Method and system for evaluating health state of ship alternating current motor, electronic device and storage medium

Abstract

The present application relates to the field of alternating current motor, provide a kind of ship alternating current motor health state evaluation method and system, electronic equipment, storage medium, method includes: obtaining the three-phase alternating current signal of motor to be measured;Convert the three-phase alternating current signal into two-phase current signal by equal power transformation;Determine the state circle corresponding to the two-phase current signal;Based on the maximum radial deviation of the state circle, calculate the health index of the motor to be measured;The health state of the motor to be measured is evaluated based on the health index of the motor to be measured.To solve the installation feasibility is not high in the related art, or there is a dilemma of dull and sensitive in monitoring effect, it is difficult to take into account the early warning capability and the robustness of anti-working condition interference defects, can realize the quick, intuitive and accurate health evaluation of ship alternating current motor.

Description

Technical Field

[0001] This invention relates to the field of AC motor technology, and in particular to a method and system for assessing the health status of marine AC motors, as well as electronic devices and storage media. Background Technology

[0002] Marine AC motors are the core power source for critical loads such as ship electric propulsion, pump sets, fans, and steering gear. Their operational reliability directly affects the ship's navigation safety, operational efficiency, and personnel safety. Therefore, continuous and accurate health monitoring of such equipment to achieve early fault warning and intelligent maintenance has become an important technical direction for modern ship operation and maintenance management. However, the unique application scenario of ships presents extremely stringent technical challenges to the condition monitoring of AC motors.

[0003] In actual operation, marine AC motors are subjected to the dual effects of a complex and ever-changing marine environment and frequent changes in operating conditions. On the one hand, ships are subject to the combined effects of harsh environmental factors such as wind and waves, hull vibration, salt spray corrosion, and temperature and humidity variations, causing severe environmental interference to the motors and their sensor systems. On the other hand, marine motors do not operate under constant conditions but undergo frequent starts, stops, speed changes, and load changes depending on the navigation status and load requirements. For example, during port entry and exit, obstacle avoidance maneuvers, and operational switching, the motor current, speed, and torque all exhibit drastic and non-stable changes.

[0004] The combination of complex sea conditions and constantly changing operating conditions results in highly nonlinear, non-stationary, and multimodal characteristics in the motor's operation. Traditional health monitoring methods based on steady-state assumptions struggle to establish stable benchmark models in this scenario, easily misinterpreting normal operating condition fluctuations as faults, or masking subtle fault characteristics due to changes in operating conditions. This leads to a significant increase in the false alarm and missed alarm rates of the monitoring system, severely limiting the practicality and reliability of the monitoring results.

[0005] On the other hand, ship engine rooms and equipment layouts are generally characterized by cramped spaces and compact structures. Motors are often densely installed in limited spaces, with surrounding pipes, cables, and other equipment intertwined, severely restricting personnel access for operation and maintenance. Under these conditions, traditional contact-based health monitoring methods face significant physical installation and engineering implementation obstacles.

[0006] Traditional monitoring methods, such as temperature and vibration monitoring, face several challenges. Temperature monitoring typically uses embedded or surface-mount temperature sensors, such as thermocouples and resistance temperature detectors (RTDs), to measure the temperature of critical components like windings and bearings. However, in the confined space of a ship, sensor wiring is difficult, and drilling into the motor itself or structural modifications are required, potentially affecting the original protection level and safety of the equipment. More importantly, temperature monitoring is a typical reactive method; its heat conduction process has significant inertia, resulting in a noticeable lag in response. Alarms are often only triggered after a fault has progressed to a certain extent and a significant temperature rise has occurred, making it difficult to detect early signs of electrical faults. Vibration monitoring, on the other hand, uses accelerometers to collect vibration signals from the motor housing or bearing housing, providing an effective means of identifying mechanical faults such as bearing wear, misalignment, and imbalance. However, in a marine environment, vibration monitoring faces challenges such as the need for flat, rigid surfaces and precise positioning for sensor installation. On the space-constrained ship motors, it is often difficult to find suitable installation locations, and the connecting cables are susceptible to mechanical damage. At the same time, vibration signals are extremely sensitive to changes in operating conditions, with excessive sensitivity. When ship motors frequently change speed and load, the vibration amplitude and spectrum structure will change drastically. Normal operating condition switching can generate signal changes similar to fault characteristics, leading to frequent false alarms from the monitoring system. Maintenance personnel find it difficult to filter out the real equipment anomalies from a large number of alarms.

[0007] In summary, traditional monitoring methods, when applied to the specific scenario of ships, are either limited by installation feasibility or suffer from a dilemma in terms of both slowness and sensitivity in monitoring effectiveness, making it difficult to balance early warning capabilities with robustness against operational interference. Summary of the Invention

[0008] This invention provides a method, system, electronic device, and storage medium for assessing the health status of marine AC motors, which addresses the dilemmas in related technologies, such as low installation feasibility or the trade-off between slow and sensitive monitoring effects, and the difficulty in balancing early warning capabilities with robustness against operating condition interference. This invention enables rapid, intuitive, and accurate health assessment of marine AC motors.

[0009] This invention provides a method for assessing the health status of a ship's AC motor, comprising: Acquire the three-phase AC signal of the motor under test; The three-phase AC signal is converted into a two-phase current signal by equal power conversion; Determine the state circle corresponding to the two-phase current signals; The health index of the motor under test is calculated based on the maximum radial deviation of the state circle. The health status of the motor under test is assessed based on its health index.

[0010] According to the health status assessment method for marine AC motors provided by the present invention, the step of converting the three-phase AC signal into a two-phase current signal through equal power conversion includes: The three-phase AC signal is converted into two orthogonal axis components by equal power conversion, resulting in a two-phase current signal.

[0011] According to the health status assessment method for marine AC motors provided by the present invention, determining the state circle corresponding to the two-phase current signals includes: The center and radius of the state circle corresponding to the two-phase current signals are determined by the least squares method. The state circle is determined based on the center and the radius.

[0012] According to the health status assessment method for marine AC motors provided by the present invention, the step of determining the center and radius of the state circle corresponding to the two-phase current signals using the least squares method includes: Based on the two-phase current signals, the following objective function is established: in, and For two-phase current signals, A, B, and C are parameters of the state circle; The objective function is transformed into the following system of linear equations: Solve the system of linear equations to obtain the values ​​of A, B, and C; Based on the values ​​of A, B, and C, determine the center and radius of the state circle.

[0013] According to the health status assessment method for marine AC motors provided by the present invention, the step of calculating the health index of the motor under test based on the maximum radial deviation of the status circle includes: Calculate the radial distance of each point on the state circle; The maximum radial deviation of the state circle is determined based on the radial distances of all points on the state circle; The health index of the motor under test is determined based on the maximum radial deviation of the state circle and the preset maximum radial deviation error range.

[0014] According to the health status assessment method for marine AC motors provided by the present invention, the step of assessing the health status of the motor under test based on the health index of the motor under test includes: The health index of the motor under test is compared with a preset health index threshold. If the health index of the motor under test exceeds the health index threshold, the motor under test is determined to be healthy.

[0015] According to the health status assessment method for marine AC motors provided by the present invention, the health index of the motor under test is determined based on the maximum radial deviation of the status circle and a preset maximum radial deviation error range, conforming to the following formula: in, For health index, The maximum radial deviation of the state circle. This represents the maximum radial deviation error range. These are preset values, determined based on the operating conditions of the motor under test.

[0016] This invention also provides a health status assessment system for marine AC motors, which applies a health status assessment method for marine AC motors, including: The signal acquisition module is used to acquire the three-phase AC power signal of the motor under test; The signal conversion module is used to convert the three-phase AC signal into a two-phase current signal through equal power conversion; The state circle determination module is used to determine the state circle corresponding to the two-phase current signals; The health index calculation module is used to calculate the health index of the motor under test based on the maximum radial deviation of the state circle. The health status assessment module is used to assess the health status of the motor under test based on the health index of the motor under test.

[0017] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement any of the above-described methods for assessing the health status of a marine AC motor.

[0018] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the above-described methods for assessing the health status of marine AC motors.

[0019] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements any of the above-described methods for assessing the health status of marine AC motors.

[0020] The health status assessment method for marine AC motors provided by this invention can directly acquire the three-phase AC signal of the motor under test using the high-frequency stator current method without the need for additional sensors, significantly reducing construction difficulty and modification costs. Simultaneously, the three-phase AC signal can be converted into a two-phase current signal to generate a status circle, allowing for a more intuitive determination of the motor's health status. Furthermore, by calculating the maximum radial deviation of the status circle and then calculating the health index, the health status of the motor under test can be quantified, providing a numerical and intuitive reflection of its health status. This enables a rapid, intuitive, and accurate health assessment of marine AC motors. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is one of the flowcharts illustrating the health status assessment method for marine AC motors provided in this embodiment of the invention; Figure 2 This is the second flowchart illustrating the health status assessment method for marine AC motors provided in this embodiment of the invention. Figure 3 This is a schematic diagram of the state circle of a motor in a healthy state provided in an embodiment of the present invention; Figure 4 This is one of the schematic diagrams of the state circle of an abnormal state motor provided in the embodiments of the present invention; Figure 5 This is the second schematic diagram of the state circle of an abnormal motor provided in the embodiments of the present invention; Figure 6 This is a schematic diagram of the health status assessment system for marine AC motors provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the physical structure of the electronic device provided in an embodiment of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0024] Figure 1This is one of the flowcharts illustrating the health status assessment method for marine AC motors provided in this embodiment of the invention.

[0025] like Figure 1 As shown, this embodiment provides a method for assessing the health status of a ship's AC motor, including: Step 101: Obtain the three-phase AC power signal of the motor under test; In practical applications, the motor under test can be a marine AC motor. The three-phase AC signal of the motor can be directly acquired through a current transformer, eliminating the need for other complex equipment. The stator current signal can be obtained from the motor's power supply cable using existing current transformers or Hall effect sensors. In the confined space of a ship, signal acquisition points can be flexibly arranged in distribution cabinets, junction boxes, or inverter outputs, completely avoiding the problem of limited installation space on the motor itself, significantly reducing construction difficulty and modification costs. Furthermore, signal acquisition is easy; the stator current signal itself is an inherent electrical quantity during motor operation, with a large signal amplitude and strong anti-interference capability. It can be directly extracted through existing electrical protection and measurement circuits, eliminating the need for complex signal conditioning and pre-amplification, facilitating the construction of a long-term, continuous, unattended online monitoring system.

[0026] Step 102: Convert the three-phase AC signal into a two-phase current signal through equal power conversion; In practice, the three-phase AC signal can be converted into two orthogonal axis components through equal power transformation, resulting in a two-phase current signal. Through this transformation, the AC quantity that originally required three sensors (or reconstruction) to collect, which varies sinusoidally with time, is mapped into two orthogonal AC quantities that still vary sinusoidally with time. The transformation matrix from three-phase AC signal to two-phase current signal conforms to the following formula: in, , , For the collected three-phase AC signal, , The two-phase current signals obtained by conversion.

[0027] Step 103: Determine the state circle corresponding to the two-phase current signals; After equal power conversion, the three-phase current is transformed into a two-phase current, represented by d-axis and q-axis signals, respectively. The d-axis signal is defined as... The signal, the q-axis signal is Signal. The signal is used as the horizontal axis. The signal is used as the vertical axis to plot the health status diagram of stator current health monitoring.

[0028] Figure 3This is a schematic diagram of the state circle of a motor in a healthy state provided in an embodiment of the present invention.

[0029] Figure 4 This is one of the state circle diagrams of an abnormal state motor provided in the embodiments of the present invention.

[0030] Figure 5 This is the second schematic diagram of the state circle of an abnormal state motor provided in the embodiment of the present invention.

[0031] in, Figure 3 This is a schematic diagram of the state circle of the motor under test in a healthy state. When the motor under test malfunctions, its state diagram will also show, for example... Figure 4 and Figure 5 The various problems shown are as follows: the distribution of the inner and outer circles is large, not completely distributed on the standard circle, with some angles densely distributed and others scattered. Therefore, it can be determined that the greater the difference from the standard circle stator current status monitoring diagram, the more severe the fault of the ship's AC motor. Based on this, the solution of this application can formulate the status circle of the motor under test, calculate the maximum radial deviation, and further calculate the health index, which reflects the health status of the motor under test. The specific steps are as follows.

[0032] Step 104: Calculate the health index of the motor under test based on the maximum radial deviation of the state circle; In practical applications, the formula for the state circle is first defined as follows: Substituting the two-phase current signals of the motor under test into the state circle formula, we obtain the following formula: in, The radius of the set state circle. , These are the x-coordinate and y-coordinate of the center of the state circle, respectively. In practice, the radius and center are unknown parameters. The purpose of this step is to determine the state circle by calculating and solving for the radius and center.

[0033] Expanding the above formula for the state circle yields the following formula: Among them, can be defined , C= Thus, the above formula can be transformed into: Furthermore, the center of the state circle is , radius .

[0034] According to least squares fitting, N points can be given. Establish the following objective function: This is equivalent to solving the following system of linear equations: It can make , Thus, the solution to the above system of linear equations is In other words, the values ​​of A, B, and C were calculated, which determined the center and radius of the state circle.

[0035] Furthermore, each point on the state circle The radial distance is: Radial deviation can be: >0 indicates that the point is outside the circle. A value less than 0 indicates that the point lies within the circle. The absolute value of the deviation reflects the degree to which the point deviates from the ideal circle. For a set of points, the maximum radial deviation is a direct measure of the irregularity of the point set; the smaller the value, the closer the point is to a perfect circle. The maximum radial deviation is defined by the following formula: To avoid the influence of the original coordinate scale on the fitting results, the coordinate points are normalized to the range [0,1]. This effectively removes the influence of inconsistent power levels. To intuitively represent the health status, a scoring system is constructed, letting... This represents the maximum radial deviation of the standard circle (reflecting system noise or acceptable error). To test the maximum radial deviation of the circle, The threshold is set (and needs to be adjusted appropriately depending on the working conditions). The index is designed with a maximum score of 100, representing an ideal health state, and a minimum score of 1, representing the worst (completely unacceptable) state. The health index can be obtained using the following mapping formula, Equation 11: Step 105: Assess the health status of the motor under test based on its health index.

[0036] In practical applications, such as Figure 2As shown, multiple health index thresholds are preset. For example, a first health index threshold and a second health index threshold can be preset. When the health index of the motor under test is greater than or equal to the first health index threshold, the motor under test is determined to be in a normal state. When the health index of the motor under test is less than the first health index threshold but greater than the second health index threshold, the motor under test is determined to be in a warning state. When the health index of the motor under test is less than or equal to the second health index threshold, the motor under test is determined to be in an abnormal state. The first health index threshold can be 80, and the second health index threshold can be 60.

[0037] The health status assessment system for marine AC motors provided by this invention is described below. The health status assessment system for marine AC motors described below can be referred to in correspondence with the health status assessment method for marine AC motors described above.

[0038] Figure 6 This is a schematic diagram of the health status assessment system for ship AC motors provided in an embodiment of the present invention.

[0039] like Figure 6 As shown, the health status assessment system for marine AC motors provided in this embodiment includes: The signal acquisition module 601 is used to acquire the three-phase AC power signal of the motor under test; Signal conversion module 602 is used to convert the three-phase AC signal into a two-phase current signal through equal power conversion; The state circle determination module 603 is used to determine the state circle corresponding to the two-phase current signals; The health index calculation module 604 is used to calculate the health index of the motor under test based on the maximum radial deviation of the state circle. The health status assessment module 605 is used to assess the health status of the motor under test based on the health index of the motor under test.

[0040] The specific implementation method of the health status assessment system for ship AC motors provided in this embodiment can be implemented with reference to the above embodiment, and will not be repeated here.

[0041] Figure 7 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 7As shown, the electronic device may include: a processor 710, a communication interface 720, a memory 730, and a communication bus 740, wherein the processor 710, the communication interface 720, and the memory 730 communicate with each other via the communication bus 740. The processor 710 can call logical instructions in the memory 730 to execute a health status assessment method for a ship's AC motor, the method including: Acquire the three-phase AC signal of the motor under test; The three-phase AC signal is converted into a two-phase current signal by equal power conversion; Determine the state circle corresponding to the two-phase current signals; The health index of the motor under test is calculated based on the maximum radial deviation of the state circle. The health status of the motor under test is assessed based on its health index.

[0042] Furthermore, the logical instructions in the aforementioned memory 730 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0043] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer is able to perform the health status assessment method for ship AC motors provided by the above methods, the method comprising: Acquire the three-phase AC signal of the motor under test; The three-phase AC signal is converted into a two-phase current signal by equal power conversion; Determine the state circle corresponding to the two-phase current signals; The health index of the motor under test is calculated based on the maximum radial deviation of the state circle. The health status of the motor under test is assessed based on its health index.

[0044] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to perform the health status assessment method for ship AC motors provided by the methods described above, the method comprising: Acquire the three-phase AC signal of the motor under test; The three-phase AC signal is converted into a two-phase current signal by equal power conversion; Determine the state circle corresponding to the two-phase current signals; The health index of the motor under test is calculated based on the maximum radial deviation of the state circle. The health status of the motor under test is assessed based on its health index.

[0045] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0046] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of various embodiments or some parts of embodiments.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for assessing the health status of marine AC motors, characterized in that, include: Acquire the three-phase AC signal of the motor under test; The three-phase AC signal is converted into a two-phase current signal by equal power conversion; Determine the state circle corresponding to the two-phase current signals; The health index of the motor under test is calculated based on the maximum radial deviation of the state circle. The health status of the motor under test is assessed based on its health index.

2. The method for assessing the health status of marine AC motors according to claim 1, characterized in that, The process of converting the three-phase AC signal into a two-phase current signal through equal power conversion includes: The three-phase AC signal is converted into two orthogonal axis components by equal power conversion, resulting in a two-phase current signal.

3. The method for assessing the health status of marine AC motors according to claim 1, characterized in that, Determining the state circle corresponding to the two-phase current signals includes: The center and radius of the state circle corresponding to the two-phase current signals are determined by the least squares method. The state circle is determined based on the center and the radius.

4. The method for assessing the health status of a ship's AC motor according to claim 3, characterized in that, The determination of the center and radius of the state circle corresponding to the two-phase current signals using the least squares method includes: Based on the two-phase current signals, the following objective function is established: in, and For two-phase current signals, A, B, and C are parameters of the state circle; The objective function is transformed into the following system of linear equations: Solve the system of linear equations to obtain the values ​​of A, B, and C; Based on the values ​​of A, B, and C, determine the center and radius of the state circle.

5. The method for assessing the health status of a ship's AC motor according to claim 1, characterized in that, The calculation of the health index of the motor under test based on the maximum radial deviation of the state circle includes: Calculate the radial distance of each point on the state circle; The maximum radial deviation of the state circle is determined based on the radial distances of all points on the state circle; The health index of the motor under test is determined based on the maximum radial deviation of the state circle and the preset maximum radial deviation error range.

6. The method for assessing the health status of a ship's AC motor according to claim 1, characterized in that, The assessment of the health status of the motor under test based on its health index includes: The health index of the motor under test is compared with a preset health index threshold. If the health index of the motor under test exceeds the health index threshold, the motor under test is determined to be healthy.

7. The method for assessing the health status of a ship's AC motor according to claim 5, characterized in that, The health index of the motor under test is determined based on the maximum radial deviation of the state circle and a preset maximum radial deviation error range, conforming to the following formula: in, For health index, The maximum radial deviation of the state circle. This represents the maximum radial deviation error range. The preset value is determined based on the operating conditions of the motor under test.

8. A health status assessment system for marine AC motors, employing the health status assessment method for marine AC motors as described in any one of claims 1-7, characterized in that, include: The signal acquisition module is used to acquire the three-phase AC power signal of the motor under test; The signal conversion module is used to convert the three-phase AC signal into a two-phase current signal through equal power conversion. The state circle determination module is used to determine the state circle corresponding to the two-phase current signals; The health index calculation module is used to calculate the health index of the motor under test based on the maximum radial deviation of the state circle. The health status assessment module is used to assess the health status of the motor under test based on the health index of the motor under test.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the health status assessment method for marine AC motors as described in any one of claims 1-7.

10. A non-transitory computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the health status assessment method for marine AC motors as described in any one of claims 1-7.

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