Motor winding turn-to-turn discharge monitoring method and device based on Rogowski coil

Abstract

The invention relates to the technical field of motor insulation state monitoring, and discloses a motor winding turn-to-turn discharge monitoring method and device based on Rogowski coils. The high-pass integrator is matched to carry out integral operation on coil output signals in a centralized mode to obtain high-frequency discharge current data, then fault characteristic quantity is constructed based on the data, the fault position of the motor cable is determined, an independent monitoring module does not need to be configured for each phase of cable, and the single high-pass integrator can complete centralized processing of multi-coil signals. Not only is the use amount of core monitoring parts greatly reduced to reduce the monitoring cost, but also the hardware layout is remarkably simplified to save the installation space, and meanwhile, the data processing nodes are reduced to reduce processor resource occupation, and the problems of high monitoring cost, large space and resource consumption and low monitoring efficiency in the prior art are effectively solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor insulation state monitoring, in particular to a motor winding inter-turn discharge monitoring method and device based on a Rogowski coil. BACKGROUND

[0002] In the field of modern industry and high-end equipment, in systems such as aerospace and new energy vehicles, the motor as the core power source directly affects the safety and efficiency of the system. The motor insulation system, especially the winding inter-turn insulation, is the weakest and most easily aged link, and its performance will gradually deteriorate after long-term exposure to multiple stresses such as electricity and heat. The early typical sign is inter-turn discharge. This small electric spark between adjacent conductor insulation layers can accelerate insulation erosion and eventually cause inter-turn short circuit, leading to motor overheating, burning and other serious faults, causing economic losses and safety accidents. Therefore, early, online and accurate monitoring of the inter-turn insulation state of the motor winding is the key to realizing predictive maintenance of the motor and has important engineering value.

[0003] When inter-turn discharge occurs in the motor winding, the phase current will produce high-frequency spikes. Therefore, the traditional monitoring method collects the phase current through a flexible Rogowski coil or a PCB Rogowski coil, and needs to configure an integrator and a high-frequency sampling channel for each coil. However, the above method not only leads to high monitoring cost, but also occupies a lot of space and processor resources, reducing the monitoring efficiency. SUMMARY

[0004] The present application provides a motor winding inter-turn discharge monitoring method and device based on a Rogowski coil to solve the problem that the prior art not only leads to high monitoring cost, but also occupies a lot of space and processor resources, reducing the monitoring efficiency.

[0005] In a first aspect, the present application provides a motor winding inter-turn discharge monitoring method based on a Rogowski coil, applied to a discharge monitoring system, the discharge monitoring system comprising a plurality of series-connected Rogowski coils, each of the Rogowski coils being sleeved on a corresponding phase cable, the method comprising: obtaining the output signal of the series-connected Rogowski coils and inputting it into a high-pass integrator, and performing integral operation on the output signal through the high-pass integrator to obtain high-frequency discharge current data; based on the high-frequency discharge current data, constructing a fault feature quantity; determining the cable fault position of the motor according to the corresponding numerical value of the fault feature quantity.

[0006] This invention employs a structural design with multiple series-connected Rogowski coils corresponding to the phase cables. A high-pass integrator is used to centrally integrate the coil output signals to obtain high-frequency discharge current data. Based on this data, fault characteristic quantities are constructed to determine the fault location of the motor cable. There is no need to configure an independent monitoring module for each phase cable; a single high-pass integrator can complete the centralized processing of signals from multiple coils. This not only significantly reduces the number of core monitoring components to lower monitoring costs but also significantly simplifies the hardware layout to save installation space. Simultaneously, it reduces data processing nodes to lower processor resource consumption, effectively solving the problems of high monitoring costs, large space and resource consumption, and low monitoring efficiency in existing technologies.

[0007] In one optional implementation, the step of acquiring the output signal of the series-connected Rogowski coils and inputting it into a high-pass integrator, and then integrating the output signal through the high-pass integrator to obtain high-frequency discharge current data, includes: Obtain the output signal of the series-connected Rogowski coils; wherein the Rogowski coils include a first Rogowski coil and a second Rogowski coil connected in opposite phases, a second Rogowski coil and a third Rogowski coil connected in opposite phases, and a third Rogowski coil and a fourth Rogowski coil connected in the same phase. The output signal is input into a high-pass integrator; The high-pass integrator sequentially performs integration and high-frequency filtering on the output signal to generate high-frequency discharge current data.

[0008] This invention employs a differentiated series structure, consisting of first and second Rogowski coils, second and third Rogowski coils connected in reverse phase, and third and fourth Rogowski coils connected in phase. Combined with a high-pass integrator, the output signal is sequentially integrated and filtered to generate high-frequency discharge current data. The reverse-phase series structure cancels interference signals during normal cable operation, while the phase-in-phase series structure enhances fault discharge signals. Combined with high-frequency filtering, data accuracy is further improved. This eliminates the need for additional independent anti-interference modules and complex filtering equipment, reducing hardware investment and space requirements, lowering monitoring costs and processor resource consumption. It also solves the problems of data distortion and low monitoring efficiency caused by interference in existing technologies.

[0009] In one optional implementation, constructing fault characteristic quantities based on the high-frequency discharge current data includes: Based on the high-frequency discharge current data, fault characteristic quantities are constructed; wherein, the calculation formula for the fault characteristic quantities is: ; In the formula, K It is a constant; for A The discharge fault current of the phase cable; for BThe discharge fault current of the phase cable; for C The discharge fault current of the phase cable.

[0010] This invention accurately extracts fault-specific signals by performing differentiated weighting and combination calculations on the discharge current of three-phase cables. It achieves efficient aggregation and amplification of fault characteristics using only this formula, without relying on complex multi-dimensional data modeling or additional hardware investment.

[0011] In one optional implementation, determining the location of the motor cable fault based on the value corresponding to the fault characteristic quantity includes: Calculate the numerical values ​​corresponding to the fault characteristic quantities; When the value corresponding to the fault characteristic quantity is a preset first amplification factor, the AC phase cable is determined to be the location of the motor cable fault. When the value corresponding to the fault characteristic quantity is a preset second amplification factor, the AB phase cable is determined to be the cable fault location of the motor. When the value corresponding to the fault characteristic quantity is the preset third amplification factor, the BC phase cable is determined to be the cable fault location of the motor.

[0012] This invention calculates fault characteristic values ​​and matches them with preset first, second, and third amplification factors, enabling precise identification of AC, AB, and BC phase cables as motor cable fault locations. It eliminates the need for complex multi-phase comparison hardware or redundant signal analysis processes; rapid fault phase identification is achieved solely through the correspondence between numerical values ​​and amplification factors.

[0013] In one alternative implementation, it further includes: The value corresponding to the fault characteristic quantity is compared with the preset fault threshold, and the cable health status of the motor is determined based on the comparison result. Based on the cable's health status, a corresponding maintenance plan will be developed; The location of the cable fault, the cable health status, and the corresponding repair plan are sent to the maintenance personnel.

[0014] This invention determines the health status of motor cables by comparing fault characteristic values ​​with preset fault thresholds, and formulates corresponding maintenance plans based on the fault location and sends them to maintenance personnel. It eliminates the need for manual inspection and experience-based judgment, and can achieve automated quantitative assessment of cable health status and accurate delivery of maintenance plans.

[0015] In one optional implementation, comparing the value corresponding to the fault characteristic quantity with a preset fault threshold, and determining the cable health status of the motor based on the comparison result, includes: Determine whether the fault characteristic quantity is less than or equal to a preset fault threshold; If so, the health status of the motor's cable is determined to be normal. If not, then determine whether the fault characteristic quantity is greater than the preset fault threshold and less than or equal to the preset fault warning threshold; If so, the health status of the motor's cable will be determined as a warning level state. If not, determine whether the fault characteristic quantity is greater than the preset fault warning threshold and less than or equal to the preset fault alarm threshold. If so, the health status of the motor's cable will be determined as a warning-level alarm status; If not, determine whether the fault characteristic quantity is greater than the preset fault alarm threshold; If so, the health status of the motor's cable will be determined as an alarm-level alarm status.

[0016] This invention achieves refined classification of motor cable health status (normal, warning level, warning level, and alarm level) through a multi-level threshold progressive judgment logic, eliminating the need for subjective manual assessment or complex testing procedures. It not only solves the maintenance delays caused by ambiguous health status judgments and inaccurate classifications in existing technologies, but also reduces human error through standardized threshold judgment rules, allowing maintenance personnel to clearly understand the severity of cable faults.

[0017] Secondly, the present invention provides a motor winding inter-turn discharge monitoring device based on Rogowski coils, applied to a discharge monitoring system. The discharge monitoring system includes multiple Rogowski coils connected in series, each Rogowski coil being respectively wound on a corresponding phase cable. The device includes: The acquisition module is used to acquire the output signal of the series-connected Rogowski coil and input it into a high-pass integrator, and perform integration on the output signal through the high-pass integrator to obtain high-frequency discharge current data. The construction module is used to construct fault characteristic quantities based on the high-frequency discharge current data; The fault module is used to determine the location of the motor cable fault based on the values ​​corresponding to the fault characteristic quantities.

[0018] Thirdly, the present invention provides an electronic device, comprising: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the above-described method for monitoring inter-turn discharge of motor windings based on Rogowski coils, as described in the first aspect or any corresponding embodiment.

[0019] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to execute the Rogowski coil-based motor winding inter-turn discharge monitoring method described in the first aspect or any corresponding embodiment thereof.

[0020] Fifthly, the present invention provides a computer program product, including computer instructions for causing a computer to execute the Rogowski coil-based inter-turn discharge monitoring method for motor windings described in the first aspect or any corresponding embodiment. 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 This is a schematic diagram of traditional motor winding inter-turn discharge monitoring; Figure 2 This is a schematic flowchart of a first method for monitoring inter-turn discharge of motor windings based on Rogowski coils according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the structural connection of a motor winding inter-turn discharge monitoring method based on Rogowski coils according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the second process of the motor winding inter-turn discharge monitoring method based on Rogowski coil according to an embodiment of the present invention; Figure 5 This is a circuit diagram of a high-pass integrator according to an embodiment of the present invention; Figure 6 This is a flowchart illustrating the process of determining the health status of a motor's cables according to an embodiment of the present invention; Figure 7 This is a structural block diagram of a motor winding inter-turn discharge monitoring device based on a Rogowski coil according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention.

[0023] The following are explanations of the reference numerals in the attached figures: 11. First Rogowski coil; 12. Second Rogowski coil; 13. Third Rogowski coil; 14. Fourth Rogowski coil; 15. High-pass integrator. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments 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.

[0025] It is understood that before using the technical solutions disclosed in the various embodiments of the present invention, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in the present invention and their authorization should be obtained in accordance with relevant laws and regulations through appropriate means.

[0026] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0027] This invention provides a method for monitoring inter-turn discharge in motor windings based on Rogowski coils. When inter-turn discharge occurs in the motor windings, high-frequency spikes are generated in the phase current. Capturing these current spikes using a high-frequency current sensor can be used to monitor the inter-turn insulation status of the motor windings. Traditional methods use flexible Rogowski coils or PCB Rogowski coils to collect the current of each phase of the motor separately, such as... Figure 1 As shown, this method requires a separate integrator and high-frequency sampling channel for each Rogowski coil, resulting in high cost, large space and processor resource consumption, and limiting its application scope. Therefore, this invention adopts a structural design with multiple series-connected Rogowski coils corresponding to phase cables, and uses a high-pass integrator to centrally integrate the coil output signals to obtain high-frequency discharge current data. Based on this data, fault characteristic quantities are constructed and the fault location of the motor cable is determined. There is no need to configure an independent monitoring module for each phase cable. A single high-pass integrator can complete the centralized processing of signals from multiple coils. This not only significantly reduces the number of core monitoring components to lower monitoring costs, but also significantly simplifies the hardware layout to save installation space. At the same time, it reduces data processing nodes to lower processor resource consumption, thereby solving the problems of high monitoring costs, large space and resource consumption, and low monitoring efficiency in existing technologies.

[0028] This embodiment provides a method for monitoring inter-turn discharge in motor windings based on Rogowski coils, applied to a discharge monitoring system. The discharge monitoring system includes multiple Rogowski coils connected in series, each Rogowski coil being wound on a corresponding phase cable. Figure 2This is a flowchart of a method for monitoring inter-turn discharge in motor windings based on Rogowski coils according to an embodiment of the present invention, as shown below. Figure 2 As shown, the process includes the following steps: Step S101: Obtain the output signal of the series-connected Rogowski coil and input it into the high-pass integrator 15. Then, perform integration on the output signal through the high-pass integrator 15 to obtain high-frequency discharge current data.

[0029] It should be noted that the discharge monitoring system refers to the system corresponding to the inter-turn discharge monitoring method of motor windings based on Rogowski coils.

[0030] A Rogowski coil is a type of air-core coil that is used to measure alternating current based on the principle of electromagnetic induction. It features wide bandwidth and fast response, and can sense the alternating magnetic field around a cable and output a voltage signal that is related to the rate of change of current.

[0031] The Qualcomm integrator 15 refers to a circuit device that can integrate high-frequency signals, converting the voltage signal output by the Rogowski coil, which is related to the rate of change of current, into a voltage signal related to the magnitude of current.

[0032] High-frequency discharge current data refers to numerical information reflecting the magnitude of the discharge current in the motor cable at high frequencies.

[0033] In embodiments of the present invention, such as Figure 3 As shown, the Rogowski coil includes a first Rogowski coil 11 and a second Rogowski coil 12 connected in opposite phases, a second Rogowski coil 12 and a third Rogowski coil 13 connected in opposite phases, and a third Rogowski coil 13 and a fourth Rogowski coil 14 connected in the same phase. The first Rogowski coil 11 is mounted on the A-phase cable of the motor and is used to monitor the current of the A-phase cable. The second Rogowski coil 12 is mounted on the B-phase cable of the motor and is used to monitor the current of the B-phase cable. The third Rogowski coil 13 and the fourth Rogowski coil 14 are both mounted on the C-phase cable of the motor and are used to monitor the current of the C-phase cable.

[0034] The output signal, after being connected in series, is transmitted to the high-pass integrator 15. The high-pass integrator 15 performs integration processing on the output signal to obtain high-frequency discharge current data.

[0035] Specifically, when coils are connected in series in opposite phases, the induced voltages of the coils cancel each other out; when coils are connected in series in the same phase, the induced voltages of the coils are superimposed.

[0036] Step S102: Based on the high-frequency discharge current data, construct fault characteristic quantities.

[0037] It should be noted that fault characteristic quantity refers to a quantitative indicator obtained by processing high-frequency discharge current data through a specific algorithm, which can centrally reflect the specific characteristics of cable faults.

[0038] In this embodiment of the invention, based on high-frequency discharge current data, a preset feature extraction algorithm is used to perform differentiated calculation processing on it. By integrating the feature information of high-frequency discharge current data corresponding to different phase cables, a fault feature quantity that can accurately reflect the fault characteristics of motor cables is constructed.

[0039] Step S103: Determine the location of the motor cable fault based on the values ​​corresponding to the fault characteristic quantities.

[0040] It should be noted that the location of the cable fault refers to the specific phase segment in the motor cable where the discharge fault occurred, namely a segment of the AC phase, AB phase, or BC phase cable.

[0041] In this embodiment of the invention, by accurately comparing the value corresponding to the fault characteristic quantity with the preset fault threshold of each phase cable, the fault location of the AB, AC or BC phase cable can be determined as the cable fault location of the motor, thus enabling rapid location of the cable fault location.

[0042] This embodiment provides a method for monitoring inter-turn discharge in motor windings based on Rogowski coils, applied to a discharge monitoring system. The discharge monitoring system includes multiple Rogowski coils connected in series, each Rogowski coil being wound on a corresponding phase cable. Figure 4 This is a flowchart of a method for monitoring inter-turn discharge in motor windings based on Rogowski coils according to an embodiment of the present invention, as shown below. Figure 4 As shown, the process includes the following steps: Step S201: Obtain the output signal of the series-connected Rogowski coil and input it into the high-pass integrator 15. Then, perform integration on the output signal through the high-pass integrator 15 to obtain high-frequency discharge current data.

[0043] Specifically, step S201 includes: Step S2011: Obtain the output signal of the series-connected Rogowski coils; wherein the Rogowski coils include a first Rogowski coil 11 and a second Rogowski coil 12 connected in opposite phases, a second Rogowski coil 12 and a third Rogowski coil 13 connected in opposite phases, and a third Rogowski coil 13 and a fourth Rogowski coil 14 connected in the same phase.

[0044] It should be noted that anti-phase series connection refers to connecting two Rogowski coils with opposite polarities, so that the interference components in opposite directions in the coil output signal cancel each other out, thereby reducing the impact of electromagnetic interference generated by the normally operating cable on the monitoring signal.

[0045] In-phase series connection refers to connecting two Rogowski coils in the same polarity, which makes the fault discharge components in the same direction in the coil output signal superimposed and enhanced, thereby improving the amplitude and recognizability of the fault signal.

[0046] The output signal refers to the final electrical signal output after being processed by a series connection of Rogowski coils.

[0047] In this embodiment of the invention, the first Rogowski coil 11 is mounted on the A-phase cable of the motor to monitor the current of the A-phase cable; the second Rogowski coil 12 is mounted on the B-phase cable of the motor to monitor the current of the B-phase cable; and the third Rogowski coil 13 and the fourth Rogowski coil 14 are both mounted on the C-phase cable of the motor to monitor the current of the C-phase cable. The anti-phase series structure cancels out the interference signals generated by the A-phase, B-phase, and C-phase cables during normal operation, while the in-phase series structure of the third Rogowski coil 13 and the fourth Rogowski coil 14 amplifies the discharge signal during cable faults, ultimately outputting a composite electrical signal after interference suppression and fault signal amplification.

[0048] Specifically, Rogowski coils 11 to 14 are connected in series, and their output signal is: (1) In the formula, , , These are the three-phase currents (A, B, and C) of the motor, respectively. k It is a constant.

[0049] Step S2012: Input the output signal into the high-pass integrator 15.

[0050] In this embodiment of the invention, the composite electrical signal after interference suppression and fault signal amplification is input into the high-pass integrator 15.

[0051] In step S2013, the output signal is integrated and filtered sequentially by the high-pass integrator 15 to generate high-frequency discharge current data.

[0052] It should be noted that integration refers to one of the core processing steps of the Qualcomm Integrator 15, which is used to convert the voltage signal output by the Rogowski coil, which is proportional to the rate of change of current, into a voltage signal proportional to the actual current of the cable.

[0053] High-frequency filtering refers to the signal optimization step performed after integration. The Qualcomm Integrator 15 uses a built-in filtering module to filter out invalid components such as low-frequency interference and environmental noise from the signal, retaining only the effective signal related to high-frequency discharge of the cable.

[0054] In this embodiment of the invention, the voltage signal related to the rate of change of cable current in the output signal is converted into an initial electrical signal corresponding to the current magnitude, and then the low-frequency interference components and invalid noise are filtered out to finally generate high-frequency discharge current data that can accurately reflect the high-frequency discharge state of the motor cable.

[0055] Specifically, the Qualcomm integrator 15, such asFigure 5 As shown, VIN is the input signal of the high-pass integrator 15 (i.e., the output signal of the Rogowski coil), U1 is an operational amplifier, and R1, R2, R3, C1, C2, and C3 are the integrating resistor and capacitor, respectively. The parallel connection of resistor R3 and capacitor C2 limits the low-frequency bandwidth of the integrator, outputting only the high-frequency component of the current, i.e., the high-frequency discharge current data. The integrating resistor and capacitor form an analog integrator to integrate the input signal. C3 and R4 form a high-pass filter to further filter out DC bias signals and low-frequency signals.

[0056] Step S202: Based on the high-frequency discharge current data, construct fault characteristic quantities.

[0057] Specifically, step S202 includes: Step S2021: Based on high-frequency discharge current data, construct fault characteristic quantities; wherein, the calculation formula for the fault characteristic quantities is: ; In the formula, K It is a constant; for A The discharge fault current of the phase cable; for B The discharge fault current of the phase cable; for C The discharge fault current of the phase cable.

[0058] In this embodiment of the invention, the output formula of the Qualcomm integrator 15 is: (2) In the formula, The input signal of the high-pass integrator 15 is the output signal of the Rogowski coil, which corresponds to the output of formula (1), i.e.: (3) Substituting equation (3) into equation (2), and assuming there is no high-frequency disturbance at the initial time (t=0), That is, we get: Qualcomm integrator output = (4); At this time, Merge into a new constant K (Right now Simultaneously, the high-frequency component of the high-frequency discharge current is used. , , Replace with , , The following formula can be obtained: (5) Using formula (5), the fault characteristic quantity IF is constructed. The formula for the fault characteristic quantity IF is: (6); In the formula, K It is a constant; for A The discharge fault current of the phase cable; for B The discharge fault current of the phase cable; for C The discharge fault current of the phase cable.

[0059] Step S203: Determine the location of the motor cable fault based on the values ​​corresponding to the fault characteristic quantities.

[0060] Specifically, step S203 includes: Step S2031: Calculate the values ​​corresponding to the fault characteristic quantities.

[0061] In this embodiment of the invention, a preset feature quantity calculation model is used, and the generated high-frequency discharge current data is substituted into it for differential calculation processing to quickly obtain specific numerical results that can quantitatively reflect the fault characteristics of motor cables.

[0062] Step S2032: When the value corresponding to the fault characteristic quantity is the preset first amplification factor, the AC phase cable is determined to be the cable fault location of the motor.

[0063] It should be noted that the first magnification factor refers to a preset characteristic value standard specifically corresponding to AC phase cable faults, which is a key threshold parameter for determining whether an AC phase cable has a fault.

[0064] AC phase cable refers to the line segment composed of the A phase cable and the C phase cable in the three-phase power supply cable of the motor.

[0065] The location of a cable fault refers to the specific phase of the motor cable where a discharge fault has occurred.

[0066] In this embodiment of the invention, high-frequency fault currents always occur in pairs between two phases and in opposite directions. Therefore, when a high-frequency discharge current occurs between AC phases, The fault characteristic quantity IF is: (7) In the formula, K It is a constant; for C The discharge fault current of the phase cable.

[0067] As can be seen from the above formula (7), a discharge fault current occurs between the AC phases, that is, the AC phase cable is determined to be the cable fault location of the motor.

[0068] Step S2033: When the value corresponding to the fault characteristic quantity is the preset second amplification factor, the AB phase cable is determined as the cable fault location of the motor.

[0069] It should be noted that the second amplification factor refers to a preset characteristic value standard specifically corresponding to AB phase cable faults, which is a key threshold parameter for determining whether AB phase cable faults have occurred.

[0070] AB phase cable refers to the line segment consisting of phase A and phase B cables in the three-phase power supply cable for motors.

[0071] In this embodiment of the invention, high-frequency fault currents always occur in pairs between two phases and in opposite directions. Therefore, when a high-frequency discharge current occurs between phases A and B, The fault characteristic quantity IF is: (8) In the formula, K It is a constant; for A The discharge fault current of the phase cable.

[0072] According to the above formula (8), a discharge fault current occurs between phases A and B, which means that the AB phase cable is determined to be the cable fault location of the motor.

[0073] Step S2034: When the value corresponding to the fault characteristic quantity is the preset third amplification factor, the BC phase cable is determined to be the cable fault location of the motor.

[0074] It should be noted that the third amplification factor refers to a preset characteristic value standard specifically corresponding to BC phase cable faults, which is a key threshold parameter for determining whether BC phase cable faults have occurred.

[0075] BC phase cable refers to the line segment composed of the B phase cable and the C phase cable in the three-phase power supply cable for motor.

[0076] In this embodiment of the invention, high-frequency fault currents always occur in pairs between two phases and in opposite directions. Therefore, when a high-frequency discharge current occurs between phases B and C, The fault characteristic quantity IF is: (9) In the formula, K It is a constant; for C The discharge fault current of the phase cable.

[0077] According to the above formula (9), a discharge fault current occurs between phases BC, which means that the BC phase cable is determined to be the cable fault location of the motor.

[0078] Specifically, the fault characteristic quantities output by the monitoring circuit proposed in this invention can be effectively quantified, and the fault current between different phases can be amplified by different factors, which can then be used to locate the fault location.

[0079] It is worth mentioning that the fault characteristic quantities themselves indicate that the output of the high-pass integrator 15 can indicate the presence of high-frequency fault discharge current in the motor. Secondly, the high-pass integrator 15 output has different amplification factors for the high-frequency discharge current between different phases; this difference can be used to distinguish and locate the faulty phase. In addition to locating the fault, the fault characteristic quantities can also be used to quantify the severity of the fault, and based on the severity, assess the monitoring status of the motor insulation.

[0080] Step S204: Compare the values ​​corresponding to the fault characteristic quantities with the preset fault thresholds, and determine the health status of the motor's cables based on the comparison results.

[0081] In some optional implementations, step S204 above includes: Step S2041: Determine whether the fault characteristic quantity is less than or equal to the preset fault threshold.

[0082] It should be noted that the preset fault threshold ( ( ) refers to the pre-set baseline value for judging the health status of cables, which is the critical value that distinguishes between normal operation of cables and the presence of fault risk.

[0083] In embodiments of the present invention, such as Figure 6 As shown, the preset fault threshold As the primary criterion for classifying the health status of motor cables, this threshold comparison is used to initially screen whether the cable is in the normal operating range.

[0084] Step S2042: If yes, then the health status of the motor's cables is determined to be normal.

[0085] It should be noted that cable health status refers to the status classification that reflects the current operating status of motor cables, including normal status, various levels of warning / alarm status, etc.

[0086] Normal condition refers to a state in which the motor cables do not show obvious discharge faults and all operating parameters meet safety standards.

[0087] In an embodiment of the present invention, if If the result is positive, the motor's cable health status is considered to be normal.

[0088] Step S2043: If not, determine whether the fault characteristic quantity is greater than the preset fault threshold and less than or equal to the preset fault warning threshold.

[0089] It should be noted that the preset fault warning threshold ( The threshold value (FQV) is a judgment value between the preset fault threshold and the fault alarm threshold. It is the key boundary for distinguishing between minor fault risks and serious fault risks.

[0090] In an embodiment of the present invention, if This indicates that the cable has a fault risk. Then, it is determined whether the fault characteristic quantity is greater than the preset fault threshold and less than or equal to the preset fault warning threshold, so as to carry out the next level of accurate judgment of the health status.

[0091] Step S2044: If yes, then the health status of the motor's cables is determined to be a warning-level state.

[0092] It should be noted that the "attention level" warning status refers to the cable health status where the corresponding fault characteristic quantity is between the preset fault threshold and the preset fault warning threshold. This indicates that the cable has a slight discharge abnormality, which needs to be monitored and checked in a timely manner, but does not require emergency shutdown.

[0093] In this embodiment of the invention, if the determination result is If the condition is not met, the health status of the motor's cables will be set to a warning level, indicating that there is a minor abnormality in the cables but it does not affect normal operation at present. Maintenance personnel need to pay close attention and plan to check them in a timely manner.

[0094] Step S2045: If not, determine whether the fault characteristic quantity is greater than the preset fault warning threshold and less than or equal to the preset fault alarm threshold.

[0095] It should be noted that the preset fault alarm threshold ( The threshold value for judging the severity of cable faults is a pre-set threshold value. When the value is higher than the preset fault warning threshold, it is the core standard for distinguishing between the warning level alarm state and the alarm level alarm state. When the fault characteristic quantity reaches or exceeds the threshold value, it means that the cable fault has endangered the operational safety and the highest level emergency response procedure needs to be triggered.

[0096] In an embodiment of the present invention, if This indicates that the risk of cable faults has been further escalated. Therefore, it is necessary to determine whether the fault characteristic quantity is greater than the preset fault warning threshold and less than or equal to the preset fault alarm threshold, so as to carry out a higher level of fault risk assessment.

[0097] Step S2046: If yes, then the health status of the motor's cable is determined to be a warning-level alarm status.

[0098] It should be noted that the warning-level alarm status refers to the cable health status when the corresponding fault characteristic quantity is greater than the preset fault warning threshold but less than or equal to the preset fault alarm threshold. It is a fault level between the attention-level warning and the serious alarm, indicating that there is a significant fault in the cable and timely intervention is required.

[0099] In an embodiment of the present invention, if If the health status of the motor's cables is determined to be in a warning-level alarm state, it indicates that the cables have experienced a significant discharge fault. Continued operation may lead to further deterioration of the fault. Maintenance personnel should arrange for a shutdown inspection and targeted treatment as soon as possible to prevent the fault from escalating and causing abnormal motor operation or safety risks.

[0100] Step S2047: If not, determine whether the fault characteristic quantity is greater than the preset fault alarm threshold.

[0101] In this embodiment of the invention, if the determination result of whether the fault characteristic quantity is greater than the preset fault warning threshold and less than or equal to the preset fault alarm threshold is negative, it indicates that the cable fault has reached a relatively serious level. Then, it is determined whether the fault characteristic quantity is greater than the preset fault alarm threshold, thereby completing the highest level risk determination of the health status.

[0102] Step S2048: If yes, then the health status of the motor's cables is determined to be an alarm-level alarm status.

[0103] It should be noted that the alarm level refers to the health status of the motor cable when the corresponding fault characteristic quantity is greater than the preset fault alarm threshold. It is the highest risk level in the cable health status classification, indicating that the cable has a serious discharge fault and that emergency measures such as immediate shutdown and maintenance are required.

[0104] In an embodiment of the present invention, if If the health status of the motor's cables is determined to be at the alarm level, it indicates that a serious discharge fault has occurred in the cables. If operation continues, it will directly threaten the overall operational safety of the motor, and may even cause equipment damage or safety accidents. The highest level emergency response mechanism must be triggered immediately to notify the operation and maintenance personnel to shut down the machine immediately and carry out a comprehensive inspection to quickly eliminate potential faults and avoid further losses.

[0105] Step S205: Based on the cable health status, formulate a corresponding maintenance plan.

[0106] It should be noted that a maintenance plan refers to a targeted solution based on the cable's health status and fault-related information, including core elements such as maintenance timing, maintenance content, operating procedures, and safety precautions.

[0107] In this embodiment of the invention, a corresponding maintenance plan is formulated based on the cable health status, a preset maintenance strategy matching rule, and core information such as cable fault location and fault characteristic value. For the normal state, no maintenance measures are required; for the alert level warning state, a regular inspection and status monitoring enhancement plan is formulated; for the warning level alarm state, a time-limited shutdown maintenance plan is formulated; and for the alarm level alarm state, an immediate shutdown and comprehensive maintenance plan is formulated to ensure that the maintenance measures are accurately matched with the severity of the fault.

[0108] Step S206: Send the cable fault location, cable health status, and corresponding repair plan to the maintenance personnel.

[0109] In this embodiment of the invention, the cable fault location, cable health status, and corresponding repair plan are sent to the terminal device of the maintenance personnel in real time through a preset communication module. At the same time, key values ​​of fault characteristics and simple handling instructions are also included to ensure that maintenance personnel can quickly and accurately obtain the core information of the cable fault. They can clarify the repair direction and operation focus without repeated on-site investigation, which greatly improves the efficiency of fault handling and the accuracy of repair.

[0110] This embodiment also provides a Rogowski coil-based inter-turn discharge monitoring device for motor windings, used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0111] This embodiment provides a Rogowski coil-based inter-turn discharge monitoring device for motor windings, applied to a discharge monitoring system. The discharge monitoring system includes multiple Rogowski coils connected in series, each coil being wound on a corresponding phase cable. Figure 7 As shown, this device includes: The acquisition module 301 is used to acquire the output signal of the series-connected Rogowski coil and input it into the high-pass integrator 15, and perform integration calculation on the output signal through the high-pass integrator 15 to obtain high-frequency discharge current data. Module 302 is used to construct fault characteristic quantities based on high-frequency discharge current data; The fault module 303 is used to determine the location of the motor cable fault based on the value corresponding to the fault characteristic quantity.

[0112] In some optional implementations, the acquisition module 301 includes: The acquisition unit is used to acquire the output signal of the series-connected Rogowski coils; wherein the Rogowski coils include a first Rogowski coil 11 and a second Rogowski coil 12 connected in opposite phases, a second Rogowski coil 12 and a third Rogowski coil 13 connected in opposite phases, and a third Rogowski coil 13 and a fourth Rogowski coil 14 connected in the same phase. The input unit is used to input the output signal into the high-pass integrator 15; The processing unit is used to perform integration and high-frequency filtering on the output signal sequentially through the high-pass integrator 15 to generate high-frequency discharge current data.

[0113] In some alternative implementations, the construction module 302 includes: A construction unit is used to construct fault characteristic quantities based on high-frequency discharge current data; the calculation formula for the fault characteristic quantities is as follows: ; In the formula, K It is a constant; for A The discharge fault current of the phase cable; for B The discharge fault current of the phase cable; for C The discharge fault current of the phase cable.

[0114] In some alternative implementations, the fault module 303 includes: The calculation unit is used to calculate the numerical values ​​corresponding to the fault characteristic quantities. The first fault unit is used to determine the AC phase cable as the location of the motor cable fault when the value corresponding to the fault characteristic quantity is a preset first amplification factor. The second fault unit is used to determine the AB phase cable as the cable fault location of the motor when the value corresponding to the fault characteristic quantity is a preset second amplification factor. The third fault unit is used to determine the BC phase cable as the cable fault location of the motor when the value corresponding to the fault characteristic quantity is a preset third amplification factor.

[0115] In some alternative embodiments, the device further includes: The comparison unit is used to compare the value corresponding to the fault characteristic quantity with the preset fault threshold, and determine the health status of the motor's cable based on the comparison result. The design unit is used to develop corresponding maintenance plans based on the health status of the cables; The sending unit is used to send the cable fault location, cable health status, and corresponding repair plan to the maintenance personnel.

[0116] In some alternative implementations, the comparison unit includes: The first judgment subunit is used to determine whether the fault characteristic quantity is less than or equal to the preset fault threshold. The normal subunit is used to determine the health status of the motor's cables as normal if the condition is met. The second judgment subunit is used to determine whether the fault characteristic quantity is greater than the preset fault threshold and less than or equal to the preset fault warning threshold if no. Note the sub-unit, which is used to determine the health status of the motor's cables as a warning level if the condition is met. The third judgment subunit is used to determine whether the fault characteristic quantity is greater than the preset fault warning threshold and less than or equal to the preset fault alarm threshold if no. The early warning subunit is used to determine the health status of the motor's cables as an early warning level alarm state if the condition is met. The fourth judgment subunit is used to determine whether the fault characteristic quantity is greater than the preset fault alarm threshold if no. The alarm subunit is used to determine the health status of the motor's cables as an alarm-level alarm state if the condition is met.

[0117] The Rogowski coil-based motor winding inter-turn discharge monitoring device provided in this embodiment of the invention can execute the Rogowski coil-based motor winding inter-turn discharge monitoring method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the method. Further functional descriptions of the above modules and units are the same as in the corresponding embodiments described above, and will not be repeated here.

[0118] Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention.

[0119] The following is a detailed reference. Figure 8 This diagram illustrates a structural schematic suitable for implementing an electronic device according to embodiments of the present invention. The electronic device may include a processor (e.g., a central processing unit, graphics processor, etc.) 401, which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 402 or a program loaded from memory 408 into random access memory (RAM) 403. The RAM 403 also stores various programs and data required for the operation of the electronic device. The processor 401, ROM 402, and RAM 403 are interconnected via a bus 404. An input / output (I / O) interface 405 is also connected to the bus 404.

[0120] Typically, the following devices can be connected to I / O interface 405: input devices 406 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 407 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; memory devices 408 including, for example, magnetic tapes, hard disks, etc.; and communication devices 409. Communication device 409 allows electronic devices to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 8 Electronic devices with various devices are shown, but it should be understood that it is not required to implement or have all of the devices shown, and more or fewer devices may be implemented or have instead.

[0121] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 409, or installed from a memory 408, or installed from a ROM 402. When the computer program is executed by the processor 401, it performs the functions defined in the Rogowski coil-based motor winding inter-turn discharge monitoring method of the present invention.

[0122] Figure 8 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments of the present invention.

[0123] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the method for monitoring inter-turn discharge of motor windings based on Rogowski coils shown in the above embodiments is implemented.

[0124] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0125] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method of monitoring turn-to-turn discharges in windings of an electric machine based on a Roebel coil, characterized in that, The method is applied to a discharge monitoring system, the discharge monitoring system comprising a plurality of series-connected Rogowski coils, each of the Rogowski coils being sleeved on a corresponding phase cable, and the method comprising: obtaining an output signal of the series-connected Rogowski coils and inputting the output signal into a high-pass integrator, and performing integral operation on the output signal by the high-pass integrator to obtain high-frequency discharge current data; constructing a fault characteristic quantity based on the high-frequency discharge current data; determining a cable fault position of a motor according to a numerical value corresponding to the fault characteristic quantity.

2. The method of claim 1, wherein, The method of obtaining an output signal of the series-connected Rogowski coils and inputting the output signal into a high-pass integrator, and performing integral operation on the output signal by the high-pass integrator to obtain high-frequency discharge current data comprises: obtaining an output signal of the series-connected Rogowski coils; wherein the Rogowski coils comprise a first Rogowski coil and a second Rogowski coil connected in anti-phase, the second Rogowski coil and a third Rogowski coil connected in anti-phase, and the third Rogowski coil and a fourth Rogowski coil connected in phase; inputting the output signal into a high-pass integrator; performing integral operation and high-frequency filtering processing on the output signal by the high-pass integrator in sequence to generate high-frequency discharge current data.

3. The method of claim 1, wherein, The method of constructing a fault characteristic quantity based on the high-frequency discharge current data comprises: constructing a fault characteristic quantity based on the high-frequency discharge current data; wherein a calculation formula of the fault characteristic quantity is: ； wherein K is a constant; is A the discharge fault current of the phase cable; is B the discharge fault current of the phase cable; is C the discharge fault current of the phase cable.

4. The method of claim 1, wherein, The method of determining a cable fault position of a motor according to a numerical value corresponding to the fault characteristic quantity comprises: calculating the numerical value corresponding to the fault characteristic quantity; when the numerical value corresponding to the fault characteristic quantity is a preset first amplification multiple, an AC phase cable is determined as the cable fault position of the motor; when the numerical value corresponding to the fault characteristic quantity is a preset second amplification multiple, an AB phase cable is determined as the cable fault position of the motor; when the numerical value corresponding to the fault characteristic quantity is a preset third amplification multiple, a BC phase cable is determined as the cable fault position of the motor.

5. The method of claim 4, wherein, The method further comprises: comparing a size between the numerical value corresponding to the fault characteristic quantity and a preset fault threshold value, and determining a cable health state of the motor according to a comparison result; formulating a corresponding maintenance scheme based on the cable health state; sending the cable fault position, the cable health state and the corresponding maintenance scheme to a maintenance personnel.

6. The method of claim 5, wherein, The method of comparing a size between the numerical value corresponding to the fault characteristic quantity and a preset fault threshold value, and determining a cable health state of the motor according to a comparison result comprises: judging whether the fault characteristic quantity is less than or equal to a preset fault threshold value; if yes, determining the cable health state of the motor as a normal state; if no, judging whether the fault characteristic quantity is greater than the preset fault threshold value and less than or equal to a preset fault warning threshold value; if yes, determining the cable health state of the motor as a warning-level warning state; if no, judging whether the fault characteristic quantity is greater than the preset fault warning threshold value and less than or equal to a preset fault alarm threshold value; if yes, determining the cable health state of the motor as a warning-level alarm state; if no, judging whether the fault characteristic quantity is greater than the preset fault alarm threshold value; If yes, the cable health status of the motor is determined as an alarm level alarm state.

7. A device for monitoring turn-to-turn discharges in windings of an electric machine based on a Roebel coil, characterized in that The device is applied to a discharge monitoring system, and the discharge monitoring system comprises a plurality of series-connected Rogowski coils, each of which is sleeved on a corresponding phase cable. An acquisition module is configured to acquire an output signal of the series-connected Rogowski coils and input the output signal into a high-pass integrator, and perform integral operation on the output signal by the high-pass integrator to obtain high-frequency discharge current data. A construction module is configured to construct a fault feature quantity based on the high-frequency discharge current data. A fault module is configured to determine a cable fault position of a motor according to a value corresponding to the fault feature quantity.

8. An electronic device, comprising: The device comprises: a memory and a processor, which are communicatively connected, and the memory stores computer instructions, and the processor executes the computer instructions to perform the method for monitoring inter-turn discharge of a motor winding based on a Rogowski coil according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer instructions, and the computer instructions are used to make a computer execute the method for monitoring inter-turn discharge of a motor winding based on a Rogowski coil according to any one of claims 1 to 6.

10. A computer program product, characterised in that, The computer instructions are used to make a computer execute the method for monitoring inter-turn discharge of a motor winding based on a Rogowski coil according to any one of claims 1 to 6.

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