and the 2N-wire motor to obtain a no-load loss; Step S106: according to the total loss, copper loss and no-load loss obtained by testing the stator body of the N-wire motor and the 2N-wire motor, the core loss of the stator body of the N-wire motor and the 2N-wire motor at different test points is obtained; Step S107: Use the obtained core loss value to correct the core loss simulation model of the N-wire motor and the 2N-wire motor, and output the core loss of the N-wire and 2N-wire motors at different speeds and torques.

2. The method for separating and measuring AC copper loss and iron loss of a motor according to claim 1, characterized in that: In speed control, the armature magnetic field of part of the stator body rotates at the same speed as the rotor magnetic field; The synchronous rotation angles of the armature magnetic field and the rotor magnetic field between the partial stator bodies of the N-line motor and the 2N-line motor at each test point are consistent.

3. The method for separating and measuring AC copper loss and iron loss of a motor according to claim 1, characterized in that: The step S102 includes: obtaining the total loss of the two devices under test according to the difference between the power input power and the output power of the motor under test by installing torque and speed sensors between the towing motor and the motor under test; The motor input active power is obtained from the input current and input voltage: P0=U0I0cosφ Among them, P0 is the motor input active power, U0 is the input voltage, I0 is the input current, and φ is the phase angle between the input voltage and the input current; According to the torque and speed sensors installed between the towing motor and the motor under test, the output power of the motor under test is obtained by the following formula: Among them, P m is the motor output power, T is the torque, and n is the speed (r / min); Based on the input active power and output power, the total loss of the test device is obtained: P=P0-P m Among them, P is the total loss of the motor, P0 is the active power input of the motor, and P m is the output power.

4. The method for separating and measuring AC copper loss and iron loss of a motor according to claim 1, characterized in that: The step S103 includes: while keeping the rotation speed and current of the two motors consistent, obtaining the difference ΔP of the AC copper loss at each rotation speed and current value by the difference of the total loss of part of the stator body of the N-wire motor and the 2N-wire motor. e .

5. The method for separating and measuring AC copper loss and iron loss of a motor according to claim 1, characterized in that: The step S103 further includes: obtaining the equivalent resistance difference ΔR of the partial stator windings of the N-wire motor and the 2N-wire motor according to the external circuit characteristics of the partial stator bodies of the N-wire motor and the 2N-wire motor, while keeping the rotation speed and current of the two motors consistent, according to the magnitude of the terminal voltage and its phase with the current, and also calculating the difference ΔP of the AC copper loss at each rotation speed and current value by the following formula: e : ΔP e =nI 2 ΔR Among them, n is the number of motor phases and I is the effective value of current.

6. The method for separating and measuring AC copper loss and iron loss of a motor according to claim 1, characterized in that: The step S105 includes: replacing the rotor with an unmagnetized rotor, driving the rotor with a towing motor, and measuring the no-load loss at various speeds and current values ​​according to the torque and speed sensors, that is, the sum of wind friction loss, bearing loss and stray loss: Among them, P f is the no-load loss, T1 is the torque, and n1 is the speed (rpm).

7. The method for separating and measuring AC copper loss and iron loss of a motor according to claim 1, characterized in that: The step S106 includes: obtaining the core loss by subtracting the no-load loss and the AC copper loss of the winding from the total loss of the partial stator and the full rotor structure: P Fe =P-P e -P f Among them, P Fe is the motor core loss, P is the total motor loss, P e is the motor AC copper loss, P f It is the no-load loss of the motor.

8. A system capable of separating and measuring AC copper loss and iron loss of a motor, based on the method for separating and measuring AC copper loss and iron loss of a motor according to any one of claims 1 to 7, characterized in that: include: A motor rotor (1), two opposed partial stator bodies (2), a rotating shaft (3), a winding retaining ring (4), a rectangular conductor (5), a partial stator body fixture (6), and a pair of motors; The pair of motors are connected to a rotating shaft (3), and the motor rotor (1) is located between a portion of the stator body clamps (6) and rotates around the rotating shaft (3); The two partial stator bodies (2) are symmetrically arranged on both sides of the motor rotor (1); The winding retaining rings (4) are arranged at both ends of the motor rotor (1); and the rectangular wire (5) is wound around the part of the stator body (2).

9. The system for separating and measuring AC copper loss and iron loss of a motor according to claim 8, characterized in that: The contour features of the two partial stator bodies (2) are consistent with the shape of the motor being measured, and each partial stator body (2) comprises at least one number of slots corresponding to the number of pole pairs; A torque speed sensor is arranged between the motor rotor (1) and the towing motor; The rectangular wires (5) of the two symmetrically arranged partial stator bodies (2) are wound in opposite directions.

10. The system for separating and measuring AC copper loss and iron loss of a motor according to claim 8, characterized in that: The partial stator body (2) is respectively wound with N-wire and 2N-wire conductors in each slot to form an N-wire motor and a 2N-wire motor; during the winding, the winding is performed in opposite directions between the two stator bodies, and the shape of the winding conductor is such that the width of the N-wire and 2N-wire motors is the same, the height of the N-wire winding conductor is twice that of the 2N-wire winding conductor, and the total copper cross-section of the conductor in each slot is kept equal to that of the 2N-wire winding conductor; The 2N line winding uses two wires wound in parallel on the connecting line, that is, the current passing through the single wire of the N line motor and the double wires of the 2N line motor are consistent, and the average current density is consistent.

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