A method for analyzing on-load voltage regulation applied to transformer voltage transformation

Abstract

The present invention discloses an on-load voltage regulation analysis method applied to transformer voltage transformation, which solves the shortcomings of the prior art and comprises the following steps: step 1, the transformer receives a voltage transformation control instruction, and the transformer checks and detects whether a voltage transformation state is met. If the voltage transformation state is met, the transformer is prepared for voltage transformation; step 2, the transformer adjusts the number of winding turns to perform voltage transformation; step 3, after the voltage transformation is completed, it is detected whether the working parameters of the transformer are normal. If the working parameters are abnormal, the transformer is switched back to the initial state, and relevant personnel are informed of the voltage transformation failure at the same time, and the process jumps to step 4; step 4, state data when the voltage transformation fails is recorded; step 5, cluster analysis is performed on all state data to determine the cluster center, and the cluster center is characteristic data; step 6, relevant personnel analyze the characteristic data to find the cause of the transformer voltage transformation failure.

Description

Technical Field

[0001] The present invention relates to the technical field of transformers, and in particular to an on-load voltage regulation analysis method applied to transformer voltage transformation. Background Art

[0002] Transformers are essential equipment for power transmission and distribution, widely used in industries such as industry, agriculture, transportation, and urban communities. Transformers are crucial components in AC power transmission, and their safe operation is crucial to the reliability and stability of power systems. With the continuous expansion of power grids and the continuous increase in voltage levels, transformer testing has become increasingly important.

[0003] When existing transformers are performing transformation, if the transformation fails, they will only sound an alarm to remind relevant personnel to take timely measures. The cause of the transformation failure cannot be found or the cause of the transformation failure is not analyzed, which causes problems in the transformer's working safety and also affects the transformer's working efficiency.

[0004] China Patent Publication No. CN111044101A, published on April 21, 2020, and titled "Transformer Monitoring System and Monitoring Method," discloses a transformer monitoring system comprising: a meteorological connection device, a transformer detection device, a transformer compensation device, and a drive device. The meteorological connection device obtains meteorological data within a preset range and determines whether it meets a preset meteorological data threshold, outputting the determination result to the drive device; the drive device sends a first call instruction to the transformer detection device; the transformer detection device detects whether the transformer's operating data meets a preset safety threshold based on the first call instruction and outputs the detection result to the drive device; the drive device sends a second call instruction to the transformer compensation device based on the detection result; and the transformer compensation device compensates the transformer based on the second call instruction. The disadvantage is that this patent only monitors the transformer's working environment and cannot monitor the transformer's transformation process or identify the cause of transformer transformation failure. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects in the prior art that if a transformer fails to transform, the cause of the transformation failure cannot be found or the cause of the transformation failure is lacking analysis, and to provide an on-load tap change analysis method applied to transformer transformation.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A method for analyzing on-load tap change applied to transformer voltage transformation includes the following steps:

[0008] Step 1: The transformer receives a voltage transformation control instruction, and checks whether the transformer meets the voltage transformation state. If the transformer meets the voltage transformation state, the transformer prepares for voltage transformation.

[0009] Step 2: The transformer adjusts the number of winding turns to transform the voltage;

[0010] Step 3: After the transformation is completed, check whether the working parameters of the transformer are normal. If the working parameters are normal, the transformation is completed; if the working parameters are abnormal, the transformer is switched back to the initial state, and the relevant personnel are informed of the transformation failure, and jump to step 4;

[0011] Step 4, recording the status data when the transformation fails, the status data including the parameter data of the transformer before and after the transformation, and recording the external environmental parameters at that time and the operating parameters of the line where the transformer is located;

[0012] Step 5: Perform cluster analysis on all state data to determine the cluster center, which is the feature data;

[0013] Step 6: Relevant personnel analyze the characteristic data to find the cause of the transformer failure.

[0014] In this solution, if the transformer fails to transform, the various required parameter data when the transformer fails to transform are recorded in time, and then by clustering the parameter data, the clusters can be found to obtain the characteristic data of all transformers when the transformer fails to transform. Relevant personnel can analyze the characteristic data to find out the cause of the transformation failure in time, and thus take corresponding measures to improve the stability of the transformer operation and improve the working efficiency of the transformer.

[0015] Preferably, the on-load tap-changing analysis method applied to transformer transformation further analyzes the state of the transformer when it is ready to transform, and determines whether the transformer can successfully transform based on the analysis results, specifically:

[0016] Sub-step 1: collecting current state data of the transformer when preparing for transformation, the current state data including parameter data before transformation, external environmental parameters at that time, and operating parameters of the line where the transformer is located;

[0017] Sub-step 2: performing a similarity comparison between the current state data of the transformer when it is ready to be transformed and the parameter data of the transformer before the transformation, the external environmental parameters at that time, and the operating parameters of the line where the transformer is located in the historical data, and finding the most similar historical state data. The corresponding parameter data after the transformation in the most similar historical state data is used as the estimated parameter data of the current transformer after the transformation, and the estimated parameter data of the current transformer after the transformation is used as part of the current state data.

[0018] Sub-step 3, performing cluster analysis on the current state data of the transformer when it is ready to transform as the data to be analyzed;

[0019] Sub-step 4: If the Euclidean distance between the clustering result and a certain cluster center is less than or equal to a set threshold, then the clustering result is judged to be similar to the feature data corresponding to the cluster center, and the probability of successful transformer transformation is judged to be low; if the Euclidean distance between the clustering result and a certain cluster center is greater than a set first threshold, then the probability of successful transformer transformation is judged to be high;

[0020] Sub-step 5: If the probability of the transformer successfully transforming is low, the relevant personnel are informed and the relevant personnel determine whether the transformation is needed. If the probability of the transformer successfully transforming is high, the transformer adjusts the number of winding turns to transform.

[0021] This scheme can predict whether the transformer can perform stable voltage transformation. If the Euclidean distance between the clustering result and a certain cluster center is less than or equal to the set threshold, it indicates that the current working state of the transformer is similar to the working state when the transformer failed to transform in the past. In this case, the probability of successful voltage transformation of the transformer is low. Otherwise, the probability of successful voltage transformation of the transformer is high.

[0022] Preferably, in the sub-step 2, the similarity comparison includes comparison in three dimensions: parameter data of the transformer before transformation, external environmental parameters at that time, and operating parameters of the line where the transformer is located. The parameter data of the transformer before transformation include the original voltage value of the transformer ready for transformation, the transformer transformation method, the transformer operation time and the location of the transformer; the external environmental parameters at that time include temperature, humidity and time, and the operating parameters of the line where the transformer is located include line operation time and line operation load. The weight of each specific parameter is derived based on expert experience.

[0023] Preferably, in sub-step 4, if the Euclidean distance between the clustering result and a certain state data is less than a set second threshold, the probability of the transformer successfully transforming is determined to be low. The value of the second threshold is less than the first threshold. This solution indicates that even if the Euclidean distance between the clustering result and the cluster center is far but the Euclidean distance between the cluster result and a certain state data is close, the probability of the transformer successfully transforming is still determined to be low.

[0024] Preferably, the transformer has three voltage transformation modes, including linear voltage regulation, positive and negative voltage regulation, and coarse and fine voltage regulation.

[0025] Preferably, the linear voltage regulation is as follows: the tap winding is fixed in the main winding, the voltage ratio is changed by increasing or decreasing the turns of the tap winding, and any tap position can be used as the rated position.

[0026] Preferably, the positive and negative voltage regulation is specifically as follows: the tap winding is connected to the high-voltage basic winding in the positive or negative direction, and the tap winding is one-half of the entire voltage regulation range segment; a polarity selector is configured in the vacuum on-load tap changer to implement the polarity conversion operation of the tap winding, and a unipolar selector is used for the positive and negative voltage regulation, thereby roughly doubling the tap range; the unipolar selector connects the tap winding to the main winding in a vector addition or subtraction manner, thereby increasing the tap winding voltage regulation range or reducing the number of taps.

[0027] Preferably, the coarse and fine voltage regulation is as follows: the tap winding is composed of a coarse and a fine adjustment part, the fine adjustment winding is connected in series with the coarse adjustment winding and the high-voltage basic winding, or the fine adjustment winding is connected only to the high-voltage basic winding; a coarse adjustment selector is configured in the vacuum on-load tap changer to perform the coarse and fine adjustment switching operation of the tap winding; a single coarse adjustment selector is used for the coarse and fine voltage regulation, so that the tap winding can be added to or subtracted from the coarse adjustment winding to increase or decrease the voltage regulation range.

[0028] Preferably, when the voltage transformation scenario is 220kV transformer transformation, the voltage transformation method is positive and negative voltage regulation or coarse and fine voltage regulation; when the voltage transformation scenario is 10kV or 35kV transformer transformation, the voltage transformation method is linear voltage regulation.

[0029] The beneficial effects of the present invention are as follows: when a transformer fails to transform, the on-load tap-changing analysis method of the present invention promptly records various required parameter data when the transformer fails to transform, then performs cluster analysis on the parameter data to find clusters to obtain characteristic data of all transformer failures. Relevant personnel can promptly identify the cause of the transformation failure by analyzing the characteristic data, thereby taking corresponding measures to improve the stability of the transformer and improve the working efficiency of the transformer. At the same time, the present invention detects the real-time status of the transformer and promptly determines whether the transformer can transform normally, further improving the stability and effectiveness of the transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0031] The present invention will be further described below with reference to the accompanying drawings and examples.

[0032] Example:

[0033] A method for analyzing on-load tap change applied to transformer voltage transformation, such as Figure 1 As shown, the following steps are included:

[0034] Step 1: The transformer receives a voltage transformation control instruction, and checks whether the transformer meets the voltage transformation state. If the transformer meets the voltage transformation state, the transformer prepares for voltage transformation.

[0035] Step 2: The transformer adjusts the number of winding turns to transform the voltage;

[0036] Step 3: After the transformation is completed, check whether the working parameters of the transformer are normal. If the working parameters are normal, the transformation is completed; if the working parameters are abnormal, the transformer is switched back to the initial state, and the relevant personnel are informed of the transformation failure, and jump to step 4;

[0037] Step 4, recording the status data when the transformation fails, the status data including the parameter data of the transformer before and after the transformation, and recording the external environmental parameters at that time and the operating parameters of the line where the transformer is located;

[0038] Step 5: Perform cluster analysis on all state data to determine the cluster center, which is the feature data;

[0039] Step 6: Relevant personnel analyze the characteristic data to find the cause of the transformer failure.

[0040] In this solution, if the transformer fails to transform, the various required parameter data when the transformer fails to transform are recorded in time, and then by clustering the parameter data, the clusters can be found to obtain the characteristic data of all transformers when the transformer fails to transform. Relevant personnel can analyze the characteristic data to find out the cause of the transformation failure in time, and thus take corresponding measures to improve the stability of the transformer operation and improve the working efficiency of the transformer.

[0041] The on-load tap change analysis method applied to transformer transformation also analyzes the state of the transformer when it is ready to transform, and determines whether the transformer can successfully transform based on the analysis results. Specifically:

[0042] Sub-step 1: collecting current state data of the transformer when preparing for transformation, the current state data including parameter data before transformation, external environmental parameters at that time, and operating parameters of the line where the transformer is located;

[0043] Sub-step 2: performing a similarity comparison between the current state data of the transformer when it is ready to be transformed and the parameter data of the transformer before the transformation, the external environmental parameters at that time, and the operating parameters of the line where the transformer is located in the historical data, and finding the most similar historical state data. The corresponding parameter data after the transformation in the most similar historical state data is used as the estimated parameter data of the current transformer after the transformation, and the estimated parameter data of the current transformer after the transformation is used as part of the current state data.

[0044] Sub-step 3, performing cluster analysis on the current state data of the transformer when it is ready to transform as the data to be analyzed;

[0045] Sub-step 4: If the Euclidean distance between the clustering result and a certain cluster center is less than or equal to a set threshold, then the clustering result is judged to be similar to the feature data corresponding to the cluster center, and the probability of successful transformer transformation is judged to be low; if the Euclidean distance between the clustering result and a certain cluster center is greater than a set first threshold, then the probability of successful transformer transformation is judged to be high;

[0046] Sub-step 5: If the probability of the transformer successfully transforming is low, the relevant personnel are informed and the relevant personnel determine whether the transformation is needed. If the probability of the transformer successfully transforming is high, the transformer adjusts the number of winding turns to transform.

[0047] This scheme can predict whether the transformer can perform stable voltage transformation. If the Euclidean distance between the clustering result and a certain cluster center is less than or equal to the set threshold, it indicates that the current working state of the transformer is similar to the working state when the transformer failed to transform in the past. In this case, the probability of successful voltage transformation of the transformer is low. Otherwise, the probability of successful voltage transformation of the transformer is high.

[0048] In the sub-step 2, the similarity comparison includes comparisons in three dimensions: parameter data of the transformer before transformation, external environmental parameters at that time, and operating parameters of the line where the transformer is located. The parameter data of the transformer before transformation includes the original voltage value of the transformer ready for transformation, the transformer transformation method, the transformer operation time, and the location of the transformer; the external environmental parameters at that time include temperature, humidity, and time; the operating parameters of the line where the transformer is located include line operation time and line operation load, and the weight of each specific parameter is derived based on expert experience.

[0049] In sub-step 4, if the Euclidean distance between the clustering result and a particular state data point is less than a set second threshold, the probability of the transformer successfully transforming is determined to be low. The second threshold is smaller than the first threshold. This solution indicates that even if the Euclidean distance between the clustering result and the cluster center is far but the Euclidean distance to a particular state data point is close, the probability of the transformer successfully transforming is still determined to be low.

[0050] There are three ways of voltage transformation of the transformer, including linear voltage regulation, positive and negative voltage regulation and coarse and fine voltage regulation.

[0051] The linear voltage regulation is specifically as follows: the tap winding is fixed in the main winding, and the voltage ratio is changed by increasing or decreasing the turns of the tap winding. Any tap position can be used as the rated position.

[0052] The positive and negative voltage regulation is specifically as follows: the tap winding is connected to the high-voltage basic winding in the positive or negative direction, and the tap winding accounts for half of the entire voltage regulation range; a polarity selector is configured in the vacuum on-load tap changer to implement polarity conversion of the tap winding; a unipolar selector is used for positive and negative voltage regulation, which roughly doubles the tap range; and the unipolar selector connects the tap winding to the main winding in a vector addition or subtraction manner, thereby increasing the tap winding voltage regulation range or reducing the number of taps.

[0053] The coarse and fine voltage regulation described is specifically as follows: the tap winding consists of a coarse and a fine adjustment part, the fine adjustment winding is connected in series with the coarse adjustment winding and the high-voltage basic winding, or the fine adjustment winding is connected only to the high-voltage basic winding; a coarse adjustment selector is configured in the vacuum on-load tap changer to perform the coarse and fine adjustment switching operation of the tap winding; a single coarse adjustment selector is used for the coarse and fine voltage regulation, so that the tap winding can be added to or subtracted from the coarse adjustment winding to increase or decrease the voltage regulation range.

[0054] When the voltage transformation scenario is a 220kV transformer, the voltage transformation method is forward and reverse voltage regulation or coarse and fine voltage regulation. When the voltage transformation scenario is a 10kV or 35kV transformer, the voltage transformation method is linear voltage regulation.

[0055] The embodiment described above is only a preferred solution of the present invention and does not limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solution described in the claims.

Claims

1. A method for analyzing on-load tap change applied to transformer voltage transformation, characterized in that: The following steps are involved: Step 1: The transformer receives a voltage transformation control instruction, and checks whether the transformer meets the voltage transformation state. If the transformer meets the voltage transformation state, the transformer prepares for voltage transformation. Step 2: The transformer adjusts the number of winding turns to transform the voltage; Step 3: After the transformation is completed, check whether the working parameters of the transformer are normal. If the working parameters are normal, the transformation is completed; if the working parameters are abnormal, the transformer is switched back to the initial state, and the relevant personnel are informed of the transformation failure, and jump to step 4; Step 4, recording the status data when the transformation fails, the status data including the parameter data of the transformer before and after the transformation, and recording the external environmental parameters at that time and the operating parameters of the line where the transformer is located; Step 5: Perform cluster analysis on all state data to determine the cluster center, which is the feature data; Step 6: Relevant personnel analyze the characteristic data to find the cause of the transformer failure; The state of the transformer when it is ready to transform is also analyzed, and based on the analysis results, it is determined whether the transformer can successfully transform. Specifically: Sub-step 1: collecting current state data of the transformer when preparing for transformation, the current state data including parameter data before transformation, external environmental parameters at that time, and operating parameters of the line where the transformer is located; Sub-step 2: performing a similarity comparison between the current state data of the transformer when it is ready to be transformed and the parameter data of the transformer before the transformation, the external environmental parameters at that time, and the operating parameters of the line where the transformer is located in the historical data, and finding the most similar historical state data. The corresponding parameter data after the transformation in the most similar historical state data is used as the estimated parameter data of the current transformer after the transformation, and the estimated parameter data of the current transformer after the transformation is used as part of the current state data. Sub-step 3, performing cluster analysis on the current state data of the transformer when it is ready to transform as the data to be analyzed; Sub-step 4: If the Euclidean distance between the clustering result and a certain cluster center is less than or equal to a set threshold, then the clustering result is judged to be similar to the feature data corresponding to the cluster center, and the probability of successful transformer transformation is judged to be low; if the Euclidean distance between the clustering result and a certain cluster center is greater than a set first threshold, then the probability of successful transformer transformation is judged to be high; Sub-step 5: If the probability of the transformer successfully transforming is low, the relevant personnel are informed and the relevant personnel determine whether the transformation is needed. If the probability of the transformer successfully transforming is high, the transformer adjusts the number of winding turns to transform.

2. The on-load tap change analysis method for transformer transformation according to claim 1 is characterized in that: In the sub-step 2, the similarity comparison includes comparisons in three dimensions: parameter data of the transformer before transformation, external environmental parameters at that time, and operating parameters of the line where the transformer is located. The parameter data of the transformer before transformation includes the original voltage value of the transformer ready for transformation, the transformer transformation method, the transformer operation time, and the location of the transformer; the external environmental parameters at that time include temperature, humidity, and time; the operating parameters of the line where the transformer is located include line operation time and line operation load, and the weight of each specific parameter is derived based on expert experience.

3. The on-load tap change analysis method for transformer transformation according to claim 1 is characterized in that: In sub-step 4, if the Euclidean distance between the clustering result and a certain state data is less than a set second threshold, it is determined that the probability of successful voltage transformation of the transformer is low.

4. The on-load tap change analysis method for transformer transformation according to claim 2 is characterized in that: There are three ways of voltage transformation of the transformer, including linear voltage regulation, positive and negative voltage regulation and coarse and fine voltage regulation.

5. The on-load tap change analysis method for transformer transformation according to claim 4 is characterized in that: The linear voltage regulation is specifically as follows: the tap winding is fixed in the main winding, and the voltage ratio is changed by increasing or decreasing the turns of the tap winding. Any tap position can be used as the rated position.

6. The on-load tap change analysis method for transformer transformation according to claim 4 is characterized in that: The positive and negative voltage regulation is specifically as follows: the tap winding is connected to the high-voltage basic winding in the positive or negative direction, and the tap winding accounts for half of the total voltage regulation range; a polarity selector is configured in the vacuum on-load tap changer to implement polarity conversion of the tap winding; a unipolar selector is used for positive and negative voltage regulation, doubling the tap range; the unipolar selector connects the tap winding to the main winding in a vector addition or subtraction manner, thereby increasing the tap winding voltage regulation range or reducing the number of taps.

7. The on-load tap change analysis method for transformer transformation according to claim 4 is characterized in that: The coarse and fine voltage regulation described is specifically as follows: the tap winding consists of a coarse and a fine adjustment part, the fine adjustment winding is connected in series with the coarse adjustment winding and the high-voltage basic winding, or the fine adjustment winding is connected only to the high-voltage basic winding; a coarse adjustment selector is configured in the vacuum on-load tap changer to perform the coarse and fine adjustment switching operation of the tap winding; a single coarse adjustment selector is used for the coarse and fine voltage regulation, so that the tap winding can be added to or subtracted from the coarse adjustment winding to increase or decrease the voltage regulation range.

8. The on-load tap-changing analysis method for transformer transformation according to claim 4 is characterized in that: When the voltage transformation scenario is a 220kV transformer, the voltage transformation method is forward and reverse voltage regulation or coarse and fine voltage regulation. When the voltage transformation scenario is a 10kV or 35kV transformer, the voltage transformation method is linear voltage regulation.

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