Cooler water flow signal analysis method and system

Abstract

The present invention discloses a cooler water flow signal analysis method and system, wherein the method comprises: obtaining a cooler water flow signal monitoring data source, including a flow switch value and an analog signal output by a cooler flow meter; performing cooler water flow signal judgment based on the cooler water flow signal monitoring data source, including judgment of the cooler water flow signal quality, judgment of the cooler commissioning status, and judgment of cooler water flow anomalies; and selecting whether to output a cooler fault alarm signal and a cooler start / stop control command based on the cooler water flow signal judgment result. The present invention uses the flow switch value and analog signal output by the flow meter installed on the cooler body as the cooler water flow signal monitoring data source, and processes and analyzes the data source through an adaptive water flow signal judgment method, effectively improving the reliability of the cooler water flow signal judgment, thereby solving the problem that the water flow signal judgment is easily interfered with by external environmental factors and frequently causes false alarms.

Description

Technical Field

[0001] The present invention relates to the technical field of power transformer operation, and in particular to a cooler water flow signal analysis method and system. Background Art

[0002] Large power transformers typically require a cooling system to control the transformer's operating temperature rise. Water cooling is a common cooling method, where the cooler uses flowing water to exchange and dissipate the heat generated by the transformer's operation. To monitor the operation of cooling water and accessories such as pipelines, monitoring equipment such as probes or flow meters are installed in the pipelines to monitor the cooler's water flow signal in real time. However, in actual applications, probes or flow meters are easily affected by external environmental factors such as installation location limitations, poor water quality, and electromagnetic interference. The cooler's water flow signal has a high false alarm rate, such as false alarms of abnormal water flow when the cooler is operating normally, and false alarms of normal water flow when the cooler is shut down. These abnormal alarm signals frequently cause false alarms to refresh monitoring events and frequently start and stop standby coolers, seriously affecting the monitoring of transformer cooler operation. Summary of the Invention

[0003] In order to solve the above problems, the present invention proposes a cooler water flow signal analysis method and system, which uses the flow switch quantity and analog signal output by the flow meter installed on the cooler body as the cooler water flow signal monitoring data source, and reliably judges the cooler water flow signal through an adaptive water flow signal judgment method.

[0004] The technical solution adopted in the present invention is as follows:

[0005] In one aspect, the present invention provides a method for analyzing a cooler water flow signal, comprising:

[0006] Obtain the cooler water flow signal monitoring data source, including the flow switch value and analog signal output by the cooler flow meter;

[0007] Based on the cooler water flow signal monitoring data source, the cooler water flow signal is judged, including the cooler water flow signal quality judgment, the cooler operation status judgment and the cooler water flow abnormality judgment;

[0008] Based on the cooler water flow signal judgment result, it is selected whether to output the cooler fault alarm signal and the cooler start-stop control command.

[0009] Furthermore, the cooler water flow signal quality judgment includes: judging whether only one of the switch signal and the analog signal has input, whether the switch signal frequently jitters, or whether the analog signal exceeds the upper limit or lower limit based on the switch signal and the analog signal output by the cooler flow meter, thereby judging whether the cooler water flow signal quality is normal.

[0010] Furthermore, if the quality of the water flow signal of one or several coolers is judged to be unqualified, an abnormal alarm signal of the cooler water flow signal quality is output and the alarm signal is reported to the monitoring system; if the quality of the water flow signal of all coolers is judged to be qualified, the cooler operation status is judged.

[0011] Furthermore, the cooler operation status judgment includes: if the actual value of the cooler water flow is greater than the cooler water flow threshold, and the cooler control system has output a command to start the cooler, then the cooler is judged to be in operation.

[0012] Furthermore, the cooler water flow abnormality judgment includes:

[0013] Step S3-1: Calculate the total water flow rate Q of the cooler 总 =Q1+Q2+......+Q n , which is the sum of the water flow output by all cooler flow meters;

[0014] Step S3-2: Calculate the average flow rate Q of the cooler water flow 平 =Q 总 / M, where M is the number of coolers in operation determined by the cooler control system, and the obtained Q 平 That is the theoretical water flow rate value of each cooler currently in operation;

[0015] Step S3-3: Calculate the mean difference Q of the water flow rate of the i-th cooler that should be in operation iD =Q i -Q 平 , the obtained Q iD That is, the deviation between the actual water flow rate of cooler No. i and the theoretical water flow rate, where 1≤i≤n;

[0016] Step S3-4: If the water flow rate of the i-th cooler that should be in operation is different from the mean value Q iD is a negative deviation and |Q iD |>Q FD , it is judged that the water flow rate of the cooler is lower than the actual water flow rate, where Q FD The value includes the water flow rate at the minimum allowable opening of the cooler design or 60% Q 平 ;

[0017] Step S3-5: If the water flow rate of the kth cooler that should be in operation is different from the mean value Q kD is a positive deviation and |Q kD |>Q ZD , it is judged that the water flow rate of the cooler is greater than the actual water flow rate, where 1≤k≤n, k≠i, Q ZD The value includes 20%Q 平;

[0018] Step S3-6: If the number of coolers meeting the criteria determined in step S3-4 is greater than or equal to 1, and the number of coolers meeting the criteria determined in step S3-5 is greater than or equal to 1, it is determined that there is an abnormality in the water flow of the cooler;

[0019] Step S3-7: If the water flow rate of cooler No. i, which should be in operation, meets the criteria of step S3-4 and step S3-6, the water flow of cooler No. i is judged to be abnormal, a cooler fault alarm signal is output, and a start-stop command is output to control the shutdown of the water flow fault cooler and the start-up of the standby cooler.

[0020] In another aspect, the present invention provides a cooler water flow signal analysis system, comprising:

[0021] A data acquisition module is configured to obtain a data source for monitoring a water flow signal of the cooler, including a flow switch value and an analog signal output by a flow meter of the cooler;

[0022] A water flow signal judgment module is configured to judge the cooler water flow signal based on the cooler water flow signal monitoring data source, including a cooler water flow signal quality judgment unit, a cooler operation status judgment unit, and a cooler water flow abnormality judgment unit;

[0023] The alarm signal output module is configured to select whether to output a cooler fault alarm signal and a cooler start / stop control command based on the cooler water flow signal judgment result.

[0024] Furthermore, the cooler water flow signal quality judgment unit is configured to: judge whether only one of the switch signal and the analog signal has input, whether the switch signal frequently jitters, or whether the analog signal exceeds the upper limit or lower limit based on the switch signal and the analog signal output by the cooler flow meter, thereby judging whether the quality of the cooler water flow signal is normal.

[0025] Furthermore, if the quality of the water flow signal of one or several coolers is judged to be unqualified, an abnormal alarm signal of the cooler water flow signal quality is output and the alarm signal is reported to the monitoring system; if the quality of the water flow signal of all coolers is judged to be qualified, the cooler operation status is judged.

[0026] Furthermore, the cooler operation status judgment unit is configured to: if the actual value of the cooler water flow is greater than the cooler water flow threshold, and the cooler control system has output a command to start the cooler, then judge that the cooler is in operation.

[0027] Furthermore, the cooler water flow abnormality judgment unit is configured to perform the following steps:

[0028] Step S3-1: Calculate the total water flow rate Q of the cooler 总 =Q1+Q2+......+Q n , which is the sum of the water flow output by all cooler flow meters;

[0029] Step S3-2: Calculate the average flow rate Q of the cooler water flow 平 =Q 总 / M, where M is the number of coolers in operation determined by the cooler control system, and the obtained Q 平 That is the theoretical water flow rate value of each cooler currently in operation;

[0030] Step S3-3: Calculate the mean difference Q of the water flow rate of the i-th cooler that should be in operation iD =Q i -Q 平 , the obtained Q iD That is, the deviation between the actual water flow rate of cooler No. i and the theoretical water flow rate, where 1≤i≤n;

[0031] Step S3-4: If the water flow rate of the i-th cooler that should be in operation is different from the mean value Q iD is a negative deviation and |Q iD |>Q FD , it is judged that the water flow rate of the cooler is lower than the actual water flow rate, where Q FD The value includes the water flow rate at the minimum allowable opening of the cooler design or 60% Q 平 ;

[0032] Step S3-5: If the water flow rate of the kth cooler that should be in operation is different from the mean value Q kD is a positive deviation and |Q kD |>Q ZD , it is judged that the water flow rate of the cooler is greater than the actual water flow rate, where 1≤k≤n, k≠i, Q ZD The value includes 20%Q 平 ;

[0033] Step S3-6: If the number of coolers meeting the criteria determined in step S3-4 is greater than or equal to 1, and the number of coolers meeting the criteria determined in step S3-5 is greater than or equal to 1, it is determined that there is an abnormality in the water flow of the cooler;

[0034] Step S3-7: If the water flow rate of cooler No. i, which should be in operation, meets the criteria of step S3-4 and step S3-6, the water flow of cooler No. i is judged to be abnormal, a cooler fault alarm signal is output, and a start-stop command is output to control the shutdown of the water flow fault cooler and the start-up of the standby cooler.

[0035] The beneficial effects of the present invention are:

[0036] 1. The present invention uses the flow switch value and analog signal output by the flow meter installed on the cooler body as the data source for monitoring the water flow signal of the cooler, and processes and analyzes the data source through an adaptive water flow signal judgment method. The reliability of the water flow signal judgment of the cooler is effectively improved, thereby solving the problem that the water flow signal judgment is easily affected by external environmental factors and frequently causes false alarms.

[0037] 2. The present invention connects the switch value and analog signal output by the flow meter to the cooler control system as the data source for monitoring the cooler water flow signal. It does not rely on a single signal as the main transformer cooler water flow signal judgment, which can avoid the misjudgment of the main transformer cooler water flow signal due to abnormality of a single signal source.

[0038] 3. The cooler water flow rate judgment method proposed in the present invention has a simple and reliable algorithm for judging water flow rate changes, and effectively improves the reliability of the cooler water flow signal judgment, thereby solving the problem that the water flow signal judgment is easily affected by external environmental factors and frequently causes false alarms. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a flow chart of a cooler water flow signal analysis method of the present invention.

[0040] Figure 2 It is a schematic diagram of the power system cooler and its control system.

[0041] Figure 3 This is a flow chart of a cooler water flow signal judgment method of the present invention. DETAILED DESCRIPTION

[0042] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention are now described. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. That is, the embodiments described are only part of the embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0043] like Figure 1 As shown, this embodiment provides a cooler water flow signal analysis method, including:

[0044] Obtain the cooler water flow signal monitoring data source, including the flow switch value and analog signal output by the cooler flow meter;

[0045] Based on the cooler water flow signal monitoring data source, the cooler water flow signal is judged, including the cooler water flow signal quality judgment, the cooler operation status judgment and the cooler water flow abnormality judgment;

[0046] Based on the cooler water flow signal judgment result, it is selected whether to output the cooler fault alarm signal and the cooler start-stop control command.

[0047] Accordingly, this embodiment further provides a cooler water flow signal analysis system, comprising:

[0048] A data acquisition module is configured to obtain a data source for monitoring a water flow signal of the cooler, including a flow switch value and an analog signal output by a flow meter of the cooler;

[0049] A water flow signal judgment module is configured to judge the cooler water flow signal based on the cooler water flow signal monitoring data source, including a cooler water flow signal quality judgment unit, a cooler operation status judgment unit, and a cooler water flow abnormality judgment unit;

[0050] The alarm signal output module is configured to select whether to output a cooler fault alarm signal and a cooler start / stop control command based on the cooler water flow signal judgment result.

[0051] like Figure 2 As shown, the on-off and analog signals output by the flowmeter are connected to the cooler control system as the data source for monitoring the cooler water flow signal and used for cooler water flow signal judgment. The cooler control system judges the cooler water flow signal based on the received on-off and analog signals. Based on the judgment result, it outputs a cooler fault alarm signal and starts and stops the cooler with water flow fault and the standby cooler, ensuring that the number of operating coolers meets the operating temperature rise requirements.

[0052] In this embodiment, each cooler is equipped with a flow meter. The flow meter is preferably installed in a straight section of the water pipe, and it is recommended that the installation location be at least 10 pipe diameters away from the water pipe bend or inlet and outlet mains. Preferably, the flow meter can output both flow rate switching and analog signals. Passive contact signals are preferred for switching signals, and 4-20mA signals are preferred for analog signals.

[0053] like Figure 3 As shown, this embodiment takes a system with 6 coolers as an example to explain in detail the method for determining the cooler water flow signal:

[0054] Step S1: Determine the quality of the cooler water flow signal

[0055] Based on the switch quantity and analog signal output by each cooler flow meter, determine whether the quality of the water flow signal of each cooler is normal. It is used to determine whether the output signal of the cooler flow meter or the corresponding input module is normal. The judgment logic includes but is not limited to only one of the switch quantity and analog signal being input, the switch quantity signal frequently jittering, and the analog signal exceeding the upper or lower limit.

[0056] If the quality of the water flow signal of the n#th cooler is judged to be unqualified, the cooler control system outputs an abnormal alarm signal of the water flow signal quality of the n# cooler, and sends the alarm signal to the monitoring system to remind the operation and maintenance personnel to check; if the quality of the water flow signals of the 6 coolers are all judged to be qualified, step S2 can be executed.

[0057] Step S2: Determine the cooler operation status

[0058] The operation status of the n# cooler is judged by the water flow rate Q of the n# cooler. n Greater than the water flow threshold Q mk The cooler control system issues a command to start the n# cooler and makes a judgment.

[0059] Among them, the cooler water flow threshold value Q mk Usually, the water flow rate is adjusted to avoid the interference caused by water pipe bends or water flow fluctuations in and out of the main pipe when the water valve is normally closed; the cooler control system issues a command to start the n# cooler, which is output by the control system's start and stop logic.

[0060] If the water flow rate of the n# cooler is Q n Greater than the water flow threshold Q mk , and the cooler control system issues a command to start the cooler, then the n# cooler is judged to be in operation.

[0061] If the cooler control system determines that the number of coolers in operation is greater than or equal to 1, step S3 may be executed.

[0062] Step S3: Determine if the water flow in the cooler is abnormal

[0063] Take a practical application as an example: the current cooler control system outputs commands to turn on coolers 1#, 2#, and 3#. The water flow of cooler 3# is reduced to 0 due to a water valve failure, that is, Q3 = 0;

[0064] In this practical application case, step S2 is satisfied and step S3 can be executed.

[0065] Step S3-1: Calculate the total water flow of the cooler

[0066] Q 总 =Q1+Q2+......+Q n =Q1+Q2+Q3=Q1+Q2=2Q1 (Q1 and Q2 are basically the same size);

[0067] Step S3-2: Calculate the average flow rate Q of the cooler water flow 平 =Q 总 / 3=2Q1 / 3, at this time the cooler control system determines that the number of coolers in operation is M, which is 3, and the obtained Q平 This is the theoretical water flow rate of each cooler currently in operation. This value is basically consistent with the flow rate of 1#, 2#, and 3# coolers during normal operation.

[0068] Step S3-3: Calculate the mean deviation Q of the water flow rate of cooler 1# 1D =Q1-Q 平 =Q1-2Q1 / 3=Q1 / 3, the obtained Q 1D That is, the deviation between the actual water flow rate of 1# cooler and the theoretical water flow rate; the deviation of the water flow rate of 2# cooler from the mean Q 2D =Q2-Q 平 =Q1-2Q1 / 3=Q1 / 3, the obtained Q 2D That is the deviation between the actual water flow rate of 2# cooler and the theoretical water flow rate; the deviation of the water flow rate of 3# cooler from the mean Q 3D =Q3-Q 平 = -2Q1 / 3, the obtained Q 3D That is, the deviation between the actual water flow rate of 3# cooler and the theoretical water flow rate;

[0069] Step S3-4: The water flow deviation Q of the 3# cooler that should be in operation 3D is a negative deviation and |Q nD |=2Q1 / 3>Q FD , it is judged that the water flow rate of 3# cooler is lower than the actual water flow rate, Q FD Press 60% Q 平 Setting;

[0070] Step S3-5: The water flow deviation Q of the 1# cooler that should be in operation 1D is a positive deviation and |Q 1D |=Q1 / 3>Q ZD ; The water flow deviation from the average value Q of the 2# cooler that should be in operation 1D is a positive deviation and |Q 2D |=Q1 / 3>Q ZD ; It is judged that the water flow rate of 1# and 2# coolers is larger than the actual water flow rate, Q ZD Press 20% Q 平 Setting;

[0071] Step S3-6: If the number of coolers meeting the criteria determined in step S3-4 is greater than or equal to 1, and if the number of coolers meeting the criteria determined in step S3-5 is greater than or equal to 1, then it is determined that there is an abnormality in the water flow of the cooler;

[0072] Step S3-7: If the water flow rate of cooler 3#, which should be in operation, meets the requirements of step S3-4 and step S3-6, then the water flow of cooler 3# is determined to be abnormal. The cooler control system outputs a fault alarm signal for cooler 3# and starts and stops the cooler with the water flow failure and the standby cooler.

[0073] It should be noted that, for the sake of simplicity, the aforementioned method embodiments are described as a series of action combinations. However, those skilled in the art should be aware that this application is not limited by the order of the actions described, because according to this application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in this specification are all preferred embodiments, and the actions and modules involved are not necessarily required by this application.

Claims

1. A method for analyzing cooler water flow signals, characterized in that: include: Obtain the cooler water flow signal monitoring data source, including the flow switch value and analog signal output by the cooler flow meter; Based on the cooler water flow signal monitoring data source, the cooler water flow signal is judged, including the cooler water flow signal quality judgment, the cooler operation status judgment and the cooler water flow abnormality judgment; Based on the cooler water flow signal judgment result, select whether to output a cooler fault alarm signal and a cooler start / stop control command; The abnormality judgment of cooler water flow includes: Step S3-1: Calculate the total water flow rate Q of the cooler 总 =Q1+Q2+......+Q n , which is the sum of the water flow output by all cooler flow meters; Step S3-2: Calculate the average flow rate Q of the cooler water flow 平 =Q 总 / M, where M is the number of coolers in operation determined by the cooler control system, and the obtained Q 平 That is the theoretical water flow rate value of each cooler currently in operation; Step S3-3: Calculate the mean difference Q of the water flow rate of the i-th cooler that should be in operation iD =Q i -Q 平 , the obtained Q iD That is, the deviation between the actual water flow rate of cooler No. i and the theoretical water flow rate, where 1≤i≤n; Step S3-4: If the water flow rate of the i-th cooler that should be in operation is different from the mean value Q iD is a negative deviation and |Q iD |>Q FD , it is judged that the water flow rate of the cooler is lower than the theoretical water flow rate, where Q FD The value of includes the water flow rate at the minimum allowable opening of the cooler design or 60% of Q 平 ; Step S3-5: If the water flow rate of the kth cooler that should be in operation is different from the mean value Q kD is a positive deviation and |Q kD |>Q ZD , it is judged that the water flow rate of the cooler is greater than the theoretical water flow rate, where 1≤k≤n, k≠i, Q ZD The value includes 20% of Q 平 ; Step S3-6: If the number of coolers meeting the criteria determined in step S3-4 is greater than or equal to 1, and the number of coolers meeting the criteria determined in step S3-5 is greater than or equal to 1, it is determined that there is an abnormality in the water flow of the cooler; Step S3-7: If the water flow rate of cooler No. i, which should be in operation, meets the criteria of step S3-4 and step S3-6, the water flow of cooler No. i is judged to be abnormal, a cooler fault alarm signal is output, and a start-stop command is output to control the shutdown of the water flow fault cooler and the start-up of the standby cooler.

2. A cooler water flow signal analysis method according to claim 1, characterized in that: The cooler water flow signal quality judgment includes: judging whether only one of the switch signal and the analog signal has input, whether the switch signal frequently jitters, or whether the analog signal exceeds the upper limit or the lower limit based on the switch signal and the analog signal output by the cooler flow meter, thereby judging whether the cooler water flow signal quality is normal.

3. The method for analyzing cooler water flow signals according to claim 2, characterized in that: If the quality of the water flow signal of one or several coolers is judged to be unqualified, an abnormal alarm signal of the cooler water flow signal quality will be output and reported to the monitoring system; if the quality of the water flow signal of all coolers is judged to be qualified, the cooler operation status will be judged.

4. The method for analyzing cooler water flow signals according to claim 1, characterized in that: The cooler operation status judgment includes: if the actual value of the cooler water flow is greater than the cooler water flow threshold, and the cooler control system has output a command to start the cooler, then the cooler is judged to be in operation.

5. A cooler water flow signal analysis system, characterized in that: include: A data acquisition module is configured to obtain a data source for monitoring a water flow signal of the cooler, including a flow switch value and an analog signal output by a flow meter of the cooler; A water flow signal judgment module is configured to judge the cooler water flow signal based on the cooler water flow signal monitoring data source, including a cooler water flow signal quality judgment unit, a cooler operation status judgment unit, and a cooler water flow abnormality judgment unit; an alarm signal output module, configured to select whether to output a cooler fault alarm signal and a cooler start / stop control command based on a cooler water flow signal judgment result; The cooler water flow abnormality judgment unit is configured to perform the following steps: Step S3-1: Calculate the total water flow rate Q of the cooler 总 =Q1+Q2+......+Q n , which is the sum of the water flow output by all cooler flow meters; Step S3-2: Calculate the average flow rate Q of the cooler water flow 平 =Q 总 / M, where M is the number of coolers in operation determined by the cooler control system, and the obtained Q 平 That is the theoretical water flow rate value of each cooler currently in operation; Step S3-3: Calculate the mean difference Q of the water flow rate of the i-th cooler that should be in operation iD =Q i -Q 平 , the obtained Q iD That is, the deviation between the actual water flow rate of cooler No. i and the theoretical water flow rate, where 1≤i≤n; Step S3-4: If the water flow rate of the i-th cooler that should be in operation is different from the mean value Q iD is a negative deviation and |Q iD |>Q FD , it is judged that the water flow rate of the cooler is lower than the theoretical water flow rate, where Q FD The value of includes the water flow rate at the minimum allowable opening of the cooler design or 60% of Q 平 ; Step S3-5: If the water flow rate of the kth cooler that should be in operation is different from the mean value Q kD is a positive deviation and |Q kD |>Q ZD , it is judged that the water flow rate of the cooler is greater than the theoretical water flow rate, where 1≤k≤n, k≠i, Q ZD The value includes 20% of Q 平 ; Step S3-6: If the number of coolers meeting the criteria determined in step S3-4 is greater than or equal to 1, and the number of coolers meeting the criteria determined in step S3-5 is greater than or equal to 1, it is determined that there is an abnormality in the water flow of the cooler; Step S3-7: If the water flow rate of cooler No. i, which should be in operation, meets the criteria of step S3-4 and step S3-6, the water flow of cooler No. i is judged to be abnormal, a cooler fault alarm signal is output, and a start-stop command is output to control the shutdown of the water flow fault cooler and the start-up of the standby cooler.

6. The cooler water flow signal analysis system according to claim 5, characterized in that: The cooler water flow signal quality judgment unit is configured to: judge whether only one of the switch signal and the analog signal has input, whether the switch signal frequently jitters, or whether the analog signal exceeds the upper limit or the lower limit based on the switch signal and the analog signal output by the cooler flow meter, thereby judging whether the quality of the cooler water flow signal is normal.

7. The cooler water flow signal analysis system according to claim 6, characterized in that: If the quality of the water flow signal of one or several coolers is judged to be unqualified, an abnormal alarm signal of the cooler water flow signal quality will be output and reported to the monitoring system; if the quality of the water flow signal of all coolers is judged to be qualified, the cooler operation status will be judged.

8. The cooler water flow signal analysis system according to claim 7, characterized in that: The cooler operation status judgment unit is configured to: if the actual value of the cooler water flow is greater than the cooler water flow threshold, and the cooler control system has output a command to start the cooler, then judge that the cooler is in operation.

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