Shaft voltage measurement method, device, equipment, readable storage medium and program product

Abstract

The application relates to an axle voltage measurement method, device, equipment, readable storage medium and program product. The application is applied to an axle voltage measurement system, the axle voltage measurement system comprises a target motor, the target motor is provided with a motor shaft and a signal inductor, the motor shaft and the signal inductor are not in contact, the method comprises the following steps: under the condition that a preset electric field coupling condition is met between the motor shaft and the signal inductor, an electric field operation signal generated by the motor shaft is collected through the signal inductor under the electric field coupling effect; electric parameter characteristic information of the motor shaft is extracted from the electric field operation signal, wherein the electric parameter characteristic information is used for representing the electric parameter change condition of the motor shaft under the electric field coupling effect; and the axle voltage of the motor shaft is measured according to the electric parameter characteristic information. The method reduces the measurement limitation of axle voltage measurement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of shaft voltage detection, in particular to a shaft voltage measurement method and device, a shaft voltage measurement equipment, a computer readable storage medium and a computer program product. BACKGROUND

[0002] During the operation of a large generator, shaft voltage is induced on the generator shaft due to reasons such as magnetic circuit asymmetry, static excitation system and electrostatic effect. In a vehicle, the motor is often the core component of the drive system. Once the shaft voltage is generated on the shaft during the operation of the motor, electromagnetic noise will be radiated outward through the transmission from the transmission shaft, thereby causing radio noise problems. Therefore, it is necessary to measure the shaft voltage of the motor to quantify the noise reduction effect of the vehicle.

[0003] Currently, a conductive object is usually used to contact the motor shaft for measurement. However, in some application scenarios where the surface material of the motor shaft is not conductive, the shape is complex or the space is limited, if the motor shaft cannot provide a contact surface for the conductive object, it will lead to the failure of contact measurement of the shaft voltage, and thus the noise reduction effect cannot be quantified. Therefore, the current shaft voltage measurement has high measurement limitations. SUMMARY

[0004] Therefore, it is necessary to provide a shaft voltage measurement method, device, equipment, computer readable storage medium and computer program product for reducing the measurement limitations of shaft voltage measurement.

[0005] In a first aspect, the present application provides a shaft voltage measurement method applied to a shaft voltage measurement system, the shaft voltage measurement system comprising a target motor, the target motor being provided with a motor shaft and a signal inductor, wherein the motor shaft and the signal inductor are not in contact, and the method comprises:

[0006] In the case where a preset electric field coupling condition is met between the motor shaft and the signal inductor, an electric field operating signal generated by the motor shaft is collected through the signal inductor under the electric field coupling effect;

[0007] Extracting electrical parameter characteristic information of the motor shaft from the electric field operating signal, wherein the electrical parameter characteristic information is used to represent the change of the electrical parameter of the motor shaft under the electric field coupling effect;

[0008] According to the electrical parameter characteristic information, the shaft voltage of the motor shaft is measured.

[0009] In one of the embodiments, the target motor is provided with a machine shell, a rotor winding and a stator winding, the rotor winding and the motor shaft are fixedly connected through a rotor core, the stator winding is fixed to the machine shell, the rotor winding and the stator winding are coupled through an electromagnetic field, and the machine shell is used to protect the motor shaft; the shaft voltage measurement of the motor shaft according to the electrical parameter characteristic information comprises:

[0010] determining a first capacitance characteristic value of the motor shaft under the electric field coupling effect according to a first capacitance and a second capacitance, wherein the first capacitance refers to the capacitance generated between the rotor winding and the motor shaft, and the second capacitance refers to the capacitance generated between the machine shell and the motor shaft;

[0011] measuring the shaft voltage of the motor shaft according to the voltage characteristic value of the rotor winding and the first capacitance characteristic value.

[0012] In one of the embodiments, the method for determining the first capacitance characteristic value of the motor shaft under the electric field coupling effect according to the first capacitance and the second capacitance comprises:

[0013] obtaining a third capacitance generated between the rotor winding and the machine shell, a fourth capacitance generated between the motor shaft and the signal sensor, a fifth capacitance generated between the signal sensor and the machine shell, and a sixth capacitance generated between the rotor winding and the signal sensor;

[0014] fusing the first capacitance, the second capacitance, the third capacitance, the fourth capacitance, the fifth capacitance and the sixth capacitance to obtain the first capacitance characteristic value.

[0015] In one of the embodiments, the signal sensor comprises an electric field shielding assembly; the method for determining the shaft voltage of the motor shaft according to the voltage characteristic value of the rotor winding and the first capacitance characteristic value comprises:

[0016] converting the voltage characteristic value of the rotor winding through the electric field shielding assembly to obtain a converted voltage characteristic value;

[0017] fusing the converted voltage characteristic value and the first capacitance characteristic value to obtain the shaft voltage of the motor shaft.

[0018] In one of the embodiments, the method for measuring the shaft voltage of the motor shaft according to the voltage characteristic value of the rotor winding and the first capacitance characteristic value comprises:

[0019] obtaining a first voltage characteristic value of an actual shaft voltage of the motor shaft;

[0020] According to the voltage characteristic value of the rotor winding and the first capacitance characteristic value, a measurement shaft voltage of the motor shaft is measured;

[0021] A Fourier transform is performed on a time waveform of the measurement shaft voltage to obtain a second voltage characteristic value of the measurement shaft voltage;

[0022] In a case where a voltage characteristic difference between the first voltage characteristic value and the second voltage characteristic value is less than a preset voltage characteristic difference threshold, the measurement shaft voltage is taken as a target shaft voltage of the motor shaft.

[0023] In one of the embodiments, after the measurement shaft voltage is taken as the target shaft voltage of the motor shaft, the method further includes:

[0024] According to the fourth capacitance and the fifth capacitance, a second capacitance characteristic value of the signal sensor under the electric field coupling effect is determined;

[0025] The target shaft voltage and the second capacitance characteristic value are fused to obtain a voltage value of the signal sensor.

[0026] In a second aspect, the application further provides an axis voltage measurement device applied to an axis voltage measurement system, the axis voltage measurement system including a target motor, the target motor being provided with a motor shaft and a signal sensor, wherein the motor shaft and the signal sensor are not in contact, and the device includes:

[0027] A collection module is configured to collect, under the electric field coupling effect, an electric field operation signal generated by the motor shaft through the signal sensor in a case where a preset electric field coupling condition is met between the motor shaft and the signal sensor;

[0028] An extraction module is configured to extract electrical parameter characteristic information of the motor shaft from the electric field operation signal, wherein the electrical parameter characteristic information is used to represent an electrical parameter change of the motor shaft under the electric field coupling effect;

[0029] A measurement module is configured to measure an axis voltage of the motor shaft according to the electrical parameter characteristic information.

[0030] In one of the embodiments, the target motor is provided with a machine shell, a rotor winding and a stator winding, the rotor winding and the motor shaft are fixedly connected through a rotor core, the stator winding is fixed to the machine shell, the rotor winding and the stator winding are coupled through an electromagnetic field, and the machine shell is used to protect the motor shaft, and the measurement module is further configured to:

[0031] determine a first capacitance characteristic value of the motor shaft under the electric field coupling effect according to a first capacitance and a second capacitance, wherein the first capacitance refers to a capacitance generated between the rotor winding and the motor shaft, and the second capacitance refers to a capacitance generated between the motor casing and the motor shaft; and measure a shaft voltage of the motor shaft according to a voltage characteristic value of the rotor winding and the first capacitance characteristic value.

[0032] In one of the embodiments, the measurement module is further configured to:

[0033] obtain a third capacitance generated between the rotor winding and the motor casing, a fourth capacitance generated between the motor shaft and the signal sensor, a fifth capacitance generated between the signal sensor and the motor casing, and a sixth capacitance generated between the rotor winding and the signal sensor; and fuse the first capacitance, the second capacitance, the third capacitance, the fourth capacitance, the fifth capacitance, and the sixth capacitance to obtain the first capacitance characteristic value.

[0034] In one of the embodiments, the signal sensor comprises an electric field shielding component; and the measurement module is further configured to:

[0035] convert the voltage characteristic value of the rotor winding through the electric field shielding component to obtain a converted voltage characteristic value; and fuse the converted voltage characteristic value and the first capacitance characteristic value to obtain the shaft voltage of the motor shaft.

[0036] In one of the embodiments, the measurement module is further configured to:

[0037] obtain a first voltage characteristic value of an actual shaft voltage of the motor shaft; measure a measurement shaft voltage of the motor shaft according to the voltage characteristic value of the rotor winding and the first capacitance characteristic value; perform Fourier transform on a time waveform of the measurement shaft voltage to obtain a second voltage characteristic value of the measurement shaft voltage; and in a case where a voltage characteristic difference between the first voltage characteristic value and the second voltage characteristic value is less than a preset voltage characteristic difference threshold value, take the measurement shaft voltage as a target shaft voltage of the motor shaft.

[0038] In one of the embodiments, the shaft voltage measurement device is further configured to:

[0039] determine a second capacitance characteristic value of the signal sensor under the electric field coupling effect according to the fourth capacitance and the fifth capacitance; and fuse the target shaft voltage and the second capacitance characteristic value to obtain a voltage value of the signal sensor.

[0040] In a third aspect, the present application also provides a shaft voltage measurement device, comprising a memory and a processor, the memory stores a computer program, and the processor implements the following steps when executing the computer program:

[0041] In the case that the preset electric field coupling condition is met between the motor shaft and the signal sensor, an electric field operation signal generated by the motor shaft is collected through the signal sensor under the electric field coupling effect; the electric parameter characteristic information of the motor shaft is extracted from the electric field operation signal, wherein the electric parameter characteristic information is used to represent the change of the electric parameter of the motor shaft under the electric field coupling effect; and the shaft voltage of the motor shaft is measured according to the electric parameter characteristic information.

[0042] In a fourth aspect, the present application also provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the following steps:

[0043] In the case that the preset electric field coupling condition is met between the motor shaft and the signal sensor, an electric field operation signal generated by the motor shaft is collected through the signal sensor under the electric field coupling effect; the electric parameter characteristic information of the motor shaft is extracted from the electric field operation signal, wherein the electric parameter characteristic information is used to represent the change of the electric parameter of the motor shaft under the electric field coupling effect; and the shaft voltage of the motor shaft is measured according to the electric parameter characteristic information.

[0044] In a fifth aspect, the present application also provides a computer program product, comprising a computer program, and the computer program is executed by a processor to implement the following steps:

[0045] In the case that the preset electric field coupling condition is met between the motor shaft and the signal sensor, an electric field operation signal generated by the motor shaft is collected through the signal sensor under the electric field coupling effect; the electric parameter characteristic information of the motor shaft is extracted from the electric field operation signal, wherein the electric parameter characteristic information is used to represent the change of the electric parameter of the motor shaft under the electric field coupling effect; and the shaft voltage of the motor shaft is measured according to the electric parameter characteristic information.

[0046] The aforementioned shaft voltage measurement method, apparatus, device, computer-readable storage medium, and computer program are applied to a shaft voltage measurement system. The shaft voltage measurement system includes a target motor with a motor shaft mounted on it, and a signal sensor that is not in contact with the motor shaft. First, under the condition that a preset electric field coupling condition is met between the electrode shaft and the signal sensor, the signal sensor collects the electric field operation signal generated by the motor shaft under the action of electric field coupling. Then, electrical parameter characteristic information characterizing the changes in electrical parameters of the motor shaft under the action of electric field coupling is extracted from the electric field operation signal. Finally, based on the electrical parameter characteristics... By measuring the shaft voltage of the motor shaft through signal sensor information, the purpose of measuring the shaft voltage of the motor shaft can be achieved through electric field coupling, without the motor shaft and signal sensor being in contact. Therefore, it overcomes the technical defect that contact measurement requires a conductive object to be provided on the motor shaft. In some application scenarios, such as when the surface material of the motor shaft is non-conductive, the shape is complex, or the space is limited, if the motor shaft cannot provide a conductive object to be provided, the shaft voltage cannot be measured by contact, which may lead to the inability to quantify the noise reduction effect. Therefore, it reduces the measurement limitations of shaft voltage measurement. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a flowchart illustrating a shaft voltage measurement method in one embodiment;

[0049] Figure 2 This is a flowchart illustrating the shaft voltage measurement method in another embodiment;

[0050] Figure 3 This is a schematic diagram of the equivalent circuit model of the shaft voltage measurement method in one embodiment;

[0051] Figure 4 This is a structural block diagram of the shaft voltage measuring device in one embodiment;

[0052] Figure 5 This is an internal structural diagram of a shaft voltage measuring device in one embodiment. Detailed Implementation

[0053] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0054] Firstly, it should be understood that high-voltage systems have been widely used due to the advantage of reducing the loss of power transmission systems, and the problems existing in the high-voltage system include the problem of excessive shaft voltage. It can be understood that the shaft voltage is generated between the motor shaft and the shell, and the shaft voltage is usually divided by the capacitance between the coil and the shaft and the capacitance between the shaft and the shell. Moreover, the shaft voltage can also cause the shortening of bearing life and the Electro Magnetic Compatibility (EMC) problem. In the system of pulse width modulation control, the shaft voltage also has the characteristics of step and rectangular waveform. The amplitude of the shaft voltage usually varies from several volts to several tens of volts. In vehicles, when the shaft voltage is generated, electromagnetic noise will be radiated from the transmission shaft through the transmission, thereby causing problems such as radio noise. In the process of reducing noise, it is necessary to measure the shaft voltage. In the process of measuring the shaft voltage, the shaft is usually in contact with a conductive object to complete the measurement, for example, an electric brush is placed on the contact surface. The contact position of the electric brush is usually the circumference of the motor shaft or the end plate. The end plate prevents the protrusion of the magnet to suppress eccentricity. In the conventional shaft design, in order to minimize the length of the motor shaft, there is no space for the electric brush to contact on the motor shaft. If the motor shaft is lengthened, the voltage may change unexpectedly. At the same time, the end plate cannot be flat to ensure its fixation and prevent eccentricity. Therefore, in the application scenarios where the surface material of the motor shaft is conductive, the shape is complex, or the space is limited, the motor shaft cannot provide a contact surface for the electric brush, thereby making it impossible to complete the contact measurement of the shaft voltage. Finally, it is easy to appear the case that the noise reduction effect cannot be quantified. Therefore, there is an urgent need for a shaft voltage measurement method for reducing the measurement limitations of shaft voltage measurement.

[0055] In one embodiment, as Figure 1As shown, a shaft voltage measurement method is provided, and in the embodiment, the method is applied to a shaft voltage measurement system, the shaft voltage measurement system comprises a target motor, the target motor is provided with a motor shaft and a signal sensor, wherein the motor shaft and the signal sensor are not in contact, the shaft voltage measurement system is deployed on a shaft voltage measurement device, and the shaft voltage measurement device includes but is not limited to a shaft voltage tester and a power test device, etc., wherein the power test device can be a clamp ammeter, a wave recorder and a power analyzer, etc., and it can be understood that the shaft voltage measurement system comprises a collection module, an extraction module and a measurement module, the collection module is used to collect the electric field running signal generated by the motor shaft under the electric field coupling effect through the signal sensor when the preset electric field coupling condition is met between the motor shaft and the signal sensor, the extraction module is used to extract the electrical parameter characteristic information of the motor shaft in the electric field running signal, wherein the electrical parameter characteristic information is used to represent the electrical parameter change of the motor shaft under the electric field coupling effect, and the measurement module is used to measure the shaft voltage of the motor shaft according to the electrical parameter characteristic information, through the information interaction between the collection module, the extraction module and the measurement module, the electric field running signal generated by the motor shaft can be collected through the electric field coupling effect between the motor shaft and the signal sensor when the motor shaft and the signal sensor are not in contact, and finally the shaft voltage of the motor shaft can be measured through the electrical parameter characteristic information extracted from the electric field running signal, that is, the purpose of measuring the shaft voltage of the motor shaft can be achieved through the electric field coupling effect when the motor shaft and the signal sensor are not in contact, so that the measurement limitation of the shaft voltage measurement can be reduced. In the embodiment, the method comprises the following steps:

[0056] Step 202, under the electric field coupling effect, the electric field running signal generated by the motor shaft is collected through the signal sensor when the preset electric field coupling condition is met between the motor shaft and the signal sensor.

[0057] It should be noted that when there is a distributed capacitance between two circuit elements, an electric field will be formed between the two circuit elements, which can cause the charge change on one circuit element to affect the charge change on the other circuit element. Based on the principle of electromagnetic induction, when the motor shaft of the target motor is charged, an electric field will be formed around it, and the change of the electric field can be captured by the signal sensor which does not contact the motor shaft, that is, the signal sensor can capture the electric field running signal generated by the motor shaft, and through the analysis and processing of the electric field running signal, the non-contact measurement of the shaft voltage of the motor shaft can be indirectly realized, wherein the signal sensor can be a specially designed antenna, for example, in an implementable manner, when the antenna faces the rotor end of the target motor, an electric field coupling effect can be generated, that is, based on the principle of capacitance, there is a voltage difference between two conductors, and then an electric field will be formed between the two conductors, which can transmit energy or signals without physical contact.

[0058] It should be noted that the electric field coupling effect between the motor shaft and the signal sensor is required to meet the preset electric field coupling condition between the motor shaft and the signal sensor. For example, in an implementable manner, the motor shaft is powered when the interval distance between the motor shaft and the signal sensor is less than the preset interval distance threshold, and the electric field operating signal collected can be processed and converted to realize non-contact measurement of the shaft voltage. For example, in an implementable manner, assuming that the signal sensor is an electrode, the antenna size and position are determined according to the electromagnetic field simulation result; the antenna shaft voltage design range is determined so that the installation of the antenna will not cause the shaft voltage to change by more than 5%; simulation analysis is performed to determine that the maximum outer diameter of the antenna should be φ122mm or less to keep the influence on the shaft voltage within an acceptable range.

[0059] As an example, step 202 includes: powering the motor shaft of the target motor when the interval distance between the motor shaft and the antenna is less than the preset interval distance threshold, and forming an electric field coupling effect between the motor shaft and the antenna, and collecting the electric field operating signal generated by the motor shaft through the antenna under the electric field coupling effect.

[0060] Step 204, extracting the electrical parameter characteristic information of the motor shaft in the electric field operating signal, wherein the electrical parameter characteristic information is used to represent the electrical parameter change of the motor shaft under the electric field coupling effect.

[0061] It should be noted that the electrical parameter characteristic information is used to represent the electrical parameter change of the motor shaft under the electric field coupling effect, which can be the capacitance value between the motor shaft and the rotor winding on the target motor, the capacitance value between the motor shaft and the casing on the target motor, and the coil voltage on the target motor, etc. The electrical parameter characteristic information of the motor shaft can be extracted by analyzing the electric field operating signal.

[0062] As an example, step 204 includes: analyzing the electric field operating signal to obtain the electrical parameter characteristic information of the motor shaft.

[0063] Step 206, measuring the shaft voltage of the motor shaft according to the electrical parameter characteristic information.

[0064] It should be noted that the electrical parameter characteristic information is used to represent the electrical parameter change of the motor shaft under the electric field coupling effect, and the measured shaft voltage of the motor shaft can be measured through the electrical parameter characteristic information. For example, in an implementable manner, the front and rear end shaft voltages of the motor are measured simultaneously by a double-channel or multi-channel oscilloscope based on the electrical parameter characteristic information.

[0065] As an example, step 206 includes measuring the shaft voltage of the motor shaft through the electrical parameter feature information.

[0066] In the above shaft voltage measurement method, first, in the case that the interval distance between the motor shaft and the signal sensor is less than the preset interval distance threshold, the motor shaft is energized to form an electric field coupling effect between the motor shaft and the signal sensor, and the electric field operation signal generated by the motor shaft can be collected by the signal sensor under the electric field coupling effect, and then the electric field operation signal is analyzed and processed to obtain the electrical parameter feature information for representing the change of the electrical parameter of the motor shaft under the electric field coupling effect. Finally, the shaft voltage of the motor shaft is measured through the electrical parameter feature information, that is, the purpose of measuring the shaft voltage of the motor shaft is achieved through the electric field coupling effect without contacting the signal sensor. Therefore, the technical defect that the shaft voltage cannot be measured by contact measurement if the motor shaft cannot provide a contact surface for the conductive object in some application scenarios such as non-conductive surface material, complex shape or limited space of the motor shaft is overcome, and the measurement limitation of shaft voltage measurement is reduced.

[0067] In one embodiment, as shown in Figure 2 The target motor is deployed with a machine shell, a rotor winding and a stator winding, the rotor winding and the motor shaft are fixedly connected through a rotor core, the stator winding is fixed to the machine shell, the rotor winding and the stator winding are coupled through an electromagnetic field, and the machine shell is used to protect the motor shaft. According to the electrical parameter feature information, the shaft voltage of the motor shaft is measured, including:

[0068] Step 302, according to the first capacitance and the second capacitance, determining the first capacitance feature value of the motor shaft under the electric field coupling effect, wherein the first capacitance refers to the capacitance generated between the rotor winding and the motor shaft, and the second capacitance refers to the capacitance generated between the machine shell and the motor shaft.

[0069] It should be noted that in the process of measuring the shaft voltage of the motor shaft based on the electrical static coupling between the signal sensor and the motor shaft, the relevant information can be collected by the signal sensor based on the specific structure of the target motor, and the measurement shaft voltage of the motor shaft can be calculated by using a pre-designed calculation formula, wherein the target motor is provided with a machine shell, a rotor winding and a stator winding, the rotor winding and the motor shaft are fixedly connected through a rotor core, the stator winding is fixed to the machine shell, the rotor winding and the stator winding are coupled through an electromagnetic field during the rotating operation of the motor shaft, and the machine shell is used for protecting the motor shaft. For example, in an implementable manner, the first capacitance refers to the capacitance generated between the rotor winding and the motor shaft, the second capacitance refers to the capacitance generated between the machine shell and the motor shaft, the first capacitance characteristic value is the ratio between the first capacitance and the first capacitance sum, and the voltage characteristic value of the rotor winding is the voltage value of the rotor winding, i.e. the coil voltage. Then, the measurement shaft voltage of the motor shaft can be obtained by fusing the first capacitance characteristic value and the coil voltage.

[0070] As an example, step 302 includes: adding the first capacitance and the second capacitance to obtain the first capacitance sum, and taking the ratio between the first capacitance and the first capacitance sum as the first capacitance characteristic value.

[0071] Step 304, measuring the shaft voltage of the motor shaft according to the voltage characteristic value of the rotor winding and the first capacitance characteristic value.

[0072] As an example, step 304 includes: inputting the voltage characteristic value of the rotor winding and the first capacitance characteristic value into a preset shaft voltage calculation formula to obtain the shaft voltage of the motor shaft, wherein the preset shaft voltage calculation formula is as follows:

[0073]

[0074] wherein, is the measurement shaft voltage of the motor shaft, is the voltage characteristic value of the rotor winding, is the first capacitance characteristic value, is the first capacitance, is the second capacitance.

[0075] In the embodiment, when the shaft voltage of the motor shaft is measured, the electrostatic coupling effect formed by the coupling of the electromagnetic field between the signal sensor and the rotor winding of the target motor generates the electric field operating signal, provides the voltage characteristic value of the first capacitor generated between the rotor winding and the motor shaft, the second capacitor generated between the motor housing and the motor shaft, and the rotor winding, and inputs the above parameters into the preset shaft voltage calculation formula, so that the shaft voltage of the motor shaft is calculated, that is, the purpose of measuring the shaft voltage of the motor shaft based on the electrostatic coupling principle and the capacitive non-contact measurement is realized, so that the measurement limitation of the shaft voltage measurement is further reduced.

[0076] In one embodiment, according to the first capacitor and the second capacitor, the first capacitor characteristic value of the motor shaft under the electric field coupling effect is determined, including:

[0077] The third capacitor generated between the rotor winding and the motor housing, the fourth capacitor generated between the motor shaft and the signal sensor, the fifth capacitor generated between the signal sensor and the motor housing, and the sixth capacitor generated between the rotor winding and the signal sensor are obtained; the first capacitor, the second capacitor, the third capacitor, the fourth capacitor, the fifth capacitor and the sixth capacitor are fused to obtain the first capacitor characteristic value.

[0078] It should be noted that when the rotor winding and the stator winding are coupled by the electromagnetic field, the capacitor relationship formed between the signal sensor and the target motor is complex, and further to improve the accuracy of the shaft voltage measurement of the motor shaft, an equivalent circuit can be used to simulate the capacitor relationship between the target motor and the signal sensor. For example, in one implementable manner, referring to Figure 3 , Figure 3 is a schematic diagram of an equivalent circuit model, wherein 11 is an inverter, 12 is a coil of the rotor winding, 13 is a rotor shaft, 14 is a stator, is a third capacitor generated between the rotor winding and the motor housing, is a fourth capacitor generated between the motor shaft and the signal sensor, is a fifth capacitor generated between the signal sensor and the motor housing, is a sixth capacitor generated between the signal sensor and the rotor winding.

[0079] As an example, a third capacitance generated between the rotor winding and the shell, a fourth capacitance generated between the motor shaft and the signal sensor, a fifth capacitance generated between the signal sensor and the shell, and a sixth capacitance generated between the rotor winding and the signal sensor are obtained; the first capacitance, the second capacitance, the third capacitance, the fourth capacitance, the fifth capacitance, and the sixth capacitance are weighted and fused to obtain a first capacitance characteristic value. Since the first capacitance characteristic value of the motor shaft under the electric field coupling effect is determined, the complex capacitance relationship between the target motor and the signal sensor in the coupling process of the rotor winding and the stator winding through the electromagnetic field is fully considered, and the simulation is performed through the equivalent circuit model, so that the first capacitance characteristic value is fused depending on the capacitances formed between different parts of the target motor and the signal sensor, and the purpose of accurately obtaining the first capacitance characteristic value is achieved, that is, the foundation for improving the measurement accuracy of the shaft voltage is laid.

[0080] In one embodiment, the signal sensor comprises an electric field shielding component; and the shaft voltage of the motor shaft is determined according to the voltage characteristic value of the rotor winding and the first capacitance characteristic value, comprising:

[0081] The voltage characteristic value of the rotor winding is converted through the electric field shielding component to obtain a converted voltage characteristic value; and the converted voltage characteristic value and the first capacitance characteristic value are fused to obtain the shaft voltage of the motor shaft.

[0082] It should be noted that, in order to accurately measure the shaft voltage of the motor shaft, an electric field shielding component can also be deployed on the signal sensor, wherein the electric field shielding component can be a protection electrode, which is used to reduce the electric static coupling between the signal sensor and the rotor winding, that is, to ensure that the voltage of the rotor winding is accurately characterized, thereby reducing the technical defects that the noise generated by the rotor winding indirectly affects the shaft voltage of the motor shaft by affecting the voltage characteristic value of the rotor winding. For example, in one implementable manner, the protection electrode is designed as a grounded electrode, which can convert the voltage characteristic value of the rotor winding that may be coupled to the signal sensor into a voltage coupled to the shell by changing the distribution of the electric field, thereby ensuring that the signal sensor (antenna) can measure the voltage caused by the shaft voltage.

[0083] As an example, the voltage characteristic value of the rotor winding is converted through the electric field shielding component to obtain a converted voltage characteristic value; and the product of the first capacitance characteristic value and the converted voltage characteristic value is taken as the shaft voltage of the motor shaft. Since the electric field shielding component can change the electromagnetic field distribution between the signal sensor and the motor shaft, and the converted voltage characteristic value can eliminate the influence of the noise generated by the rotor winding on the accuracy of the voltage after the voltage characteristic value of the rotor winding is converted through the electric field shielding component, the measurement accuracy of the shaft voltage measurement is further improved.

[0084] In one embodiment, the shaft voltage measurement of the motor shaft according to the voltage characteristic value of the rotor winding and the first capacitance characteristic value comprises:

[0085] The first voltage characteristic value of the actual shaft voltage of the motor shaft is obtained; the measured shaft voltage of the motor shaft is measured according to the voltage characteristic value of the rotor winding and the first capacitance characteristic value; the second voltage characteristic value of the measured shaft voltage is obtained by performing Fourier transform on the time waveform of the measured shaft voltage; and in the case that the voltage characteristic difference between the first voltage characteristic value and the second voltage characteristic value is less than the preset voltage characteristic difference threshold value, the measured shaft voltage is taken as the target shaft voltage of the motor shaft.

[0086] It should be noted that, in the process of measuring the shaft voltage of the motor shaft, in order to ensure the usability of the non-contact measurement method, the measurement results of the contact measurement and the non-contact measurement can be compared, so that the measured shaft voltage obtained by the non-contact measurement can be taken as the target shaft voltage to guide the subsequent work, wherein the voltage characteristic value can be the voltage frequency, and the preset voltage characteristic difference threshold value can be 6dB. For example, in one implementable manner, the process of measuring the shaft voltage of the motor shaft is as follows: 1) setting the measurement environment: the device configuration can be to use a motor equipped with a specially designed antenna, and a correction circuit, a differential voltage probe and an oscilloscope; the circuit adjustment can be to adjust the voltage amplitude ratio to 10:1 through the correction circuit to adapt to the non-contact measurement; 2) verifying the propagation of the shaft voltage to the antenna: the voltage application method is to apply ±200V square wave voltage to the motor coil, and the measurement method is to simultaneously perform contact and non-contact measurement and compare the results of the two; 3) verifying the propagation of the coil voltage: grounding the shaft and the shell of the motor to isolate the shaft voltage and only observe the ringing phenomenon caused by the switch operation; 4) verifying the frequency characteristics of the antenna voltage: under the condition that the shaft is not grounded, performing fast Fourier transform (FFT) on the time waveform to analyze the frequency characteristics of the antenna voltage; 5) analyzing the measurement results: time waveform analysis, checking the rectangular wave voltage displayed by the non-contact measurement which is synchronized with the shaft voltage, and ensuring the timing and amplitude ratio match; protection electrode verification, confirming the effectiveness of the protection electrode and ensuring that the non-contact measurement only measures the shaft voltage and is not affected by the coil voltage; 6) frequency characteristic comparison: comparing the frequency characteristics of the non-contact measurement with the actual shaft voltage to ensure that the error is controlled within 6dB in the frequency range of 100kHz to 30MHz; 7) result confirmation: based on the measurement results, verifying that the designed antenna can effectively quantify the shaft voltage, and providing a new solution for the measurement of the shaft voltage in the electric drive system.

[0087] As an example, a first voltage frequency of an actual shaft voltage of the motor shaft is obtained; a voltage eigenvalue of the rotor winding and a first capacitance eigenvalue are taken as a measured shaft voltage of the motor shaft; a time waveform of the measured shaft voltage is subjected to Fourier transform to obtain a second voltage frequency of the measured shaft voltage; a voltage frequency difference between the first voltage frequency and the second voltage frequency is determined, and in a case where the voltage frequency difference is less than a preset voltage frequency difference threshold, the measured shaft voltage is taken as a target shaft voltage of the motor shaft. In this embodiment, the actual shaft voltage of the motor shaft is taken as a reference object, and the measured shaft voltage measured by the signal sensor and the motor shaft in a non-contact state is verified in real time to ensure that the measured shaft voltage is always effective, thereby laying a foundation for improving the measurement effect of the shaft voltage measurement.

[0088] In one embodiment, after the measured shaft voltage is taken as the target shaft voltage of the motor shaft, the method further comprises:

[0089] According to the fourth capacitance and the fifth capacitance, a second capacitance eigenvalue of the signal sensor under the electric field coupling effect is determined; and the target shaft voltage and the second capacitance eigenvalue are fused to obtain a voltage value of the signal sensor.

[0090] It should be noted that after the target shaft voltage of the motor shaft is measured, the voltage of the signal sensor can also be adaptively calculated based on the target shaft voltage, that is, by means of a preset signal sensor voltage calculation formula, the voltage value of the signal sensor is accurately calculated based on the capacitance change between the signal sensor and the target motor and the target shaft voltage.

[0091] As an example, a second capacitance sum of the fourth capacitance and the fifth capacitance is obtained, and a ratio between the fourth capacitance and the second capacitance sum is taken as a second capacitance eigenvalue of the signal sensor under the electric field coupling effect; the target shaft voltage and the second capacitance eigenvalue are jointly input into a preset signal sensor voltage calculation formula to obtain a voltage value of the signal sensor, wherein the preset signal sensor voltage calculation formula can be specifically:

[0092]

[0093] wherein, the target shaft voltage of the motor shaft, the voltage value of the signal sensor, the second capacitance eigenvalue, the fourth capacitance, the fifth capacitance, for example, assuming that the fourth capacitance is 5 pF, the fifth capacitance is 15 pF, and the target shaft voltage is 100 V, then the voltage value of the signal sensor is 25 V.

[0094] In an implementable manner, the non-contact shaft voltage measurement method provided by the embodiment is mainly used to achieve a measurement error of 6dB or less in a frequency range of 100kHz to 30MHz, because this is where inverter noise usually occurs, and the general process is as follows: the relationship between the capacitance change between the motor shaft and the signal sensor is analyzed by using an equivalent circuit model to determine the first capacitance characteristic value, and then the converted voltage characteristic value is extracted by the electric field shielding component, and the first capacitance characteristic value and the converted voltage characteristic value are fused to obtain the measurement shaft voltage of the motor shaft. Further, by using the size relationship between the voltage frequency difference between the actual shaft voltage of the motor shaft and the measurement shaft voltage and the preset voltage frequency difference threshold, the effectiveness of the measurement shaft voltage is determined, and in the case of effective measurement shaft voltage, the measurement shaft voltage is taken as the target shaft voltage.

[0095] Therefore, the purpose of measuring the shaft voltage of the motor shaft can be achieved through the electric field coupling effect without contacting the motor shaft and the signal sensor, thereby overcoming the technical defects that in some application scenarios such as non-conductive surface material, complex shape or limited space of the motor shaft, if the motor shaft cannot provide a contact surface for the conductive object, the shaft voltage cannot be measured by contact, and the noise reduction effect cannot be quantified. Therefore, the measurement limitation of the shaft voltage measurement is reduced.

[0096] It should be understood that, although each step in the flowchart involved in the above embodiments is displayed in sequence according to the arrow, these steps are not necessarily executed in the order indicated by the arrow. Unless otherwise specified herein, the execution of these steps has no strict order limitation, and these steps can be executed in other orders. Moreover, at least part of the steps in the flowchart involved in the above embodiments can include multiple steps or stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily sequential, but can be alternately executed with other steps or steps or stages in other steps.

[0097] Based on the same inventive concept, the embodiment of the present application also provides a shaft voltage measurement device for implementing the above-mentioned shaft voltage measurement method. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme described in the above method, so the specific limitations in one or more shaft voltage measurement device embodiments provided below can refer to the limitations of the shaft voltage measurement method in the above text, which will not be repeated here.

[0098] In an exemplary embodiment, as Figure 4As shown, a shaft voltage measurement device is provided, applied to a shaft voltage measurement system, the shaft voltage measurement system comprising a target motor, the target motor being provided with a motor shaft and a signal inductor, wherein the motor shaft and the signal inductor are not in contact, the shaft voltage measurement device comprising: an acquisition module 401, an extraction module 402 and a measurement module 403, wherein:

[0099] The acquisition module 401 is configured to acquire, under the action of an electric field coupling, an electric field operation signal generated by the motor shaft through the signal inductor when a preset electric field coupling condition is met between the motor shaft and the signal inductor.

[0100] The extraction module 402 is configured to extract electric parameter characteristic information of the motor shaft from the electric field operation signal, wherein the electric parameter characteristic information is used to represent the change of the electric parameter of the motor shaft under the action of the electric field coupling.

[0101] The measurement module 403 is configured to measure the shaft voltage of the motor shaft according to the electric parameter characteristic information.

[0102] In one of the embodiments, the target motor is provided with a machine shell, a rotor winding and a stator winding, the rotor winding and the motor shaft are fixedly connected through a rotor core, the stator winding is fixed to the machine shell, the rotor winding and the stator winding are coupled through an electromagnetic field, and the machine shell is used to protect the motor shaft. The measurement module 403 is further configured to:

[0103] According to the first capacitance and the second capacitance, a first capacitance characteristic value of the motor shaft under the action of the electric field coupling is determined, wherein the first capacitance refers to the capacitance generated between the rotor winding and the motor shaft, and the second capacitance refers to the capacitance generated between the machine shell and the motor shaft; and according to the voltage characteristic value of the rotor winding and the first capacitance characteristic value, the shaft voltage of the motor shaft is measured.

[0104] In one of the embodiments, the measurement module 403 is further configured to:

[0105] The third capacitance generated between the rotor winding and the machine shell, the fourth capacitance generated between the motor shaft and the signal inductor, the fifth capacitance generated between the signal inductor and the machine shell, and the sixth capacitance generated between the rotor winding and the signal inductor are obtained; and the first capacitance, the second capacitance, the third capacitance, the fourth capacitance, the fifth capacitance and the sixth capacitance are fused to obtain the first capacitance characteristic value.

[0106] In one of the embodiments, the signal inductor comprises an electric field shielding assembly; and the measurement module 403 is further configured to:

[0107] The voltage eigenvalue of the rotor winding is converted by the electric field shielding assembly, and a converted voltage eigenvalue is obtained; the converted voltage eigenvalue and the first capacitance eigenvalue are fused, and an axle voltage of the motor axle is obtained.

[0108] In one of the embodiments, the measurement module 403 is further configured to:

[0109] The first voltage eigenvalue of the actual axle voltage of the motor axle is obtained; the measurement axle voltage of the motor axle is measured according to the voltage eigenvalue of the rotor winding and the first capacitance eigenvalue; the time waveform of the measurement axle voltage is subjected to Fourier transform, and the second voltage eigenvalue of the measurement axle voltage is obtained; and in the case that the voltage eigenvalue difference between the first voltage eigenvalue and the second voltage eigenvalue is less than a preset voltage eigenvalue difference threshold, the measurement axle voltage is taken as the target axle voltage of the motor axle.

[0110] In one of the embodiments, the axle voltage measurement device is further configured to:

[0111] The second capacitance eigenvalue of the signal inductor under the electric field coupling effect is determined according to the fourth capacitance and the fifth capacitance; and the target axle voltage and the second capacitance eigenvalue are fused, and a voltage value of the signal inductor is obtained.

[0112] The above-mentioned various modules in the axle voltage measurement device can be realized by software, hardware and combinations thereof in whole or in part. The above-mentioned various modules can be embedded in or independent of the processor in the axle voltage measurement device in hardware form, or can be stored in the memory in the axle voltage measurement device in software form, so as to be called and executed by the processor to perform the operations corresponding to the above-mentioned various modules.

[0113] In one exemplary embodiment, an axle voltage measurement device is provided, which can be a terminal, and the internal structure diagram thereof can be as shown in Figure 5The shaft voltage measurement device includes a processor, a memory, an input / output interface, a communication interface, a display unit and an input device. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input / output interface. The processor of the shaft voltage measurement device is configured to provide computing and control capabilities. The memory of the shaft voltage measurement device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run. The input / output interface of the shaft voltage measurement device is configured to exchange information between the processor and external devices. The communication interface of the shaft voltage measurement device is configured to perform wired or wireless communication with external terminals. The wireless communication can be achieved through WIFI, mobile cellular network, NFC (Near Field Communication) or other technologies. The computer program is executed by the processor to implement a shaft voltage measurement method. Those skilled in the art can understand that, Figure 5 The structure shown in the figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the shaft voltage measurement device to which the scheme of the present application is applied. The specific shaft voltage measurement device can include more or fewer components than those shown in the figure, or combine certain components, or have a different component arrangement.

[0114] In one embodiment, a shaft voltage measurement device is also provided, including a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps in the above method embodiments.

[0115] In one embodiment, a computer readable storage medium is provided, which stores a computer program, and the computer program is executed by a processor to implement the steps in the above method embodiments.

[0116] In one embodiment, a computer program product is provided, including a computer program, and the computer program is executed by a processor to implement the steps in the above method embodiments.

[0117] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when the computer program is executed, the processes of the above-mentioned embodiments of the methods can be included. Any reference to memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The database involved in the embodiments provided in the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on a block chain, etc., without being limited thereto. The processor involved in the embodiments provided in the present application can be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., without being limited thereto.

[0118] Any combination of the technical features of the above embodiments can be made. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combination of the technical features does not exist, it should be considered as the scope of the present application.

[0119] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A shaft voltage measurement method characterized by, The application is applied to an axle voltage measurement system, the axle voltage measurement system comprises a target motor, the target motor is provided with a motor shaft and a signal sensor, wherein the motor shaft and the signal sensor are not in contact, and the method comprises the following steps: In the case that a preset electric field coupling condition is met between the motor shaft and the signal sensor, an electric field operation signal generated by the motor shaft is collected through the signal sensor under the electric field coupling effect; Extracting electric parameter characteristic information of the motor shaft from the electric field operation signal, wherein the electric parameter characteristic information is used to represent the electric parameter change of the motor shaft under the electric field coupling effect; According to the electric parameter characteristic information, the axle voltage of the motor shaft is measured, wherein the target motor is provided with a machine shell, a rotor winding and a stator winding, the rotor winding and the motor shaft are fixedly connected through a rotor core, the stator winding is fixed to the machine shell, the rotor winding and the stator winding are coupled through an electromagnetic field, and the machine shell is used to protect the motor shaft; according to the electric parameter characteristic information, the axle voltage of the motor shaft is measured, which comprises the following steps: According to the first capacitor and the second capacitor, a first capacitance characteristic value of the motor shaft under the electric field coupling effect is determined, wherein the first capacitor refers to the capacitance generated between the rotor winding and the motor shaft, and the second capacitor refers to the capacitance generated between the machine shell and the motor shaft; According to the voltage characteristic value of the rotor winding and the first capacitance characteristic value, the axle voltage of the motor shaft is measured.

2. The method of claim 1, wherein, According to the first capacitor and the second capacitor, a first capacitance characteristic value of the motor shaft under the electric field coupling effect is determined, which comprises the following steps: The third capacitor generated between the rotor winding and the machine shell, the fourth capacitor generated between the motor shaft and the signal sensor, the fifth capacitor generated between the signal sensor and the machine shell and the sixth capacitor generated between the rotor winding and the signal sensor are obtained; The first capacitor, the second capacitor, the third capacitor, the fourth capacitor, the fifth capacitor and the sixth capacitor are fused to obtain the first capacitance characteristic value.

3. The method of claim 2, wherein, The signal sensor comprises an electric field shielding assembly; according to the voltage characteristic value of the rotor winding and the first capacitance characteristic value, the axle voltage of the motor shaft is determined, which comprises the following steps: The voltage characteristic value of the rotor winding is converted through the electric field shielding assembly to obtain a converted voltage characteristic value; The converted voltage characteristic value and the first capacitance characteristic value are fused to obtain the axle voltage of the motor shaft.

4. The method of claim 2, wherein, According to the voltage characteristic value of the rotor winding and the first capacitance characteristic value, the axle voltage of the motor shaft is measured, which comprises the following steps: A first voltage characteristic value of the actual axle voltage of the motor shaft is obtained; According to the voltage characteristic value of the rotor winding and the first capacitance characteristic value, a measurement axle voltage of the motor shaft is measured; The time waveform of the measurement axle voltage is subjected to Fourier transform to obtain a second voltage characteristic value of the measurement axle voltage; In a case where a voltage characteristic difference between the first voltage characteristic value and the second voltage characteristic value is less than a preset voltage characteristic difference threshold, the measured shaft voltage is taken as a target shaft voltage of the motor shaft.

5. The method of claim 4, wherein, After the measured shaft voltage is taken as the target shaft voltage of the motor shaft, the method further comprises: According to the fourth capacitance and the fifth capacitance, a second capacitance characteristic value of the signal sensor under the electric field coupling effect is determined. The target shaft voltage and the second capacitance characteristic value are fused to obtain a voltage value of the signal sensor.

6. An axle voltage measuring device, characterized by The application is applied to a shaft voltage measurement system, and the shaft voltage measurement system comprises a target motor, and the target motor is provided with a motor shaft and a signal sensor, wherein the motor shaft and the signal sensor are not in contact, and the device comprises: The acquisition module is configured to acquire, in a case where a preset electric field coupling condition is met between the motor shaft and the signal sensor, an electric field operation signal generated by the motor shaft through the signal sensor under electric field coupling effect. The extraction module is configured to extract electric parameter characteristic information of the motor shaft from the electric field operation signal, wherein the electric parameter characteristic information is used to represent an electric parameter change of the motor shaft under the electric field coupling effect. The measurement module is configured to measure a shaft voltage of the motor shaft according to the electric parameter characteristic information, wherein the target motor is provided with a machine shell, a rotor winding and a stator winding, the rotor winding and the motor shaft are fixedly connected through a rotor core, the stator winding is fixed to the machine shell, the rotor winding and the stator winding are coupled through an electromagnetic field, and the machine shell is used to protect the motor shaft; and the measurement module is further configured to: According to the first capacitance and the second capacitance, a first capacitance characteristic value of the motor shaft under the electric field coupling effect is determined, wherein the first capacitance refers to a capacitance generated between the rotor winding and the motor shaft, and the second capacitance refers to a capacitance generated between the machine shell and the motor shaft. The measurement module is further configured to:

7. The apparatus of claim 6, wherein, Obtain a third capacitance generated between the rotor winding and the machine shell, a fourth capacitance generated between the motor shaft and the signal sensor, a fifth capacitance generated between the signal sensor and the machine shell, and a sixth capacitance generated between the rotor winding and the signal sensor. Fuse the first capacitance, the second capacitance, the third capacitance, the fourth capacitance, the fifth capacitance and the sixth capacitance to obtain the first capacitance characteristic value. The processor executes the computer program to realize the steps of the method in any one of claims 1 to 5.

8. An axle voltage measurement apparatus comprising a memory and a processor, the memory storing a computer program, characterized in that, The computer program is executed by the processor to realize the steps of the method in any one of claims 1 to 5.

9. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to realize the steps of the method in any one of claims 1 to 5.

10. A computer program product comprising a computer program, characterized in that, ​

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