A method and apparatus for testing the temperature rise of a three-winding transformer.

Abstract

This invention provides a method and apparatus for temperature rise testing of a three-winding transformer. The three-winding transformer includes a high-voltage winding, a medium-voltage winding, and a low-voltage winding. The temperature rise testing method includes: obtaining the rated parameters of each winding of the three-winding transformer, including rated capacity, rated voltage, and rated current; establishing an equivalent circuit of the three-winding transformer based on the rated parameters of each winding; calculating the impedance of each winding based on the rated parameters and the equivalent circuit; connecting a load sample to the winding with the lower impedance between the medium-voltage and low-voltage windings, and short-circuiting the winding with the higher impedance, to perform a temperature rise test. The load sample is a load with measurable losses. This invention can reduce the test time and increase the speed of temperature rise testing for three-winding transformers.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, and in particular to a method and apparatus for testing the temperature rise of a three-winding transformer. Background Technology

[0002] Temperature rise tests for three-winding transformers are often conducted using the short-circuit method. The short-circuit method involves short-circuiting the medium-voltage and low-voltage windings of the three-winding transformer, while applying the rated voltage to the high-voltage winding.

[0003] During this temperature rise test, because the impedances of each winding are not the same, neither the medium-voltage side nor the low-voltage side reaches the rated state after a short circuit. For example, the actual loss on the medium-voltage side is only 80% of the rated loss. Therefore, the temperature rise test time needs to be increased to ensure that the temperature of the medium-voltage winding reaches the set temperature. However, increasing the temperature rise test time is too long, for example, several hours, resulting in a long temperature rise test time and low efficiency for the three-winding transformer. Summary of the Invention

[0004] This invention provides a method and apparatus for temperature rise testing of a three-winding transformer, which can reduce the test time and increase the test speed of the temperature rise test of the three-winding transformer.

[0005] In a first aspect, the present invention provides a temperature rise test method for a three-winding transformer, the three-winding transformer including a high-voltage winding, a medium-voltage winding and a low-voltage winding, the temperature rise test method comprising: obtaining the rated parameters of each winding of the three-winding transformer, the rated parameters including rated capacity, rated voltage and rated current; establishing an equivalent circuit of the three-winding transformer based on the rated parameters of each winding; calculating the impedance of each winding based on the rated parameters of each winding and the equivalent circuit; connecting a load test object to the winding with the smaller impedance in the medium-voltage winding and the low-voltage winding, and short-circuiting the winding with the larger impedance, and performing a temperature rise test, the load test object being a load with measurable losses.

[0006] This invention provides a method for temperature rise testing of a three-winding transformer. By establishing an equivalent circuit and calculating the impedance of each winding based on the equivalent circuit, a load test sample is connected to the winding with the lower impedance between the medium-voltage and low-voltage windings, while the winding with the higher impedance is short-circuited for temperature rise testing. The load test sample is a load with measurable losses. Connecting the load test sample to the winding with the lower impedance increases the short-circuit loss of the three-winding transformer during the temperature rise process, thereby increasing the total loss during the temperature rise test and enabling the three-winding transformer to reach temperature faster. This reduces the test time and improves the speed of the temperature rise test for the three-winding transformer.

[0007] In one possible implementation, the load test specimen is connected to the winding with lower impedance between the medium-voltage winding and the low-voltage winding, while the winding with higher impedance is short-circuited. Before conducting the temperature rise test, the method further includes: calculating the equivalent impedance of the first winding and the high-voltage winding based on the rated parameters of the high-voltage winding and the first winding; wherein, the first winding is the winding with lower impedance between the medium-voltage winding and the low-voltage winding; calculating the equivalent impedance of the first winding at rated loss during the temperature rise test based on the rated parameters of the first winding and another winding; the other winding is the winding other than the first winding between the medium-voltage winding and the low-voltage winding; and determining the impedance of the load test specimen based on the equivalent impedance and the equivalent impedance of the first winding and the high-voltage winding.

[0008] In one possible implementation, the equivalent impedance of the first winding and the high-voltage winding is calculated based on the rated parameters of the high-voltage winding and the first winding, including: determining the equivalent impedance of the first winding and the high-voltage winding based on the following formula;

[0009]

[0010] Among them, K HM U is the equivalent impedance of the first winding and the high-voltage winding. MN I is the rated voltage of the first winding of a three-winding transformer. MN U is the rated current of the first winding of a three-winding transformer. KHM S is the sum of the per-unit values ​​of the short-circuit impedance of the high-voltage winding and the first winding of a three-winding transformer. MN S represents the rated capacity of the first winding of a three-winding transformer. HN This refers to the rated capacity of the high-voltage winding of a three-winding transformer.

[0011] In one possible implementation, based on the rated parameters of the first winding and the other winding, the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test is calculated, including: determining a first converted value of the rated current of the first winding on the high-voltage side based on the rated current of the first winding and the voltage ratio between the first winding and the high-voltage winding; determining a second converted value of the rated current of the other winding on the high-voltage side based on the rated current of the other winding and the voltage ratio between the other winding and the high-voltage winding; and determining the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test based on the first converted value, the second converted value, and the short-circuit impedance of the other winding.

[0012] In one possible implementation, the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test is determined based on the first converted value, the second converted value, and the short-circuit impedance of the other winding, including: determining the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test based on the following formula.

[0013]

[0014] Among them, Z' M Z is the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test. L For the short-circuit impedance of the other winding, I' L The second converted value, I' M This is the first converted value.

[0015] In one possible implementation, the impedance of the load test specimen is determined based on the equivalent impedance and the equivalent impedance of the first winding and the high-voltage winding, including: determining the impedance of the load test specimen based on the following formula;

[0016]

[0017] Where X is the impedance of the loaded sample, Z H Z' is the short-circuit impedance of the high-voltage winding of a three-winding transformer. M U is the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test. KHM K is the sum of the per-unit values ​​of the short-circuit impedance of the high-voltage winding and the first winding of a three-winding transformer. HM This represents the equivalent impedance of the first winding and the high-voltage winding.

[0018] In one possible implementation, the impedance of each winding is calculated based on the rated parameters and equivalent circuit of each winding, including determining the impedance of each winding based on the following formula;

[0019]

[0020] Among them, Z H Z is the short-circuit impedance of the high-voltage winding of a three-winding transformer. M Z is the short-circuit impedance of the medium-voltage winding of a three-winding transformer. L Z1 is the short-circuit impedance of the low-voltage winding of the three-winding transformer, Z2 is the measured value of the high-voltage winding after the medium-voltage winding is short-circuited, Z3 is the measured value of the high-voltage winding after the low-voltage winding is short-circuited, and Z4 is the measured value of the medium-voltage winding after the low-voltage winding is short-circuited.

[0021] In one possible implementation, the load test specimen is connected in parallel with a loss detection module; the temperature rise test method also includes: detecting the loss of the load test specimen during the temperature rise test; and calculating the total loss of the three-winding transformer during the temperature rise test based on the loss of the load test specimen during the temperature rise test and the loss of each winding of the three-winding transformer.

[0022] Secondly, embodiments of the present invention provide a temperature rise testing device for a three-winding transformer. The three-winding transformer includes a high-voltage winding, a medium-voltage winding, and a low-voltage winding. The temperature rise testing device includes: a communication module for acquiring the rated parameters of each winding of the three-winding transformer, including rated capacity, rated voltage, and rated current; a processing module for establishing an equivalent circuit of the three-winding transformer based on the rated parameters of each winding; calculating the impedance of each winding based on the rated parameters and the equivalent circuit; and connecting a load test specimen to the winding with the smaller impedance in the medium-voltage winding and the low-voltage winding, while short-circuiting the winding with the larger impedance, to conduct a temperature rise test. The load test specimen is a load with measurable losses.

[0023] In one possible implementation, the processing module is further configured to calculate the equivalent impedance of the first winding and the high-voltage winding based on the rated parameters of the high-voltage winding and the first winding; wherein the first winding is the winding with the smaller impedance among the medium-voltage winding and the low-voltage winding; calculate the equivalent impedance corresponding to the first winding reaching the rated loss during the temperature rise test based on the rated parameters of the first winding and the other winding; the other winding is the winding other than the first winding among the medium-voltage winding and the low-voltage winding; and determine the impedance of the load test specimen based on the equivalent impedance and the equivalent impedance of the first winding and the high-voltage winding.

[0024] In one possible implementation, the processing module is specifically used to determine the equivalent impedance of the first winding and the high-voltage winding based on the following formula;

[0025]

[0026] Among them, K HM U is the equivalent impedance of the first winding and the high-voltage winding. MN I is the rated voltage of the first winding of a three-winding transformer. MN U is the rated current of the first winding of a three-winding transformer. KHM S is the sum of the per-unit values ​​of the short-circuit impedance of the high-voltage winding and the first winding of a three-winding transformer. MN S represents the rated capacity of the first winding of a three-winding transformer. HN This refers to the rated capacity of the high-voltage winding of a three-winding transformer.

[0027] In one possible implementation, the processing module is specifically used to determine a first equivalent value of the rated current of the first winding on the high-voltage side based on the rated current of the first winding and the voltage ratio between the first winding and the high-voltage winding; to determine a second equivalent value of the rated current of the other winding on the high-voltage side based on the rated current of the other winding and the voltage ratio between the other winding and the high-voltage winding; and to determine the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test based on the first equivalent value, the second equivalent value, and the short-circuit impedance of the other winding.

[0028] In one possible implementation, the processing module is specifically used to determine the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test based on the following formula.

[0029]

[0030] Among them, Z' M Z is the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test. L For the short-circuit impedance of the other winding, I' L The second converted value, I' M This is the first converted value.

[0031] In one possible implementation, the processing module is specifically used to determine the impedance of the load specimen based on the following formula;

[0032]

[0033] Where X is the impedance of the loaded sample, Z H Z' is the short-circuit impedance of the high-voltage winding of a three-winding transformer. M U is the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test. KHM K is the sum of the per-unit values ​​of the short-circuit impedance of the high-voltage winding and the first winding of a three-winding transformer. HM This represents the equivalent impedance of the first winding and the high-voltage winding.

[0034] In one possible implementation, the processing module is specifically used to determine the impedance of each winding based on the following formula;

[0035]

[0036] Among them, Z H Z is the short-circuit impedance of the high-voltage winding of a three-winding transformer. M Z is the short-circuit impedance of the medium-voltage winding of a three-winding transformer. L Z1 is the short-circuit impedance of the low-voltage winding of the three-winding transformer, Z2 is the measured value of the high-voltage winding after the medium-voltage winding is short-circuited, Z3 is the measured value of the high-voltage winding after the low-voltage winding is short-circuited, and Z4 is the measured value of the medium-voltage winding after the low-voltage winding is short-circuited.

[0037] In one possible implementation, the load test specimen is connected in parallel with a loss detection module; the communication module is also used to detect the loss of the load test specimen during the temperature rise test; and the processing module is also used to calculate the total loss of the three-winding transformer during the temperature rise test based on the loss of the load test specimen during the temperature rise test and the loss of each winding of the three-winding transformer.

[0038] Thirdly, embodiments of the present invention provide an electronic device, characterized in that the electronic device includes a memory and a processor, the memory storing a computer program, and the processor being configured to call and run the computer program stored in the memory to perform the steps of the method as described in the first aspect and any possible implementation thereof.

[0039] Fourthly, embodiments of the present invention provide a computer-readable storage medium storing a computer program, characterized in that, when the computer program is executed by a processor, it implements the steps of the method as described in the first aspect and any possible implementation thereof.

[0040] The technical effects of any of the implementation methods in the second to fourth aspects mentioned above can be found in the technical effects of the corresponding implementation method in the first aspect, and will not be repeated here. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the temperature rise test wiring for a three-winding transformer provided in an embodiment of the present invention;

[0043] Figure 2 This is a schematic flowchart of a temperature rise test method for a three-winding transformer provided in an embodiment of the present invention;

[0044] Figure 3 This is a schematic diagram of the equivalent circuit of a three-winding transformer provided in an embodiment of the present invention;

[0045] Figure 4 This is a wiring diagram of another three-winding transformer temperature rise test provided in an embodiment of the present invention;

[0046] Figure 5 This is a schematic flowchart of another temperature rise test method for a three-winding transformer provided in an embodiment of the present invention;

[0047] Figure 6 This is a schematic flowchart of another temperature rise test method for a three-winding transformer provided in an embodiment of the present invention;

[0048] Figure 7 This is a schematic diagram of the structure of a temperature rise test device for a three-winding transformer provided in an embodiment of the present invention;

[0049] Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0050] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0051] In the description of this invention, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The term "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Furthermore, "at least one" and "more than one" refer to two or more. The terms "first," "second," etc., do not limit the quantity or order of execution, and "first," "second," etc., do not necessarily imply differences.

[0052] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner to facilitate understanding.

[0053] Furthermore, the terms "comprising" and "having," and any variations thereof, used in the description of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or modules is not limited to the steps or modules listed, but may optionally include other steps or modules not listed, or may optionally include other steps or modules inherent to such process, method, product, or device.

[0054] To make the objectives, technical solutions, and advantages of the present invention clearer, the following description will be provided in conjunction with the accompanying drawings and specific embodiments.

[0055] As described in the background section, three-winding transformers currently suffer from the technical problem of requiring a long temperature rise test period.

[0056] like Figure 1The diagram shows a wiring schematic for a temperature rise test of a three-winding transformer according to an embodiment of this application. During the temperature rise test, the low-voltage and medium-voltage windings are short-circuited to ensure that neither winding is overloaded. However, the impedances of each winding are not the same, and neither the medium-voltage nor low-voltage winding operates at its rated state. For example, the actual loss on the medium-voltage side is only 80% of the rated loss. This necessitates increasing the temperature rise test time to ensure the medium-voltage winding meets the test requirements, resulting in a longer temperature rise test duration for the three-winding transformer.

[0057] like Figure 2 As shown, this embodiment of the invention provides a temperature rise test method for a three-winding transformer, the main body of which is a temperature rise test device, and the temperature rise test method includes steps S101-S105.

[0058] S101. Obtain the rated parameters of each winding of the three-winding transformer.

[0059] In this embodiment of the application, the rated parameters include rated capacity, rated voltage, and rated current.

[0060] S102. Based on the rated parameters of each winding, establish the equivalent circuit of the three-winding transformer.

[0061] For example, Figure 3 This is a schematic diagram of the equivalent circuit of a three-winding transformer provided in an embodiment of the present invention. The equivalent circuit includes a high-voltage winding, a medium-voltage winding, and a low-voltage winding.

[0062] For example, the rated parameters of each winding in this invention can be the parameters for a transformer with a tap position of 9. For instance, the rated voltage can be the 9-tap voltage, and the rated current can be the 9-tap current.

[0063] S103. Calculate the impedance of each winding based on the rated parameters and equivalent circuit of each winding.

[0064] As one possible implementation, the temperature rise test device can be based on the following formula, combined with Figure 3 The equivalent circuit shown determines the impedance of each winding.

[0065]

[0066] Among them, Z H Z is the short-circuit impedance of the high-voltage winding of a three-winding transformer. M Z is the short-circuit impedance of the medium-voltage winding of a three-winding transformer. L Z1 is the short-circuit impedance of the low-voltage winding of the three-winding transformer, Z2 is the measured value of the high-voltage winding after the medium-voltage winding is short-circuited, Z3 is the measured value of the high-voltage winding after the low-voltage winding is short-circuited, and Z4 is the measured value of the medium-voltage winding after the low-voltage winding is short-circuited.

[0067] For example, suppose Then, through calculation, we can obtain

[0068] S104. Connect the load test object to the winding with lower impedance in the medium-voltage winding and the low-voltage winding, and short-circuit the winding with higher impedance to conduct a temperature rise test.

[0069] In this embodiment of the application, the load sample is a load with measurable loss.

[0070] For example, such as Figure 4 As shown, the present invention provides a wiring diagram for a temperature rise test of a three-winding transformer. Figure 4 The medium-voltage winding is a winding with relatively low impedance. In this invention, a load sample is connected to the medium-voltage winding to complete the temperature rise test.

[0071] This invention provides a method for temperature rise testing of a three-winding transformer. By establishing an equivalent circuit and calculating the impedance of each winding based on the equivalent circuit, a load sample is connected to the winding with the lower impedance between the medium-voltage and low-voltage windings, while the winding with the higher impedance is short-circuited for temperature rise testing. The load sample is a load with measurable losses. Connecting the load sample to the winding with the lower impedance increases the short-circuit loss of the three-winding transformer during the temperature rise process, thereby increasing the total loss during the temperature rise test and enabling the three-winding transformer to reach temperature faster, thus reducing the test time.

[0072] Optional, such as Figure 5 As shown, before step S104, the temperature rise test method for a three-winding transformer provided in this embodiment of the invention further includes steps S201-S203.

[0073] S201. Based on the rated parameters of the high-voltage winding and the first winding, calculate the equivalent impedance of the first winding and the high-voltage winding.

[0074] The first winding is the winding with the smaller impedance between the medium-voltage winding and the low-voltage winding.

[0075] As one possible implementation, the temperature rise test device can determine the equivalent impedance of the first winding and the high-voltage winding based on the following formula;

[0076]

[0077] Among them, K HM U is the equivalent impedance of the first winding and the high-voltage winding. MN I is the rated voltage of the first winding of a three-winding transformer. MN U is the rated current of the first winding of a three-winding transformer. KHM S is the sum of the per-unit values ​​of the short-circuit impedance of the high-voltage winding and the first winding of a three-winding transformer. MNS represents the rated capacity of the first winding of a three-winding transformer. HN This refers to the rated capacity of the high-voltage winding of a three-winding transformer.

[0078] It should be noted that the equivalent impedance of the first winding and the high-voltage winding is the impedance viewed from the intermediate voltage side, representing the impedance of the intermediate voltage side and the high-voltage side, respectively. For example, the equivalent impedance can be a nominal value.

[0079] For example, assuming the rated voltage of the medium-voltage winding is 3.5kV, the rated current of the medium-voltage winding is 824.8A, the sum of the per-unit short-circuit impedances of the high-voltage and medium-voltage windings of a three-winding transformer is 12.31%, the rated capacity of the medium-voltage winding is 50kW, and the rated capacity of the high-voltage winding is 63kW, then the equivalent impedance of the first winding and the high-voltage winding is: K HM =(35000 / (824.8 / 1.732))×12.31%×(50000 / 63000)=7.180Ω.

[0080] S202. Based on the rated parameters of the first winding and the other winding, calculate the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test.

[0081] In some embodiments, the other winding is a winding other than the first winding among the medium-voltage winding and the low-voltage winding.

[0082] For example, if the first winding is a medium-voltage winding, then the other winding is a low-voltage winding. If the first winding is a low-voltage winding, then the other winding is a medium-voltage winding.

[0083] As one possible implementation, the temperature rise test device can determine the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test based on steps S2021-S2023.

[0084] S2021. Based on the rated current of the first winding and the voltage ratio between the first winding and the high-voltage winding, determine the first converted value of the rated current of the first winding on the high-voltage side.

[0085] As one possible implementation, the temperature rise test device can determine the first converted value based on the following formula.

[0086]

[0087] Among them, I' M As the first converted value, I M K1 is the rated current of the first winding and the voltage ratio between the first winding and the high-voltage winding.

[0088] For example, assuming the rated current of the medium-voltage winding is 824.8A and the voltage ratio between the medium-voltage winding and the high-voltage winding is 150 / 35, then the first converted value I'M =824.8 / (150 / 35)=192.4A.

[0089] S2022. Based on the rated current of the other winding and the voltage ratio between the other winding and the high-voltage winding, determine the second converted value of the rated current of the other winding on the high-voltage side.

[0090] Determine the first converted value of the rated current of the first winding on the high-voltage side.

[0091] As one possible implementation, the temperature rise test device can determine the first converted value based on the following formula.

[0092]

[0093] Among them, I' L For the second conversion value, I L K1 is the rated current of the other winding, and K2 is the voltage ratio between the other winding and the high-voltage winding.

[0094] For example, assuming the rated current of the low-voltage winding is 1191.4A and the voltage ratio between the low-voltage winding and the high-voltage winding is 150 / 6.3, then the second converted value I' L =1191.4 / (150 / 6.3)=50.0A.

[0095] S2023. Based on the first converted value, the second converted value, and the short-circuit impedance of the other winding, determine the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test.

[0096] As one possible implementation, the temperature rise test device can determine the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test based on the following formula.

[0097]

[0098] Among them, Z' M Z is the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test. L For the short-circuit impedance of the other winding, I' L The second converted value, I' M This is the first converted value.

[0099] For example, assuming the first equivalent value is 192.4A, the second equivalent value is 50A, and the impedance of the low-voltage winding is 8.77%, then the equivalent impedance of the medium-voltage winding is Z'. M =8.77% × 50 / 192.4 = 2.279%.

[0100] S203. Based on the equivalent impedance and the equivalent impedance of the first winding and the high-voltage winding, determine the impedance of the load test specimen.

[0101] As one possible implementation, the temperature rise test device can determine the impedance of the loaded specimen based on the following formula;

[0102]

[0103] Where X is the impedance of the loaded sample, Z H Z' is the short-circuit impedance of the high-voltage winding of a three-winding transformer. M U is the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test. KHM K is the sum of the per-unit values ​​of the short-circuit impedance of the high-voltage winding and the first winding of a three-winding transformer. HM This represents the equivalent impedance of the first winding and the high-voltage winding.

[0104] For example, assuming the short-circuit impedance of the high-voltage winding is 13.01%, the equivalent impedance of the medium-voltage winding is 2.279%, the sum of the per-unit values ​​of the short-circuit impedances of the high-voltage and medium-voltage windings is 12.31%, and the equivalent impedance of the first winding and the high-voltage winding is 7.18Ω, then the impedance of the load sample X = (13.01% + 2.279%) / 12.31% × 7.180 - 7.180 = 1.737Ω.

[0105] In this way, the present invention can obtain the load sample with the optimal impedance by calculating the impedance value of the load sample, thereby minimizing the temperature rise test time and increasing the temperature rise test speed.

[0106] Optionally, a loss detection module is connected in parallel with the load sample.

[0107] Correspondingly, such as Figure 6 As shown, the temperature rise test method for a three-winding transformer provided in this embodiment of the invention further includes steps S301-S302.

[0108] S301, Detect the loss of the load sample during the temperature rise test.

[0109] S302. Based on the losses of the load test specimen during the temperature rise test and the losses of each winding of the three-winding transformer, calculate the total losses of the three-winding transformer during the temperature rise test.

[0110] In this way, the present invention can calculate the losses during the temperature rise test while reducing the temperature rise test time and increasing the temperature rise test speed.

[0111] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0112] The following are device embodiments of the present invention. For details not described in detail, please refer to the corresponding method embodiments described above.

[0113] Figure 7 A schematic diagram of a temperature rise testing device for a three-winding transformer according to an embodiment of the present invention is shown. The three-winding transformer includes a high-voltage winding, a medium-voltage winding, and a low-voltage winding. The temperature rise testing device 400 includes a communication module 401 and a processing module 402.

[0114] The communication module 401 is used to obtain the rated parameters of each winding of the three-winding transformer, including rated capacity, rated voltage and rated current.

[0115] The processing module 402 is used to establish an equivalent circuit of the three-winding transformer based on the rated parameters of each winding; calculate the impedance of each winding based on the rated parameters of each winding and the equivalent circuit; connect a load test specimen to the winding with smaller impedance in the medium-voltage winding and the low-voltage winding, and short-circuit the winding with larger impedance to conduct a temperature rise test, wherein the load test specimen is a load with measurable losses.

[0116] In one possible implementation, the processing module 402 is further configured to calculate the equivalent impedance of the first winding and the high-voltage winding based on the rated parameters of the high-voltage winding and the first winding; wherein the first winding is the winding with smaller impedance among the medium-voltage winding and the low-voltage winding; calculate the equivalent impedance corresponding to the first winding reaching rated loss during the temperature rise test based on the rated parameters of the first winding and another winding; the other winding is the winding other than the first winding among the medium-voltage winding and the low-voltage winding; and determine the impedance of the load test specimen based on the equivalent impedance and the equivalent impedance of the first winding and the high-voltage winding.

[0117] In one possible implementation, the processing module 402 is specifically used to determine the equivalent impedance of the first winding and the high-voltage winding based on the following formula;

[0118]

[0119] Among them, K HM U is the equivalent impedance of the first winding and the high-voltage winding. MN I is the rated voltage of the first winding of the three-winding transformer. MN U is the rated current of the first winding of the three-winding transformer. KHM S is the sum of the per-unit values ​​of the short-circuit impedance of the high-voltage winding and the first winding of the three-winding transformer. MN S represents the rated capacity of the first winding of the three-winding transformer. HN This refers to the rated capacity of the high-voltage winding of the three-winding transformer.

[0120] In one possible implementation, the processing module 402 is specifically configured to: determine a first equivalent value of the rated current of the first winding on the high-voltage side based on the rated current of the first winding and the voltage ratio between the first winding and the high-voltage winding; determine a second equivalent value of the rated current of the other winding on the high-voltage side based on the rated current of the other winding and the voltage ratio between the other winding and the high-voltage winding; and determine the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test based on the first equivalent value, the second equivalent value, and the short-circuit impedance of the other winding.

[0121] In one possible implementation, the processing module 402 is specifically used to determine the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test based on the following formula;

[0122]

[0123] Among them, Z' M Z is the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test. L I' is the short-circuit impedance of the other winding. L The second converted value, I' M This is the first converted value.

[0124] In one possible implementation, the processing module 402 is specifically used to determine the impedance of the load specimen based on the following formula;

[0125]

[0126] Where X is the impedance of the loaded sample, and Z... H Z' is the short-circuit impedance of the high-voltage winding of the three-winding transformer. M U is the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test. KHM K is the sum of the per-unit values ​​of the short-circuit impedance of the high-voltage winding and the first winding of the three-winding transformer. HM The equivalent impedance of the first winding and the high-voltage winding is given.

[0127] In one possible implementation, the processing module 402 is specifically used to determine the impedance of each winding based on the following formula;

[0128]

[0129] Among them, Z H Z is the short-circuit impedance of the high-voltage winding of the three-winding transformer. M Z is the short-circuit impedance of the intermediate voltage winding of the three-winding transformer. LZ1 is the short-circuit impedance of the low-voltage winding of the three-winding transformer, Z2 is the detected value of the high-voltage winding after the medium-voltage winding is short-circuited, Z3 is the detected value of the high-voltage winding after the low-voltage winding is short-circuited, and Z4 is the detected value of the medium-voltage winding after the low-voltage winding is short-circuited.

[0130] In one possible implementation, a loss detection module is connected in parallel with the load test specimen; the communication module 401 is also used to detect the loss of the load test specimen during the temperature rise test; the processing module 402 is also used to calculate the total loss of the three-winding transformer during the temperature rise test based on the loss of the load test specimen during the temperature rise test and the loss of each winding of the three-winding transformer.

[0131] Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. For example... Figure 8 As shown, the electronic device 500 of this embodiment includes: a processor 501, a memory 502, and a computer program 503 stored in the memory 502 and executable on the processor 501. When the processor 501 executes the computer program 503, it implements the steps in the above-described method embodiments, for example... Figure 2 Steps 101 to 104 are shown. Alternatively, when the processor 501 executes the computer program 503, it implements the functions of each module / unit in the above-described device embodiments, for example... Figure 7 The functions of the communication module 401 and the processing module 402 shown are illustrated.

[0132] For example, the computer program 503 can be divided into one or more modules / units, which are stored in the memory 502 and executed by the processor 501 to complete the present invention. The one or more modules / units can be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program 503 in the electronic device 500. For example, the computer program 503 can be divided into... Figure 7 The communication module 401 and the processing module 402 are shown.

[0133] The processor 501 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0134] The memory 502 can be an internal storage unit of the electronic device 500, such as a hard disk or memory of the electronic device 500. The memory 502 can also be an external storage device of the electronic device 500, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the electronic device 500. Furthermore, the memory 502 can include both internal and external storage units of the electronic device 500. The memory 502 is used to store the computer program and other programs and data required by the terminal. The memory 502 can also be used to temporarily store data that has been output or will be output.

[0135] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0136] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0137] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0138] In the embodiments provided by this invention, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0139] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0140] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0141] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0142] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A temperature rise test method for a three-winding transformer, characterized by, The three-winding transformer comprises a high-voltage winding, a medium-voltage winding and a low-voltage winding, and the temperature rise test method comprises the following steps: obtaining rated parameters of each winding of the three-winding transformer, the rated parameters comprising rated capacity, rated voltage and rated current; establishing an equivalent circuit of the three-winding transformer based on the rated parameters of each winding; calculating the impedance of each winding based on the rated parameters of each winding and the equivalent circuit; connecting a load test sample to the winding with smaller impedance among the medium-voltage winding and the low-voltage winding and short-circuiting the winding with larger impedance, and performing a temperature rise test, the load test sample being a load with measurable loss; Before the step of connecting the load test sample to the winding with smaller impedance among the medium-voltage winding and the low-voltage winding and short-circuiting the winding with larger impedance and performing a temperature rise test, the method further comprises the following steps: calculating equivalent impedance of the first winding and the high-voltage winding based on the rated parameters of the high-voltage winding and the first winding, wherein the first winding is the winding with smaller impedance among the medium-voltage winding and the low-voltage winding; calculating equivalent impedance corresponding to rated loss of the first winding during the temperature rise test based on the rated parameters of the first winding and another winding, wherein the another winding is the winding other than the first winding among the medium-voltage winding and the low-voltage winding; and determining the impedance of the load test sample based on the equivalent impedance and the equivalent impedance of the first winding and the high-voltage winding.

2. The temperature rise test method of a three-winding transformer according to claim 1, characterized by, The step of calculating equivalent impedance of the first winding and the high-voltage winding based on the rated parameters of the high-voltage winding and the first winding comprises the following steps: determining the equivalent impedance of the first winding and the high-voltage winding based on the following formula; ； wherein is the equivalent impedance of the first winding and the high voltage winding, is the rated voltage of the first winding of the three winding transformer, is the rated current of the first winding of the three winding transformer, is the sum of the short circuit impedance base values of the high voltage winding and the first winding of the three winding transformer, is the rated capacity of the first winding of the three winding transformer, is the rated capacity of the high voltage winding of the three winding transformer.

3. The temperature rise test method of a three-winding transformer according to claim 1, characterized by, The step of calculating equivalent impedance corresponding to rated loss of the first winding during the temperature rise test based on the rated parameters of the first winding and another winding comprises the following steps: determining a first converted value of the rated current of the first winding on the high-voltage side based on the rated current of the first winding and the voltage transformation ratio of the first winding and the high-voltage winding; determining a second converted value of the rated current of the another winding on the high-voltage side based on the rated current of the another winding and the voltage transformation ratio of the another winding and the high-voltage winding; determining the equivalent impedance corresponding to rated loss of the first winding during the temperature rise test based on the first converted value, the second converted value and the short-circuit impedance of the another winding.

4. The temperature rise test method of a three-winding transformer according to claim 3, characterized by, The step of determining the equivalent impedance corresponding to rated loss of the first winding during the temperature rise test based on the first converted value, the second converted value and the short-circuit impedance of the another winding comprises the following steps: determining the equivalent impedance corresponding to rated loss of the first winding during the temperature rise test based on the following formula; ； wherein, is an equivalent impedance of the first winding corresponding to rated loss at the time of temperature rise test, is a short-circuit impedance of the other winding, is a second reduced value, is a first reduced value.

5. The temperature rise test method of a three-winding transformer according to claim 1, characterized by, The step of determining the impedance of the load test sample based on the equivalent impedance and the equivalent impedance of the first winding and the high-voltage winding comprises the following steps: determining the impedance of the load test sample based on the following formula; ； wherein, Z is the impedance of the load, Z is the short circuit impedance of the high voltage winding of the three winding transformer, Z is the equivalent impedance of the first winding at the rated loss during the temperature rise test, Z is the sum of the short circuit impedance of the high voltage winding and the first winding of the three winding transformer in per unit, Z is the equivalent impedance of the first winding and the high voltage winding.

6. The temperature rise test method of a three-winding transformer according to claim 1, characterized by, The step of calculating the impedance of each winding based on the rated parameters of each winding and the equivalent circuit comprises the following steps: determining the impedance of each winding based on the following formula; ； wherein ZHP is the short circuit impedance of the high voltage winding of the three winding transformer, ZMV is the short circuit impedance of the medium voltage winding of the three winding transformer, ZLV is the short circuit impedance of the low voltage winding of the three winding transformer, ZHPMV is the detection value of the high voltage winding after short circuit of the medium voltage winding, ZHPLV is the detection value of the high voltage winding after short circuit of the low voltage winding, ZMVLV is the detection value of the medium voltage winding after short circuit of the low voltage winding.

7. The temperature rise test method of a three-winding transformer according to claim 1, characterized by, The load test sample is connected in parallel with a loss detection module. The temperature rise test method further comprises the following steps: detecting loss of the load test sample during the temperature rise test; The total loss of the three-winding transformer during the temperature rise test is calculated based on the loss of the load sample and the loss of each winding of the three-winding transformer.

8. A temperature rise test device for a three-winding transformer, characterized by The three-winding transformer comprises a high-voltage winding, a medium-voltage winding and a low-voltage winding, and the temperature rise test device comprises: The communication module is configured to acquire rated parameters of each winding of the three-winding transformer, the rated parameters comprising rated capacity, rated voltage and rated current. The processing module is configured to establish an equivalent circuit of the three-winding transformer based on the rated parameters of each winding, calculate the impedance of each winding based on the rated parameters of each winding and the equivalent circuit, connect the load sample to the winding with smaller impedance among the medium-voltage winding and the low-voltage winding and short-circuit the winding with larger impedance to perform the temperature rise test, and the load sample is a load with measurable loss. The processing module is further configured to calculate the equivalent impedance of the first winding and the high-voltage winding based on the rated parameters of the first winding and the high-voltage winding, wherein the first winding is the winding with smaller impedance among the medium-voltage winding and the low-voltage winding, calculate the equivalent impedance corresponding to the rated loss of the first winding during the temperature rise test based on the rated parameters of the first winding and another winding, wherein the another winding is the winding other than the first winding among the medium-voltage winding and the low-voltage winding, and determine the impedance of the load sample based on the equivalent impedance and the equivalent impedance of the first winding and the high-voltage winding.

9. An electronic device, comprising: The electronic device comprises a memory and a processor, the memory stores a computer program, and the processor is configured to call and run the computer program stored in the memory to execute the method according to any one of claims 1 to 7. The electronic device comprises a memory and a processor, the memory stores a computer program, and the processor is configured to call and run the computer program stored in the memory to execute the method according to any one of claims 1 to 7.

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