Transformer winding fault analysis system and method and related equipment
By sending excitation signals of different frequencies in the transformer winding fault analysis system and analyzing the response signals, the frequency response curve of the transformer is solved, and the problem that traditional methods are difficult to accurately respond to the dynamic changes of the transformer is realized, and accurate winding fault analysis is achieved.
Patent Information
- Application Number
- CN202411953442.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-03-28
AI Technical Summary
Traditional transformer performance analysis methods are difficult to accurately reflect the dynamic changes of the transformer, resulting in the inability to accurately judge the fault status of the winding.
A transformer winding fault analysis system is designed. By sending excitation signals of different frequencies in the transformer to be analyzed, and adjusting circuit parameters using variable capacitance and variable resistance, receiving and analyzing the response signals to construct the frequency response curve of the transformer, thereby performing fault analysis.
The system can have a more comprehensive understanding of the performance of the transformer in different working states, provide accurate winding fault analysis results, and provide a scientific basis for the maintenance and optimization of the transformer.
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Figure CN119716658A_ABST
Abstract
Description
[Technical field]
[0001] The present invention relates to the technical field of transformer winding fault analysis, and in particular to a transformer winding fault analysis system, method and related equipment. [Background technology]
[0002] Accurate diagnosis of transformer winding faults is crucial to maintaining the normal operation of the power grid. As an important equipment in the power system, the transformer bears the heavy responsibility of power transmission. Any winding fault may have a profound impact on the stability of the system. During long-term operation, the transformer windings are often affected by various factors such as ambient temperature changes, electromagnetic shock, vibration, and insulation aging, and mechanical deformation, displacement, looseness and other faults often occur. These faults will not only affect the working performance of the transformer, resulting in reduced energy efficiency and power loss, but may also cause serious power accidents, bringing immeasurable economic losses and social impacts. Therefore, regular monitoring and diagnosis of the status of transformer windings has become an important task in power system maintenance.
[0003] Traditional transformer performance analysis methods mostly rely on test equipment with fixed parameters, which is difficult to accurately respond to the dynamic changes in transformer characteristics, resulting in an inability to accurately judge the fault status of the winding. [Summary of the invention]
[0004] In view of this, the present invention provides a transformer winding fault analysis system, method and related equipment.
[0005] The specific technical solution of the first embodiment of the present invention is: a transformer winding fault analysis system, characterized in that the system includes: a transformer to be analyzed, a station transformer, a variable capacitor, a variable resistor, a current sensor, a signal converter, a first host computer, a digital signal generator and a second host computer; the output end of the first host computer is connected to the input end of the digital signal generator, the output end of the digital signal generator is connected to the input end of the variable capacitor and the input end of the variable resistor, the input end of the station transformer is connected to the output end of the variable capacitor and the output end of the variable resistor, the output end of the station transformer is connected to the input end of the transformer to be analyzed; the output end of the transformer to be analyzed is connected to the input end of the current sensor, The output end of the flow sensor is connected to the input end of the signal converter, and the output end of the signal converter is connected to a second host computer; the first host computer is used to send excitation signals of different frequencies to the variable capacitor and the variable resistor through the digital signal generator, and the excitation signal is input to the transformer to be analyzed through the variable capacitor and the variable resistor; the transformer to be analyzed receives the excitation signal and outputs a response signal; the second host computer is used to receive the response signal output by the transformer to be analyzed through the current sensor and the signal converter, and analyze according to the excitation signals of different frequencies, the capacitance value of the variable capacitor, the resistance value of the variable resistor and the response signal to obtain the winding fault analysis result of the transformer to be analyzed.
[0006] The specific technical scheme of the second embodiment of the present invention is: a transformer winding fault analysis method, applied to the transformer winding fault analysis system as described in the first embodiment of the present application, characterized in that the method comprises: the variable capacitor and the variable resistor are in a short-circuit state; the first host computer sends excitation signals of different frequencies to the variable capacitor and the variable resistor through the digital signal generator, and the excitation signal is input to the transformer to be analyzed through the variable capacitor and the variable resistor; the transformer to be analyzed receives the excitation signal and sends a response signal; the second host computer receives the response signal through the current sensor and the signal converter; according to the excitation signals of different frequencies The invention relates to a method for analyzing a transformer to be analyzed, wherein the first frequency response curve of the transformer to be analyzed is constructed according to the excitation signals of different frequencies and the target response signals corresponding to the excitation signals of different frequencies; the target capacitance value of the variable capacitor and the target resistance value of the variable resistor corresponding to the excitation signals of different frequencies are obtained by using the excitation signals and the response signals corresponding to the excitation signals of different frequencies; the variable capacitor is adjusted to the target capacitance value and the variable resistor is adjusted to the target resistance value according to the frequency of the excitation signal; the target response signals corresponding to the excitation signals of different frequencies under the conditions of the target capacitance value and the target resistance value are obtained; the first frequency response curve of the transformer to be analyzed is constructed according to the excitation signals of different frequencies and the target response signals; and the winding fault analysis result of the transformer to be analyzed is obtained according to the first frequency response curve and the second frequency response curve of the transformer without winding fault.
[0007] Preferably, the obtaining of the winding fault analysis result of the transformer to be analyzed based on the first frequency response curve and the second frequency response curve of the transformer without winding fault includes: obtaining a longitudinal slope evaluation index of the first frequency response curve based on the first frequency response curve and the second frequency response curve of the transformer without winding fault; the longitudinal slope evaluation index is used to characterize the degree of winding fault of the transformer to be analyzed; and obtaining the winding fault analysis result of the transformer to be analyzed based on the longitudinal slope evaluation index and a preset threshold.
[0008] Preferably, the target capacitance value is obtained using the following formula:
[0009]
[0010] Among them, C j is the target capacitance value when the excitation signal frequency is j, R z is the first equivalent resistance of the station transformer, f j is the frequency of the excitation signal, L z is the first equivalent inductance of the station transformer, C z is the first equivalent capacitance of the station transformer, U in_j is the voltage of the excitation signal when the frequency of the excitation signal is j, R b is the second equivalent resistance of the transformer to be analyzed, Lb is the second equivalent inductance of the transformer to be analyzed, C b is the second equivalent capacitance of the transformer to be analyzed, U out_j is the response signal output by the transformer to be analyzed when the frequency of the excitation signal is j, and k1, k2 and k3 are constants.
[0011] Preferably, the target resistance value is obtained using the following formula:
[0012]
[0013] Among them, R j is the target resistance value when the frequency of the excitation signal is j, R z is the first equivalent resistance of the station transformer, U in_j is the voltage of the excitation signal when the frequency of the excitation signal is j, R b is the second equivalent resistance of the transformer to be analyzed, C z is the first equivalent capacitance of the station transformer, C b is the second equivalent capacitance of the transformer to be analyzed, U out_j is the response signal output by the transformer to be analyzed when the frequency of the excitation signal is j, and k4, k5 and k6 are constants.
[0014] Preferably, obtaining the longitudinal slope evaluation index of the first frequency response curve based on the first frequency response curve and the second frequency response curve of the transformer without winding fault includes: obtaining first amplitudes corresponding to different frequencies in the first frequency response curve, and obtaining second amplitudes corresponding to different frequencies in the second frequency response curve; and obtaining the longitudinal slope evaluation index of the first frequency response curve based on the first amplitude and the second amplitude.
[0015] Preferably, the longitudinal slope evaluation index is obtained using the following formula:
[0016]
[0017] Among them, T is the longitudinal slope evaluation index, A i is the first amplitude corresponding to the i-th frequency of the first frequency response curve, AO i is the second amplitude corresponding to the i-th frequency of the second frequency response curve, A i+1 is the first amplitude corresponding to the i+1th frequency of the first frequency response curve, AO i+1 is the second amplitude corresponding to the i+1th frequency of the second frequency response curve, f i is the ith frequency, f i-1 is the i-1th frequency, k7 and k8 are constants.
[0018] Preferably, the winding fault analysis result of the transformer to be analyzed is obtained based on the longitudinal tilt evaluation index and the preset threshold, including: if the longitudinal tilt evaluation index is greater than or equal to the preset threshold, a winding fault occurs in the transformer to be analyzed; if the longitudinal tilt evaluation index is less than the preset threshold, no winding fault occurs in the transformer to be analyzed.
[0019] The specific technical solution of the third embodiment of the present invention is: a transformer winding fault analysis device, comprising a memory and a processor, the memory storing a computer program, and when the computer program is executed by the processor, the processor executes the steps of the method described in any one of the second embodiments of the present application.
[0020] The specific technical solution of the fourth embodiment of the present invention is: a computer-readable storage medium storing a computer program, which, when executed by a processor, enables the processor to perform the steps of the method described in any one of the second embodiments of the present application.
[0021] Implementing the embodiments of the present invention will have the following beneficial effects:
[0022] In the present invention, the first host computer sends excitation signals of different frequencies to the variable capacitor and the variable resistor through a digital signal generator, and finally inputs them into the transformer to be analyzed. The transformer to be analyzed receives the excitation signal and outputs a response signal; the second host computer is used to receive the response signal output by the transformer to be analyzed through a current sensor and a signal converter, and analyzes according to the excitation signals of different frequencies, the capacitance value of the variable capacitor, the resistance value of the variable resistor, and the response signal to obtain the winding fault analysis result of the transformer to be analyzed. By adjusting the variable capacitor and the variable resistor to the target value and measuring the response characteristics under the excitation signal of different frequencies, the frequency response curve of the transformer to be analyzed is constructed, which helps to more comprehensively understand the performance of the transformer under different working conditions, thereby obtaining accurate winding fault analysis results, and providing a scientific basis for the maintenance and optimization of the transformer.
Brief Description of the Drawings
[0023] In order to more clearly illustrate the embodiments of the present application 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 application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0024] Figure 1 It is a structural schematic diagram of a transformer winding fault analysis system;
[0025] Figure 2 A flowchart of the steps of a transformer winding fault analysis method;
[0026] Figure 3 A diagram of the internal structure of a computer device;
[0027] Among them, 1. transformer box; 2. iron core; 3. low voltage winding; 4. medium voltage winding; 5. high voltage winding; 6. low voltage bushing; 7. medium voltage bushing; 8. high voltage bushing; 9. station transformer; 10. variable capacitor; 11. variable resistor; 12. current sensor; 13. signal converter; 14. first host computer; 15. digital signal generator; 16. second host computer; 121. first grounding device; 122. second grounding device; 101. first resistor; 102. second resistor; 901. first inductor; 902. second inductor; 111. first capacitor; 112. second capacitor. [Specific implementation method]
[0028] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0029] The terms "first", "second", etc. in the specification, claims and drawings of this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or modules is not limited to the listed steps or modules, but optionally includes steps or modules that are not listed, or optionally includes other steps or modules that are inherent to these processes, methods, products or devices.
[0030] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0031] See also Figure 1, is a structural schematic diagram of a transformer winding fault analysis system in the first embodiment of the present application, so as to obtain accurate winding fault analysis results, the system includes: a transformer to be analyzed, a station transformer 9, a variable capacitor 10, a variable resistor 11, a current sensor 12, a signal converter 13, a first host computer 14, a digital signal generator 15 and a second host computer 16; the output end of the first host computer 14 is connected to the input end of the digital signal generator 15, the output end of the digital signal generator 15 is connected to the input end of the variable capacitor 15 and the input end of the variable resistor 11, the input end of the station transformer 9 is connected to the output end of the variable capacitor 10 and the output end of the variable resistor 14, the output end of the station transformer 9 is connected to the input end of the transformer to be analyzed; the output end of the transformer to be analyzed is connected to the current sensor 12 The input end of the current sensor 12 is connected to the input end of the signal converter 13, and the output end of the signal converter 13 is connected to the second host computer 16; the first host computer 14 is used to send excitation signals of different frequencies to the variable capacitor 10 and the variable resistor 11 through the digital signal generator 15, and the excitation signal is input to the transformer to be analyzed through the variable capacitor 10 and the variable resistor 11; the transformer to be analyzed receives the excitation signal and outputs a response signal; the second host computer 16 is used to receive the response signal output by the transformer to be analyzed through the current sensor 12 and the signal converter 13, and analyze according to the excitation signals of different frequencies, the capacitance value of the variable capacitor, the resistance value of the variable resistor and the response signal to obtain the winding fault analysis result of the transformer to be analyzed.
[0032] Specifically, the transformer to be analyzed includes a transformer box 1, an iron core 2, a low-voltage winding 3, a medium-voltage winding 4, a high-voltage winding 5, a low-voltage bushing 6, a medium-voltage bushing 7 and a high-voltage bushing 8. The first host computer 14 is connected to a digital signal generator 15, and the digital signal generator 15 is connected to a variable capacitor 10 and a variable resistor 11. The variable capacitor 10 is connected to the variable resistor 11 in parallel. The station transformer 9 is connected to the variable capacitor 10 and the variable resistor 11. The station transformer 9 is connected to the low-voltage bushing 6, and the low-voltage bushing 6 is connected to the first inductor 901, the first inductor 901 is connected to the first resistor 101, and the first resistor 101 is connected to the first capacitor 111. A capacitor 111 is connected to a first grounding device 121; a high-voltage bushing 8 is connected to a second inductor 902, the second inductor 902 is connected to a second resistor 102, the second resistor 102 is connected to a second capacitor 112, the second capacitor 112 is connected to a second grounding device 122, a current sensor 12 is sleeved on the line, the current sensor 12 is connected to a signal converter 13, and the signal converter 13 is connected to a second host computer 16; the iron core 2, the low-voltage winding 3, the medium-voltage winding 4, and the high-voltage winding 5 are all placed in the transformer box 1, and the low-voltage bushing 6, the medium-voltage bushing 7, and the high-voltage bushing 8 are respectively connected to the low-voltage winding 3, the medium-voltage winding 4, and the high-voltage winding 5. The first capacitor 111, the first resistor 101, the first inductor 901, the second inductor 902, the second resistor 102, and the second capacitor 112 are used to simulate the operating state of the transformer to be analyzed.
[0033] The system in this embodiment adjusts the variable capacitor and the variable resistor to the target values and then measures the response characteristics under different frequency excitation signals, thereby constructing a frequency response curve of the transformer to be analyzed, which helps to more comprehensively understand the performance of the transformer under different working conditions, thereby obtaining accurate winding fault analysis results, and providing a scientific basis for the maintenance and optimization of the transformer.
[0034] In the specific embodiments, see Figure 2 , is a flowchart of a transformer winding fault analysis method in the second embodiment of the present application, which is applied to the transformer winding fault analysis system as described in the first embodiment of the present application, and the method includes:
[0035] Step 201, putting the variable capacitor and the variable resistor in a short-circuit state;
[0036] Step 202: the first host computer sends excitation signals of different frequencies to the variable capacitor and the variable resistor through the digital signal generator, and the excitation signal is input to the transformer to be analyzed through the variable capacitor and the variable resistor; the transformer to be analyzed receives the excitation signal and sends a response signal;
[0037] Step 203: the second host computer receives the response signal through the current sensor and the signal converter;
[0038] Step 204: acquiring target capacitance values of the variable capacitor and target resistance values of the variable resistor corresponding to the excitation signals of different frequencies according to the excitation signals of different frequencies and the response signals corresponding to the excitation signals of different frequencies;
[0039] Step 205: adjusting the variable capacitor to the target capacitance value and the variable resistor to the target resistance value according to the frequency of the excitation signal;
[0040] Step 206: Obtain target response signals corresponding to the excitation signals of different frequencies under the conditions of the target capacitance value and the target resistance value;
[0041] Step 207: construct a first frequency response curve of the transformer to be analyzed according to the excitation signals of different frequencies and the target response signal;
[0042] Step 208: Obtain a winding fault analysis result of the transformer to be analyzed according to the first frequency response curve and a second frequency response curve of a transformer without winding fault.
[0043] Specifically, obtain the reference injection signal and reference output signal of the station variable injection power supply
[0044] The measuring station uses the injection signal and output signal of the variable injection power supply to first control the variable inductor 14 and the variable resistor 11 to be in a short-circuit state, and then uses the first host computer 14 to generate excitation signals of different frequencies through the digital signal generator 15. The generated excitation signal is injected into the transformer winding through the low-voltage bushing 6, flows through the low-voltage winding 3, the medium-voltage winding 4, and the high-voltage winding 5, and then flows out of the transformer through the high-voltage bushing 8. The output response signal is measured by the second host computer 16, and the input voltage of the excitation signal is measured to be U in =[U in_1 U in_2 ...U in_n ], the output voltage of the response signal is U out =[U out_ 1U out_2 ...U out_n ], where U in_n is the amplitude of the input voltage of the excitation signal after stabilization at the nth input frequency, U out_n is the amplitude of the output voltage of the response signal after it stabilizes when the nth input frequency is input. The frequency range is [1kHz, 1MHz], and the n range is [1, 2, 3, ..., n]. According to U in and U outA target capacitance value of the variable capacitor and a target resistance value of the variable resistor are obtained, such as when the frequency is f1, the target capacitance value is m1 and the target resistance value is n1; when the frequency is f2, the target capacitance value is m2 and the target resistance value is n2; then, the target resistance value and the target capacitance value at different frequencies are adjusted according to the frequency of the excitation signal, and the response signal is recovered, and a first frequency response curve is constructed according to the recovered response signal and the excitation signal, and a winding fault analysis result of the transformer to be analyzed is obtained according to the first frequency response curve and the second frequency response curve of the transformer without winding fault.
[0045] In a specific embodiment, obtaining the winding fault analysis result of the transformer to be analyzed according to the first frequency response curve and the second frequency response curve of the transformer without winding fault includes: obtaining the longitudinal slope evaluation index of the first frequency response curve according to the first frequency response curve and the second frequency response curve of the transformer without winding fault; the longitudinal slope evaluation index is used to characterize the degree of winding fault of the transformer to be analyzed; and obtaining the winding fault analysis result of the transformer to be analyzed according to the longitudinal slope evaluation index and a preset threshold. The frequency response curve can reflect the response characteristics of the transformer winding at different frequencies, including changes in amplitude and phase. By analyzing these changes, it is possible to accurately diagnose whether the winding has deformation, short circuit, open circuit and other faults. This method is more accurate and reliable than traditional appearance inspection or simple electrical testing. Frequency response curve analysis can quickly locate the location and type of winding faults. For example, by comparing the frequency response curves of different phases or different time points, it can be determined which part of the winding the fault occurs in, whether it is overall deformation or local deformation, mechanical fault or electrical fault. This helps maintenance personnel to quickly formulate repair plans and reduce downtime and maintenance costs.
[0046] In a specific embodiment, obtaining a longitudinal slope evaluation index of the first frequency response curve according to the first frequency response curve and a second frequency response curve of a transformer without a winding fault includes: obtaining first amplitudes corresponding to different frequencies in the first frequency response curve, and obtaining second amplitudes corresponding to different frequencies in the second frequency response curve; and obtaining a longitudinal slope evaluation index of the first frequency response curve according to the first amplitude and the second amplitude.
[0047] Specifically, all first amplitudes in the first frequency response curve are obtained, and all second amplitudes in the second frequency response curve are obtained; a longitudinal slope evaluation index of the first frequency response curve is obtained according to all first amplitudes and all second amplitudes, and a winding fault analysis result of the transformer to be analyzed is obtained according to the longitudinal slope evaluation index and a preset threshold.
[0048] Specifically, the first amplitude is obtained using the following formula:
[0049]
[0050] Among them, A j is the first amplitude of the first frequency response curve at the jth input frequency, U RCout_j is the amplitude of the target response signal when the target capacitance and resistance are connected at the jth input frequency, U RCin_j is the amplitude of the excitation signal at the jth input frequency.
[0051] In a specific embodiment, the winding fault analysis result of the transformer to be analyzed is obtained based on the longitudinal tilt evaluation index and the preset threshold, including: if the longitudinal tilt evaluation index is greater than or equal to the preset threshold, then the transformer to be analyzed has a winding fault; if the longitudinal tilt evaluation index is less than the preset threshold, then the transformer to be analyzed has not a winding fault.
[0052] Specifically, if the longitudinal inclination evaluation index T≥K (K is a preset threshold), it is judged that the transformer winding has a fault; if T<K, it is judged that the transformer winding has no fault, where K is a constant related to the transformer model, winding connection method, and external equipment.
[0053] In a specific embodiment, the target capacitance value is obtained using the following formula:
[0054]
[0055] Among them, C j is the target capacitance value when the excitation signal frequency is j, R z is the first equivalent resistance of the station transformer, f j is the frequency of the excitation signal, L z is the first equivalent inductance of the station transformer, C z is the first equivalent capacitance of the station transformer, U in_j is the voltage of the excitation signal when the frequency of the excitation signal is j, R b is the second equivalent resistance of the transformer to be analyzed, L b is the second equivalent inductance of the transformer to be analyzed, C b is the second equivalent capacitance of the transformer to be analyzed, U out_j is the response signal output by the transformer to be analyzed when the frequency of the excitation signal is j, and k1, k2 and k3 are constants.
[0056] Specifically, the values of k1, k2 and k3 can be set according to actual conditions. For example, the specific formula for obtaining the target capacitance value is:
[0057]
[0058] In a specific embodiment, the target resistance value is obtained using the following formula:
[0059]
[0060] Among them, R j is the target resistance value when the frequency of the excitation signal is j, R z is the first equivalent resistance of the station transformer, U in_j is the voltage of the excitation signal when the frequency of the excitation signal is j, R b is the second equivalent resistance of the transformer to be analyzed, C z is the first equivalent capacitance of the station transformer, C b is the second equivalent capacitance of the transformer to be analyzed, U out_j is the response signal output by the transformer to be analyzed when the frequency of the excitation signal is j, and k4, k5 and k6 are constants.
[0061] Specifically, the values of k4, k5 and k6 can be set according to actual conditions. For example, the specific formula for obtaining the target resistance value is:
[0062]
[0063] 7. The transformer winding fault analysis method according to claim 6, characterized in that the longitudinal inclination evaluation index is obtained by using the following formula:
[0064]
[0065] Among them, T is the longitudinal slope evaluation index, A i is the first amplitude corresponding to the i-th frequency of the first frequency response curve, AO i is the second amplitude corresponding to the i-th frequency of the second frequency response curve, A i+1 is the first amplitude corresponding to the i+1th frequency of the first frequency response curve, AO i+1 is the second amplitude corresponding to the i+1th frequency of the second frequency response curve, f i is the ith frequency, f i-1 is the i-1th frequency, k7 and k8 are constants.
[0066] In a specific embodiment, the values of k7 and k8 can be set according to actual conditions. For example, the specific formula for obtaining the target capacitance value is:
[0067]
[0068] In a specific embodiment, the third embodiment of the present application provides a transformer winding fault analysis device, including a memory and a processor, the memory storing a computer program, and when the computer program is executed by the processor, the processor executes the steps of the method as described in any one of the second embodiments of the present application.
[0069] In a specific embodiment, the fourth embodiment of the present application provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the processor executes the steps of the method as described in any one of the second embodiments of the present application.
[0070] Figure 3 The internal structure of a computer device in one embodiment is shown. The computer device can be a terminal or a server. Figure 3 The computer device includes a processor, a memory, etc. connected via a system bus. 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 the method in this embodiment. The internal memory may also store a computer program. When the computer program is executed by the processor, the processor can implement the method in this 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.
[0071] The above 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 modifications 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.
[0072] The above description is only a preferred embodiment of the present invention and does not limit the present invention in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes and apply it to other fields. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.
Claims
1. A transformer winding fault analysis system, characterized in that: The system comprises: a transformer to be analyzed, a station transformer, a variable capacitor, a variable resistor, a current sensor, a signal converter, a first host computer, a digital signal generator and a second host computer; The output end of the first host computer is connected to the input end of the digital signal generator, the output end of the digital signal generator is connected to the input end of the variable capacitor and the input end of the variable resistor, the input end of the station transformer is connected to the output end of the variable capacitor and the output end of the variable resistor, and the output end of the station transformer is connected to the input end of the transformer to be analyzed; The output end of the transformer to be analyzed is connected to the input end of the current sensor, the output end of the current sensor is connected to the input end of the signal converter, and the output end of the signal converter is connected to the second host computer; The first host computer is used to send excitation signals of different frequencies to the variable capacitor and the variable resistor through the digital signal generator, and the excitation signal is input to the transformer to be analyzed through the variable capacitor and the variable resistor; the transformer to be analyzed receives the excitation signal and outputs a response signal; The second host computer is used to receive the response signal output by the transformer to be analyzed through the current sensor and the signal converter, and perform analysis based on the excitation signals of different frequencies, the capacitance value of the variable capacitor, the resistance value of the variable resistor and the response signal to obtain the winding fault analysis result of the transformer to be analyzed.
2. A transformer winding fault analysis method, applied to the transformer winding fault analysis system as claimed in claim 1, characterized in that: The method comprises: Put the variable capacitor and the variable resistor in a short-circuit state; The first host computer sends excitation signals of different frequencies to the variable capacitor and the variable resistor through the digital signal generator, and the excitation signal is input to the transformer to be analyzed through the variable capacitor and the variable resistor; the transformer to be analyzed receives the excitation signal and sends a response signal; The second host computer receives the response signal through the current sensor and the signal converter; Obtaining target capacitance values of the variable capacitor and target resistance values of the variable resistor corresponding to the excitation signals of different frequencies according to the excitation signals of different frequencies and the response signals corresponding to the excitation signals of different frequencies; adjusting the variable capacitor to the target capacitance value and the variable resistor to the target resistance value according to the frequency of the excitation signal; Acquire a target response signal corresponding to the excitation signal of different frequencies under the conditions of the target capacitance value and the target resistance value; Constructing a first frequency response curve of the transformer to be analyzed according to the excitation signals of different frequencies and the target response signal; The winding fault analysis result of the transformer to be analyzed is obtained according to the first frequency response curve and the second frequency response curve of the transformer without winding fault.
3. The transformer winding fault analysis method according to claim 2, characterized in that: The step of obtaining the winding fault analysis result of the transformer to be analyzed according to the first frequency response curve and the second frequency response curve of the transformer without winding fault comprises: Obtaining a vertical slope evaluation index of the first frequency response curve according to the first frequency response curve and a second frequency response curve of a transformer without winding fault; the vertical slope evaluation index is used to characterize the degree of winding fault of the transformer to be analyzed; The winding fault analysis result of the transformer to be analyzed is obtained according to the longitudinal inclination evaluation index and the preset threshold.
4. The transformer winding fault analysis method according to claim 2, characterized in that: The target capacitance value is obtained using the following formula: Among them, C j is the target capacitance value when the excitation signal frequency is j, R z is the first equivalent resistance of the station transformer, f j is the frequency of the excitation signal, L z is the first equivalent inductance of the station transformer, C z is the first equivalent capacitance of the station transformer, U in_j is the voltage of the excitation signal when the frequency of the excitation signal is j, R b is the second equivalent resistance of the transformer to be analyzed, L b is the second equivalent inductance of the transformer to be analyzed, C b is the second equivalent capacitance of the transformer to be analyzed, U out_j is the response signal output by the transformer to be analyzed when the frequency of the excitation signal is j, and k1, k2 and k3 are constants.
5. The transformer winding fault analysis method according to claim 2, characterized in that: The target resistance value is obtained using the following formula: Among them, R j is the target resistance value when the frequency of the excitation signal is j, R z is the first equivalent resistance of the station transformer, U in_j is the voltage of the excitation signal when the frequency of the excitation signal is j, R b is the second equivalent resistance of the transformer to be analyzed, C z is the first equivalent capacitance of the station transformer, C b is the second equivalent capacitance of the transformer to be analyzed, U out_j is the response signal output by the transformer to be analyzed when the frequency of the excitation signal is j, and k4, k5 and k6 are constants.
6. The transformer winding fault analysis method according to claim 2, characterized in that: The step of obtaining a longitudinal slope evaluation index of the first frequency response curve according to the first frequency response curve and a second frequency response curve of a transformer without winding fault comprises: Acquire first amplitudes corresponding to different frequencies in the first frequency response curve, and acquire second amplitudes corresponding to different frequencies in the second frequency response curve; A vertical slope evaluation index of the first frequency response curve is obtained according to the first amplitude and the second amplitude.
7. The transformer winding fault analysis method according to claim 6, characterized in that: The longitudinal slope evaluation index is obtained by the following formula: Among them, T is the longitudinal slope evaluation index, A i is the first amplitude corresponding to the i-th frequency of the first frequency response curve, AO i is the second amplitude corresponding to the i-th frequency of the second frequency response curve, A i+1 is the first amplitude corresponding to the i+1th frequency of the first frequency response curve, AO i+1 is the second amplitude corresponding to the i+1th frequency of the second frequency response curve, f i is the ith frequency, f i-1 is the i-1th frequency, k7 and k8 are constants.
8. The transformer winding fault analysis method according to claim 3, characterized in that: The step of obtaining the winding fault analysis result of the transformer to be analyzed according to the longitudinal inclination evaluation index and a preset threshold value includes: If the longitudinal inclination evaluation index is greater than or equal to the preset threshold, a winding fault occurs in the transformer to be analyzed; If the longitudinal inclination evaluation index is less than the preset threshold, the transformer to be analyzed has no winding fault.
9. A transformer winding fault analysis device, comprising a memory and a processor, characterized in that: The memory stores a computer program, and when the computer program is executed by the processor, the processor is caused to perform the steps of the method according to any one of claims 2 to 8.
10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the processor is caused to perform the steps of the method according to any one of claims 2 to 8.