Virtual machine testing of electric machines using physical domain performance characteristic maps

Abstract

A system, method, and computer program product for virtually machine testing an electric machine (8). A test signature comprising parameter values measured during one or more static tests of the electric machine (8) is compared to a reference signature generated by performing a similar series of static tests on a reference machine (42). The reference machine is then validated by subjecting it to full load dynamic tests. The test signature and the reference signature can comprise a plurality of parameters each characterizing a physical property of the respective machine (8, 42) in one or more physical domains. The parameters are selected by comparing the test signature to the reference signature such that the electric machine (8) can be qualified for field operation, thereby avoiding the need for full load dynamic tests of the electric machine (8).

Description

Technical Field

[0001] This invention relates generally to the testing of electric machines, and more particularly to methods, systems, and computer program products for factory acceptance testing of large electric machines used in wind turbine power generation. Background Technology

[0002] Wind turbines are becoming an increasingly important source of electricity due to their low carbon footprint and growing concern about the environmental impact of traditional power generation methods. However, to accelerate the replacement of fossil fuel-dependent plant equipment with wind turbines and remain competitive with other forms of renewable energy, it is crucial to continue reducing the cost of power generation from wind turbines. One source of cost associated with wind turbines is the factory acceptance testing of the generators.

[0003] Due to the costs of transporting and installing generators in wind power applications, wind power system operators typically require each generator to undergo full-load testing before acceptance. Compared to onshore systems, the reliability of wind turbine components, such as generators, is particularly important for offshore wind power systems due to the increased costs and time involved in maintaining these turbines.

[0004] A standard full-load test of a generator involves mechanically connecting the rotor of the generator under test to another motor operating as an electric motor. The electric motor converts electrical energy into rotational energy supplied to the generator, and the generator converts this rotational energy back into electrical energy. Additional power from the grid is used to supplement the power generated by the generator under test, compensating for power losses in both the electric motor and the generator, and feeding this power back into the electric motor.

[0005] Because full-load testing requires replicating the mechanical and electrical systems under full operating conditions, it can be expensive. Costs include capital costs for the test equipment, the time required for testing, and the labor resources needed to conduct the tests. As generator size increases, the electrical and mechanical forces involved in generator full-load testing also increase. This raises the size and cost of the test equipment, as well as the time spent setting up the test. Therefore, testing costs are proportional to the size and rated power of the generator being tested. Furthermore, these testing costs may need to be repeated at all manufacturing sites, further increasing the total product cost.

[0006] To meet the increasing demand for wind energy, manufacturers have developed wind turbines with larger capacities, which require correspondingly larger generators. Furthermore, many of these large-capacity wind turbines are deployed offshore to take advantage of favorable wind conditions found there and to reduce the impact of wind turbines on people living in coastal areas. Consequently, the need to test generators used in wind power systems and the cost of such testing are both on the rise.

[0007] Therefore, there is a need for improved systems, methods, and computer programs for testing production machines that provide a high level of confidence that the production machines will function properly, without the time and expense of full-scale dynamic testing. Summary of the Invention

[0008] In an embodiment of the present invention, an apparatus for testing an electric motor is provided. The apparatus includes one or more processors and a memory coupled to the one or more processors. The memory includes program code that, when executed by the one or more processors, causes the apparatus to: measure a first value of a first parameter indicating the response of at least one device under test (DUT) to a static test; and generate a test signature map at least in part based on the first value of the first parameter. The apparatus compares the test signature map with a reference signature map. If the test signature map matches the reference signature map, the apparatus allows the at least one DUT to pass. If the test signature map does not match the reference signature map, the apparatus causes the at least one DUT to fail.

[0009] In one aspect of the invention, the program code may also enable the device to: stimulate the at least one device under test using at least one stimulus source, and the response of the at least one device under test may be a reaction to the stimulus source.

[0010] In another aspect of the invention, the at least one excitation source can simulate the operating conditions of the device under test.

[0011] In another aspect of the invention, the reference feature map can be generated by measuring a second value of a first parameter of the response of the reference device to the static test, and generating the reference feature map based at least in part on the second value of the first parameter.

[0012] In another aspect of the invention, a second value of the first parameter used to generate the reference feature map can be measured before the reference device is subjected to a conformity test, and a third value of the first parameter used to generate the reference feature map can be measured after the reference device is subjected to a conformity test. A post-performance test feature map can be generated based on the third value of the first parameter, and one or more of the reliability prediction, wear prediction, or aging prediction of the reference device can be determined by comparing the post-performance test feature map with the reference feature map.

[0013] In another aspect of the invention, the test feature map includes at least a portion of a test map of the at least one device under test, the reference feature map includes at least a portion of a reference map of a reference device, and a first parameter of the at least one device under test is determined based on the at least a portion of the test map.

[0014] In another aspect of the invention, each test image and each reference image are divided into multiple cells, and the first parameter of each cell in the test image is compared with the first parameter of the corresponding cell in the reference image.

[0015] In another aspect of the invention, the first parameter defines a first physical property of the first physical domain, wherein the first physical domain is one of a magnetic domain, an electric domain, a thermal domain, and a mechanical domain.

[0016] In another aspect of the invention, the first parameter may define a first physical property of the first physical domain, and each feature map in the test feature map and the reference feature map may include a second parameter, which defines a second physical property of a second physical domain that is different from the first physical domain.

[0017] In another aspect of the invention, the first physical domain may be one of a magnetic domain, an electric domain, a thermal domain, and a mechanical domain, and the second physical domain may be another of a magnetic domain, an electric domain, a thermal domain, and a mechanical domain.

[0018] In another aspect of the invention, the at least one device under test may include the stator of a test machine, the at least one excitation source may include an electrical signal applied to the windings of the stator, and the first parameter may include the temperature of the stator.

[0019] In another aspect of the invention, the test feature map may include at least a portion of the test thermal map of the at least one device under test, the reference feature map may include at least a portion of the reference thermal map of the reference device, and the temperature of the at least one device under test may be determined based on the at least a portion of the test thermal map.

[0020] In another aspect of the invention, each heatmap can be divided into multiple cells, and the temperature of each cell in the test heatmap can be compared with the temperature of the corresponding cell in the reference heatmap.

[0021] In another aspect of the invention, the testing machine may include one or more thermal sensors, and a test thermal map is used to calibrate the one or more thermal sensors.

[0022] In another aspect of the invention, the at least one excitation source may include a mechanical forcing function applied to the input point of the at least one device under test, and the first parameter may be the vibration of the at least one device under test.

[0023] In another aspect of the invention, the test feature map may include at least a portion of the test vibration map of the at least one device under test, the reference feature map may include at least a portion of the reference vibration map of the reference device, and the vibration of the at least one device under test may be determined based on the at least a portion of the test vibration map.

[0024] In another aspect of the invention, each vibration diagram can be divided into multiple cells, and the vibration of each cell in the test vibration diagram can be compared with the vibration of the corresponding cell in the reference vibration diagram.

[0025] In another aspect of the invention, the at least one excitation source may include an excitation mode comprising a plurality of mechanically forced functions, each of which may have an independent amplitude, an independent phase, an independent orientation, and an independent input point.

[0026] In another aspect of the invention, the at least one reference device may include components of a reference machine that have passed all conformity tests.

[0027] In another aspect of the invention, the test feature map and the reference feature map may each include a second parameter that defines a second physical property of a second physical domain that is different from the first physical domain.

[0028] In another aspect of the invention, the motor is a generator for a wind turbine, and the test of the motor is performed before the generator is installed in the wind turbine.

[0029] In another embodiment of the invention, a method for manufacturing a wind turbine is provided. The method includes: measuring a first value of a first parameter indicating the response of at least one device under test (DUT) to a static test; generating a test feature map based at least in part on the first value of the first parameter; and comparing the test feature map with a reference feature map. If the test feature map matches the reference feature map, the at least one DUT is installed in the wind turbine. If the test feature map does not match the reference feature map, the at least one DUT is not installed in the wind turbine.

[0030] In another aspect of the invention, the test feature map includes at least a portion of a test map of the at least one device under test, the reference feature map includes at least a portion of a reference map of a reference device, and a first parameter of the at least one device under test is determined based on the at least a portion of the test map.

[0031] In another aspect of the invention, each test image and each reference image are divided into multiple cells, and the first parameter of each cell in the test image is compared with the first parameter of the corresponding cell in the reference image.

[0032] In another aspect of the invention, the first parameter defines a first physical property of a first physical domain, wherein the first physical domain is one of a magnetic domain, an electric domain, a thermal domain, and a mechanical domain.

[0033] In another embodiment of the invention, a method for testing an electric motor is provided. The method includes: measuring a first value of a first parameter indicating the response of at least one device under test to a static test; generating a test feature map based at least in part on the first value of the first parameter; and comparing the test feature map with a reference feature map. If the test feature map matches the reference feature map, the method allows the at least one device under test to pass. If the test feature map does not match the reference feature map, the method allows the at least one device under test to fail.

[0034] In another embodiment of the invention, a computer program product is provided. The computer program product includes a non-transitory computer-readable storage medium and program code stored on the non-transitory computer-readable storage medium. The program code is configured such that, when executed by one or more processors, the program code causes the one or more processors to: measure a first value of a first parameter indicating the response of the at least one device under test to a static test; generate a test feature map based at least in part on the first value of the first parameter; and compare the test feature map with a reference feature map. If the test feature map matches the reference feature map, the program code causes the one or more processors to pass the at least one portable device. If the test feature map does not match the reference feature map, the program code causes the one or more processors to fail the at least one portable device.

[0035] The foregoing summary presents a simplified overview of some embodiments of the invention to provide a basic understanding of certain aspects of the invention discussed herein. This summary is not intended to provide a broad overview of the invention, nor is it intended to identify any key or essential elements, or to define the scope of the invention. The sole purpose of this summary is merely to present some concepts in a simplified form as an introduction to the detailed description that follows. Attached Figure Description

[0036] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various embodiments of the invention and, together with the general description of the invention given above and the detailed description of the embodiments given below, serve to describe the embodiments of the invention.

[0037] Figure 1 This is an exploded perspective view of the rotor assembly and stator assembly of an electric motor according to an embodiment of the present invention.

[0038] Figure 2 It is shown Figure 1 A cross-sectional view of the motor.

[0039] Figure 3 It is used in, for example Figure 1 and Figure 2 A schematic view of the test setup used to perform a full-load test on the motor.

[0040] Figure 4 It is used for execution and can be used Figure 3 The flowchart shows the process of passing the conformity test of the reference machine of the testing organization.

[0041] Figure 5 It is used for using by Figure 4 The flowchart describes the process of using the generated reference feature map to perform virtual machine testing on the production machine.

[0042] Figure 6 It can be used for measurement Figure 1 and Figure 2 A graphical view of the magnetic flux system in an electric motor.

[0043] Figure 7 It can be used to execute Figure 1 and Figure 2 A diagrammatic view of the test mechanism for thermal testing of an electric motor.

[0044] Figure 8 It can be used Figure 7 A graphical view of the heatmap generated by the testing organization.

[0045] Figures 9 to 11 It can be used to execute Figure 1 and Figure 2 A diagrammatic view of the test mechanism for testing the mechanical domain of an electric motor.

[0046] Figure 12 It can be used Figures 8 to 10 A graphical view of the vibration diagram generated by the testing organization.

[0047] Figure 13 It is a flowchart for the process of comparing a test pattern obtained from the device under test with a reference pattern obtained from a reference machine.

[0048] Figure 14 It can be used to achieve Figures 3 to 13 A diagrammatic view of one or more computers depicted in a test facility, process, system, or map.

[0049] It should be understood that the accompanying drawings are not necessarily drawn to scale and may present slightly simplified representations of various features illustrating the basic principles of the invention. Specific design features of the operational sequences disclosed herein (e.g., including the specific dimensions, orientations, positions, and shapes of the various illustrated components) may be determined in part by the specific intended application and usage environment. Some features of the illustrated embodiments may be enlarged or modified relative to other features to facilitate visualization and clear understanding. In particular, thin features may be thickened, for example, for clarity or illustration. Detailed Implementation

[0050] Embodiments of this invention are directed to systems, methods, and computer program products for virtual machine testing of motors. Virtual machine testing is a method of defining one or more key parameters in one or more physical domains of a motor. These key parameters are used to provide a characteristic map indicating the performance of the motor under operating conditions. The test characteristic map, generated based on parameter values ​​measured during one or more static tests of the motor (i.e., the test machine), is compared with a reference characteristic map generated by performing a similar series of static tests on a reference machine. The reference machine may be a motor that has undergone full-load dynamic testing to ensure that the reference machine meets all test criteria. Comparing the test characteristic map with the reference characteristic map provides a reliable indication of whether the test machine performs like the reference machine under similar operating conditions. This allows for robust testing of production machines without full-load or partial-load testing.

[0051] Virtual machine testing can include reproducing one or more excitation sources within specific domain characteristics of the test machine's operating environment. These excitation sources can be reproduced, for example, by feeding energy into the device under test (e.g., the test machine or a component thereof). The response of the device under test to each excitation source can be compared with one or more responses obtained from a reference device (e.g., a reference machine or a component thereof) subjected to the same or equivalent excitation sources. Virtual machine testing of a reference device can establish a reference characteristic map for a specific type of motor tested at a specific power level. This reference characteristic map can then be used as a comparative basis for subsequent testing of similar motors.

[0052] Physical domain tests that can be used to generate reference feature maps can include, but are not limited to, magnetic domain tests, electrical domain tests, thermal domain tests, and mechanical domain tests. Virtual machine tests can include one or more static tests that generate data in one or more of the aforementioned domains. The data generated by these tests can indicate the values ​​of various parameters of the test feature map. Each of these test parameter values ​​can be compared with the corresponding reference parameter values ​​obtained from the reference machine when the reference machine undergoes the same tests. Some parameters may have multiple dimensions. Depending on the type and resolution of the virtual machine test data obtained, virtual machine testing can provide a higher degree of passability than conventional motor testing (which is typically limited by the number of sensors that can be used).

[0053] Figure 1 and Figure 2 An exemplary motor 8 according to an embodiment of the present invention is depicted, comprising a stator 10, a rotor 12, and a housing 14, and having a radial magnetic flux topology. The stator 10 and rotor 12 are concentrically arranged. The stator 10 is fixed and stationary, and the rotor 12 is configured to rotate relative to the stator 10. When the rotor 12 rotates, it generates a rotating magnetic field that interacts with the stator 10. Although the exemplary motor 8 has only one stator 10 and one rotor 12 arranged concentrically, the embodiments of the invention are not limited thereto. It should be understood that embodiments of the invention can be used with motors having one or more rotors or one or more stators. These motors may also include a stator radially disposed within a rotor, or include a stator and rotor having an axial magnetic flux topology.

[0054] The stator 10 may include: a stator frame 15 having an annular outer yoke 16, a plurality of teeth 18 projecting radially inward from the outer yoke 16 toward the rotor 12, and a plurality of coils 20 disposed in slots between adjacent teeth 18. The teeth 18 and slots thus defined may extend along the entire length L of the stator frame 15. The stator 10 remains stationary during operation of the motor 8 and represents the non-rotating portion of the motor 8. The teeth 18 and the outer yoke 16 may be made of a ferromagnetic material. Each coil 20 may comprise a ring or turn of conductive material electrically insulated from each other. Each coil 20 may also be connected in series with one or more other coils 20 to collectively form the windings of the stator 10.

[0055] The rotor 12 may include a rotor core 22, a plurality of magnetic poles 28 circumferentially distributed around the rotor core 22, and a drive shaft 24 that operatively connects the rotor core 22 to an external load (when operating as a motor) or an external rotating energy source (when operating as a generator). The drive shaft 24 is configured such that the rotor 12 is rotatable about its longitudinal axis 26. The rotor 12 may be generally cylindrical and includes a plurality of magnetic poles 28 such that an air gap 30 is defined between the magnetic poles 28 and the distal ends of the teeth 18 of the stator 10. When the motor 8 is operating, the rotor 12 rotates or spins relative to the stationary stator 10 about the longitudinal axis 26.

[0056] When operating as a generator, the stator 10 and rotor 12 of the motor 8 work together to convert rotational energy received through the drive shaft 24 into electrical energy. Thus, the motor 8 can generate electricity using the kinetic energy provided by the prime mover. Specifically, according to Faraday's law, the magnetic poles 28 of the rotor 12 induce currents in the individual coils of the stationary coils 20 of the stator 10 through motion. These currents can then be connected to an external load supplying power to it.

[0057] Although the motor 8 has a rotor 12 with magnetic poles 28 depicted as permanent magnets, the embodiments of the present invention are not limited thereto. For example, a motor 8 with a rotor 12 having magnetic poles 28 provided by an electromagnet can also be used. In addition, the motor 8 may also be configured with magnetic poles 28 in the stator 10 and coils 20 in the rotor 12.

[0058] Figure 3 An exemplary test apparatus 40 is illustrated for demonstrating the qualification of a reference machine 42 using full-load or partial-load testing. The test apparatus 40 includes a motor 44 having a rotating shaft 46 operatively connected to a rotating shaft 48 of the reference machine 42 via a coupling 50. The reference machine 42 and the motor 44 may be replicated motors and typically operate in generator mode and motor mode, respectively. The reference machine 42 may, for example, be a prototype motor used to validate a new design, or it may be a production machine selected from an assembly line to serve as a reference for virtual machine testing of other production machines.

[0059] Coupling 50 can be configured to allow adjustment of the rotation angle of shafts 46, 48 to set the displacement angle between reference machine 42 and motor 44. Since the shaft power of the synchronous machine depends on the shaft displacement angle, the load on reference machine 42 can be adjusted by changing the angle of the coupling between reference machine 42 and motor 44. Current 52 output from reference machine 42 can be fed back to motor 44 via power coupler 54. Additional current 56 from power source 58 (e.g., mains grid) can be combined with the current 52 generated by reference machine 42, and the combined current 60 is fed into motor 44. The current drawn from power source 58 is sufficient to compensate for internal losses in reference machine 42 and motor 44.

[0060] Test facility 40 provides mechanical and electronic systems that can be used to replicate the full operating conditions required for full-load testing. However, full-load testing can be expensive due to the capital costs of the test equipment and the time and labor resources required to perform each test. The scale of these costs is directly related to the machine size and rated power, and therefore, performing full-load testing on these machines becomes increasingly expensive as motor capacity increases. Routine factory acceptance testing typically requires individual production machines to operate at full torque and full power across their entire operating speed range. This necessitates the ability to perform full-load testing on each production machine.

[0061] Virtual machine testing involves using a reference machine 42 to establish a reference characteristic map, which is used to demonstrate the qualification of an additional motor reaching a similar confidence level without repeating the full-load test mechanism 40. Advantageously, this allows large production machines to be demonstrated as qualified generators without subjecting them to full-load testing.

[0062] Figure 4 A flowchart illustrating an exemplary process 70, which can be used to generate one or more reference feature maps for evaluating a motor according to an embodiment of the invention, is depicted. In block 72, process 70 selects a motor to be used as reference machine 42. This motor may be a prototype for production operation of the motor, or it may be selected from a set of production machines that have been accepted using virtual machine testing.

[0063] In response to selecting a motor, process 70 can proceed to block 74 and obtain one or more pre-performance test characteristic maps from the motor. Obtaining these test characteristic maps may include subjecting the motor or one or more components thereof to one or more static tests. Exemplary static tests may include: rotor flux testing, stator winding electrical testing, stator thermal testing, and rotor vibration testing. Exemplary systems and processes for performing static tests and obtaining parameter values ​​used to generate the test characteristic maps are described in more detail below.

[0064] In box 76, process 70 can perform a full compliance test on the selected motor. The full compliance test may include, as referenced above. Figure 3 The described full-load test, as well as any other tests required by the customer for conformity testing, are included. If the motor fails all conformity tests (the "No" branch of decision box 78), the process can proceed to box 80, rejecting the motor and returning to box 72 to select another motor to demonstrate its conformity as a reference machine. The rejected motor can be sent back to the factory for repair, or it can be scrapped, and another motor is selected for testing as a reference machine.

[0065] If the motor passes the full compliance test (the "Yes" branch of decision box 78), process 70 can proceed to box 82. In box 82, process 70 can save the pre-performance test feature map (e.g., saved in a test feature map database) for use in performing virtual machine tests on other motors. Process 70 can then proceed to box 84 and obtain the post-performance test feature map from the motor. The post-performance test feature map can be obtained from the motor in the same manner as the pre-performance test feature map.

[0066] In box 86, process 70 can save the post-performance test characteristic map for use in reliability, wear, and aging studies. Comparing the post-performance test characteristic map with its corresponding pre-performance test characteristic map can provide information about how the motor responds to aging and use. This information can be used to identify which components are most likely to fail over time and how operating conditions affect component aging and wear. Because certain aspects of the conformance tests performed on the reference machine in box 76 can be expected to cause wear on the motor, the post-performance test characteristic map of the reference machine is typically used only to characterize the impact of the tests on the reference machine. That is, the post-performance test characteristic map is generally not suitable as a reference characteristic map.

[0067] Reference feature maps stored in a database can be used for virtual machine testing of additional motors. A test feature map obtained from a production machine can be considered to match one or more reference feature maps if the difference between the test feature map and the reference feature map is within the measurement tolerance of the parameter being measured. These test feature maps can also be considered to match if they are within any other threshold level that does not produce a substantial difference between the performance of the device generating the test feature maps. For example, these threshold levels can be determined on a parameter-by-parameter basis using empirical data obtained from test motors with test feature maps having different parameter values.

[0068] Virtual machine testing is not a fully dynamic rotating machine test, but rather measures one or more parameters of the device under test (which may be a motor or its components) in one or more physical domains. Exemplary parameters can include any physical property indicating the characteristics of the device under test, such as current, voltage, impedance, magnetic flux, temperature, vibration, etc. The parameter values ​​measured for the device under test can then be compared with the parameter values ​​determined for a reference machine using the same static tests. Because motor performance is typically deterministic, with appropriate selection of the measured parameters, a device under test with parameter values ​​matching those of the reference machine can be expected to perform similarly.

[0069] Figure 5 A flowchart illustrating an exemplary process 90 for virtual machine testing of a production machine, according to an embodiment of the present invention, is depicted. In block 92, one or more test feature maps can be obtained from the production machine. These test feature maps can be obtained by performing one or more static tests and generating the test feature maps based on data collected during at least one of these tests. For example, the test feature maps may include a set of parameter values, each corresponding to the result of a specific test. Static tests performed on the production machine may include tests that determine one or more magnetic, electrical, thermal, or mechanical parameters of the production machine as a whole or of a component of the production machine (such as stator 10 or rotor 12).

[0070] Once the test feature maps are obtained, process 90 can proceed to box 94, where each test feature map in the one or more test feature maps generated for the production machine is compared with its corresponding reference feature map. If the comparison meets predefined acceptance criteria (the "Yes" branch of decision box 95), process 90 can proceed to box 96, classifying the production machine as having passed factory acceptance testing, and releasing the production machine for delivery, for example, by changing the machine's status in the inventory tracking database.

[0071] If the comparison fails to meet the predetermined acceptance criteria (the "No" branch of decision box 95), process 90 can proceed to box 98 and the production machine is rejected. Based on the results of the virtual test, the rejected production machine can be rebuilt or repaired and then retested. In other cases, certain components can be reused in other production machines, or the failing production machine can be scrapped.

[0072] Virtual machine testing, instead of relying on full-scale dynamic machine testing of production machines to verify compliance with factory acceptance criteria, extends or replaces machine testing at the component, subcomponent, or part level. These building blocks of production machines can be used in a controlled manner to stimulate test components in a controlled set of one or more physical domains. Virtual machine testing can be performed at different levels of the product lifecycle and for different reasons. For example, virtual machine testing can be performed at the factory level for factory acceptance testing as a way to avoid having to invest in fully loaded test facilities and verify high reproducibility relative to a validated reference machine. At the design verification level, specialized test chambers can be used to perform enhanced high-accelerated life testing (HALT), etc. This facilitates the study of extreme load behavior, lifecycle / reliability, etc., without requiring dynamic full-power overload test benches. Virtual machine testing can also be used to accelerate cyclic loading mechanisms, enabling tests to be completed in days or weeks instead of months. Virtual machine testing can also allow for the examination of failure modes that would be too expensive or dangerous to allow during full-power testing.

[0073] Magnetic field test

[0074] Magnetic field testing can include tests that generate data indicating one or more characteristics of the magnetic field generated by the motor, such as flux density and orientation. The magnetic field within the motor can be measured using one or more magnetic sensors, such as fluxgate sensors, Hall effect sensors, magnetoresistive sensors, induction coils, or any other suitable sensors. For example, a magnetic sensor can output a voltage or current proportional to the density of the magnetic field passing through the probe. Magnetic sensors can be positioned to measure the magnetic field density in critical areas, such as the magnetic field density in the air gap between the motor's rotor and stator. These measurements can provide an indication of whether the motor is generating a magnetic field consistent with proper operation.

[0075] Check the back electromotive force voltage V generated by the motor while the rotor is spinning. B_EMF It can provide an indication of the overall condition of the magnetic components of the motor. For permanent magnet generators, comparing the flux diagram of the device under test with that obtained from a reference machine can provide information similar to checking the back electromotive force voltage V. B_EMF The information provided is equivalent to (or even more detailed than) the information provided, but it is not necessary to make the rotor spin.

[0076] Figure 6An exemplary system 100 for measuring magnetic flux in an electric motor including a stator 102 and a rotor 104 is depicted. The rotor 104 includes a plurality of magnets 106 held in place by a retainer 107 and movable relative to the stator 102, as indicated by arrows 108, 109. The system 100 also includes a plurality of magnetic sensors 110 that may be located in the stator 102. The magnetic sensors 110 are configured such that the magnets 106 pass by the magnetic sensors 110 as the rotor 104 rotates. Each time a magnet 106 passes by a magnetic sensor 110, a signal 112 (e.g., current or voltage) may be generated by the magnetic sensors 110. The signal 112 may have an amplitude proportional to the magnetic flux density at the sensor, the rate of change of the magnetic flux density with respect to time, the orientation of the magnetic flux relative to the sensor 110, or any combination of flux density, rate of change, and orientation.

[0077] The signal 112 generated by the magnetic sensor 110 can be provided to a measuring device 114 that records the signal. For example, the signal 112 can be recorded by periodically sampling the signal. These samples may include data indicating the amplitude of the signal 112 at the time of sampling. The samples can be stored in memory as magnetic flux data indexed to the magnetic sensor 110 that provides the signal, the sampling time, the position of the rotor 104 at the time of sampling, or any combination thereof. The rotational position of the rotor 104 allows the magnetic flux data received from the magnetic sensor 110 to be associated with a specific magnet 106 of the rotor 104.

[0078] The stored magnetic flux data can be used to generate a flux map indicating the magnetic flux density relative to the position on rotor 104. The flux map provides a graphical depiction of the magnetic field density in and around rotor 104. Therefore, the flux map facilitates verification of the adequate magnetization of magnet 106 or identification of areas of rotor 104 requiring attention. The flux map obtained for generator production can be compared with a reference flux map obtained from a reference machine. Image analysis techniques can be used to quantify the differences between the flux maps. If the difference exceeds a threshold, the device under test may fail.

[0079] The magnetic sensor 110 can be permanently embedded in the stator 102 (e.g., during manufacturing), temporarily mounted to or embedded in the stator 102 (e.g., to test the rotor 104 by replacing one or more segments of the stator coil), or may include a portion of the windings of the stator 102. For embodiments where the magnet 106 is magnetized in situ, the magnetic sensor 110 can be integrated into the magnetization system. The same system used to magnetize the rotor 104 can then be used to generate a multidimensional (e.g., two-dimensional) flux map of the rotor 104. This allows for immediate analysis of flux data after the rotor 104 is magnetized, and corrective actions can be taken if any magnetic anomalies are detected. Acceptance criteria can be developed by comparing the flux map of the device under test with one or more flux maps generated for one or more reference machines. In the case of flux map matching, the back electromotive force voltage V B_EMF The test may be redundant and therefore omitted.

[0080] Electric Domain Testing

[0081] Electrical domain testing may include tests that generate data indicative of one or more characteristics of the stator windings. Winding characteristics may include: winding configuration (i.e., how the conductors are wound on the stator), conductor integrity (e.g., the presence or absence of open circuits), the integrity of the conductor insulation coating (e.g., the presence or absence of short circuits), and appropriate electrical connectivity. This data can be obtained by monitoring the stator's response to an excitation source provided by applying an electrical signal with specific characteristics (e.g., amplitude and waveform) to the windings.

[0082] Static electrical domain testing can include: insulation integrity testing (e.g., insulation resistance, high latent stress, surge testing), partial discharge testing, and measuring winding impedance parameters (e.g., resistance, inductance, capacitance) using DC current and time-varying signals with different frequency components. All parameter values ​​obtained from these tests can be tracked during production and compared with corresponding parameter values ​​obtained from a reference machine.

[0083] Thermal testing

[0084] Typically, the primary losses and critical temperatures in a motor are due to ohmic losses in the windings. Other sources of power loss can include losses due to eddy currents and hysteresis in the stator core, vibration, and skin depth effects in the windings. Static thermal testing can involve stimulating the device under test (DUT) (e.g., the stator) with a high-power alternating current while capturing thermal images of the DUT to form its thermal map. Thermal images can be captured over a period of time to record both transient and steady-state thermal characteristics of the DUT. Using these thermal images, thermal maps can be generated for the DUT under various excitation conditions. The thermal map from the production machine can then be compared with a thermal map obtained from a reference machine as part of a virtual machine test protocol.

[0085] Figure 7 An exemplary thermal testing apparatus 200 is depicted that can be used to test an electric motor or its components. The testing apparatus 200 may include: a computer 202, a thermal imaging camera 204 operably coupled to an electric motor 206 via a shaft 208, a power supply 210 (e.g., a power grid), a power control device 212 (such as a silicon controlled rectifier (SCR)), and a transformer 214. The power control device 212 can be operably coupled to the power supply 210 via the transformer 214. The computer 202 can be operably coupled to the thermal imaging camera 204, the electric motor 206, and the power control device 212 to control the test and collect data.

[0086] Transformer 214 may be a high-current transformer configured to regulate the voltage supplied by power supply 210. Transformer 214 may generate a full-load alternating current (e.g., three-phase current) at a fraction of the motor's rated power (e.g., using approximately 1% to 2% of the rated power) to provide the full-load alternating current to the device under test, such as stator 215. The voltage output from transformer 214 may be selectively applied to stator 215 by power control device 212 (e.g., by voltage pulse width modulation) to excite stator 215.

[0087] The test chamber 200 can be configured to accept the frame assembly 216, which includes a stator 215, a housing 218, a cooling chamber 220, a fan 222, and any other electrically energized parts of the motor. The cooling chamber 220 can be operatively coupled to a coolant source 224 and a fan 222 configured to supply cooling air 226 to the stator 215 during testing, so that the test chamber 200 provides a cooling level similar to that found in the operating environment of the frame assembly 216.

[0088] Without a rotor, the frame assembly 216 can be placed in the test chamber 200. The absence of a rotor facilitates the insertion of the thermal imaging camera 204 into the stator 215. The windings of the stator 215 can be electrically connected to the power supply 210 via a transformer 214 and a power control device 212, allowing the computer 202 to control the amount of power supplied to the stator 215. The amount of power supplied to the stator 215 can be varied depending on the size of the motor and the intended application. For example, the stator 215 from a generator outputting 12MW at 12kA can be excited with 200kW of power during thermal testing.

[0089] During testing, computer 202 can cause motor 206 to rotate thermal imaging camera 204 to obtain a 360-degree thermal image of the interior of stator 215 (i.e., the "center winding"). Thermal imaging camera 204, or one or more additional thermal imaging cameras (not shown), can also be moved or positioned to capture thermal images of the ends of stator 215 (i.e., the "end windings"). Computer 202 can convert the 360-degree thermal image into a heat map comprising multiple cells. Each cell entry in the heat map can then be compared to a corresponding cell in a reference heat map generated for a reference machine. This comparison may include generating a thermal divergence map, which includes cells showing the temperature difference between each cell in the test heat map and its corresponding cell in the reference heat map. The thermal divergence map can further identify the level of consistency between motors and the acceptability of each motor for certification. This thermal testing method can provide better information than load testing because it provides thermal data across the entire frame assembly 216 rather than just where the thermal sensors are located. Therefore, the thermal image can provide a thermal characteristic map of the motor, which can be compared with the thermal characteristic map of the reference machine.

[0090] The thermal imaging camera 204 can generate a two-dimensional map of the temperature of the device under test (DUT). By moving the camera, a three-dimensional representation of the DUT's thermal response can be generated. The thermal image captured by the thermal imaging camera 204 can be converted into a thermal feature map of the DUT, which is used as a basis for comparing the motor with other motors (such as a reference motor). Advantageously, the thermal image can provide thermal data with a higher spatial resolution than the actual spatial resolution of the embedded temperature probe. This higher-resolution thermal data can be used to generate one or more thermal parameters representing the total thermal response of the DUT. These thermal parameters can be used as part of a test feature map that includes parameters generated by testing in other physical domains.

[0091] As described above regarding flux maps, the thermal map generated for the device under test (DUT) can be compared with a thermal map generated from a reference machine prior to load testing. Thermal imaging tests can be performed individually on any suitable component of the motor, such as the stator and rotor. For motors using permanent magnets, thermal imaging tests may only need to be performed on the component containing the windings (typically the stator). Stator thermal imaging tests, independent of the rotor, allow mapping of the entire cylindrical surface of the stator, including end turns, cores, power leads, bus rings, terminations, etc. The spatial resolution of thermal imaging tests can be higher than tests based on thermal data obtained from discrete temperature sensors. Thermal imaging data also avoids data variability caused by variations in the arrangement of temperature sensors within the DUT.

[0092] Data extracted from the thermal map of the production machine can be compared with temperature data obtained from temperature sensors integrated into the motor. This data comparison can include generating machine-specific correlations between the component's thermal map and the component's temperature sensor. This allows for the calibration of temperature sensors in individual components. This calibration, in turn, improves the accuracy of thermal monitoring of operating motors compared to uncalibrated motors. The thermal map of the production unit can also be compared with a thermal map from a reference machine to demonstrate equivalence. Similarly, thermal maps can be generated before and after load testing of the reference machine to determine the degree of variability (if any) and characterize the aging and wear characteristics of the reference machine.

[0093] Thermal testing can include tests that generate data indicating the thermal properties of a motor or its components. Thermal properties can include the motor's ability to dissipate heat generated by electrical losses at rated output and ambient temperatures. In some embodiments, thermal images of motor components (e.g., stator, rotor, etc.) can be obtained when these components are supplied with current equivalent to rated conditions. These thermal images can then be used to determine the thermal response of the components.

[0094] Figure 8 This is a schematic view depicting an exemplary heat map 250 of stator 215. Heat map 250 includes a center winding region 252 corresponding to the center winding of stator 215, and two end winding regions 254 and 256 corresponding to the end windings at the drive end and the non-drive end of stator 215, respectively. Heat map 250 may be divided into multiple cells 258 by a grid 260 including grid lines 262. The positions of each cell 258 of heat map 250 may be identified by rows and columns (e.g., AA, AB, AC, etc.). Each cell 258 may be associated with one or more temperature parameters of a surface of stator 215 located in the region corresponding to the portion of heat map 250 defined by cell 258.

[0095] Cell 258 can be of any suitable size and can be categorized into regions corresponding to specific portions of stator 215. These regions may include end winding regions 254, 256, center winding region 252, or regions corresponding to specific components of stator 215. Specific components of stator 215 may include: teeth, slots between teeth, specific portions of windings, and electrical connections to the outside, such as slip rings, power leads, etc. These regions can be analyzed to identify individual hot spots, the average temperature within each region, and the overall average temperature of thermal map 250.

[0096] Exciting the stator 215 by feeding electrical energy into it allows the rotor to be removed during testing. Advantageously, this test configuration enables the thermal imaging camera 204 to image the inner surface of the stator 215. This allows for the direct measurement of high-resolution thermal data of the bore or inner diameter (in the case of a radial field machine) using the thermal imaging camera 204.

[0097] Although the above description focuses on the stator of a radial field motor, it should be understood that the techniques described can be used with other topologies, such as motors with external rotors, axial field motors, etc. These techniques can also be used to test other components of the motor, such as rotors with poles provided by electromagnets or those including motor windings. It should also be understood that measurements can be performed on a transient or thermally steady-state basis. Test scenarios can include testing with the cooling system in place and operational, testing with the cooling system disabled, or determining the thermal effects of disabling the cooling system after the motor has reached thermal equilibrium.

[0098] The parameter values ​​extracted from heatmap 250 can be numerically processed to provide a quantitative basis for comparing the thermal parameters of the production machine with those of a reference machine. For this purpose, the thermal parameters of the production machine can be obtained from heatmap 250 and compared with those of the reference machine. This comparison can be performed using thermal parameters obtained using the same grid lines 262, a mapped coordinate system, test conditions for motor excitation and cooling, and the same time step in the case of instantaneous measurements.

[0099] It should be understood that steady-state and transient thresholds can reveal quantitative similarities between a production machine and its reference counterpart in a variety of fundamental physical properties. These properties may include: loss characteristics of the stator core and conductor components, thermal inertia (specific heat & density) and thermal conductivity of the components of the device under test, as well as the effectiveness of the cooling system and the thermal resistance between the various heat sources and the cooling medium.

[0100] Mechanical domain testing

[0101] Mechanical testing characterizes the mechanical properties of the device under test (DUT) in a static sense. Multiple mechanical tests can be performed to ensure conformity between the device being evaluated and a reference device. These mechanical tests may include applying time-varying forces, static forces, or a combination of time-varying forces and static forces to the DUT. The response of the DUT can then be characterized and compared to the response of the reference device or one of its components to the same test conditions.

[0102] One type of mechanical domain testing is vibration testing. Vibration testing involves applying energy, in the form of a mechanically forced function, to the device under test. This can be achieved by attaching the device under test to a shaker table. However, vibration testing facilities using shakers designed for devices with wind turbine generator-level mass can be as expensive as, or even more expensive than, full-load compliance testing facilities.

[0103] To avoid the impracticality of using vibration tables in vibration testing, one or more exciters (e.g., inertial exciters) can be connected to the stator, rotor, or other device under test (DUT) to excite it. The response of the DUT to a mechanically forced excitation source can then be characterized by measuring the movement of one or more parts of the DUT.

[0104] Figure 9 An exemplary mechanical domain testing mechanism 300 according to an embodiment of the present invention is depicted. The testing mechanism 300 includes one or more (e.g., two) exciters 302, each exciter being coupled to a corresponding input point 304 of a device under test (DUT) 306. A vibration sensor 308 (e.g., an accelerometer) located closest to each input point 304 can provide a signal indicating the amount of energy being introduced into the DUT 306 at the input point 304. The testing mechanism 300 may also include one or more (e.g., two) waveform generators 310 that generate a specified forced function. The outputs of each waveform generator 310 can be operatively coupled to the corresponding exciter 302 via an amplifier 312. Each amplifier 312 can be configured to amplify the driving function so that the exciter 302 is provided with sufficient power to operate correctly. The computer 314, configured to control the test mechanism 300, can be operatively connected to the various vibration sensors 308 and waveform generator 310, as well as the vibrometer 316 (e.g., a scanning laser Doppler vibrometer (SLDV)) or other devices configured to measure the response of the device under test 306 to the mechanical force function provided by the exciter 302.

[0105] Each exciter 302 may include a transducer that delivers a time-varying force having a controlled frequency content and amplitude. Each exciter 302 may be rigidly coupled to the device under test 306 at a predetermined position and in a predetermined orientation. The position and orientation of the exciter 302 may be selected so that a mechanical forcing function is introduced into the device under test at a desired point and with a desired vector. The mechanical forcing function provided by each exciter 302 may have a phase, frequency content, and amplitude corresponding to the electrical forcing function provided by the corresponding waveform generator 310.

[0106] For forced functions with frequency content limited to below approximately 100 Hz, an exciter 302 with a servo-hydraulic or pneumatic transducer can be used. For forced functions including frequencies in the range of approximately 5 Hz to 2000 Hz, an exciter 302 with an electric transducer can be used. The energy output of the exciter 302 can be controlled by a computer 314 to maintain a predetermined amount of acceleration at the input point 304 of the device under test 306.

[0107] While the exciter 302 is exciting the device under test 306, a vibrometer 316 can be used to characterize the response of the device under test 306 to a mechanically forced function. In an embodiment of the invention using a laser Doppler vibrometer, the vibrometer 316 can measure the vibration of the surface using a laser beam aligned with the surface of the device under test 306. The amplitude and frequency of the vibration can then be determined based on the Doppler shift of the reflected laser beam caused by the surface motion. The laser Doppler vibrometer can thus generate a real-time multidimensional vibration map showing the response of the device under test 306 to the selective excitation of the exciter 302. Standing waves and instantaneous vibrations can be mapped from the three-dimensional image of the device under test 306. In an alternative embodiment of the invention, one or more vibration sensors (e.g., accelerometers) mounted to the device under test 306 can be used to determine the response of the device under test 306. The spatial resolution of the vibration map in this alternative embodiment may be limited by the number of points on the device under test 306 monitored by the vibration sensors.

[0108] The vibration diagram or "test vibration diagram" of the device under test 306 can be compared with a reference vibration diagram obtained by testing the same component of a reference machine under the same test conditions. Anomalies in the test vibration diagram may indicate inappropriate preload, material properties, joint continuity, imbalance, etc.

[0109] Another exemplary mechanical test is commonly referred to as a free vibration test, sometimes called a "collision test." A free vibration test provides an initial excitation source, such as a pulse, to the device under test (DUT) 306. The DUT 306 is then allowed to vibrate freely or "ring down." Free vibration tests can be used to identify the resonant frequencies and damping characteristics of the DUT 306.

[0110] Mapping the vibration levels of the entire device under test 306 and comparing these levels with those obtained from tests performed on the same device as the reference machine can provide mechanical conformity sufficient to meet factory acceptance testing requirements. The aforementioned mechanical testing can also provide information similar to that obtained from non-destructive ultrasonic testing used to evaluate composite materials or welded assemblies.

[0111] Vibration mapping of motor components (such as rotors or stators) can be performed in a similar manner to that discussed above regarding thermal mapping. An excitation source is introduced into the device under test (e.g., a forced function), and a map of the device under test's response to the excitation source is sampled and stored as a digital data file. This map is then compared to a map obtained from a corresponding component of a reference machine (which has been proven to meet all performance requirements for factory acceptance). Quantitative criteria can be applied to the production machine component on a cell-by-cell basis to confirm that the production machine component has equivalent quality to the corresponding component of the reference machine.

[0112] In the mechanical domain, the excitation source is provided by feeding kinetic energy into the device under test (DUT), unlike in the thermal domain where electrical energy is fed into the DUT. Therefore, the response function is the vibration on the surface of the DUT, rather than the temperature distribution. Another way to distinguish the mechanical domain from the thermal domain is that the input energy used to excite the DUT and the response of the DUT can have additional parameters that do not exist in the thermal domain.

[0113] The primary characteristic of a thermal domain excitation source is amplitude, i.e., the amount of electrical power supplied to the winding. Similarly, the primary characteristic of a thermal domain response is the temperature of the device under test. A similar amplitude variable in the mechanical domain is the amplitude of the forced function supplied to the input point, and the amount of movement that causes the device under test to move. However, vibration testing can include both a forced function and a motion vector. That is, the forced function of the device under test and the resulting movement can include movement components oriented along different axes, each with a different orientation.

[0114] Therefore, vibration testing can include exciting the device under test using "excitation modes" provided by multiple exciters, each introducing a corresponding forced function at a different input point and oriented along a different vector axis. Each exciter can generate a mechanical forced function with amplitude, frequency, and phase relationships, and this exciter is uniquely defined for a given excitation mode. Forced functions can be applied one at a time or simultaneously. Response modes measured in individual cells of a response plot can also have individual amplitude, frequency, and phase characteristics on a cell-by-cell basis.

[0115] Now, referring to Figures 10 to 12 ,exist Figure 10 In this example, the device under test, employing a rotor 12, can be excited by a plurality of exciters 320 configured to provide a mechanically forced function 322 oriented along a radial axis. Figure 11In this design, rotor 12 is depicted as being excited by a plurality of exciters 324 configured to provide a mechanically forced function 326 oriented along a tangential axis. In each case, rotor 12 or vibrometer 316 may be rotated about longitudinal axis 26 of rotor 12 so that vibrometer 316 captures a vibration response image of the entire outer surface of rotor 12.

[0116] The mechanical forcing functions 322 and 326 can be in phase or out of phase, can be applied independently or simultaneously, and can include multiple frequencies. Furthermore, it should be understood that the number, location, and orientation of the mechanical forcing functions 322 and 326 are merely exemplary. Therefore, embodiments of the present invention are not limited to any particular number, type, or orientation of the mechanical forcing functions.

[0117] The exciters 320 and 324 can be oriented to excite different parameters of the device under test. For example, by radially positioning the exciter 320 and synchronizing the mechanical forcing function 322 so that these functions are in phase, a response to radially symmetrical forces can be excited in the device under test. This excitation mode allows observation of vibration responses associated with centrifugal forces. If the exciter 320 is driven to make the mechanical forcing function 322 out of phase, a response to radial disturbances can be excited in the device under test. This out-of-phase excitation mode allows observation of vibration responses that may be associated with forces acting on the magnetic poles 28 when the rotor 12 rotates, the non-circular state of the rotor 12, etc.

[0118] The exciter 324 is positioned so that the mechanical forced function 326 has a vector tangent to the rotor 12 (e.g., ...). Figure 11 The described excitation pattern allows for the observation of phenomena associated with torque. A combination of radially and tangentially oriented exciters 320, 324 can be configured to apply a mechanically forced function with an off-axis vector to the rotor 12. This type of excitation mode can be used to simulate the response of the rotor 12 to loads such as gravity or critical speed bending.

[0119] Different excitation modes can be used to excite various operating conditions encountered by the device under test (DUT). The number of exciters, their orientation, the phase, frequency, and amplitude of the forced function, and the configuration of the mechanical supports or constraints of the DUT can be modified according to the complexity to be simulated. For example, an array of exciters configured to provide a radially oriented mechanical forced function to a component (e.g., a rotor) can be used to excite operating conditions associated with centrifugal force. Similarly, tangentially oriented exciters can be configured to simulate the torque load experienced by components of a motor under operating conditions.

[0120] It should be understood that mechanical domain virtual machine testing can be performed individually on the stator 10, rotor 12, housing, or any other component of the motor under test, or it can be applied to the entire machine. Furthermore, it should be understood that thermal and mechanical domain virtual machine testing can be performed simultaneously to allow the vibration response of the device under test to be tested at the high temperatures expected under operating conditions.

[0121] Vibration response images can provide a basis for generating vibration maps. Figure 12 An exemplary vibration diagram 328 is depicted, divided into cells 330 by a grid 332 including grid lines 334. The grid 332 can be spatially linked to the geometry of the device under test so that the distribution of cells 330 is the same for various production machines and reference machines. The positions of the individual cells 330 of the vibration diagram 328 can be identified by rows and columns (e.g., AA, AB, AC, etc.). Each cell 330 can be associated with one or more vibration parameters of a surface of the rotor 12 located in the region corresponding to the portion of the vibration diagram 328 defined by the cell 330.

[0122] Each vibration response parameter can be stored as an n-dimensional data file, which represents the excitation mode E. b The response R of cell a when applied to the device under test a (E b f c A d φ e The subscript 'b' can identify which excitation mode (e.g., E1, E2, ..., E...). n The device under test (DUT) is being excited. Variations in the excitation mode can include: the number of exciters used, the location of the individual input points to which the exciters are connected, the orientation, amplitude, phase, and frequency content of the mechanical forcing function provided by the individual exciters, and other conditions such as temperature or the current supplied to the DUT (e.g., for combined mechanical and thermal domain testing). Response R a Additional elements may include the frequency f of the vibration response associated with cell 330. c , amplitude A d and phase φ e .

[0123] The number of cells 330 can be selected to provide the desired resolution and cover certain areas of the vibration diagram 328. Each cell 330 can be associated with one or more values ​​f corresponding to one or more frequency components of the vibration in that cell. c The amplitude A of the vibration d and the phase φ of the vibration. eAssociated. The subscripts d and e can indicate axes in vector space along which the components of displacement associated with amplitude and phase values ​​are aligned. Axes d and e can include: an axis perpendicular to the cell surface, an axis tangent to the cell surface along a first tangential axis, and an axis tangent to the cell surface along a second tangential axis orthogonal to the first tangential axis.

[0124] The directional components of amplitude and phase can be determined by measuring radial displacement along the line connecting cell 330 to vibrator 316 from multiple locations. These locations may include: a first position directly above the cell, a second position laterally offset from the first position along a first tangential axis, and a third position laterally offset from the first position along a second tangential axis. The individual directional components can then be determined by applying the law of cosines to the radial displacement measured at each location. Therefore, for a given excitation mode E... b The vibration response R of the device under test a (E b f c A d φ e It can be related to the same stimulus pattern E in multiple dimensions. b The vibration response R determined for the corresponding component of the reference machine during excitation. a (E b f c A d φ e (Compare)

[0125] The vibration analysis described above can provide a quantitative and high-fidelity indication of the equivalence level between the production machine and the reference machine for each observed mechanical characteristic. Mechanically sensitive characteristics that can be used to demonstrate operational equivalence may include material density, stiffness, damping factor, preload of mechanical joints, discontinuities, voids, or other defects in the production components. It should be understood that although the above description is for devices and materials with linear responses, these methods are equally applicable to nonlinear systems where the input force amplitude and output vibration amplitude are independent variables.

[0126] Similar to cell 258 of heatmap 250, cells 330 of vibration map 328 can be of any suitable size and can be categorized into regions corresponding to specific parts of the device under test. These regions can be analyzed to identify individual regions with resonance, the average vibration response within each region, and the overall average vibration response of vibration map 328. Vibration maps generated for the device under test can be compared with corresponding vibration maps generated from a reference machine to determine whether the device under test is mechanically equivalent to the reference component.

[0127] Map comparison

[0128] Figure 12 A flowchart depicts an exemplary process 340 according to an embodiment of the invention, which can be used to compare a test plot obtained from a device under test (DUT) with a reference plot obtained from a reference machine. In block 342, process 340 can be defined as one or more test cells of a plot generated by the DUT. Test cells can be defined using a grid, for example, by overlaying a grid onto the test plot, or by any other pattern that identifies portions of the plot from which data is to be extracted for use in evaluating the DUT. Cells can have the same size, dimensions, and location as the corresponding reference cells used to define the reference plot. These cells can cover the entire test plot and reference plot, or only cover portions of the respective plots considered critical areas for evaluating the DUT.

[0129] Once the test cells have been defined, process 340 can proceed to box 344 and extract one or more parameter values ​​from each test cell. These parameter values ​​may include one or more of the mean, median, maximum, minimum, etc., values ​​of the parameters enclosed by the test cells. That is, the parameter values ​​of each test cell can be determined based on data corresponding to the portion of the graph defined by the cells. These values ​​may, for example, correspond to the intensity of pixels used to generate the graph, including the test image. Exemplary values ​​may indicate magnetic flux density, magnetic flux orientation, temperature, temperature gradient, surface displacement, or any other parameter of the test apparatus corresponding to the portion of the cell in question.

[0130] In box 346, process 340 may identify corresponding reference cells from a reference graph. This identification process may include aligning a test graph with the reference graph. The test cells used for comparison may be those aligned with predetermined reference cells selected for process 340. For example, the graphs may be aligned by performing a spatial convolution between the test and reference graphs. The test graph can then be considered aligned with the reference graph at a relative position that provides the best correlation between the graphs. It should be understood that the extraction of parameter values ​​and the identification of corresponding reference cells can be performed in an iterative process. For example, data may initially be extracted from one or more test cells to align the test graph with the reference graph. Once the graphs are aligned, additional or supplementary data for determining parameter values ​​and comparing the graphs can be extracted.

[0131] In box 348, process 340 may select a test cell before proceeding to box 350 and comparing the test cell with its corresponding reference cell. Comparing the test cell with the reference cell may include comparing the parameter value extracted from the test cell with the parameter value extracted from the corresponding reference cell. If there is a difference in the parameter values ​​exceeding a threshold (the "Yes" branch of decision box 352), process 340 may proceed to box 354, reject the test device, and terminate. If the difference in the parameter values ​​does not exceed the threshold (the "No" branch of decision box 352), process 340 may proceed to box 356.

[0132] In an alternative embodiment of the invention, if a threshold is exceeded, process 340 may continue comparing the remaining test cells with their corresponding reference cells to characterize the device under test before termination. Performing a complete comparison between the test chart and the reference chart can aid in repairing the device by identifying areas of concern for the device under test.

[0133] The threshold can be a predetermined threshold applied to individual test cells (e.g., a test cell exceeding the threshold causes the tester to be rejected), or a cumulative threshold that the number of cells or the cumulative test error must exceed before the tester is rejected. For example, when comparing heatmaps, if a test cell's thermal parameter (e.g., temperature) has a value within ±X°C of the corresponding reference cell's thermal parameter, process 340 can determine that the threshold has not been exceeded for that test cell. As another example, if the average of the thermal parameters from multiple test cells in a region is within ±Y°C of the average of the corresponding reference cell's thermal parameters, process 340 can determine that the threshold has not been exceeded for that region of the heatmap. As yet another example, if the average of the thermal parameters of the entire test heatmap is within ±Z°C of the average of the thermal parameters of the reference heatmap, process 340 can determine that the threshold has not been exceeded. In any case, process 340 can include multiple thresholds applied to multiple regions, each region comprising one or more cells that may or may not be included in another region. That is, regions can overlap.

[0134] Thresholds can be achieved using either a linear or logarithmic scale, as described above in the heatmap example. A threshold on a logarithmic scale converts the values ​​associated with each cell into decibels (dB) for comparison. The acceptable range of these values ​​can then be defined in decibels. An exemplary acceptance criterion could be that all values ​​measured for the device under test must be within ±2 dB of the corresponding values ​​obtained from a reference device.

[0135] Depending on the type of motor and application, the above thresholds can be set to different levels. A typical threshold level for a thermal graph could be ±5°C. As another example, a typical threshold for a vibration graph could be ±2 dB. Graphs can be compared under equivalent conditions on a steady-state basis or a transient basis (where the rate of change of the parameter value from a given starting point is evaluated). The rate of change can be a particularly relevant parameter in thermal testing. For example, as part of virtual machine testing, the rate of temperature change in response to turning off a cooling fan or changing the amount of power supplied to the device under test can be compared in the cells.

[0136] In box 356, process 340 can determine whether all test cells have been compared with their corresponding reference cells. If all cells have been compared (the "Yes" branch of decision box 356), process 340 can proceed to box 358, allowing the device under test to pass and terminating. If not all test cells have been compared with their corresponding reference cells (the "No" branch of decision box 356), process 340 can proceed to box 360, select the next test cell, and return to box 350 to continue comparing test cells with corresponding reference cells.

[0137] Verification matrix

[0138] Once the physical domain data for a specific test is obtained, this data can be input into a validation matrix. By breaking down the key parameters of the physical domain tests (e.g., comparing magnetic, electrical, thermal, and vibration results) and how virtual machine testing validates them, the validation matrix can be used as a virtual machine test characteristic map. Once the overall design of the motor has been validated using one or more full-load tests, the validation matrix can be designed to examine each design or component aspect indicating the level to which the corresponding parameters have been validated by virtual machine testing. For example, key parameters can be identified by comparing the physical domain test results of a motor that passed the pass test with those of a machine that failed the test or is otherwise known to be defective.

[0139] Now refer to Figure 14 The embodiments of the present invention described above, or portions thereof, can be implemented using one or more computer devices or systems, such as the exemplary computer 400. The computer 400 may include a processor 402, a memory 404, an input / output (I / O) interface 406, and a human-machine interface (HMI) 408. The computer 400 may also be operatively connected to one or more external resources 410 via a network 412 or an I / O interface 466. External resources may include, but are not limited to, servers, databases, mass storage devices, peripheral devices, cloud-based network services, or any other resources that can be used by the computer 400.

[0140] Processor 402 may include one or more devices selected from the following: microprocessor, microcontroller, digital signal processor, microcomputer, central processing unit, field-programmable gate array, programmable logic device, state machine, logic circuit, analog circuit, digital circuit, or any other device that manipulates signals (analog or digital) based on operating instructions stored in memory 404. Memory 404 may include a single memory device or multiple memory devices, including but not limited to read-only memory (ROM), random access memory (RAM), volatile memory, non-volatile memory, static random access memory (SRAM), dynamic random access memory (DRAM), flash memory, cache memory, or data storage devices such as hard disk drives, optical drives, magnetic tape drives, volatile or non-volatile solid-state devices, or any other device capable of storing data.

[0141] Processor 402 may operate under the control of operating system 414 residing in memory 404. Operating system 414 may manage computer resources so that computer program code, embodied as one or more computer software applications (such as application 416 residing in memory 404), may have instructions that can be executed by processor 402. In an alternative embodiment, processor 402 may directly execute application 416, in which case operating system 414 may be omitted. One or more data structures 418 may also reside in memory 404 and may be used by processor 402, operating system 414, or application 416 to store or manipulate data.

[0142] I / O interface 406 can provide a machine interface that operatively connects processor 402 to other devices and systems, such as external resources 410 or network 412. Thus, application 416 can communicate via I / O interface 406 to work collaboratively with external resources 410 or network 412 to provide various features, functions, applications, processes, or modules including embodiments of the present invention. Application 416 may also have program code executed by one or more external resources 410, or otherwise rely on functionality or signals provided by other system or network components outside of computer 400. In fact, given the virtually unlimited possible hardware and software configurations, those skilled in the art will understand that embodiments of the present invention can include applications located outside of computer 400, distributed among multiple computers or other external resources 410, or provided by computing resources (hardware and software) as services (such as cloud computing services) on network 412.

[0143] The HMI 408 can be operatively coupled to the processor 402 of the computer 400 to allow the user to interact directly with the computer 400. The HMI 408 may include a video or alphanumeric display, a touchscreen, speakers, and any other suitable audio and visual indicators capable of providing data to the user. The HMI 408 may also include input devices and controls (such as an alphanumeric keypad, a pointing device, a keypad, buttons, control knobs, a microphone, etc.) capable of accepting commands or input from the user and sending the input to the processor 402.

[0144] Database 420 may reside in memory 404 and may be used to collect and organize data used by the various systems and modules described herein. Database 420 may include data and supporting data structures for storing and organizing that data. In particular, database 420 may be set up using any database organization or structure, including but not limited to relational databases, hierarchical databases, network databases, or combinations thereof. A database management system in the form of a computer software application, executed as instructions on processor 402, may be used to access information or data stored in records in database 420 in response to queries, which may be dynamically determined and executed by operating system 414, other applications 416, or one or more modules.

[0145] Generally, routines executed to implement embodiments of the present invention (whether implemented as part of an operating system or as a particular application, component, program, object, module, or sequence of instructions or a subset thereof) may be referred to herein as "computer program code" or simply "program code". Program code typically comprises computer-readable instructions that reside at various times in various memories and storage devices within a computer and, when read and executed by one or more processors in the computer, cause the computer to perform operations necessary to carry out operations or components that specifically implement various aspects of embodiments of the present invention. Computer-readable program instructions for performing operations of embodiments of the present invention may, for example, be assembly language, source code, or object code written in any combination of one or more programming languages.

[0146] The various program codes described herein can be identified based on the applications implemented in specific embodiments of the invention. However, it should be understood that any particular program nomenclature below is used merely for convenience, and therefore the invention should not be limited to use only in any particular application identified or implied by such nomenclature. Moreover, given the generally unlimited number of ways in which computer programs can be organized into routines, procedures, methods, modules, objects, etc., and the various ways in which program functionality can be distributed among various software layers residing within a typical computer (e.g., operating systems, libraries, APIs, applications, applets, etc.), it should be understood that embodiments of the invention are not limited to the specific organization and distribution of program functionality described herein.

[0147] The program code implemented in any application / module described herein can be distributed individually or collectively as a computer program product in a variety of different forms. In particular, the program code can be distributed using a computer-readable storage medium having computer-readable program instructions thereon for causing a processor to execute various aspects of embodiments of the invention.

[0148] Computer-readable storage media, being inherently non-transitory, can include volatile and non-volatile media, as well as removable and non-removable tangible media, implemented in any method or technology for storing data (such as computer-readable instructions, data structures, program modules, or other data). Computer-readable storage media may also include RAM, ROM, erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other solid-state memory technologies, portable optical disc read-only memory (CD-ROM) or other optical storage devices, magnetic tape cassettes, magnetic tape, disk storage devices or other magnetic storage devices, or any other medium that can be used to store data and can be read by a computer. Computer-readable storage media should not be construed as transient signals (e.g., radio waves or other propagating electromagnetic waves, electromagnetic waves propagating through a transmission medium such as a waveguide, or electrical signals transmitted through a wire). Computer-readable program instructions can be downloaded from the computer-readable storage media to a computer, another type of programmable data processing device, or another apparatus, or downloaded via a network to an external computer or external storage device.

[0149] Computer-readable program instructions stored in a computer-readable medium can be used to direct a computer, other type of programmable data processing apparatus, or other means to function in a particular manner, causing the instructions stored in the computer-readable medium to generate an article of writing including instructions that implement the functions, actions, or operations specified in a flowchart, sequence diagram, or block diagram. The computer program instructions can be provided to one or more processors of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to generate a machine, causing the instructions, which execute via said one or more processors, to perform a series of calculations to implement the functions, actions, or operations specified in the text, flowchart, sequence diagram, or block diagram of the specification.

[0150] The flowcharts and block diagrams depicted in the accompanying drawings illustrate the architecture, functionality, or operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowcharts or block diagrams may represent a module, program segment, or instruction portion comprising one or more executable instructions for implementing one or more specified logical functions.

[0151] In some alternative embodiments, the functions, actions, or operations specified in the flowchart, sequence diagram, or block diagram may be reordered, processed sequentially, or processed concurrently according to embodiments of the invention. Furthermore, any of the flowchart, sequence diagram, or block diagram may include more or fewer blocks than those illustrated consistent with embodiments of the invention. It should also be understood that individual blocks in a block diagram or flowchart, or any combination of blocks in a block diagram or flowchart, may be implemented by a dedicated hardware-based system configured to perform the specified functions or actions, or by a combination of dedicated hardware and computer instructions.

[0152] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of the invention. As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” are intended to include both the singular and plural forms, and the terms “and” and “or” are intended to include both alternative combinations and combined combinations. It should also be understood that the term “comprising,” when used in this specification, specifies the presence of a defined feature, element, action, step, operation, element, or component, and does not exclude the presence or addition of one or more other features, elements, actions, steps, operations, elements, components, or combinations thereof. Moreover, with respect to the use of the terms “comprising,” “having,” “consisting of,” or variations thereof in any detailed description or claim, such terms are intended to be inclusive in a similar manner to the term “comprising.”

[0153] While the entire invention has been illustrated by description of various embodiments, and these embodiments have been described in considerable detail, the applicant is not intended to limit the scope of the appended claims or in any way restrict it to such details. Additional advantages and modifications will be readily apparent to those skilled in the art. Therefore, the invention, in its broader aspects, is not limited to the specific details shown and described, the representative devices and methods, and the illustrative examples. Consequently, changes to these details may be made without departing from the spirit or scope of the applicant's overall inventive concept.

Claims

1. An apparatus for testing an electric machine (8), the apparatus comprising: one or more processors (402); and a memory (404) coupled to the one or more processors (402) and comprising program code (416) that, when executed by the one or more processors (402), causes the apparatus to: measure a first value of a first parameter indicative of a response of at least one device under test (306) to a static test, the at least one device under test (306) being a component of an electric machine (8); generate a test signature based at least in part on the first value of the first parameter; compare the test signature to a reference signature; in response to the test signature matching the reference signature, pass the at least one device under test (306); and in response to the test signature not matching the reference signature, fail the at least one device under test (306), wherein the reference signature is generated by: measuring a second value of the first parameter indicative of a response of a reference device to the static test, and generating the reference signature based at least in part on the second value of the first parameter, wherein the reference device has undergone a full load dynamic test to ensure that the reference device meets all testing standards, wherein the test signature comprises at least a portion of a test thermal map (250) of the at least one device under test (306), the reference signature comprises at least a portion of a reference thermal map (250) of the reference device, and a temperature of the at least one device under test (306) is determined from the at least a portion of the test thermal map (250).

2. The apparatus of claim 1, wherein, the program code further causes the apparatus to: excite the at least one device under test (306) with at least one excitation source, wherein the response of the at least one device under test (306) is a reaction to the excitation source.

3. The apparatus of claim 2, wherein, the at least one excitation source simulates operating conditions of the device under test.

4. The apparatus of claim 1, wherein: the second value of the first parameter used to generate the reference signature is measured before subjecting the reference device to qualification testing, a third value of the first parameter used to generate the reference signature is measured after subjecting the reference device to qualification testing, a post-performance test signature is generated from the third value of the first parameter, and one or more of a reliability prediction, a wear prediction, or an aging prediction of the reference device is determined by comparing the post-performance test signature to the reference signature.

5. The apparatus of claim 1, wherein, the test signature comprises at least a portion of a test map of the at least one device under test (306), the reference signature comprises at least a portion of a reference map of the reference device, and the first parameter of the at least one device under test (306) is determined from the at least a portion of the test map.

6. The apparatus of claim 5, wherein, Each test map and each reference map is divided into a plurality of cells, and the first parameter of each cell in the test map is compared with the first parameter of a corresponding cell of the reference map.

7. The apparatus of any one of claims 1 to 4, wherein, The first parameter defines a first physical property of a first physical domain, wherein the first physical domain is one of a magnetic domain, an electrical domain, a thermal domain, and a mechanical domain.

8. The apparatus of any one of claims 1 to 6, wherein, The first parameter defines a first physical property of a first physical domain, and each of the test feature map and the reference feature map includes a second parameter defining a second physical property of a second physical domain different from the first physical domain.

9. The apparatus of claim 8, wherein, The first physical domain is one of a magnetic domain, an electrical domain, a thermal domain, and a mechanical domain, and the second physical domain is another one of the magnetic domain, the electrical domain, the thermal domain, and the mechanical domain.

10. The apparatus of any one of claims 2-6, wherein, The at least one device under test (306) includes a stator (10) of a test machine, the at least one excitation source includes an electrical signal applied to a winding of the stator (10), and the first parameter includes a temperature of the stator (10).

11. The apparatus of claim 1, wherein, Each thermal map (250) is divided into a plurality of cells (258), and the temperature of each cell (258) in the test thermal map (250) is compared with the temperature of a corresponding cell (258) in the reference thermal map (250).

12. The apparatus of claim 1, wherein, The at least one device under test (306) includes one or more thermal sensors, and the test thermal map (250) is used to calibrate the one or more thermal sensors.

13. The apparatus of any one of claims 1 to 6, wherein, The at least one excitation source includes a mechanical forcing function applied to an input point of the at least one device under test (306), and the first parameter is a vibration of the at least one device under test (306).

14. The apparatus of claim 13, wherein, The test feature map includes at least a portion of a test vibration map (328) of the at least one device under test (306), the reference feature map includes the at least a portion of a reference vibration map (328) of the reference device, and the vibration of the at least one device under test (306) is determined from the at least a portion of the test vibration map (328).

15. The apparatus of claim 14, wherein, Each vibration map (328) is divided into a plurality of cells (258), and the vibration of each cell (258) in the test vibration map (328) is compared with a corresponding cell (258) in the reference vibration map (328).

16. The apparatus of any one of claims 1 to 6, wherein, The at least one excitation source includes an excitation pattern including a plurality of mechanical forcing functions (322, 326), each mechanical forcing function having an independent amplitude, an independent phase, an independent orientation, and an independent input point.

17. The apparatus of any one of claims 1, 4-6, wherein, The at least one reference device includes a component of a reference machine that passed all qualification tests.

18. The apparatus of any one of claims 1 to 6, wherein, The test feature map and the reference feature map each include a second parameter defining a second physical property of a second physical domain different from a first physical domain, the first physical domain being one of a magnetic domain, an electrical domain, a thermal domain, and a mechanical domain.

19. The apparatus of any one of claims 1 to 6, wherein, The electric machine (8) is a generator of a wind turbine, and wherein the testing of the electric machine (8) is performed prior to installing the generator in the wind turbine.

20. A method for manufacturing a wind turbine, the method comprising the steps of: measuring a first value of a first parameter indicative of a response of at least one device under test (306) to a static test, the at least one device under test (306) being a component of an electric machine (8); generating a test signature based at least in part on the first value of the first parameter; comparing the test signature to a reference signature; in response to the test signature matching the reference signature, installing the at least one device under test (306) in the wind turbine; and in response to the test signature not matching the reference signature, not installing the at least one device under test (306) in the wind turbine, wherein the reference signature is generated by: measuring a second value of the first parameter indicative of a response of a reference device to the static test, and generating the reference signature based at least in part on the second value of the first parameter, wherein the reference device has undergone a full load dynamic test to ensure that the reference device meets all test criteria, wherein the test signature comprises at least a portion of a test thermal map (250) of the at least one device under test (306), the reference signature comprises at least a portion of a reference thermal map (250) of the reference device, and a temperature of the at least one device under test (306) is determined from the at least a portion of the test thermal map (250).

21. The method of claim 20, wherein, the test signature comprises at least a portion of a test map of the at least one device under test (306), the reference signature comprises at least a portion of a reference map of the reference device, and the first parameter of the at least one device under test (306) is determined from the at least a portion of the test map.

22. The method of claim 20 or 21, wherein, Each test map and each reference map is divided into a plurality of cells, and the first parameter of each cell in the test map is compared to the first parameter of a corresponding cell of the reference map.

23. The method of claim 20 or 21, wherein, The first parameter defines a first physical property of a first physical domain, wherein the first physical domain is one of a magnetic domain, an electrical domain, a thermal domain, and a mechanical domain.

24. A method for testing an electric machine, the method comprising the steps of: measuring a first value of a first parameter indicative of a response of at least one device under test (306) to a static test; generating a test signature based at least in part on the first value of the first parameter; comparing the test signature to a reference signature; in response to the test signature matching the reference signature, passing the at least one device under test (306); and in response to the test signature not matching the reference signature, failing the at least one device under test (306), wherein the reference signature is generated by: measuring a second value of the first parameter indicative of a response of a reference device to the static test, and generating the reference signature based at least in part on the second value of the first parameter, wherein the reference device has undergone a full load dynamic test to ensure that the reference device meets all test criteria. generating the reference signature based at least in part on the second value of the first parameter, wherein the reference device has undergone a full load dynamic test to ensure that the reference device meets all test standards, wherein the test signature comprises at least a portion of a test thermal map (250) of the at least one device under test (306), the reference signature comprises at least a portion of a reference thermal map (250) of the reference device, and a temperature of the at least one device under test (306) is determined from the at least a portion of the test thermal map (250).

25. A computer program product, the computer program product comprising: a non-transitory computer-readable storage medium; and program code (416) stored on the non-transitory computer-readable storage medium, the program code, when executed by one or more processors (402), causes the one or more processors (402) to: measure a first value of a first parameter indicative of a response of at least one device under test (306) to a static test, the at least one device under test (306) being a component of an electric machine (8); generate a test signature based at least in part on the first value of the first parameter; compare the test signature to a reference signature; in response to the test signature matching the reference signature, pass the at least one device under test (306); and in response to the test signature not matching the reference signature, fail the at least one device under test (306), wherein the reference signature is generated by: measuring a second value of the first parameter indicative of a response of a reference device to the static test, and generating the reference signature based at least in part on the second value of the first parameter, wherein the reference device has undergone a full load dynamic test to ensure that the reference device meets all test standards, wherein the test signature comprises at least a portion of a test thermal map (250) of the at least one device under test (306), the reference signature comprises at least a portion of a reference thermal map (250) of the reference device, and a temperature of the at least one device under test (306) is determined from the at least a portion of the test thermal map (250).

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