Method and device for calculating transformer winding vibrations
By acquiring the target current signal and dynamically calculating the axial displacement of the transformer winding, the problem of low accuracy in traditional detection methods is solved, and a high-precision assessment of the transformer winding's short-circuit withstand capability is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XI AN JIAOTONG UNIV
- Filing Date
- 2023-03-09
- Publication Date
- 2026-07-14
AI Technical Summary
Traditional methods have low accuracy in testing the short-circuit withstand capability of transformers and cannot accurately determine the deformation changes of the windings during vibration.
By acquiring the target current signal, the axial displacement of each coil at the target sampling time is calculated, and the target position parameters are corrected using the axial displacement at the previous sampling time. The vibration response value of the winding is dynamically calculated to improve the detection accuracy.
It enables accurate measurement of the dynamic deformation of transformer windings during short circuits, thereby improving the accuracy of short-circuit withstand capability detection.
Smart Images
Figure CN116224171B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of transformer winding vibration technology, and in particular to a method and apparatus for calculating transformer winding vibration. Background Technology
[0002] Transformers are core equipment in power systems, and their safe and reliable operation is crucial for the overall reliable operation of the power system. Transformers can experience faults during operation due to various reasons, among which short circuits are a significant cause of mechanical failures in transformer windings. Therefore, testing the short-circuit withstand capability of transformers is of paramount importance.
[0003] In traditional technology, the method for testing the short-circuit withstand capability of a transformer is the static verification method. This method uses the peak value of the short-circuit current as input to calculate the magnetic induction intensity of the leakage magnetic field, thereby obtaining the electromagnetic force distribution. Then, based on the electromagnetic force distribution, the deformation of the winding vibration is calculated, thus determining the transformer's short-circuit withstand capability.
[0004] However, traditional methods assume that the current after the first short-circuit current peak has little impact on winding deformation. In other words, the transformer's short-circuit withstand capability is considered qualified as long as it can withstand the first short-circuit current peak. But in fact, the deformation of the winding is constantly present and changing during the vibration process. Therefore, traditional methods for testing the transformer's short-circuit withstand capability have the problem of low accuracy. Summary of the Invention
[0005] Therefore, it is necessary to provide a method and apparatus for calculating transformer winding vibration that can improve the accuracy of detecting transformer short-circuit withstand capability, in order to address the above-mentioned technical problems.
[0006] In a first aspect, this application provides a method for calculating the vibration of a transformer winding. The method includes: acquiring a target current signal, which is used to excite a target transformer to produce axial deformation. The target transformer includes a winding, and the winding includes multiple coils. For each coil, a target position parameter corresponding to the coil is determined, and a target current density corresponding to the coil at each sampling moment within the target sampling period is determined based on the target current signal. For each coil, based on the target position parameter and the target current density corresponding to the coil at each sampling moment, the axial displacement corresponding to the coil at each sampling moment is calculated, and the axial displacement corresponding to the coil at the last sampling moment is taken as the total vibration response value of the coil within the target sampling period. When calculating the axial displacement corresponding to a non-first sampling moment, the target position parameter is corrected using the axial displacement corresponding to the previous sampling moment.
[0007] In one embodiment, the target current signal is a sinusoidal short-circuit current signal.
[0008] In one embodiment, the target transformer further includes a core window, and the winding is wound on the core window. Determining the target position parameters corresponding to the coil includes: establishing a coordinate system based on the position of the core window; determining the first position coordinates of the coil in the coordinate system based on the relative positional relationship between the coil and the core window; and determining the target position parameters based on the first position coordinates.
[0009] In one embodiment, determining the target position parameter based on the first position coordinates includes: determining the target line cake located on the same plane as the line cake; determining the second position coordinates of the target line cake in the coordinate system based on the relative positional relationship between the target line cake and the core window; and determining the target position parameter by combining the first position coordinates and the second position coordinates.
[0010] In one embodiment, determining the target current density corresponding to the wire disc at each sampling moment within the target sampling period based on the target current signal includes: determining a first current density of the current flowing through the wire disc at each sampling moment based on the target current signal; determining a second current density of the current flowing through the target wire disc at each sampling moment based on the target current signal; and using the first current density and the second current density as the target current density.
[0011] In one embodiment, the wire coil is a high-voltage wire coil or a low-voltage wire coil. If the wire coil is a high-voltage wire coil, the target wire coil is a low-voltage wire coil. If the wire coil is a low-voltage wire coil, the target wire coil is a high-voltage wire coil.
[0012] In one embodiment, the axial displacement of the wire disc at each sampling time is calculated based on the target position parameters and the target current density corresponding to the wire disc at each sampling time, including: calculating the electromagnetic force corresponding to the wire disc at each sampling time based on the target position parameters and the target current density corresponding to the wire disc at each sampling time; and calculating the axial displacement of the wire disc at each sampling time based on the transformer parameters of the target transformer and the electromagnetic force corresponding to the wire disc at each sampling time.
[0013] In one embodiment, the electromagnetic force corresponding to the wire at each sampling time is calculated based on the target position parameters and the target current density corresponding to the wire at each sampling time, including: calculating the leakage magnetic field magnetic induction intensity corresponding to the wire at each sampling time based on the first formula; and calculating the electromagnetic force corresponding to the wire at each sampling time based on the second formula and the leakage magnetic field magnetic induction intensity corresponding to the wire at each sampling time.
[0014] The first formula is:
[0015]
[0016] B x J represents the leakage magnetic field magnetic induction intensity corresponding to the nth coil. nLet Δx and Δy be the target current density corresponding to the nth coil, where Δx and Δy are both target position parameters, and Δx = xx. nk Δy=yy nk Let x and y be the x-coordinate and y-coordinate of any point within the nth line pie, respectively. nk and y nk y' and y' are the x and y coordinates of the k-th reference point within the n-th line pie, respectively; y' is the axial displacement corresponding to the previous sampling time of the n-th line pie; and atg is the arctangent function.
[0017] The second formula is:
[0018] F y =∫ v B x J n dv
[0019] F y Let v be the electromagnetic force corresponding to the nth coil, and v be the volume of the coil.
[0020] In one embodiment, the target transformer further includes a pad disposed between two adjacent coils, the transformer parameters including the stiffness coefficient of the pad, and the method further includes: calculating the stiffness coefficient of the pad based on the axial displacement between the two adjacent coils.
[0021] Secondly, this application also provides a transformer winding vibration calculation device. The device includes: an acquisition module for acquiring a target current signal, the target current signal being used to excite a target transformer to produce axial deformation, the target transformer including a winding, the winding including multiple coils; a determination module for determining, for each coil, the target position parameters corresponding to the coil, and determining the target current density corresponding to the coil at each sampling moment within the target sampling period based on the target current signal; and a calculation module for calculating, for each coil, based on the target position parameters and the target current density corresponding to the coil at each sampling moment, the axial displacement corresponding to the coil at each sampling moment, and using the axial displacement corresponding to the coil at the last sampling moment as the total vibration response value of the coil within the target sampling period, wherein, when calculating the axial displacement corresponding to a non-first sampling moment, the target position parameters are corrected using the axial displacement corresponding to the previous sampling moment.
[0022] In one embodiment, the target current signal is a sinusoidal short-circuit current signal.
[0023] In one embodiment, the target transformer further includes a core window, with the winding wound on the core window. The determining module is also used to establish a coordinate system based on the position of the core window; determine the first position coordinates of the wire disc in the coordinate system based on the relative positional relationship between the wire disc and the core window; and determine the target position parameters based on the first position coordinates.
[0024] In one embodiment, the determining module is further configured to determine a target line cake located on the same plane as the line cake, determine the second position coordinates of the target line cake in the coordinate system based on the relative positional relationship between the target line cake and the core window, and determine the target position parameters by combining the first position coordinates and the second position coordinates.
[0025] In one embodiment, the determining module is specifically configured to determine a first current density of the current flowing through the coil at each sampling time based on the target current signal; determine a second current density of the current flowing through the target coil at each sampling time based on the target current signal; and use the first current density and the second current density as the target current density.
[0026] In one embodiment, the wire coil is a high-voltage wire coil or a low-voltage wire coil. If the wire coil is a high-voltage wire coil, the target wire coil is a low-voltage wire coil. If the wire coil is a low-voltage wire coil, the target wire coil is a high-voltage wire coil.
[0027] In one embodiment, the calculation module is further configured to calculate the electromagnetic force corresponding to the wire disc at each sampling time based on the target position parameters and the target current density corresponding to the wire disc at each sampling time; and to calculate the axial displacement corresponding to the wire disc at each sampling time based on the transformer parameters of the target transformer and the electromagnetic force corresponding to the wire disc at each sampling time.
[0028] In one embodiment, the calculation module is specifically used to calculate the leakage magnetic field magnetic induction intensity corresponding to the wire disc at each sampling time based on the first formula; and to calculate the electromagnetic force corresponding to the wire disc at each sampling time based on the second formula and the leakage magnetic field magnetic induction intensity corresponding to the wire disc at each sampling time.
[0029] The first formula is:
[0030]
[0031] B x J represents the leakage magnetic field magnetic induction intensity corresponding to the nth coil. n Let Δx and Δy be the target current density corresponding to the nth coil, where Δx and Δy are both target position parameters, and Δx = xx. nk Δy=yy nk Let x and y be the x-coordinate and y-coordinate of any point within the nth line pie, respectively. nk and y nk y' and y' are the x and y coordinates of the k-th reference point within the n-th line pie, respectively; y' is the axial displacement corresponding to the previous sampling time of the n-th line pie; and atg is the arctangent function.
[0032] The second formula is:
[0033] F y =∫ v B xJ n dv
[0034] F y Let v be the electromagnetic force corresponding to the nth coil, and v be the volume of the coil.
[0035] In one embodiment, the target transformer further includes a pad disposed between two adjacent coils. The transformer parameters include the stiffness coefficient of the pad. The calculation module is also used to calculate the stiffness coefficient of the pad based on the axial displacement between the two adjacent coils.
[0036] Thirdly, this application also provides a computer device. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps of the method described in any of the first aspects above.
[0037] Fourthly, this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, implements the steps of the method described in any of the first aspects above.
[0038] Fifthly, this application also provides a computer program product. The computer program product includes a computer program that, when executed by a processor, implements the steps of the method described in any of the first aspects above.
[0039] The aforementioned method and apparatus for calculating transformer winding vibration involves acquiring a target current signal, which is used to excite the target transformer to produce axial deformation. The target transformer includes windings comprising multiple coils. For each coil, the target position parameters are determined, and the target current density for each sampling moment within the target sampling period is determined based on the target current signal. Then, for each coil, the axial displacement at each sampling moment is calculated based on the target position parameters and the target current density at each sampling moment. The axial displacement at the last sampling moment is taken as the total vibration response value of the coil within the target sampling period. When calculating the axial displacement corresponding to a non-first sampling moment, the axial displacement corresponding to the previous sampling moment is used relative to the target position parameters. The present application calculates the axial displacement of the coil at each sampling time by using the target current density corresponding to the coil at each sampling time and correcting the target position parameters using the axial displacement corresponding to the previous sampling time. This method realizes the calculation of the dynamic deformation of each coil in the winding under changing current. Since the target position parameters are corrected by using the axial displacement corresponding to the coil at the previous sampling time during the calculation of the axial displacement of the coil at each sampling time, the axial displacement of the coil at the last sampling time is obtained after the deformation of the coil during the target sampling period has changed dynamically. Therefore, using the axial displacement of the coil at the last sampling time as the total vibration response value of the coil during the target sampling period to measure the transformer's short-circuit withstand capability has high accuracy. Attached Figure Description
[0040] Figure 1 This is a flowchart illustrating a method for calculating transformer winding vibration in one embodiment;
[0041] Figure 2 This is a structural diagram of a target transformer in one embodiment;
[0042] Figure 3 This is a schematic diagram of the winding position relationship in one embodiment;
[0043] Figure 4 This is a schematic diagram of a mirror principle in one embodiment;
[0044] Figure 5 This is a schematic diagram illustrating an iterative calculation of the winding deformation in one embodiment.
[0045] Figure 6 This is a flowchart illustrating another method for calculating transformer winding vibration in another embodiment;
[0046] Figure 7 This is a structural block diagram of a transformer winding vibration calculation device in one embodiment;
[0047] Figure 8 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation
[0048] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.
[0049] Transformers are subjected to electrical, thermal, and mechanical stresses during operation, and have a variety of potential fault types. Short circuits are one of the important causes of mechanical faults in transformer windings. When a transformer is subjected to impacts from multiple short circuits, its condition will be severely deteriorated, and it is very likely to trip during the next impact.
[0050] Assessing the impact of short-circuit impulses on transformers requires consideration of two key factors: First, the transformer's internal mechanical and electrical strength before the short-circuit impulse. Even without winding deformation, various adverse operating conditions during operation can reduce the coil's mechanical strength and cause minor insulation damage. These adverse conditions include repeated short circuits within short intervals and inrush current during no-load closing. Second, the short-circuit current level. The magnitude of the impulse short-circuit current is a core factor affecting the transformer's short-circuit withstand capability. The maximum possible short-circuit current in each winding of the transformer is closely related to factors such as the transformer's own impedance, system impedance, and operating mode.
[0051] Calculating the vibration response of a transformer winding under a short-circuit impact can determine the transformer's short-circuit withstand capability. Currently, there are two methods for calculating this vibration response: the first is the static verification method, but the vibration response calculated by this method cannot accurately determine the transformer's short-circuit withstand capability. The second method calculates the electromagnetic field first and then the displacement field, but this method is only suitable when the synchronization of state variables between multiple physical fields is very slow. The interaction between the leakage magnetic field and the displacement field of the winding exists at any time and throughout the entire winding region, which should be a strongly coupled process. Therefore, the vibration response obtained by calculating the displacement field using this method cannot accurately determine the transformer's short-circuit withstand capability. Thus, it is necessary to propose a transformer winding vibration calculation method that can accurately determine the transformer's short-circuit withstand capability.
[0052] In one embodiment, such as Figure 1The diagram illustrates a method for calculating transformer winding vibration. This embodiment uses a terminal as an example, but it's understood that the method can also be applied to a server, or a system including both a terminal and a server, and is implemented through interaction between the terminal and the server. The terminal can be, but is not limited to, various personal computers, laptops, smartphones, and tablets. The server can be a standalone server or a server cluster composed of multiple servers. In this embodiment, the method includes the following steps:
[0053] Step 101: Obtain the target current signal. The target current signal is used to excite the target transformer to produce axial deformation. The target transformer includes windings, and the windings include multiple coils.
[0054] The target current signal is an alternating current signal that varies with time. The target transformer is a transformer with concentric windings, such as... Figure 2 As shown, a structural diagram of a target transformer is provided. The target transformer includes a core window 201 and windings. The core window 201 can be regarded as a rectangular hole in a uniform ferromagnetic material. The windings are divided into a high-voltage winding 202 and a low-voltage winding 203. Both the high-voltage winding 202 and the low-voltage winding 203 are wrapped around the core window. The windings are composed of multiple conductor coils, which are called coils. The number of coils constituting the high-voltage winding 202 is less than the number of coils constituting the low-voltage winding 203. For example, the number of coils corresponding to the high-voltage winding 202 can be 48, and the number of coils corresponding to the low-voltage winding 203 can be 58.
[0055] Optionally, a current sensor can be installed on the windings of the target transformer to obtain the target current signal when a short circuit occurs. Under the excitation of the target current signal, the target transformer will generate a leakage magnetic field. According to the right-hand screw rule, each coil will be subjected to an axial electromagnetic force, thereby producing displacement, that is, the windings of the target transformer will undergo axial deformation.
[0056] Step 102: For each line disc, determine the target position parameters corresponding to the line disc, and determine the target current density corresponding to the line disc at each sampling time within the target sampling period based on the target current signal.
[0057] The target position parameters for the line pie include the line pie's position coordinates. The target sampling period refers to the total sampling duration, and the target sampling time refers to the moment at which sampling is performed at intervals of one time step. For example, the target sampling period could be 1 second, and the time step could be 10 seconds. -4 The target current density refers to the current per unit cross-sectional area of the coil, which can be calculated using the current density calculation formula J. n =I t / A is obtained, where J nLet I be the target current density corresponding to the nth coil. t Let A be the current value in the nth coil at time t, and let A be the cross-sectional area of the nth coil, which is the same as the cross-sectional area of the conductor.
[0058] Optionally, for each line disc, it can be treated as a small rectangle, and an xoy rectangular coordinate system can be established to determine the target position parameters corresponding to the line disc. Based on the current density calculation formula, the target current density corresponding to the line disc at each sampling time can be calculated from the current value at each time step in the target current signal. Moreover, since the target current signal is an alternating current signal that varies with time, the current value obtained from the target current signal at each time step may be different, and thus the target current density calculated from the current value may also be different.
[0059] Step 103: For each wire disc, based on the target position parameters and the target current density corresponding to the wire disc at each sampling time, calculate the axial displacement corresponding to the wire disc at each sampling time, and take the axial displacement corresponding to the wire disc at the last sampling time as the total vibration response value of the wire disc within the target sampling period. When calculating the axial displacement corresponding to a time other than the first sampling time, the target position parameters are corrected by using the axial displacement corresponding to the previous sampling time.
[0060] Here, the axial displacement of the coil refers to the distance the coil moves axially under the excitation of the target current signal, due to the axial electromagnetic force. The total vibration response value of the coil during the target sampling period refers to the final axial distance the coil moves after being excited by the target current signal during the target sampling period.
[0061] Optionally, for each coil, at the first sampling time, the axial displacement of the coil at the first sampling time is calculated based on the target position parameters and the target current density corresponding to the coil at the first sampling time. At the j-th sampling time, the axial displacement of the coil at the j-th sampling time is calculated based on the corrected target position parameters and the target current density corresponding to the coil at the j-th sampling time. The corrected target position parameters are obtained by correcting the target position parameters using the axial displacement corresponding to the previous sampling time (j-1-th sampling time). Through the above iterative method, the axial displacement of the coil at the last sampling time can be obtained, and this axial displacement at the last sampling time is the total vibration response value of the coil during the target sampling period.
[0062] In summary, by acquiring the target current signal, which is used to excite the target transformer to produce axial deformation, and the target transformer including windings comprising multiple coils, the target position parameters corresponding to each coil are determined. Based on the target current signal, the target current density corresponding to each coil at each sampling moment within the target sampling period is determined. Then, for each coil, based on the target position parameters and the target current density at each sampling moment, the axial displacement corresponding to each coil at each sampling moment is calculated. The axial displacement corresponding to the coil at the last sampling moment is taken as the total vibration response value of the coil within the target sampling period. When calculating the axial displacement corresponding to a non-first sampling moment, the target position parameters are corrected using the axial displacement corresponding to the previous sampling moment. In this application, the target current density corresponding to the coil at each sampling time and the target position parameter are corrected by using the axial displacement corresponding to the previous sampling time to calculate the axial displacement corresponding to the coil at each sampling time. This method realizes the calculation of the dynamic deformation of each coil in the winding under changing current. Since the target position parameter is corrected by using the axial displacement corresponding to the coil at the previous sampling time during the calculation of the axial displacement corresponding to the coil at each sampling time, the axial displacement corresponding to the coil at the last sampling time is obtained after the deformation of the coil during the target sampling period has changed dynamically. Therefore, using the axial displacement corresponding to the coil at the last sampling time as the total vibration response value of the coil during the target sampling period to measure the transformer's short-circuit withstand capability has high accuracy.
[0063] In one embodiment, the target current signal is a sinusoidal short-circuit current signal.
[0064] Optionally, the target current signal can be a short-circuit current containing a decaying DC component and a 50Hz sinusoidal component. Assuming the short-circuit impedance of the target transformer is 1.344Ω, the peak current of the low-voltage winding is 3760A when the high-voltage winding and the low-voltage winding are short-circuited.
[0065] In one embodiment, the wire coil is a high-voltage wire coil or a low-voltage wire coil. If the wire coil is a high-voltage wire coil, the target wire coil is a low-voltage wire coil. If the wire coil is a low-voltage wire coil, the target wire coil is a high-voltage wire coil.
[0066] In one embodiment, the target transformer further includes a core window, and the winding is wound on the core window. Determining the target position parameters corresponding to the coil includes: establishing a coordinate system based on the position of the core window; determining the first position coordinates of the coil in the coordinate system based on the relative positional relationship between the coil and the core window; and determining the target position parameters based on the first position coordinates.
[0067] In one embodiment, determining the target position parameter based on the first position coordinates includes: determining the target line cake located on the same plane as the line cake; determining the second position coordinates of the target line cake in the coordinate system based on the relative positional relationship between the target line cake and the core window; and determining the target position parameter by combining the first position coordinates and the second position coordinates.
[0068] The structural diagram of the target transformer is as follows: Figure 2 As shown, the winding is divided into a high-voltage winding 202 and a low-voltage winding 203. The coil corresponding to the high-voltage winding 202 is the high-voltage coil, and the coil corresponding to the low-voltage winding 203 is the low-voltage coil.
[0069] Optionally, the target transformer includes a core window, windings, and spacers. The core window includes a core post, and the windings are wound on the core post, such as... Figure 3 As shown, a schematic diagram of the winding position relationship is provided. An xoy rectangular coordinate system is established with the core column's central axis. The core column is represented by a large rectangle. The high-voltage winding 202 and the low-voltage winding 203 are respectively formed by stacking multiple small rectangular high-voltage coils and multiple small rectangular low-voltage coils. The distance between the high-voltage and low-voltage coils is the difference between the radii of the high-voltage winding 202 and the low-voltage winding 203. The distance between adjacent coils is the thickness of the spacer. The distance from the center of the low-voltage coil to the central axis of the core column is taken as the distance from the rectangular low-voltage coil to the y-axis, and the distance from the center of the high-voltage coil to the central axis of the core column is taken as the distance from the rectangular high-voltage coil to the y-axis. This allows the determination of the first position coordinates of the coils and the second position coordinates of the target coil.
[0070] In one embodiment, determining the target current density corresponding to the wire disc at each sampling moment within the target sampling period based on the target current signal includes: determining a first current density of the current flowing through the wire disc at each sampling moment based on the target current signal; determining a second current density of the current flowing through the target wire disc at each sampling moment based on the target current signal; and using the first current density and the second current density as the target current density.
[0071] In one embodiment, the axial displacement of the wire disc at each sampling time is calculated based on the target position parameters and the target current density corresponding to the wire disc at each sampling time, including: calculating the electromagnetic force corresponding to the wire disc at each sampling time based on the target position parameters and the target current density corresponding to the wire disc at each sampling time; and calculating the axial displacement of the wire disc at each sampling time based on the transformer parameters of the target transformer and the electromagnetic force corresponding to the wire disc at each sampling time.
[0072] In one embodiment, the electromagnetic force corresponding to the wire at each sampling time is calculated based on the target position parameters and the target current density corresponding to the wire at each sampling time, including: calculating the leakage magnetic field magnetic induction intensity corresponding to the wire at each sampling time based on the first formula; and calculating the electromagnetic force corresponding to the wire at each sampling time based on the second formula and the leakage magnetic field magnetic induction intensity corresponding to the wire at each sampling time.
[0073] The first formula is:
[0074]
[0075] B x J represents the leakage magnetic field magnetic induction intensity corresponding to the nth coil. n Let Δx and Δy be the target current density corresponding to the nth coil, where Δx and Δy are both target position parameters, and Δx = xx. n k Δy=yy nk Let x and y be the x-coordinate and y-coordinate of any point within the nth line pie, respectively. nk and y nk y' and y' are the x and y coordinates of the k-th reference point within the n-th line pie, respectively; y' is the axial displacement corresponding to the previous sampling time of the n-th line pie; and atg is the arctangent function.
[0076] The second formula is:
[0077] F y =∫ v B x J n dv
[0078] F y Let v be the electromagnetic force corresponding to the nth coil, and v be the volume of the coil.
[0079] Optionally, when the target current signal is applied to the winding, induced charges will be generated inside the core window, forming multiple sets of mirror currents. The leakage magnetic field of the target transformer is actually the leakage magnetic field generated by the current in the winding and the multiple sets of mirror currents. However, since the influence of the mirror current on the magnetic induction intensity of the leakage magnetic field gradually decreases with the increase of distance, the leakage magnetic field of the target transformer can be simplified to the leakage magnetic field generated by the current in the winding and the primary mirror current, such as... Figure 4 As shown, a schematic diagram of the mirror principle is provided.
[0080] The electromagnetic force on the low-voltage coil is calculated below using a low-voltage coil as an example. The leakage magnetic field is generated by the current in the nth low-voltage coil, the nth low-voltage mirror current corresponding to the nth low-voltage coil, the current in the high-voltage coil located on the same plane as the nth low-voltage coil, and the high-voltage mirror current corresponding to the high-voltage coil. The magnetic induction intensity B of this leakage magnetic field is... x for:
[0081]
[0082] Where, when n=1, J n The first current density corresponding to the nth low-voltage coil; when n=2, J n The first current density corresponds to the nth low-voltage mirror current; when n=3, J n This is the second current density corresponding to the high-voltage coil located on the same plane as the nth low-voltage coil; when n=4, J n This represents the second current density corresponding to the high-voltage mirror current. The low-voltage line disc is a small rectangle, where k represents the vertex of the small rectangle, and Δx = xx. nk Δy=yy nk Let x and y be the x and y coordinates of any point within the nth low-voltage line pancake, respectively. nk and y nk y' and y' are the x and y coordinates of the k-th vertex within the n-th low-voltage line patch, respectively. At the first sampling time, y' is 0; at other times, y' represents the axial displacement corresponding to the previous sampling time of the n-th low-voltage line patch.
[0083] Then, using the Biot-Savart law, calculate the electromagnetic force F acting on the nth low-voltage coil. y for
[0084] F y =∫ v B x J n dv
[0085] First, calculate the leakage magnetic field magnetic induction intensity B according to the above. x Then calculate the electromagnetic force F y In this way, the electromagnetic forces f1 to f2 on each low-voltage coil can be obtained. n .
[0086] It should be noted that the above B x In reality, it is the radial component of the leakage magnetic field magnetic induction intensity, F y In reality, it is the axial component of the electromagnetic force, specifically the axial component B of the leakage magnetic field magnetic induction intensity. y And the radial component F of electromagnetic force x The calculation formulas for B are respectively with B x and F y Similarly, replacing x with y will give you the result.
[0087] The winding structure is equivalent to a concentrated equivalent mass block. The stiffness and damping of the pressure plates, fasteners, coils, and insulating materials such as pads are regarded as equivalent springs and glue bottles, respectively. A discrete dynamic model characterizing the axial vibration of the winding is established, resulting in the dynamic equations containing upper and lower pressure plates and n coils:
[0088]
[0089] Where, m T With m B The masses of the top and bottom pressure plates of the low-voltage winding are m1 to m2, respectively. n The masses of each low-voltage coil are respectively; k T With k B K represents the stiffness coefficients of the top and bottom pads of the low-voltage winding, respectively. C k represents the equivalent stiffness between the top and bottom pressure plates of the low-voltage winding. S The stiffness coefficient between the bottom pressure plate of the low-voltage winding and the ground is k1~k n-1 These are the stiffness coefficients of the spacers between the low-voltage wire discs; c T With c B c represents the damping coefficients of the top and bottom pressure plates of the low-voltage winding, respectively. S c is the damping coefficient between the bottom pressure plate of the low-voltage winding and the ground. c c1 to c2 represent the damping coefficient between the top and bottom pressure plates of the low-voltage winding. n-1 These are the damping coefficients between the low-voltage coils; y1~y n These represent the axial displacements of each low-voltage coil under electromagnetic force, y T With y B These represent the axial displacements of the top and bottom pressure plates of the low-voltage winding under the action of electromagnetic force, respectively. These represent the axial vibration velocities of each low-voltage coil. These are the axial vibration velocities of the top and bottom pressure plates of the low-voltage winding, respectively. These represent the axial vibration accelerations of each low-voltage coil. These are the axial vibration accelerations of the top and bottom pressure plates of the low-voltage winding, respectively; f c Here, m represents the clamping force parameter, and g represents the acceleration due to gravity. Additionally, it should be noted that the above m... T m B m1~m n k T k B k C k S c T c B c S c c c1~c n-1 These are all structural parameters of the target transformer, which can be obtained from the manufacturer of the target transformer.
[0090] The above dynamic equations can be written in matrix form, as follows:
[0091]
[0092] Where M is the mass matrix of the low-pressure wire disc; C is the damping coefficient matrix; and K is the stiffness coefficient matrix. y represents the axial vibration acceleration matrix, axial vibration velocity matrix, and axial displacement matrix of the low-voltage coil, respectively; F represents the electromagnetic force matrix acting on the low-voltage coil; F c This is the clamping force matrix.
[0093] The above dynamic equations were solved using the rigid differential solver ode23t to obtain the axial displacements y1 to y23t of each low-voltage coil under the action of electromagnetic force. n The calculation method for the axial displacement of each high-voltage coil under electromagnetic force is similar to that for the low-voltage coil, and will not be repeated here. If there are 58 low-voltage coils and 48 high-voltage coils, then at time t, the axial displacement matrices of the low-voltage coils (58×1) and the high-voltage coils (48×1) will be obtained. These two axial displacement matrices are continuously updated at different times.
[0094] The axial displacement y of each disc calculated at each sampling time is used as the basis for calculating the leakage magnetic field magnetic induction intensity B at the next sampling time. x The required y' is equivalent to adding a time extension term and using a cyclic iterative method to calculate the electromagnetic force and winding deformation, such as... Figure 5 The diagram illustrates a method for iteratively calculating the deformation of a winding. The axial displacement y of each winding disc calculated at each sampling time is added to its initial axial position y0 when it is not excited by the target current signal, thus obtaining the true axial position of each winding disc at each sampling time.
[0095] In one embodiment, the target transformer further includes a pad disposed between two adjacent coils, the transformer parameters including the stiffness coefficient of the pad, and the method further includes: calculating the stiffness coefficient of the pad based on the axial displacement between the two adjacent coils.
[0096] Optionally, the target transformer also includes insulating paper disposed between the pad and the coil. When solving the dynamic equation at each sampling time, the stiffness coefficient k of the pad between the low-voltage coils in the dynamic equation is:
[0097]
[0098] Where N is the number of pads; A is the area of the pads, and L is the Poisson's ratio of the pads; s and L p These are the thicknesses of the pad and the insulating paper, respectively; Es and E p Let be the elastic moduli of the pad and the insulating paper, respectively. Considering the nonlinear characteristics of the pad and the insulating paper, the stress-strain relationship and elastic modulus of the pad or the insulating paper are as follows:
[0099] σ=aε b
[0100] E = aε b-1 =a((y i+1 -y i ) / L0+ε0) b-1
[0101] ((y i+1 -y i ) / L0+ε0≥0)
[0102] Where a is the amplitude scaling factor, which can be 830 MPa, b is the nonlinearity factor, which can be 1.432, and y i and y i+1 εi represents the axial displacement of the i-th and (i+1)-th wire discs, respectively; L0 is the original thickness of the pad, and ε0 is the static strain of the pad under the action of gravity and clamping force. When the pad detaches from the wire disc, the pressure on the pad is zero, and the elastic modulus and stiffness of the corresponding pad are 0.
[0103] In one embodiment, when solving the dynamic equations at the aforementioned sampling times, the clamping force parameter in the dynamic equations is adjusted to obtain different mode shapes and natural frequencies of the target transformer model, continuously optimizing the model's calculation method during the calculation process. The table below shows the relationship between the clamping force and the first and second natural frequencies:
[0104] Clamping force / MPa First natural frequency / Hz Second natural frequency / Hz 1.5 57.7 110. 1.7 58.8 112.9 1.9 59.8 114.8 2.1 60.7 116.5 2.3 61.6 118.1 2.5 62.3 119.6 2.7 63.1 121.0 2.9 63.7 122.4 3.1 64.4 123.6
[0105] In summary, such as Figure 6The diagram illustrates another method for calculating transformer winding vibration. The target transformer includes a core window and windings wound on the core window. Each winding comprises multiple coils, which can be high-voltage or low-voltage coils. The target transformer also includes a spacer between adjacent coils. Each coil is considered a small rectangle, and a coordinate system is established with the core window in mind. The target position parameters of each coil are determined based on their relative position to the core window. At each sampling time, based on the mirror method, the electromagnetic force on each coil is calculated using the first formula, the second formula, the target position parameters, and the axial displacement of each coil at the previous sampling time. The stiffness coefficient of the spacer is determined based on the axial displacement of adjacent coils at the previous time, and the clamping force parameters are adjusted. Substituting the electromagnetic force on each coil, the adjusted clamping force parameters, and the structural parameters of the target transformer into the dynamic equations, the axial displacement of each coil can be solved using the rigid differential solver ode23t. This process is repeated until the target sampling period is reached. When calculating the axial displacement of the target transformer winding under the excitation of the target current signal, the electromagnetic force, clamping force parameters and stiffness coefficient of the pads at each sampling moment are not fixed values, but vary. This closely matches the actual situation of the transformer winding deformation process under short circuit conditions. Therefore, the winding deformation calculated by the transformer winding vibration calculation method of this application is more accurate, and thus can more accurately measure the transformer's short circuit resistance.
[0106] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.
[0107] Based on the same inventive concept, this application also provides a transformer winding vibration calculation device for implementing the transformer winding vibration calculation method described above. The solution provided by this device is similar to the implementation described in the above method; therefore, the specific limitations in one or more embodiments of the transformer winding vibration calculation device provided below can be found in the limitations of the transformer winding vibration calculation method described above, and will not be repeated here.
[0108] In one embodiment, such as Figure 7As shown, a transformer winding vibration calculation device 700 is provided, comprising: an acquisition module 701, a determination module 702, and a calculation module 703, wherein:
[0109] The acquisition module 701 is used to acquire the target current signal, which is used to excite the target transformer to produce axial deformation. The target transformer includes windings, and the windings include multiple coils.
[0110] The determination module 702 is used to determine the target position parameters corresponding to each line disc, and to determine the target current density corresponding to each sampling time of the line disc within the target sampling period based on the target current signal.
[0111] The calculation module 703 is used to calculate the axial displacement of each line disc at each sampling time based on the target position parameters and the target current density of the line disc at each sampling time, and to take the axial displacement of the line disc at the last sampling time as the total vibration response value of the line disc in the target sampling period. When calculating the axial displacement corresponding to a non-first sampling time, the target position parameters are corrected by using the axial displacement corresponding to the previous sampling time.
[0112] In one embodiment, the target current signal is a sinusoidal short-circuit current signal.
[0113] In one embodiment, the target transformer further includes a core window, and the winding is wound on the core window. The determining module 702 is also used to establish a coordinate system based on the position of the core window; determine the first position coordinate of the wire disc in the coordinate system based on the relative positional relationship between the wire disc and the core window; and determine the target position parameters based on the first position coordinate.
[0114] In one embodiment, the determining module 702 is further configured to determine a target line cake located on the same plane as the line cake, determine the second position coordinates of the target line cake in the coordinate system based on the relative positional relationship between the target line cake and the core window, and determine the target position parameters by combining the first position coordinates and the second position coordinates.
[0115] In one embodiment, the determining module 702 is specifically configured to determine a first current density of the current flowing through the wire disc at each sampling time based on the target current signal; determine a second current density of the current flowing through the target wire disc at each sampling time based on the target current signal; and use the first current density and the second current density as the target current density.
[0116] In one embodiment, the wire coil is a high-voltage wire coil or a low-voltage wire coil. If the wire coil is a high-voltage wire coil, the target wire coil is a low-voltage wire coil. If the wire coil is a low-voltage wire coil, the target wire coil is a high-voltage wire coil.
[0117] In one embodiment, the calculation module 703 is further configured to calculate the electromagnetic force corresponding to the wire at each sampling time based on the target position parameters and the target current density corresponding to the wire at each sampling time; and to calculate the axial displacement corresponding to the wire at each sampling time based on the transformer parameters of the target transformer and the electromagnetic force corresponding to the wire at each sampling time.
[0118] In one embodiment, the calculation module 703 is specifically used to calculate the leakage magnetic field magnetic induction intensity corresponding to the wire disc at each sampling time based on the first formula; and to calculate the electromagnetic force corresponding to the wire disc at each sampling time based on the second formula and the leakage magnetic field magnetic induction intensity corresponding to the wire disc at each sampling time.
[0119] The first formula is:
[0120]
[0121] B x J represents the leakage magnetic field magnetic induction intensity corresponding to the nth coil. n Let Δx and Δy be the target current density corresponding to the nth coil, where Δx and Δy are both target position parameters, and Δx = xx. nk Δy=yy nk Let x and y be the x-coordinate and y-coordinate of any point within the nth line pie, respectively. nk and y nk y' and y' are the x and y coordinates of the k-th reference point within the n-th line pie, respectively; y' is the axial displacement corresponding to the previous sampling time of the n-th line pie; and atg is the arctangent function.
[0122] The second formula is:
[0123] F y =∫ v B x J n dv
[0124] F y Let v be the electromagnetic force corresponding to the nth coil, and v be the volume of the coil.
[0125] In one embodiment, the target transformer further includes a pad disposed between two adjacent coils. The transformer parameters include the stiffness coefficient of the pad. The calculation module 703 is also used to calculate the stiffness coefficient of the pad based on the axial displacement between the two adjacent coils.
[0126] Each module in the aforementioned transformer winding vibration calculation device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.
[0127] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 8 As shown, the computer device includes a processor, memory, communication interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When executed by the processor, the computer program implements a method for calculating the vibration of transformer windings. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad on the computer device's casing, or an external keyboard, touchpad, or mouse.
[0128] Those skilled in the art will understand that Figure 8 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.
[0129] In one embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.
[0130] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.
[0131] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.
[0132] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.
[0133] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this 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 memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.
[0134] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0135] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.
Claims
1. A method for calculating transformer winding vibration, characterized in that, The method includes: A target current signal is acquired, which is used to excite a target transformer to produce axial deformation. The target transformer includes a winding, which includes multiple coils. For each of the aforementioned line discs, the target position parameters corresponding to the line disc are determined, and the target current density corresponding to the line disc at each sampling time within the target sampling period is determined based on the target current signal; wherein, the target position parameters include and , , Let x and y be the x-coordinate and y-coordinate of any point within the nth line pie, respectively. and These are the x and y coordinates of the k-th reference point within the n-th line pie, respectively. For each of the aforementioned coils, based on the target position parameters and the target current density corresponding to the coil at each sampling time, the axial displacement corresponding to the coil at each sampling time is calculated, and the axial displacement corresponding to the coil at the last sampling time is taken as the total vibration response value of the coil within the target sampling period. Specifically, when calculating the axial displacement corresponding to a non-first sampling time, the axial displacement corresponding to the previous sampling time is used relative to the target position parameters. Make corrections.
2. The method according to claim 1, characterized in that, The target current signal is a sinusoidal short-circuit current signal.
3. The method according to claim 1, characterized in that, The target transformer further includes a core window, and the winding is wound on the core window. Determining the target position parameters corresponding to the coil includes: Establish a coordinate system based on the position of the iron core window; The first position coordinates of the wire disc in the coordinate system are determined based on the relative positional relationship between the wire disc and the core window, and the target position parameters are determined based on the first position coordinates.
4. The method according to claim 3, characterized in that, Determining the target position parameters based on the first position coordinates includes: Determine a target line block that is located on the same plane as the line block, and determine the second position coordinates of the target line block in the coordinate system based on the relative positional relationship between the target line block and the core window; The target position parameters are determined by using the first position coordinates and the second position coordinates.
5. The method according to claim 4, characterized in that, Determining the target current density corresponding to the line disc at each sampling time within the target sampling period based on the target current signal includes: The first current density of the current flowing through the coil at each sampling time is determined based on the target current signal. The second current density of the current flowing through the target coil at each sampling time is determined based on the target current signal. The first current density and the second current density are used as the target current density.
6. The method according to claim 4 or 5, characterized in that, The wire coil is either a high-voltage wire coil or a low-voltage wire coil. If the wire coil is a high-voltage wire coil, the target wire coil is a low-voltage wire coil. If the wire coil is a low-voltage wire coil, the target wire coil is a high-voltage wire coil.
7. The method according to claim 5, characterized in that, The step of calculating the axial displacement of the line disc at each sampling time based on the target position parameters and the target current density corresponding to the line disc at each sampling time includes: Based on the target position parameters and the target current density corresponding to the line disc at each sampling time, the electromagnetic force corresponding to the line disc at each sampling time is calculated. Based on the transformer parameters of the target transformer and the electromagnetic force corresponding to the coil at each sampling time, the axial displacement of the coil at each sampling time is calculated.
8. The method according to claim 7, characterized in that, The step of calculating the electromagnetic force corresponding to the wire disc at each sampling time based on the target position parameters and the target current density corresponding to the wire disc at each sampling time includes: Based on the first formula, the leakage magnetic field magnetic induction intensity corresponding to the line disc at each sampling time is calculated; Based on the second formula and the leakage magnetic field magnetic induction intensity of the wire disc at each sampling time, the electromagnetic force corresponding to the wire disc at each sampling time is calculated. The first formula is: B x J represents the leakage magnetic field magnetic induction intensity corresponding to the nth coil. n The target current density corresponds to the nth coil. and These are all target location parameters. , Let x and y be the x-coordinate and y-coordinate of any point within the nth line pie, respectively. and y' and y' are the x and y coordinates of the k-th reference point within the n-th line pie, respectively; y' is the axial displacement corresponding to the previous sampling time of the n-th line pie; and atg is the arctangent function. The second formula is: F y The electromagnetic force corresponding to the nth coil. Let be the volume of the line disc.
9. The method according to claim 7, characterized in that, The target transformer further includes a spacer block disposed between two adjacent coils, the transformer parameters include the stiffness coefficient of the spacer block, and the method further includes: The stiffness coefficient of the pad is calculated based on the axial displacement between two adjacent discs.
10. A transformer winding vibration calculation device, characterized in that, The device includes: An acquisition module is used to acquire a target current signal, which is used to excite a target transformer to produce axial deformation. The target transformer includes a winding, and the winding includes multiple coils. The determining module is configured to, for each of the said line discs, determine the target position parameters corresponding to the line disc, and determine the target current density corresponding to the line disc at each sampling time within the target sampling period based on the target current signal; wherein, the target position parameters include and , , Let x and y be the x-coordinate and y-coordinate of any point within the nth line pie, respectively. and These are the x and y coordinates of the k-th reference point within the n-th line pie, respectively. The calculation module is used to calculate the axial displacement of each of the wire discs at each sampling time, based on the target position parameters and the target current density corresponding to the wire disc at each sampling time, and to take the axial displacement of the wire disc at the last sampling time as the total vibration response value of the wire disc within the target sampling period. Specifically, when calculating the axial displacement corresponding to a time other than the first sampling time, the axial displacement corresponding to the previous sampling time is used relative to the target position parameters. Make corrections.