Excitation voltage determination method for monitoring deformation of transformer winding

Abstract

The embodiment of the invention discloses an excitation voltage determination method for monitoring the deformation of a transformer winding, and the method comprises the steps: controlling a capacitor voltage transformer to sequentially inject excitation signals with different excitation voltage values into a transformer, and determining the deformation of the transformer winding based on the change of the inductance value of the winding measured after the injection of the different excitation voltage values; the slope and the target slope value are sequentially determined by combining the change of the excitation voltage value, and finally the optimal excitation voltage is determined according to the excitation voltage values of the excitation signals injected for two adjacent times corresponding to the target slope value, namely the most suitable excitation voltage is determined by adopting a quantization mode. The determined excitation voltage is prevented from being affected by subjectivity and uncertainty, so that the determined excitation voltage can accurately reflect the winding deformation state of the transformer, the accuracy and reliability of a monitoring result are improved, the risk of misjudgment is effectively reduced, the effectiveness and precision of monitoring are improved, and the monitoring accuracy is improved. Therefore, stable operation of the power system is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and in particular to a method for determining an excitation voltage for monitoring transformer winding deformation. Background Art

[0002] As a key equipment in the power system, the safe and stable operation of power transformers plays a vital role in ensuring the reliability of power supply. Winding deformation is a common fault hazard during the operation of the transformer, which may be caused by factors such as short-circuit current shock, mechanical stress, and overheating. Winding deformation not only affects the electrical performance of the transformer and reduces the transmission efficiency, but also may cause partial discharge and accelerated insulation aging. In severe cases, it may even cause short-circuit failures, causing large-scale power outages and bringing huge losses to social production and life. Therefore, strengthening the monitoring of transformer winding deformation and timely discovering and handling winding deformation fault hazards are of great practical significance for ensuring the stable operation of the power system.

[0003] Further research found that improper selection of excitation voltage for monitoring transformer winding deformation will lead to reduced accuracy and reliability of monitoring results, and even cause misjudgment, thus affecting the effectiveness and accuracy of monitoring. Therefore, determining the appropriate excitation voltage is a key technical issue that needs to be solved in practical applications.

[0004] However, the existing selection of excitation voltage for monitoring transformer winding deformation mostly relies on the experience of relevant technicians. The excitation voltage determined by this method has certain subjectivity and uncertainty, which may lead to reduced accuracy and reliability of monitoring results, or even cause misjudgment, thereby affecting the effectiveness and accuracy of monitoring. Summary of the invention

[0005] Based on this, it is necessary to propose a method for determining the excitation voltage for monitoring the deformation of transformer windings to address the above problems. By adopting a quantitative approach to determine the most appropriate excitation voltage, the determined excitation voltage is avoided from being affected by subjectivity and uncertainty, so that the determined excitation voltage can accurately reflect the deformation state of the transformer winding.

[0006] To achieve the above object, the present invention provides, in a first aspect, a method for determining an excitation voltage for monitoring transformer winding deformation, the method comprising:

[0007] Controlling the capacitor voltage transformer to sequentially inject excitation signals of different excitation voltage values ​​into the transformer, and measuring the current winding inductance value of the transformer after each injection;

[0008] Determine a plurality of winding inductance differences between two adjacent injections according to all injected current winding inductance values, and determine a plurality of excitation voltage differences between two adjacent injections according to all injected excitation voltage values ​​of the excitation signals;

[0009] Determine the slope value of each two adjacent injections according to the difference in winding inductance and the difference in excitation voltage between each two adjacent injections;

[0010] Determine a target slope value according to the slope values ​​of all two adjacent injections;

[0011] The optimal excitation voltage is determined according to the excitation voltage values ​​of the excitation signals injected twice adjacently corresponding to the target slope value.

[0012] Optionally, determining the slope value of each two adjacent injections according to the winding inductance difference and the excitation voltage difference of each two adjacent injections includes:

[0013] Obtaining an initial capacitance value and an initial transformation ratio value of a capacitive voltage transformer;

[0014] After each injection, measuring the current capacitance value and the current transformation ratio value of the capacitive transformer;

[0015] Determine the capacitance difference of each injection according to the current capacitance value of each injection and the initial capacitance value, and determine the transformation ratio difference of each injection according to the current transformation ratio value of each injection and the initial transformation ratio value;

[0016] The slope value of each two adjacent injections is determined according to the capacitance difference and the transformation ratio difference of each injection, and the winding inductance difference and the excitation voltage difference of each two adjacent injections.

[0017] Optionally, determining the slope value of each two adjacent injections according to the capacitance difference and the transformation ratio difference of each injection, and the winding inductance difference and the excitation voltage difference of each two adjacent injections, comprises:

[0018] Obtaining a rated voltage value of the transformer;

[0019] Determine the first slope value of each two adjacent injections according to the winding inductance difference and the excitation voltage difference of each two adjacent injections;

[0020] Determine a second slope value for each injection according to the capacitance difference value for each injection and the excitation voltage value of the excitation signal, as well as the initial capacitance value and the rated voltage value;

[0021] Determining a third slope value for each injection according to the transformation ratio difference value for each injection and the excitation voltage value of the excitation signal, as well as the initial transformation ratio value and the rated voltage value;

[0022] The slope value of each two adjacent injections is determined according to the first slope value of each two adjacent injections, and the second slope value and the third slope value of each injection.

[0023] Optionally, determining the first slope value of each two adjacent injections according to the winding inductance difference and the excitation voltage difference of each two adjacent injections includes:

[0024] Using the formula Determine a first slope value of each of two adjacent injections;

[0025] The step of determining the second slope value of each injection according to the capacitance difference value of each injection and the excitation voltage value of the excitation signal, as well as the initial capacitance value and the rated voltage value, comprises:

[0026] Using the formula determining a second slope value for each injection;

[0027] Determining the third slope value of each injection according to the transformation ratio difference value of each injection and the excitation voltage value of the excitation signal, as well as the initial transformation ratio value and the rated voltage value, comprises:

[0028] Using the formula determining a third slope value for each injection;

[0029] The step of determining the slope value of each two adjacent injections according to the first slope value of each two adjacent injections, and the second slope value and the third slope value of each injection, comprises:

[0030] Using formula k i =k i,1 k i,2 k i,3 Determine the slope value of each two adjacent injections;

[0031] Among them, k i,1 is the first slope value of the i-th two adjacent injections, ΔL N,i is the winding inductance difference between the i-th two adjacent injections, ΔU i is the difference between the excitation voltages of the i-th adjacent injections, k i,2 is the second slope value of the i-th injection, ΔC CVT,i is the capacitance difference of the ith injection, C CVT is the initial capacitance value, U i is the excitation voltage value of the excitation signal injected for the i-th time, U N is the rated voltage value, k i,3 is the third slope value of the i-th injection, Δk CVT,i is the ratio difference of the i-th injection, k CVT is the initial transformation ratio, k i is the slope value of the i-th two adjacent injections.

[0032] Optionally, determining the target slope value according to the slope values ​​of all two adjacent injections includes:

[0033] Among all the slope values ​​of two adjacent injections, the maximum slope value is used as the target slope value;

[0034] The step of determining the optimal excitation voltage according to the excitation voltage values ​​of two adjacent injected excitation signals corresponding to the target slope value comprises:

[0035] Among the excitation voltage values ​​of the excitation signals injected twice adjacent to the target slope value, the excitation voltage value of the excitation signal injected the latter time is used as the optimal excitation voltage.

[0036] Optionally, controlling the capacitive voltage transformer to sequentially inject excitation signals with different excitation voltage values ​​into the transformer comprises:

[0037] The capacitive voltage transformer is controlled to inject an excitation signal into the transformer, and the excitation voltage value of the injected excitation signal is adjusted according to a preset step size within a preset excitation voltage range.

[0038] Optionally, the method further comprises:

[0039] Obtaining the minimum short-circuit current value of the transformer, and the initial capacitance value, initial transformation ratio value and withstand voltage value of the capacitive voltage transformer;

[0040] Determine a minimum excitation voltage value according to the minimum short-circuit current value and the initial capacitance value;

[0041] Determine the maximum excitation voltage value according to the initial transformation ratio value and the withstand voltage value;

[0042] The preset excitation voltage range is determined according to the minimum excitation voltage value and the maximum excitation voltage value.

[0043] Optionally, determining the minimum excitation voltage value according to the minimum short-circuit current value and the initial capacitance value includes:

[0044] Using the formula Determining the minimum excitation voltage value;

[0045] The determining of the maximum excitation voltage value according to the initial transformation ratio value and the withstand voltage value comprises:

[0046] Using the formula Determining the maximum excitation voltage value;

[0047] Among them, U min is the minimum excitation voltage value, I N,min is the minimum short-circuit current value, π is the circumference of a circle, f is the preset frequency, and the typical value of f is 50 Hz. CVT is the initial capacitance value, Umax is the maximum excitation voltage value, U CVT,max is the withstand voltage value, k CVT is the initial transformation ratio value.

[0048] Optionally, obtaining the minimum short-circuit current value of the transformer includes:

[0049] Obtaining the rated voltage value, rated capacity and short-circuit impedance of the transformer;

[0050] The minimum short-circuit current value is determined according to the rated voltage value, the rated capacity and the short-circuit impedance.

[0051] Optionally, determining the minimum short-circuit current value according to the rated voltage value, the rated capacity and the short-circuit impedance includes:

[0052] Using the formula Determining the minimum short-circuit current value;

[0053] Among them, I N,min is the minimum short-circuit current value, S N is the rated capacity, U N is the rated voltage value, Z N is the short-circuit impedance.

[0054] To achieve the above object, the present invention provides, in a second aspect, a device for determining an excitation voltage for monitoring transformer winding deformation, the device comprising:

[0055] A control injection measurement module is used to control the capacitive voltage transformer to sequentially inject excitation signals of different excitation voltage values ​​into the transformer, and after each injection, measure the current winding inductance value of the transformer;

[0056] A variation determination module, used to determine a plurality of winding inductance differences between two adjacent injections according to all injected current winding inductance values, and to determine a plurality of excitation voltage differences between two adjacent injections according to all injected excitation voltage values ​​of excitation signals;

[0057] A slope determination module, used to determine the slope value of each two adjacent injections according to the difference in winding inductance and the difference in excitation voltage between each two adjacent injections;

[0058] A target slope determination module, used to determine a target slope value according to the slope values ​​of all two adjacent injections;

[0059] The optimal determination module is used to determine the optimal excitation voltage according to the excitation voltage values ​​of the excitation signals injected twice adjacently corresponding to the target slope value.

[0060] To achieve the above-mentioned object, the present invention provides in a third aspect a computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes the method as described in any one of the first aspects.

[0061] To achieve the above-mentioned purpose, the present invention provides a computer device in a fourth aspect, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the method as described in any one of the first aspects.

[0062] The embodiment of the present invention has the following beneficial effects: the method controls the capacitive voltage transformer to sequentially inject excitation signals of different excitation voltage values ​​into the transformer, and after each injection, measures the current winding inductance value of the transformer, and then determines the winding inductance difference between multiple adjacent injections based on all the injected current winding inductance values, and determines the excitation voltage difference between multiple adjacent injections based on the excitation voltage values ​​of all the injected excitation signals, and then determines the slope value of each adjacent injection based on the winding inductance difference and the excitation voltage difference between each adjacent injection, and then determines the target slope value based on the slope values ​​of all the adjacent injections, and finally determines the optimal excitation voltage based on the excitation voltage value of the adjacent injections corresponding to the target slope value, that is, By controlling the capacitive voltage transformer to inject excitation signals with different excitation voltage values ​​into the transformer in sequence, and based on the change in the winding inductance value measured after the injection of different excitation voltage values, the slope and the target slope value are determined in sequence in combination with the change in the excitation voltage value, and finally the optimal excitation voltage is determined according to the excitation voltage values ​​of the two adjacent injected excitation signals corresponding to the target slope value. That is, a quantitative method is used to determine the most appropriate excitation voltage to avoid the determined excitation voltage being affected by subjectivity and uncertainty, so that the determined excitation voltage can accurately reflect the winding deformation state of the transformer, so as to improve the accuracy and reliability of the monitoring results, effectively reduce the risk of misjudgment, and thereby improve the effectiveness and accuracy of monitoring, thereby ensuring the stable operation of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0064] in:

[0065] Figure 1A schematic diagram of a method for determining an excitation voltage for monitoring transformer winding deformation in an embodiment of the present application;

[0066] Figure 2 A schematic diagram of an excitation voltage determination device for monitoring transformer winding deformation in an embodiment of the present application;

[0067] Figure 3 1 is a diagram of the internal structure of a computer device in some embodiments. DETAILED DESCRIPTION

[0068] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0069] As a key equipment in the power system, the safe and stable operation of power transformers plays a vital role in ensuring the reliability of power supply. Winding deformation is a common fault hazard during the operation of the transformer, which may be caused by factors such as short-circuit current shock, mechanical stress, and overheating. Winding deformation not only affects the electrical performance of the transformer and reduces the transmission efficiency, but also may cause partial discharge and accelerated insulation aging. In severe cases, it may even cause short-circuit failures, causing large-scale power outages and bringing huge losses to social production and life. Therefore, strengthening the monitoring of transformer winding deformation and timely discovering and handling winding deformation fault hazards are of great practical significance for ensuring the stable operation of the power system.

[0070] Further research found that improper selection of excitation voltage for monitoring transformer winding deformation will lead to reduced accuracy and reliability of monitoring results, and even cause misjudgment, thus affecting the effectiveness and accuracy of monitoring. Therefore, determining the appropriate excitation voltage is a key technical issue that needs to be solved in practical applications.

[0071] However, the existing selection of excitation voltage for monitoring transformer winding deformation mostly relies on the experience of relevant technicians. The excitation voltage determined by this method has certain subjectivity and uncertainty, which may lead to reduced accuracy and reliability of monitoring results, or even cause misjudgment, thereby affecting the effectiveness and accuracy of monitoring.

[0072] In response to the above problems, the present application proposes a method for determining the excitation voltage for monitoring the deformation of transformer windings. The most suitable excitation voltage is determined in a quantitative manner to avoid the determined excitation voltage being affected by subjectivity and uncertainty, so that the determined excitation voltage can accurately reflect the deformation state of the transformer windings. The specific implementation principle will be described in detail in the following embodiments.

[0073] In a first aspect, the present application provides a method for determining an excitation voltage for monitoring transformer winding deformation.

[0074] See also Figure 1 , is a schematic diagram of a method for determining an excitation voltage for monitoring transformer winding deformation in an embodiment of the present application, the method comprising:

[0075] Step 110: Control the capacitor voltage transformer to sequentially inject excitation signals with different excitation voltage values ​​into the transformer, and after each injection, measure the current winding inductance value of the transformer.

[0076] It should be noted that the present application selects the winding inductance change rate of the transformer as the winding deformation sensitive parameter. Therefore, after each injection, the current winding inductance value of the transformer needs to be measured.

[0077] Step 120: Determine a plurality of winding inductance differences between two adjacent injections according to all injected current winding inductance values, and determine a plurality of excitation voltage differences between two adjacent injections according to all injected excitation voltage values ​​of the excitation signals.

[0078] It should be noted that the number between all injected current winding inductance values ​​and the difference between multiple adjacent winding inductances injected twice, and the number between all injected excitation voltage values ​​of excitation signals and the difference between multiple adjacent excitation voltages injected twice all differ by 1. If the total number of injections is I, the total number of two adjacent injections should be I-1.

[0079] In some embodiments, the formula ΔL can be used N,i =L N,i -L N,i-1 Determine the difference in winding inductance between two adjacent injections, and use the formula ΔU i =U i -U i-1 Determine the difference in excitation voltage between two adjacent injections; where ΔL N,i is the winding inductance difference between the i-th two adjacent injections, L N,i is the current winding inductance value injected for the i-th time, L N,i-1 is the current winding inductance value injected for the i-1th time, ΔU i is the excitation voltage difference between the i-th adjacent injections, U i is the excitation voltage value of the excitation signal injected for the i-th time, U i-1 is the excitation voltage value of the excitation signal injected for the i-1th time.

[0080] Step 130: Determine the slope value of each two adjacent injections according to the winding inductance difference and the excitation voltage difference of each two adjacent injections.

[0081] It should be noted that the winding inductance difference, that is, the winding inductance change rate, can be used as a winding deformation sensitive parameter in the present application, and the excitation voltage difference is the excitation voltage change rate of the excitation signal. Therefore, the slope value determined based on the winding inductance difference and the excitation voltage difference can be used to reflect the degree of correlation between the winding deformation and the signal characteristics. The present application can reflect the degree of correlation between the winding deformation and the signal characteristics through the slope value, so that the optimal excitation voltage determined subsequently has better sensitivity and accuracy when monitoring the transformer winding deformation.

[0082] In some embodiments, the ratio between the difference in winding inductance between each two adjacent injections and the difference in excitation voltage can be used as the slope value of each two adjacent injections; of course, in other embodiments, the ratio between the difference in excitation voltage between each two adjacent injections and the difference in winding inductance can also be used as the slope value of each two adjacent injections.

[0083] Step 140: Determine a target slope value according to the slope values ​​of all two adjacent injections.

[0084] It should be noted that the slope value reflects the degree of correlation between winding deformation and signal characteristics, and the target slope value is the slope value that reflects the highest degree of correlation between winding deformation and signal characteristics. The present application can highly reflect the correlation between winding deformation and signal characteristics through the target slope value, so that the optimal excitation voltage determined subsequently has the best sensitivity and accuracy when monitoring transformer winding deformation.

[0085] Regarding the method for determining the target slope value, in some embodiments, the present application may preferably use the maximum slope value among all the slope values ​​of two adjacent injections as the target slope value; of course, in other embodiments, the minimum slope value may also be used as the target slope value, or the median slope value may be used as the target slope value, which is not limited here.

[0086] Step 150: determining an optimal excitation voltage according to the excitation voltage values ​​of two adjacent injected excitation signals corresponding to the target slope value.

[0087] It should be noted that the use of the optimal excitation voltage determined in the present application can achieve optimal sensitivity and accuracy when monitoring transformer winding deformation.

[0088] Regarding the method for determining the optimal excitation voltage, in some embodiments, the present application may preferably use the excitation voltage value of the excitation signal injected in the latter of two adjacent injections corresponding to the target slope value as the optimal excitation voltage; of course, in other embodiments, the average value between the excitation voltage value of the excitation signal injected in the former of two adjacent injections corresponding to the target slope value and the excitation voltage value of the excitation signal injected in the latter may also be used as the optimal excitation voltage, which is not limited here.

[0089] In an embodiment of the present application, the capacitive voltage transformer is controlled to inject excitation signals of different excitation voltage values ​​into the transformer in sequence, and based on the change in the winding inductance value measured after the injection of different excitation voltage values, the slope and the target slope value are determined in sequence in combination with the change in the excitation voltage value. Finally, the optimal excitation voltage is determined according to the excitation voltage values ​​of the two adjacent injected excitation signals corresponding to the target slope value. That is, the most suitable excitation voltage is determined in a quantitative manner to avoid the determined excitation voltage being affected by subjectivity and uncertainty, so that the determined excitation voltage can accurately reflect the deformation state of the transformer winding, so as to improve the accuracy and reliability of the monitoring results, effectively reduce the risk of misjudgment, and thereby improve the effectiveness and accuracy of monitoring, thereby ensuring the stable operation of the power system.

[0090] In addition, the method of the present application also has the following advantages: the use of a quantitative method to determine the optimal excitation voltage reduces the impact of human factors, makes the monitoring results more stable, and enhances the consistency of the data; frequent use of inappropriate voltage excitation transformers may accelerate the wear of the equipment, and determining the appropriate excitation voltage through a quantitative method can reduce the number of unnecessary high-voltage charging and discharging times, thereby reducing equipment wear and extending equipment service life; accurate monitoring can detect potential problems early and avoid equipment damage and power outages caused by faults, thereby reducing the costs caused by equipment replacement and repair, and can also avoid unnecessary maintenance operations, further saving costs.

[0091] In a feasible implementation, step 130 in the above embodiment determines the slope value of each adjacent two injections based on the winding inductance difference and the excitation voltage difference of each adjacent two injections, including: obtaining the initial capacitance value and the initial transformation ratio value of the capacitive voltage transformer; after each injection, measuring the current capacitance value and the current transformation ratio value of the capacitive voltage transformer; determining the capacitance difference of each injection based on the current capacitance value and the initial capacitance value of each injection, and determining the transformation ratio difference of each injection based on the current transformation ratio value and the initial transformation ratio value of each injection; determining the slope value of each adjacent two injections based on the capacitance difference and the transformation ratio difference of each injection, and the winding inductance difference and the excitation voltage difference of each adjacent two injections.

[0092] It should be noted that in the present application, the capacitance difference and the transformation ratio difference, that is, the capacitance change rate and the transformation ratio change rate, can also reflect the relationship between the winding deformation and the signal characteristics to a certain extent. Therefore, the present application further introduces the capacitance difference and the transformation ratio difference, and based on the slope value determined by combining the winding inductance difference and the excitation voltage difference, it can more accurately reflect the degree of correlation between the winding deformation and the signal characteristics.

[0093] Regarding the method for obtaining the initial capacitance value, in some embodiments, before the injection in step 110, an electrical testing instrument may be used to perform a capacitance measurement test on the capacitive voltage transformer to obtain the initial capacitance value.

[0094] Regarding the method of obtaining the initial transformation ratio value, in some embodiments, the primary side of the transformer ratio tester can be connected to the primary winding of the capacitor voltage transformer, and the secondary side of the transformer ratio tester can be connected to the secondary winding of the capacitor voltage transformer, and then the transformer ratio tester is used to perform a transformation ratio measurement test on the capacitor voltage transformer to obtain the initial transformation ratio value.

[0095] In an embodiment of the present application, by introducing capacitance difference and transformation ratio difference (i.e., capacitance change rate and transformation ratio change rate), the changes of the capacitive voltage transformer can be considered more comprehensively, so that the subsequently determined slope value more accurately represents the relationship between the winding deformation and the signal characteristics. This more comprehensive and accurate analysis method helps to improve the sensitivity and accuracy of the ultimately determined optimal excitation voltage, and further improve the reliability and accuracy of monitoring transformer winding deformation, thereby effectively reducing the risk of misjudgment, improving the effectiveness and accuracy of monitoring, and thus ensuring the stable operation of the power system.

[0096] In a feasible implementation, the above-mentioned embodiment determines the slope value of each adjacent injection based on the capacitance difference and the transformation ratio difference of each injection, as well as the winding inductance difference and the excitation voltage difference of each adjacent injection, including: obtaining the rated voltage value of the transformer; determining the first slope value of each adjacent injection based on the winding inductance difference and the excitation voltage difference of each adjacent injection; determining the second slope value of each injection based on the capacitance difference of each injection and the excitation voltage value of the excitation signal, as well as the initial capacitance value and the rated voltage value; determining the third slope value of each injection based on the transformation ratio difference of each injection and the excitation voltage value of the excitation signal, as well as the initial transformation ratio value and the rated voltage value; determining the slope value of each adjacent injection based on the first slope value of each adjacent injection, as well as the second slope value and the third slope value of each injection.

[0097] In an embodiment of the present application, the slope value is determined by introducing a rated voltage value, and determining the first slope value, the second slope value, and the third slope value in sequence, that is, by combining multiple factors to determine the slope value, various changes of the transformer can be more comprehensively considered, so that the slope value can more accurately reflect the degree of correlation between the winding deformation and the signal characteristics. This more comprehensive and accurate analysis method helps to improve the sensitivity and accuracy of the ultimately determined optimal excitation voltage, further improve the reliability and accuracy of monitoring the transformer winding deformation, effectively reduce the risk of misjudgment, and improve the effectiveness and accuracy of monitoring, thereby ensuring the stable operation of the power system.

[0098] In a feasible implementation, the method of determining the first slope value of each of two adjacent injections according to the winding inductance difference and the excitation voltage difference of each of two adjacent injections in the above embodiment includes:

[0099] Using the formula Determine a first slope value of each of two adjacent injections;

[0100] Determining a second slope value for each injection according to the capacitance difference value for each injection and the excitation voltage value of the excitation signal, as well as the initial capacitance value and the rated voltage value, including:

[0101] Using the formula determining a second slope value for each injection;

[0102] The third slope value of each injection is determined according to the transformation ratio difference value of each injection and the excitation voltage value of the excitation signal, as well as the initial transformation ratio value and the rated voltage value, including:

[0103] Using the formula determining a third slope value for each injection;

[0104] Determining the slope value of each of two adjacent injections according to the first slope value of each of the two adjacent injections, and the second slope value and the third slope value of each injection, including:

[0105] Using formula k i =k i,1 k i,2 k i,3 Determine the slope value of each two adjacent injections;

[0106] Among them, k i,1 is the first slope value of the i-th two adjacent injections, ΔL N,i is the winding inductance difference between the i-th two adjacent injections, ΔU i is the difference between the excitation voltages of the i-th adjacent injections, k i,2 is the second slope value of the i-th injection, ΔC CVT,i is the capacitance difference of the ith injection, CCVT is the initial capacitance value, U i is the excitation voltage value of the excitation signal injected for the i-th time, U N is the rated voltage value, k i,3 is the third slope value of the i-th injection, Δk CVT,i is the ratio difference of the i-th injection, k CVT is the initial transformation ratio, k i is the slope value of the i-th two adjacent injections.

[0107] In the embodiments of the present application, rigorous calculation formulas for the first slope value, the second slope value, the third slope value, and the slope value are provided from a mathematical perspective. The accuracy of the calculated first slope value, the second slope value, the third slope value, and the slope value can be ensured from the rigor of mathematical logic, and the above-mentioned calculation formulas are preferably shown to provide reference, understanding, calculation, etc. for technical personnel.

[0108] In addition, by adopting the calculation formula of the first slope value, the second slope value, the third slope value and the slope value preferably provided in the above-mentioned present application to calculate the first slope value, the second slope value, the third slope value and the slope value, the obtained slope value has a higher accuracy, can more accurately reflect the degree of correlation between the winding deformation and the signal characteristics, and help to improve the sensitivity and accuracy of the ultimately determined optimal excitation voltage, further improve the reliability and accuracy of monitoring the transformer winding deformation, effectively reduce the risk of misjudgment, and improve the effectiveness and accuracy of monitoring.

[0109] In a feasible implementation, step 140 in the above embodiment, determining the target slope value according to the slope values ​​of all two adjacent injections, includes: among all the slope values ​​of two adjacent injections, taking the maximum slope value as the target slope value.

[0110] Step 150 in the above embodiment determines the optimal excitation voltage based on the excitation voltage values ​​of the excitation signals injected twice adjacent to the target slope value, including: among the excitation voltage values ​​of the excitation signals injected twice adjacent to the target slope value, taking the excitation voltage value of the excitation signal injected once later as the optimal excitation voltage.

[0111] In an embodiment of the present application, by taking the maximum slope value as the target slope value, it is ensured that the selected slope value can reflect the strongest correlation between the transformer winding deformation and the signal characteristics, which means that the selected optimal excitation voltage can have higher sensitivity and accuracy when monitoring the transformer winding deformation, and by selecting the excitation voltage value of the latter excitation signal injected from the excitation voltage values ​​of the two adjacent injected excitation signals corresponding to the target slope value as the optimal excitation voltage, the consistency and stability of the selection result are ensured, which can further improve the accuracy and reliability of monitoring.

[0112] In a feasible implementation, step 110 in the above embodiment, controlling the capacitor voltage transformer to sequentially inject excitation signals of different excitation voltage values ​​into the transformer, includes: controlling the capacitor voltage transformer to inject the excitation signal into the transformer, and adjusting the excitation voltage value of the injected excitation signal according to a preset step size within a preset excitation voltage range.

[0113] The preset excitation voltage range and the preset step size can be obtained and preset by the operator based on a large amount of experience, experiments or statistics. Of course, they can also be set by the operator according to actual needs.

[0114] In an embodiment of the present application, by adjusting the excitation voltage value of the injected excitation signal according to a preset step size within a preset excitation voltage range, systematic multi-point monitoring of the transformer winding deformation is achieved, ensuring the comprehensiveness and accuracy of the monitoring coverage. This method can more carefully explore and examine the correlation between the winding deformation and different excitation voltage values, which helps to more accurately determine the optimal excitation voltage. The pre-set fixed step size can also effectively reduce the complexity of the experiment and improve the efficiency of the monitoring work.

[0115] In addition, more diverse data can be collected through this method, providing richer information support for subsequent analysis, thereby improving the reliability and accuracy of monitoring results, effectively reducing the risks caused by misjudgment, and ensuring the stable operation of the power system.

[0116] In a feasible implementation, the method in the above embodiment also includes: obtaining the minimum short-circuit current value of the transformer, and the initial capacitance value, initial transformation ratio value and withstand voltage value of the capacitive voltage transformer; determining the minimum excitation voltage value based on the minimum short-circuit current value and the initial capacitance value; determining the maximum excitation voltage value based on the initial transformation ratio value and the withstand voltage value; and determining a preset excitation voltage range based on the minimum excitation voltage value and the maximum excitation voltage value.

[0117] Regarding the method of obtaining the withstand voltage value, in some embodiments, a withstand voltage test device can be used to perform a withstand voltage test on the capacitive voltage transformer to obtain the withstand voltage value; wherein, during the test, the withstand voltage test device is controlled to gradually increase the voltage applied to the capacitive voltage transformer until the specified withstand voltage value is reached, and maintained for a certain period of time to determine whether the capacitive voltage transformer can withstand the voltage without breakdown or damage, etc., thereby determining whether its withstand voltage value meets the requirements. If it can withstand the voltage, then the voltage is the withstand voltage value.

[0118] In an embodiment of the present application, by obtaining the minimum short-circuit current value of the transformer and determining the minimum excitation voltage value in combination with the initial capacitance value of the capacitive voltage transformer, it is possible to prevent safety problems caused by short-circuit current during monitoring and reduce safety hazards; at the same time, by obtaining the withstand voltage value of the capacitive voltage transformer and determining the maximum excitation voltage value in combination with the initial transformation ratio value, it is possible to ensure that the withstand voltage range of the capacitive voltage transformer will not be exceeded during the monitoring process, thereby avoiding equipment damage and extending the service life of the equipment.

[0119] Furthermore, setting a reasonable preset excitation voltage range not only ensures the effectiveness and accuracy of monitoring, but also avoids unnecessary high-voltage charge and discharge times, thereby reducing wear on the equipment, helping to stabilize equipment performance and improve the economy of equipment use.

[0120] In a feasible implementation, the method of determining the minimum excitation voltage value according to the minimum short-circuit current value and the initial capacitance value in the above embodiment includes:

[0121] Using the formula Determine the minimum excitation voltage value;

[0122] In the above embodiment, the maximum excitation voltage value is determined according to the initial transformation ratio value and the withstand voltage value, including:

[0123] Using the formula Determine the maximum excitation voltage value;

[0124] Among them, U min is the minimum excitation voltage value, I N,min is the minimum short-circuit current value, π is the circumference of a circle, f is the preset frequency, and the typical value of f is 50Hz. CVT is the initial capacitance value, U max is the maximum excitation voltage value, U CVT,max is the withstand voltage value, k CVT is the initial transformation ratio value.

[0125] In the embodiments of the present application, a rigorous calculation formula for the minimum excitation voltage value and the maximum excitation voltage value is provided from a mathematical perspective. The accuracy of the calculated minimum excitation voltage value and the maximum excitation voltage value can be ensured from the rigor of mathematical logic, and the above-mentioned calculation formula is preferably shown to provide reference, understanding and calculation for technical personnel.

[0126] In addition, by adopting the calculation formula for the minimum excitation voltage value and the maximum excitation voltage value preferably provided in the above-mentioned application to calculate the minimum excitation voltage value and the maximum excitation voltage value, the obtained preset excitation voltage range has a high rationality, which can ensure that the selected excitation voltage is within a safe range, and can more accurately reflect the relationship between the transformer winding deformation and the signal characteristics, thereby improving the accuracy and reliability of monitoring.

[0127] In a feasible implementation, obtaining the minimum short-circuit current value of the transformer in the above embodiment includes: obtaining the rated voltage value, rated capacity and short-circuit impedance of the transformer; and determining the minimum short-circuit current value based on the rated voltage value, rated capacity and short-circuit impedance.

[0128] In an embodiment of the present application, by obtaining the rated voltage value, rated capacity and short-circuit impedance of the transformer and combining these parameters to determine the minimum short-circuit current value, it can be ensured that when monitoring the transformer winding deformation, the minimum excitation voltage value can fully consider the safety requirements of the transformer under short-circuit conditions, avoid safety risks caused by excessively high excitation voltage, and thus improve the safety and reliability of monitoring.

[0129] In a feasible implementation, the minimum short-circuit current value is determined according to the rated voltage value, the rated capacity and the short-circuit impedance in the above embodiment, including:

[0130] Using the formula Determine the minimum short-circuit current value;

[0131] Among them, I N,min is the minimum short-circuit current value, S N is the rated capacity, U N is the rated voltage, Z N is the short circuit impedance.

[0132] In the embodiments of the present application, a rigorous calculation formula for the minimum short-circuit current value is provided from a mathematical perspective. The accuracy of the calculated minimum short-circuit current value can be ensured from the rigor of mathematical logic, and the above calculation formula is preferably shown to provide reference, understanding and calculation for technical personnel.

[0133] In addition, by adopting the calculation formula of the minimum short-circuit current value preferably provided in the above-mentioned application to calculate the minimum short-circuit current value, the obtained minimum short-circuit current value has a higher accuracy, so that the selected minimum excitation voltage value is more reasonable, which can effectively avoid equipment failure or safety hazards caused by improper voltage setting and improve the reliability of monitoring.

[0134] In a second aspect, the present application provides an excitation voltage determination device for monitoring transformer winding deformation.

[0135] See also Figure 2 , is a schematic diagram of an excitation voltage determination device for monitoring transformer winding deformation in an embodiment of the present application, the device 210 includes:

[0136] A control injection measurement module 211 is used to control the capacitive voltage transformer to sequentially inject excitation signals of different excitation voltage values ​​into the transformer, and after each injection, measure the current winding inductance value of the transformer;

[0137] The variation determination module 212 is used to determine the winding inductance difference between two adjacent injections according to all injected current winding inductance values, and to determine the excitation voltage difference between two adjacent injections according to all injected excitation voltage values ​​of the excitation signal;

[0138] A slope determination module 213, used to determine the slope value of each two adjacent injections according to the winding inductance difference and the excitation voltage difference of each two adjacent injections;

[0139] A target slope determination module 214, configured to determine a target slope value according to the slope values ​​of all two adjacent injections;

[0140] The optimal determination module 215 is used to determine the optimal excitation voltage according to the excitation voltage values ​​of the excitation signals injected twice adjacently corresponding to the target slope value.

[0141] In the embodiment of the present application, the relevant contents of the control injection measurement module 211, the variation determination module 212, the slope determination module 213, the target slope determination module 214 and the optimal determination module 215 can be referred to. Figure 1 The contents in the illustrated embodiment will not be described in detail here.

[0142] It should be noted that the device 210 of the present application also includes some other modules. It can be understood that the method of the present application and the device 210 have a one-to-one correspondence. Therefore, some other modules of the device 210 of the present application are the contents corresponding to the method of the present application in the above-mentioned embodiment.

[0143] In an embodiment of the present application, the capacitive voltage transformer is controlled to inject excitation signals of different excitation voltage values ​​into the transformer in sequence, and based on the change in the winding inductance value measured after the injection of different excitation voltage values, the slope and the target slope value are determined in sequence in combination with the change in the excitation voltage value. Finally, the optimal excitation voltage is determined according to the excitation voltage values ​​of the two adjacent injected excitation signals corresponding to the target slope value. That is, the most suitable excitation voltage is determined in a quantitative manner to avoid the determined excitation voltage being affected by subjectivity and uncertainty, so that the determined excitation voltage can accurately reflect the deformation state of the transformer winding, so as to improve the accuracy and reliability of the monitoring results, effectively reduce the risk of misjudgment, and thereby improve the effectiveness and accuracy of monitoring, thereby ensuring the stable operation of the power system.

[0144] In addition, the method of the present application also has the following advantages: the use of a quantitative method to determine the optimal excitation voltage reduces the impact of human factors, makes the monitoring results more stable, and enhances the consistency of the data; frequent use of inappropriate voltage excitation transformers may accelerate the wear of the equipment, and determining the appropriate excitation voltage through a quantitative method can reduce the number of unnecessary high-voltage charging and discharging times, thereby reducing equipment wear and extending equipment service life; accurate monitoring can detect potential problems early and avoid equipment damage and power outages caused by faults, thereby reducing the costs caused by equipment replacement and repair, and can also avoid unnecessary maintenance operations, further saving costs.

[0145] In a third aspect, the present application further provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the processor executes a method for determining an excitation voltage for monitoring transformer winding deformation in the above method embodiment.

[0146] In a fourth aspect, the present application further provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes a method for determining an excitation voltage for monitoring transformer winding deformation in the above method embodiment.

[0147] Figure 3 The internal structure diagram of a computer device in some embodiments is shown. The computer device may be a terminal, a server, or a gateway. Figure 3 As shown, the computer device includes a processor, a memory and a network interface connected through a system bus.

[0148] The memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium of the computer device stores an operating system and may also store a computer program. When the computer program is executed by the processor, the processor can implement each step in the above method embodiment. The internal memory may also store a computer program. When the computer program is executed by the processor, the processor can implement each step in the above method embodiment. Those skilled in the art can understand that Figure 3 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0149] A person skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing related hardware through a computer program. The program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods.

[0150] Among them, any reference to memory, storage, database or other media used in the embodiments provided in the present application may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synch li nk) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0151] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, 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.

[0152] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for determining an excitation voltage for monitoring transformer winding deformation, characterized in that: The method comprises: Controlling the capacitor voltage transformer to sequentially inject excitation signals of different excitation voltage values ​​into the transformer, and measuring the current winding inductance value of the transformer after each injection; Determine a plurality of winding inductance differences between two adjacent injections according to all injected current winding inductance values, and determine a plurality of excitation voltage differences between two adjacent injections according to all injected excitation voltage values ​​of the excitation signals; Determine the slope value of each two adjacent injections according to the difference in winding inductance and the difference in excitation voltage between each two adjacent injections; Determine a target slope value according to the slope values ​​of all two adjacent injections; The optimal excitation voltage is determined according to the excitation voltage values ​​of the excitation signals injected twice adjacently corresponding to the target slope value.

2. The method according to claim 1, characterized in that The step of determining the slope value of each two adjacent injections according to the winding inductance difference and the excitation voltage difference of each two adjacent injections comprises: Obtaining an initial capacitance value and an initial transformation ratio value of a capacitive voltage transformer; After each injection, measuring the current capacitance value and the current transformation ratio value of the capacitive transformer; Determine the capacitance difference of each injection according to the current capacitance value of each injection and the initial capacitance value, and determine the transformation ratio difference of each injection according to the current transformation ratio value of each injection and the initial transformation ratio value; The slope value of each two adjacent injections is determined according to the capacitance difference and the transformation ratio difference of each injection, and the winding inductance difference and the excitation voltage difference of each two adjacent injections.

3. The method according to claim 2, characterized in that Determining the slope value of each two adjacent injections according to the capacitance difference and the transformation ratio difference of each injection, and the winding inductance difference and the excitation voltage difference of each two adjacent injections, comprises: Obtaining a rated voltage value of the transformer; Determine the first slope value of each two adjacent injections according to the winding inductance difference and the excitation voltage difference of each two adjacent injections; Determine a second slope value for each injection according to the capacitance difference value for each injection and the excitation voltage value of the excitation signal, as well as the initial capacitance value and the rated voltage value; Determining a third slope value for each injection according to the transformation ratio difference value for each injection and the excitation voltage value of the excitation signal, as well as the initial transformation ratio value and the rated voltage value; The slope value of each two adjacent injections is determined according to the first slope value of each two adjacent injections, and the second slope value and the third slope value of each injection.

4. The method according to claim 3, characterized in that The step of determining the first slope value of each two adjacent injections according to the winding inductance difference and the excitation voltage difference of each two adjacent injections comprises: Using the formula Determine a first slope value of each of two adjacent injections; The step of determining the second slope value of each injection according to the capacitance difference value of each injection and the excitation voltage value of the excitation signal, as well as the initial capacitance value and the rated voltage value, comprises: Using the formula determining a second slope value for each injection; Determining the third slope value of each injection according to the transformation ratio difference value of each injection and the excitation voltage value of the excitation signal, as well as the initial transformation ratio value and the rated voltage value, comprises: Using the formula determining a third slope value for each injection; The step of determining the slope value of each two adjacent injections according to the first slope value of each two adjacent injections, and the second slope value and the third slope value of each injection, comprises: Using formula k i =k i,1 k i,2 k i,3 Determine the slope value of each two adjacent injections; Among them, k i,1 is the first slope value of the i-th two adjacent injections, ΔL N,i is the winding inductance difference between the i-th two adjacent injections, ΔU i is the difference between the excitation voltages of the i-th adjacent injections, k i,2 is the second slope value of the i-th injection, ΔC CVT,i is the capacitance difference of the ith injection, C CVT is the initial capacitance value, U i is the excitation voltage value of the excitation signal injected for the i-th time, U N is the rated voltage value, k i,3 is the third slope value of the i-th injection, Δk CVT,i is the ratio difference of the i-th injection, k CVT is the initial transformation ratio, k i is the slope value of the i-th two adjacent injections.

5. The method according to claim 1, characterized in that The step of determining the target slope value according to the slope values ​​of all two adjacent injections includes: Among all the slope values ​​of two adjacent injections, the maximum slope value is used as the target slope value; The step of determining the optimal excitation voltage according to the excitation voltage values ​​of two adjacent injected excitation signals corresponding to the target slope value comprises: Among the excitation voltage values ​​of the excitation signals injected twice adjacent to the target slope value, the excitation voltage value of the excitation signal injected the latter time is used as the optimal excitation voltage.

6. The method according to claim 1, characterized in that The step of controlling the capacitive voltage transformer to sequentially inject excitation signals with different excitation voltage values ​​into the transformer comprises: The capacitive voltage transformer is controlled to inject an excitation signal into the transformer, and the excitation voltage value of the injected excitation signal is adjusted according to a preset step size within a preset excitation voltage range.

7. The method according to claim 6, characterized in that The method further comprises: Obtaining the minimum short-circuit current value of the transformer, and the initial capacitance value, initial transformation ratio value and withstand voltage value of the capacitive voltage transformer; Determine a minimum excitation voltage value according to the minimum short-circuit current value and the initial capacitance value; Determine the maximum excitation voltage value according to the initial transformation ratio value and the withstand voltage value; The preset excitation voltage range is determined according to the minimum excitation voltage value and the maximum excitation voltage value.

8. The method according to claim 7, characterized in that The determining of the minimum excitation voltage value according to the minimum short-circuit current value and the initial capacitance value comprises: Using the formula Determining the minimum excitation voltage value; The determining of the maximum excitation voltage value according to the initial transformation ratio value and the withstand voltage value comprises: Using the formula Determining the maximum excitation voltage value; Among them, U min is the minimum excitation voltage value, I N,min is the minimum short-circuit current value, π is the circumference of a circle, f is the preset frequency, and the typical value of f is 50 Hz. CVT is the initial capacitance value, U max is the maximum excitation voltage value, U CVT,max is the withstand voltage value, k CVT is the initial transformation ratio value.

9. The method according to claim 7, characterized in that: The obtaining of the minimum short-circuit current value of the transformer comprises: Obtaining the rated voltage value, rated capacity and short-circuit impedance of the transformer; The minimum short-circuit current value is determined according to the rated voltage value, the rated capacity and the short-circuit impedance.

10. The method according to claim 9, characterized in that The determining the minimum short-circuit current value according to the rated voltage value, the rated capacity and the short-circuit impedance comprises: Using the formula Determining the minimum short-circuit current value; Among them, I N,min is the minimum short-circuit current value, S N is the rated capacity, U N is the rated voltage value, Z N is the short-circuit impedance.

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