Motor controller uses ripple current measurement method, measuring instrument, medium and equipment

Abstract

The present application belongs to the field of measurement technology, and specifically relates to a motor controller ripple current measurement method, a measuring instrument, a medium and equipment. The motor controller ripple current measurement method comprises: entering a data matching mode, obtaining high and low precision ripple currents to form a corresponding table; entering a motor non-rotation mode, obtaining corresponding high precision ripple currents from the low precision Rogowski coil and the corresponding table; and entering a motor rotation mode, outputting the high precision ripple current collected by the high precision Rogowski coil as the actual ripple current. The present application improves the detection accuracy of the low precision Rogowski coil and reduces the loss of the high precision Rogowski coil. The detection result of the low precision Rogowski coil is used to verify the detection accuracy of the high precision Rogowski coil through the corresponding table. Even if the low precision Rogowski coil is damaged, the detection result of the low precision Rogowski coil is recalibrated to ensure high persistence, high stability and high detection accuracy within a limited budget.

Description

Technical Field

[0001] This invention belongs to the field of measurement technology, specifically relating to methods for testing electrical performance, and particularly to a method, measuring instrument, medium, and equipment for measuring ripple current in a motor controller. Background Technology

[0002] In motor controllers (such as inverters), thin-film capacitors on the DC bus are used to suppress current fluctuations caused by frequent switching of power devices. The magnitude of the ripple current they withstand affects system stability and capacitor lifespan.

[0003] Existing methods for measuring this type of current still have certain limitations. For example, using a shunt resistor to measure current requires connecting the device in series with the main circuit, which not only changes the original circuit structure but also introduces additional parasitic parameters, adversely affecting high-frequency characteristics, and also results in significant power loss and heat generation. Furthermore, when using Hall effect current sensors, their bandwidth is limited, leading to insufficient accuracy in high-frequency ripple measurement scenarios, and their relatively large size makes them difficult to place in situations with limited bus space. Finally, calculation methods based on three-phase current rely on PWM switching state signals, requiring high sampling synchronization accuracy and being easily affected by changes in control strategies, thus reducing the reliability of the measurement results.

[0004] Using Rogowski coils to measure ripple current does not require changing the original system structure and has a high frequency response capability. However, since the Rogowski coil is placed outside the DC bus conductor and does not have direct electrical contact with the DC bus conductor, the Rogowski coil is prone to positional displacement due to motor vibration, temperature, etc., which affect the stability and accuracy of the detection. At the same time, high-precision Rogowski coils are very expensive, and long-term operation results in wear and tear, which also affects the accuracy of the detection.

[0005] Therefore, there is an urgent need to develop a new method, instrument, medium, and equipment for measuring ripple current in motor controllers to solve the technical problems of high loss, decreased detection stability, and decreased detection accuracy of high-precision Rogowski coils during continuous ripple current detection.

[0006] It should be noted that the information disclosed in this background section is only for understanding the background technology of this application concept, and therefore, the above description is not considered to constitute prior art information. Summary of the Invention

[0007] This disclosure provides at least one method, measuring instrument, medium, and device for measuring ripple current in motor controllers.

[0008] In a first aspect, embodiments of this disclosure provide a method for measuring ripple current in a motor controller. This method employs a ripple current measuring instrument to perform the following steps: entering a data matching mode; simultaneously acquiring low-precision and high-precision ripple currents under different operating parameters using both low-precision and high-precision Rogowski coils to form a correspondence table regarding conductor temperature, bus voltage, low-precision ripple current, and high-precision ripple current; determining whether the motor is rotating; and selecting one of the following modes to enter: entering a non-rotating motor mode; acquiring low-precision ripple current using the low-precision Rogowski coil; and real-time collecting conductor temperature and bus voltage to obtain data from the correspondence table. The corresponding high-precision ripple current is obtained; upon entering motor rotation mode, the corresponding high-precision ripple current is indirectly obtained through a low-precision Rogowski coil, and the corresponding high-precision ripple current is directly obtained through a high-precision Rogowski coil. If the difference between the two high-precision ripple currents is within a set threshold, the high-precision ripple current collected by the high-precision Rogowski coil is output as the actual ripple current; or, if the difference between the two high-precision ripple currents exceeds the set threshold, the high-precision ripple current under standard test parameters is obtained through the high-precision Rogowski coil to confirm whether the high-precision Rogowski coil or the low-precision Rogowski coil is abnormal. In this case, the data matching mode is re-entered to construct a new correspondence table.

[0009] In one optional implementation, the method for entering the data matching mode includes: operating under arbitrary operating parameters, acquiring the current low-precision ripple current and high-precision ripple current through a low-precision Rogowski coil and a high-precision Rogowski coil, and acquiring the current conductor temperature and bus voltage through a temperature sensor and a voltage sensor to obtain a data set regarding conductor temperature, bus voltage, low-precision ripple current, and high-precision ripple current; operating under different operating parameters to obtain corresponding data sets; and integrating all data sets to form a correspondence table regarding conductor temperature, bus voltage, low-precision ripple current, and high-precision ripple current.

[0010] In one optional implementation, the method for entering the non-rotating mode of the motor includes: obtaining a low-precision ripple current through a low-precision Rogowski coil, and obtaining the corresponding conductor temperature and bus voltage through a temperature sensor and a voltage sensor; comparing the conductor temperature, bus voltage, and low-precision ripple current with each data group in a corresponding table; and when the conductor temperature, bus voltage, and low-precision ripple current match the data group in the corresponding table, outputting the high-precision ripple current in that data group, i.e., obtaining the corresponding high-precision ripple current from the corresponding table.

[0011] In one optional implementation, the method for entering the motor rotation mode includes: indirectly obtaining the corresponding high-precision ripple current through a low-precision Rogowski coil. I rc1 High-precision ripple current is directly obtained through a high-precision Rogowski coil. Irc2 When | I rc1 - I rc2 |≤ I D That is, when the difference between two high-precision ripple currents is within a set threshold, the high-precision ripple current collected by the high-precision Rogowski coil is output. I rc2 Actual ripple current I R .

[0012] In one optional implementation, the method for entering the motor rotation mode further includes: when | I rc1 - I rc2 |> I D When the difference between two high-precision ripple currents exceeds a set threshold, a high-precision Rogowski coil is used to obtain the high-precision ripple current under standard test parameters. I rc2 When high-precision ripple current I rc2 Compared with standard test ripple current I S If there is a discrepancy, the high-precision Rogowski coil is confirmed to be faulty; when the high-precision ripple current... I rc2 Compared with standard test ripple current I S If the results are consistent, then the low-precision Rogowski coil is confirmed to be faulty.

[0013] In one alternative implementation, when a low-precision Rogowski coil is confirmed to be abnormal, the system re-enters the data matching mode to construct a new correspondence table; when a high-precision Rogowski coil is confirmed to be abnormal, a corresponding maintenance alarm signal is output.

[0014] In one optional embodiment, a low-precision Rogowski coil and a high-precision Rogowski coil are sequentially arranged on the bus conductor along the current transmission direction, with the low-precision Rogowski coil and the high-precision Rogowski coil located on opposite sides of the thin-film capacitor.

[0015] Secondly, this disclosure also provides a ripple current measuring instrument for a motor controller employing the ripple current measurement method for a motor controller as described above. The instrument includes: a control module, a low-precision Rogowski coil, a high-precision Rogowski coil, a temperature sensor, and a voltage sensor electrically connected to the control module; wherein the control module is configured to perform the following: entering a data matching mode, simultaneously acquiring low-precision and high-precision ripple currents under different operating parameters through the low-precision and high-precision Rogowski coils, and collecting corresponding conductor temperature and bus voltage through the temperature sensor and voltage sensor to form a correspondence table of conductor temperature, bus voltage, low-precision ripple current, and high-precision ripple current; determining whether the motor is rotating, and selectively entering one of the following modes, i.e., entering a motor non-rotation mode, through the low-precision... The system uses a Rogowski coil to acquire low-precision ripple current and collects conductor temperature and bus voltage in real time to obtain the corresponding high-precision ripple current from a matching table. Upon entering motor rotation mode, it indirectly acquires the corresponding high-precision ripple current through the low-precision Rogowski coil and directly acquires the corresponding high-precision ripple current through the high-precision Rogowski coil. If the difference between the two high-precision ripple currents is within a set threshold, the high-precision ripple current acquired by the high-precision Rogowski coil is output as the actual ripple current. Alternatively, if the difference between the two high-precision ripple currents exceeds the set threshold, the high-precision Rogowski coil acquires the high-precision ripple current under standard test parameters to confirm whether the high-precision or low-precision Rogowski coil is abnormal. When the low-precision Rogowski coil is confirmed to be abnormal, the system re-enters data matching mode to construct a new matching table.

[0016] Thirdly, embodiments of this disclosure also provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method.

[0017] Fourthly, embodiments of this disclosure also provide an electronic device, comprising: a non-transitory computer-readable storage medium; and a motor controller; wherein the non-transitory computer-readable storage medium stores instructions that, when executed by the motor controller, cause the motor controller to perform the steps according to the method described above.

[0018] The beneficial effects of this invention are that it simultaneously acquires low-precision and high-precision ripple currents under different operating parameters using both low-precision and high-precision Rogowski coils. This allows for the correlation between the low-precision and high-precision ripple currents, along with conductor temperature and bus voltage, reducing interference from external factors. In non-rotating motor mode, the low-precision Rogowski coil replaces the high-precision Rogowski coil, outputting the ripple current through a correspondence table, thus improving the detection accuracy of the low-precision Rogowski coil and reducing losses in the high-precision Rogowski coil. In rotating motor mode, the high-precision Rogowski coil ensures accurate ripple current detection, and the correspondence table allows the detection results of the low-precision Rogowski coil to verify the accuracy of the high-precision Rogowski coil's ripple current detection. Even after losses occur in the low-precision Rogowski coil, the high-precision Rogowski coil can recalibrate the detection results, achieving high continuity, high stability, and high detection accuracy within a limited budget.

[0019] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

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

[0022] Figure 1 A flowchart illustrating a method for measuring ripple current in a motor controller, provided in this embodiment of the disclosure; Figure 2 A flowchart illustrating the process of entering a data matching mode, as provided in this embodiment of the disclosure; Figure 3 A flowchart illustrating a process for entering a non-rotating motor mode, as provided in an embodiment of this disclosure; Figure 4 This is a flowchart illustrating a process for entering a motor rotation mode, as provided in an embodiment of this disclosure. Detailed Implementation

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

[0024] The terminology used herein is for the purpose of describing specific exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may also be intended to include plural forms unless otherwise clearly stated herein. The terms “comprising,” “including,” and “having” are inclusive and thus specify the presence of features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein should not be construed as requiring them to be performed in the specific order discussed or shown, unless specifically identified as such. Additional or alternative steps may be employed.

[0025] As used herein, the phrases “in one embodiment,” “according to one embodiment,” “in some embodiments,” etc., generally refer to the fact that a particular feature, structure, or characteristic following the phrase can be included in at least one embodiment of this disclosure. Therefore, a particular feature, structure, or characteristic can be included in more than one embodiment of this disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, the terms “example,” “exemplary,” etc., are used to “serve as an example, instance, or illustration.” Any implementation, aspect, or design described herein as “example” or “exemplary” is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. Rather, the use of the terms “example,” “exemplary,” etc., is intended to present concepts in a specific manner.

[0026] Research has revealed that in motor controllers (such as inverters), thin-film capacitors on the DC bus are used to suppress current fluctuations caused by frequent switching of power devices. The magnitude of the ripple current they withstand affects system stability and capacitor lifespan. Existing methods for measuring this type of current still have certain limitations. For example, using shunt resistors to measure current requires connecting the device in series with the main circuit, which not only changes the original circuit structure but also introduces additional parasitic parameters, adversely affecting high-frequency characteristics, and also results in significant power loss and heat generation. Furthermore, when using Hall effect current sensors, their bandwidth is limited, leading to insufficient accuracy in high-frequency ripple measurement scenarios, and their relatively large size makes them difficult to arrange in situations where bus space is limited. Finally, calculation methods based on three-phase current rely on PWM switching state signals, requiring high sampling synchronization accuracy and being easily affected by changes in control strategies, thus reducing the reliability of the measurement results. Using Rogowski coils to measure ripple current does not require changing the original system structure and has a high frequency response capability. However, since the Rogowski coil is placed outside the DC bus conductor and does not have direct electrical contact with the DC bus conductor, the Rogowski coil is prone to positional displacement due to motor vibration, temperature, etc., which affect the stability and accuracy of the detection. At the same time, high-precision Rogowski coils are very expensive, and long-term operation results in wear and tear, which also affects the accuracy of the detection.

[0027] Based on the above research, this disclosure provides a method, measuring instrument, medium, and device for measuring ripple current in a motor controller. This invention simultaneously acquires low-precision and high-precision ripple currents under different operating parameters using both low-precision and high-precision Rogowski coils. It can correlate the low-precision and high-precision ripple currents, along with conductor temperature and bus voltage, reducing interference from external factors. In non-rotating motor mode, the low-precision Rogowski coil replaces the high-precision Rogowski coil, outputting the ripple current through a correspondence table, improving the detection accuracy of the low-precision Rogowski coil and reducing losses in the high-precision Rogowski coil. In rotating motor mode, the high-precision Rogowski coil ensures accurate ripple current detection, and the correspondence table allows the detection results of the low-precision Rogowski coil to verify the accuracy of the high-precision Rogowski coil's ripple current detection. Even after losses occur in the low-precision Rogowski coil, the high-precision Rogowski coil can recalibrate the detection results of the low-precision Rogowski coil, achieving high continuity, high stability, and high detection accuracy within a limited budget.

[0028] The shortcomings of the above solutions are the result of the inventor's practical experience and careful research. Therefore, the discovery process of the above problems and the solutions proposed in this disclosure below should be considered as the inventor's contribution to this disclosure.

[0029] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0030] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0031] like Figures 1 to 4 As shown, at least one embodiment provides a method for measuring ripple current in a motor controller. This method employs a ripple current measuring instrument to perform the following steps: entering a data matching mode; simultaneously acquiring low-precision and high-precision ripple currents under different operating parameters using both low-precision and high-precision Rogowski coils to form a correspondence table regarding conductor temperature, bus voltage, low-precision ripple current, and high-precision ripple current; determining whether the motor is rotating; and selecting one of the following modes to enter a non-rotating motor mode; acquiring low-precision ripple current using the low-precision Rogowski coil and real-time collecting conductor temperature and bus voltage to obtain the corresponding high-precision ripple current from the correspondence table. The system enters motor rotation mode, indirectly acquiring the corresponding high-precision ripple current through a low-precision Rogowski coil, and directly acquiring the corresponding high-precision ripple current through a high-precision Rogowski coil. When the difference between the two high-precision ripple currents is within a set threshold, the high-precision ripple current acquired by the high-precision Rogowski coil is output as the actual ripple current. Alternatively, when the difference between the two high-precision ripple currents exceeds the set threshold, the high-precision ripple current under standard test parameters is acquired through the high-precision Rogowski coil to confirm whether the high-precision Rogowski coil or the low-precision Rogowski coil is abnormal. When the low-precision Rogowski coil is confirmed to be abnormal, the system re-enters data matching mode to construct a new correspondence table.

[0032] In at least one embodiment, by simultaneously acquiring low-precision and high-precision ripple currents under different operating parameters using both low-precision and high-precision Rogowski coils, the low-precision and high-precision ripple currents can be correlated. Simultaneously, conductor temperature and bus voltage can be correlated to reduce interference from external factors. In non-rotating motor mode, the low-precision Rogowski coil replaces the high-precision Rogowski coil, outputting the ripple current through a correspondence table. This improves the detection accuracy of the low-precision Rogowski coil and reduces losses in the high-precision Rogowski coil. In rotating motor mode, the high-precision Rogowski coil ensures accurate ripple current detection, and the correspondence table allows the detection results of the low-precision Rogowski coil to verify the accuracy of the high-precision Rogowski coil's ripple current detection. Even if the low-precision Rogowski coil experiences losses, the high-precision Rogowski coil can recalibrate the detection results, achieving high continuity, high stability, and high detection accuracy within a limited budget.

[0033] Specifically, the current on the bus conductor is detected by low-precision Rogowski coils and high-precision Rogowski coils, and the output signal is processed by an external integrating circuit or a built-in integrating module to obtain a signal corresponding to the current. Then, the signal is sampled by an oscilloscope or data acquisition device. During the sampling process, it is necessary to ensure that the system bandwidth can cover the switching frequency and its harmonic components, and the sampling rate meets the requirements of the basic sampling theorem to ensure signal integrity.

[0034] Specifically, the acquired data is processed to obtain an instantaneous waveform. This current signal contains a DC component, low-frequency load current, and high-frequency ripple components generated by the switching of power devices. The ripple component is extracted from this current signal. This process can be achieved in various ways, such as using a high-pass filter to remove the DC and low-frequency components, retaining only the high-frequency portion; or calculating the average current and performing differential processing to obtain the ripple current; or using spectral analysis to extract signal components within a specific frequency band. By using these methods individually or in combination, the AC ripple current that the thin-film capacitor can withstand can be effectively obtained.

[0035] In at least one embodiment, a low-precision Rogowski coil and a high-precision Rogowski coil are sequentially arranged on the bus conductor along the current transmission direction, and the low-precision Rogowski coil and the high-precision Rogowski coil are located on both sides of the thin-film capacitor.

[0036] Specifically, by arranging low-precision Rogowski coils and high-precision Rogowski coils outside the bus conductor, non-intrusive acquisition of bus current is achieved. Without changing the original circuit structure, the current signal is directly acquired, thus avoiding the parasitic parameters and system disturbance problems caused by the introduction of additional devices in traditional methods.

[0037] In at least one embodiment, please refer to Figure 2 The method for entering the data matching mode includes: operating under arbitrary operating parameters, acquiring the low-precision ripple current and high-precision ripple current at the current moment through low-precision Rogowski coils and high-precision Rogowski coils, and acquiring the conductor temperature and bus voltage at the current moment through temperature sensors and voltage sensors to obtain data sets regarding conductor temperature, bus voltage, low-precision ripple current, and high-precision ripple current; operating under different operating parameters to obtain corresponding data sets; and integrating all data sets to form a correspondence table regarding conductor temperature, bus voltage, low-precision ripple current, and high-precision ripple current.

[0038] Specifically, the current signal is generated at the source and then transmitted through the bus conductor. In addition to being affected by the source, the low-precision ripple current and the high-precision ripple current are also affected by the conductor temperature and the bus voltage. By forming a data group and associating the conductor temperature, the bus voltage, the low-precision ripple current and the high-precision ripple current, the accuracy of the low-precision ripple current and the high-precision ripple current after association can be guaranteed. That is, the high-precision ripple current obtained by the low-precision ripple current through the correspondence table is almost equivalent to the high-precision ripple current collected by the high-precision Rogowski coil.

[0039] In at least one embodiment, please refer to Figure 3 The method for entering the non-rotating mode of the motor includes: obtaining a low-precision ripple current through a low-precision Rogowski coil, and obtaining the corresponding conductor temperature and bus voltage through a temperature sensor and a voltage sensor; comparing the conductor temperature, bus voltage, and low-precision ripple current with each data group in the corresponding table; when the conductor temperature, bus voltage, and low-precision ripple current are consistent with those in a data group in the corresponding table, then outputting the high-precision ripple current in that data group, that is, obtaining the corresponding high-precision ripple current from the corresponding table.

[0040] Specifically, the following table is provided for the correspondence of some of the data:

[0041] The above parameter settings can be adjusted according to the actual situation; this case is only used as an example.

[0042] Specifically, the low-precision ripple current of 2.08A is obtained through a low-precision Rogowski coil, and the corresponding conductor temperature of 25℃ and bus voltage of 48V are obtained through temperature and voltage sensors. The corresponding data set in the table is (25℃, 48V, 2.08A, 2.00A). The high-precision ripple current of this data set is then output as 2.00A, that is, the corresponding high-precision ripple current of 2.00A is obtained from the corresponding table.

[0043] In at least one embodiment, please refer to Figure 4 The method for entering the motor rotation mode includes: indirectly obtaining the corresponding high-precision ripple current through a low-precision Rogowski coil. I rc1 High-precision ripple current is directly obtained through a high-precision Rogowski coil. I rc2 When | I rc1 - I rc2 |≤ I D That is, when the difference between two high-precision ripple currents is within a set threshold, the high-precision ripple current collected by the high-precision Rogowski coil is output. Irc2 Actual ripple current I R .

[0044] Specifically, the threshold can be set to (-0.1, 0.1), and the corresponding high-precision ripple current can be indirectly obtained through a low-precision Rogowski coil. I rc1 The current is 2.08A; the corresponding high-precision ripple current is directly obtained through a high-precision Rogowski coil. I rc2 If the difference between the two high-precision ripple currents is 2.00A, and the difference is within the set threshold, then the high-precision ripple current collected by the high-precision Rogowski coil will be output. I rc2 Actual ripple current I R That is, the actual ripple current I R It is 2.00A.

[0045] In at least one embodiment, please refer to Figure 4 The method for entering the motor rotation mode further includes: when | I rc1 - I rc2 |> I D When the difference between two high-precision ripple currents exceeds a set threshold, a high-precision Rogowski coil is used to obtain the high-precision ripple current under standard test parameters. I rc2 When high-precision ripple current I rc2 Compared with standard test ripple current I S If there is a discrepancy, the high-precision Rogowski coil is confirmed to be faulty; when the high-precision ripple current... I rc2 Compared with standard test ripple current I S If the results are consistent, then the low-precision Rogowski coil is confirmed to be faulty.

[0046] Specifically, the threshold can be set to (-0.1, 0.1), and the corresponding high-precision ripple current can be indirectly obtained through a low-precision Rogowski coil. I rc1 The current is 2.12A; the corresponding high-precision ripple current is directly obtained through a high-precision Rogowski coil. I rc2 If the current is 2.00A, then the difference between the two high-precision ripple currents exceeds the set threshold. A high-precision Rogowski coil is then used to re-acquire the high-precision ripple current under standard test parameters. I rc2The standard test ripple current is 1.00A. I S If it is 1.00A, then the high-precision ripple current is... I rc2 Compared with standard test ripple current I S If they match, the low-precision Rogowski coil is confirmed to be faulty; if the difference between the two high-precision ripple currents exceeds the set threshold, the high-precision ripple current under standard test parameters is re-acquired using the high-precision Rogowski coil. I rc2 The standard test ripple current is 1.05A. I S If it is 1.00A, then the high-precision ripple current is... I rc2 Compared with standard test ripple current I S If there is a discrepancy, the high-precision Rogowski coil is confirmed to be faulty.

[0047] Specifically, consistency can refer to the range of error, while inconsistency can refer to the range of error, with the error range being ±0.01A.

[0048] In at least one embodiment, when the high-precision Rogowski coil is confirmed to be abnormal, a corresponding maintenance alarm signal is output.

[0049] Based on the same technical concept, at least one embodiment also provides a measurement system employing the ripple current measurement method for a motor controller as described above, comprising: a motor controller, a low-precision Rogowski coil, a high-precision Rogowski coil, a temperature sensor, and a voltage sensor; wherein the motor controller is configured to perform: entering a data matching mode, simultaneously acquiring low-precision and high-precision ripple currents under different operating parameters through the low-precision and high-precision Rogowski coils, and acquiring corresponding conductor temperatures and bus voltages through the temperature and voltage sensors to form a correspondence table regarding conductor temperature, bus voltage, low-precision ripple current, and high-precision ripple current; entering a motor non-rotation mode, acquiring low-precision ripple current through the low-precision Rogowski coil, and... The system collects conductor temperature and bus voltage in real time to obtain the corresponding high-precision ripple current from a corresponding table. Upon entering motor rotation mode, it indirectly obtains the corresponding high-precision ripple current through a low-precision Rogowski coil and directly obtains the corresponding high-precision ripple current through a high-precision Rogowski coil. When the difference between the two high-precision ripple currents is within a set threshold, the high-precision ripple current collected by the high-precision Rogowski coil is output as the actual ripple current. Alternatively, when the difference between the two high-precision ripple currents exceeds the set threshold, the high-precision ripple current under standard test parameters is obtained through the high-precision Rogowski coil to confirm whether the high-precision or low-precision Rogowski coil is abnormal. When the low-precision Rogowski coil is confirmed to be abnormal, the system re-enters data matching mode to construct a new corresponding table.

[0050] Based on the same technical concept, at least one embodiment also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method.

[0051] Based on the same technical concept, at least one embodiment also provides an electronic device, which includes: a non-transitory computer-readable storage medium; a motor controller; wherein the non-transitory computer-readable storage medium stores instructions that, when executed by the motor controller, cause the motor controller to perform the steps according to the method described above.

[0052] In summary, this invention simultaneously acquires low-precision and high-precision ripple currents under different operating parameters using both low-precision and high-precision Rogowski coils. It can correlate the low-precision and high-precision ripple currents, along with conductor temperature and bus voltage, reducing interference from external factors. In non-rotating motor mode, the low-precision Rogowski coil replaces the high-precision Rogowski coil, outputting the ripple current through a correspondence table, improving the detection accuracy of the low-precision Rogowski coil and reducing losses in the high-precision Rogowski coil. In rotating motor mode, the high-precision Rogowski coil ensures accurate ripple current detection, and the correspondence table allows the detection results of the low-precision Rogowski coil to verify the accuracy of the high-precision Rogowski coil. Even if the low-precision Rogowski coil experiences losses, the high-precision Rogowski coil can recalibrate the detection results, achieving high continuity, high stability, and high detection accuracy within a limited budget.

[0053] The disclosures and other solutions, examples, embodiments, modules, and functional operations described in this document can be implemented in digital electronic circuits, or computer software, firmware, or hardware, including the structures disclosed in this document and their structural equivalents, or combinations thereof. The disclosures and other embodiments can be implemented as one or more computer program products, i.e., one or more modules of computer program instructions encoded on a tangible and non-volatile computer-readable medium for execution by a data processing apparatus or for controlling the operation of the data processing apparatus. The computer-readable medium can be a machine-readable storage device, a machine-readable storage substrate, a storage device, a material composition that influences machine-readable propagated signals, or one or more of these. The terms "data processing unit" or "data processing apparatus" include all means, devices, and machines for processing data, including, for example, programmable processors, computers, or multiprocessors or computer groups. In addition to hardware, the apparatus may also include code that creates an execution environment for a computer program, such as code constituting processor firmware, a protocol stack, a database management system, an operating system, or combinations thereof. The propagated signals are artificially generated signals, such as machine-generated electrical, optical, or electromagnetic signals, which are generated to encode information for transmission to a suitable receiver device.

[0054] Computer programs (also known as programs, software, software applications, scripts, or code) can be written in any programming language (including compiled or interpreted languages) and can be deployed in any form, including as standalone programs or as modules, components, subroutines, or other units suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to that program, or in multiple coordinating files (e.g., a file storing one or more modules, subroutines, or portions of code). Computer programs can be deployed and executed on one or more computers located at a single site or distributed across multiple sites interconnected by a communication network.

[0055] The processing and logic flows described in this document can be executed by one or more programmable processors that execute one or more computer programs to perform functions by manipulating input data and generating outputs. The processing and logic flows can also be executed by special-purpose logic circuitry, and the devices can be implemented as special-purpose logic circuitry, such as FPGAs (Field-Programmable Gate Arrays) or ASICs (Application-Specific Integrated Circuits).

[0056] For example, processors suitable for executing computer programs include general-purpose and special-purpose microprocessors, as well as any one or more of any type of digital computer. Typically, the processor receives instructions and data from read-only memory or random access memory, or both. The basic components of a computer are a processor that executes instructions and one or more storage devices that store the instructions and data. Typically, a computer will also include one or more mass storage devices for storing data, such as magnetic disks, magneto-optical disks, or optical disks, or operatively coupled to receive data from or transfer data to mass storage devices, or both. However, a computer does not necessarily have such devices. Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and memory devices, including, for example, semiconductor memory devices such as erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), and flash memory devices; magnetic disks, such as internal hard disks or removable disks; magneto-optical disks; and optical disc read-only memory (CD ROM) and digital versatile optical disc read-only memory (DVD-ROM). The processor and memory may be supplemented by dedicated logic circuitry or incorporated into dedicated logic circuitry.

[0057] While this patent document contains numerous details, it should not be construed as limiting the scope of any invention or claim, but rather as a description of features of specific embodiments of a particular invention. Certain features described in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various functions described in the context of a single embodiment may also be implemented individually in multiple embodiments, or in any suitable sub-combination. Furthermore, although the foregoing features may be described as functioning in certain combinations, or even initially claimed to be so, in certain circumstances, one or more features from a combination of claims may be removed from the combination, and a combination of claims may refer to a sub-combination or a variation of a sub-combination.

[0058] Similarly, although the operations are described in a specific order in the accompanying drawings, this should not be construed as requiring the specific order or sequence shown to perform such operations, or all the described operations, in order to obtain the desired result. Furthermore, the separation of various system components in the embodiments of this patent document should not be construed as requiring such separation in all embodiments.

[0059] Only some implementations and examples are described; other implementations, enhancements, and variations can be made based on the content described and illustrated in this patent document.

[0060] When no intermediate component exists other than a line, trace, or other medium between the first and second components, the first component is directly coupled to the second component. When an intermediate component other than a line, trace, or other medium exists between the first and second components, the first component is indirectly coupled to the second component. The term "coupling" and its variations include direct coupling and indirect coupling. Unless otherwise stated, the term "about" is used to mean a range including upper and lower 10% of the value.

[0061] While several embodiments are provided in this disclosure, it should be understood that the disclosed systems and methods may be embodied in many other specific forms without departing from the spirit or scope of this disclosure. The present examples are intended to be illustrative rather than restrictive and are not limited to the details given. For example, various elements or components may be combined or integrated into another system, or certain features may be omitted or not implemented.

[0062] In the several embodiments provided herein, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative; for example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0063] Furthermore, without departing from the scope of this disclosure, the discrete or individual technologies, systems, subsystems, and methods described and illustrated in the various embodiments may be combined or integrated with other systems, modules, technologies, or methods. Other items shown or discussed as coupled may be directly connected or indirectly coupled or communicated via some interface, device, or intermediate component in an electrical, mechanical, or other manner. Those skilled in the art can identify other examples of changes, substitutions, and modifications without departing from the spirit and scope of this disclosure.

Claims

1. A method for measuring ripple current in a motor controller, characterized in that, The following steps are performed using a ripple current meter: Entering the data matching mode, the low-precision ripple current and high-precision ripple current under different operating parameters are obtained simultaneously through low-precision Rogowski coils and high-precision Rogowski coils to form a correspondence table about conductor temperature, bus voltage, low-precision ripple current and high-precision ripple current. Determine if the motor is rotating to select one of the following modes: Entering the non-rotating mode of the motor, the low-precision ripple current is obtained through the low-precision Rogowski coil, and the conductor temperature and bus voltage are collected in real time to obtain the corresponding high-precision ripple current from the corresponding table. Upon entering motor rotation mode, the corresponding high-precision ripple current is indirectly obtained through a low-precision Rogowski coil, and the corresponding high-precision ripple current is directly obtained through a high-precision Rogowski coil. If the difference between the two high-precision ripple currents is within a set threshold, the high-precision ripple current collected by the high-precision Rogowski coil is output as the actual ripple current. Alternatively, if the difference between the two high-precision ripple currents exceeds the set threshold, the high-precision ripple current under standard test parameters is obtained through the high-precision Rogowski coil. If either the high-precision or low-precision Rogowski coil is abnormal, the data matching mode is re-entered to construct a new correspondence table.

2. The ripple current measurement method for a motor controller as described in claim 1, characterized in that, The method for entering the data matching mode includes: Under arbitrary operating parameters, the system obtains the low-precision ripple current and high-precision ripple current at the current moment through low-precision Rogowski coils and high-precision Rogowski coils, and obtains the conductor temperature and bus voltage at the current moment through temperature sensors and voltage sensors, so as to obtain a data set on conductor temperature, bus voltage, low-precision ripple current and high-precision ripple current. Run under different operating parameters to obtain the corresponding data sets; All data sets are integrated to form a table showing the correspondence between conductor temperature, bus voltage, low-precision ripple current, and high-precision ripple current.

3. The ripple current measurement method for a motor controller as described in claim 2, characterized in that, The method for entering the non-rotating motor mode includes: Low-precision ripple current is obtained by using a low-precision Rogowski coil, and the corresponding conductor temperature and bus voltage are obtained by temperature and voltage sensors. The conductor temperature, bus voltage, and low-precision ripple current are compared with the data sets in the corresponding table. When they match the conductor temperature, bus voltage, and low-precision ripple current in a data set in the corresponding table, the high-precision ripple current in that data set is output, that is, the corresponding high-precision ripple current is obtained from the corresponding table.

4. The ripple current measurement method for a motor controller as described in claim 3, characterized in that, The method for entering the motor rotation mode includes: The corresponding high-precision ripple current is indirectly obtained through a low-precision Rogowski coil. I rc1 ; The corresponding high-precision ripple current is directly obtained through a high-precision Rogowski coil. I rc2 ; When | I rc1 - I rc2 |≤ I D That is, when the difference between two high-precision ripple currents is within a set threshold, the high-precision ripple current collected by the high-precision Rogowski coil is output. I rc2 Actual ripple current I R .

5. The ripple current measurement method for a motor controller as described in claim 4, characterized in that, The method for entering the motor rotation mode further includes: When | I rc1 - I rc2 |> I D When the difference between two high-precision ripple currents exceeds a set threshold, a high-precision Rogowski coil is used to obtain the high-precision ripple current under standard test parameters. I rc2 ; When high-precision ripple current I rc2 Compared with standard test ripple current I S If there is a discrepancy, the high-precision Rogowski coil is confirmed to be abnormal; When high-precision ripple current I rc2 Compared with standard test ripple current I S If the results are consistent, then the low-precision Rogowski coil is confirmed to be faulty.

6. The ripple current measurement method for a motor controller as described in claim 5, characterized in that, When the low-precision Rogowski coil is confirmed to be abnormal, re-enter the data matching mode to build a new correspondence table; When the high-precision Rogowski coil is confirmed to be abnormal, a corresponding maintenance alarm signal will be output.

7. The ripple current measurement method for a motor controller as described in claim 1, characterized in that, Low-precision Rogowski coils and high-precision Rogowski coils are sequentially arranged on the bus conductor along the current transmission direction, with the low-precision Rogowski coils and high-precision Rogowski coils located on both sides of the film capacitor.

8. A ripple current measuring instrument for a motor controller employing the ripple current measuring method for a motor controller as described in any one of claims 1-7, characterized in that, It includes: The control module, and the low-precision Rogowski coil, high-precision Rogowski coil, temperature sensor, and voltage sensor electrically connected to the control module; in The control module is configured to execute: Entering the data matching mode, the low-precision ripple current and high-precision ripple current under different operating parameters are simultaneously obtained through low-precision Rogowski coils and high-precision Rogowski coils. The corresponding conductor temperature and bus voltage are collected through temperature sensors and voltage sensors to form a correspondence table of conductor temperature, bus voltage, low-precision ripple current and high-precision ripple current. Determine if the motor is rotating to select one of the following modes: Entering the non-rotating mode of the motor, the low-precision ripple current is obtained through the low-precision Rogowski coil, and the conductor temperature and bus voltage are collected in real time to obtain the corresponding high-precision ripple current from the corresponding table. When the motor enters rotation mode, the corresponding high-precision ripple current is indirectly obtained through a low-precision Rogowski coil, and the corresponding high-precision ripple current is directly obtained through a high-precision Rogowski coil. If the difference between the two high-precision ripple currents is within a set threshold, the high-precision ripple current collected by the high-precision Rogowski coil is output as the actual ripple current; or, if the difference between the two high-precision ripple currents exceeds the set threshold, the high-precision ripple current under standard test parameters is obtained through the high-precision Rogowski coil to confirm whether the high-precision Rogowski coil or the low-precision Rogowski coil is abnormal. as well as When the low-precision Rogowski coil is confirmed to be abnormal, the system re-enters data matching mode to build a new correspondence table.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of the method according to any one of claims 1-7.

10. An electronic device, characterized in that, include: Non-transitory computer-readable storage medium; Motor controller; The non-transitory computer-readable storage medium stores instructions that, when executed by the motor controller, cause the motor controller to perform the steps of the method according to any one of claims 1-7.

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