A method and apparatus for monitoring operation of a power capacitor bank

Abstract

This invention provides a method and apparatus for monitoring the operation of a power capacitor bank. The method includes: monitoring the current monitoring values ​​corresponding to all capacitor units in the power capacitor bank; calculating the sum of distances between each current monitoring value and the center; obtaining the minimum value among the sums of distances as a monitoring reference value; calculating the deviation value of each capacitor unit based on the reference value; and judging the fault of the capacitor unit based on the deviation value, thereby realizing the operation monitoring of the capacitor unit. This invention provides a method for monitoring the operation of a power capacitor bank by monitoring the current corresponding to each capacitor unit and calculating the current deviation of each capacitor unit to form a judgment on the degree of current concentration and deviation of each capacitor unit in the power capacitor bank. This allows for direct fault judgment of the capacitor unit without the need to monitor the voltage value of the capacitor unit, greatly reducing monitoring costs and improving the efficiency of power capacitor bank monitoring.

Description

Technical Field

[0001] This invention relates to the field of capacitor bank monitoring technology, and in particular to a method and device for monitoring the operation of power capacitor banks. Background Technology

[0002] As core equipment for reactive power compensation and voltage stability maintenance in substations, the safe operation of power capacitor banks plays a crucial role in improving power system stability. Current technology for monitoring the operation of power capacitor banks primarily involves monitoring the current and voltage values ​​flowing through each capacitor cell to calculate its capacity. This capacity is then compared to the rated capacity of the capacitor cell. If the deviation is significant, the capacitor cell is considered faulty, and the monitoring system automatically issues an alarm.

[0003] However, the existing monitoring process requires monitoring the voltage value of the capacitor unit and calculating the capacitance value of the capacitor unit in combination with the monitoring current value before monitoring and judgment can be made. Therefore, the monitoring is relatively complicated and increases the cost of monitoring equipment. Summary of the Invention

[0004] The present invention aims to provide a method and device for monitoring the operation of power capacitor banks, so as to solve the above-mentioned technical problems, improve monitoring efficiency, and greatly reduce monitoring costs.

[0005] To address the aforementioned technical problems, this invention provides a method for monitoring the operation of a power capacitor bank, comprising the following steps:

[0006] Monitor the current values ​​corresponding to all capacitor units in the power capacitor bank;

[0007] Using each current monitoring value as the center, calculate the sum of the distances between other current monitoring values ​​and that center;

[0008] The minimum value of the distance and the sum is used as the baseline value for monitoring;

[0009] The deviation value of each capacitor unit is calculated based on the reference value;

[0010] The capacitor unit is fault-detected based on the deviation value, thereby enabling the monitoring of the capacitor unit's operation.

[0011] The above scheme calculates the deviation value of each capacitor unit by monitoring the current monitoring value corresponding to the capacitor unit, so as to form a judgment on the degree of current concentration and deviation of each phase of the power capacitor bank. It can directly diagnose the fault of the capacitor unit without monitoring the voltage value of the capacitor unit, which greatly reduces the monitoring cost and improves the monitoring efficiency of the power capacitor bank.

[0012] Furthermore, the calculation of the deviation value of each capacitor unit based on the reference value specifically involves: the expression for the deviation value of each capacitor unit is as follows:

[0013]

[0014] Where: m i I represents the deviation value of the i-th capacitor unit; i This represents the current monitoring value of the i-th capacitor cell; I k This represents the current value of the capacitor cell at the kth center.

[0015] In the above scheme, by calculating the deviation value of each capacitor unit, it is possible to judge the degree of concentration and deviation of the current values ​​of each phase of the power capacitor bank. This avoids the need to monitor the voltage value of the capacitor unit during the monitoring process, thus saving monitoring costs and improving monitoring efficiency.

[0016] Furthermore, the monitoring of the current monitoring values ​​corresponding to all capacitor units of the power capacitor bank specifically involves using a miniature current sensor to monitor the current monitoring values ​​corresponding to all capacitor units of the power capacitor bank.

[0017] Furthermore, after monitoring the current monitoring values ​​corresponding to all capacitor units of the power capacitor bank, the method further includes: collecting the total current value of each phase of the power capacitor bank, and performing accuracy verification processing on the miniature current sensor based on the current value and the current monitoring values ​​corresponding to all capacitor units of each phase.

[0018] In the above scheme, it is necessary to maintain the accuracy of monitoring at all times during the monitoring of the power capacitor bank. Therefore, by collecting the total current value of each phase of the power capacitor bank and comparing it with the current monitoring value monitored by each micro current sensor, it is possible to directly obtain whether each micro current sensor is in normal working condition and with normal accuracy, thus ensuring the accuracy of monitoring.

[0019] Furthermore, the process of collecting the total current value of each phase of the power capacitor bank and performing accuracy verification processing on the miniature current sensor based on the current value and the current monitoring value corresponding to all capacitor units in that phase is as follows: collecting the total current value of each phase of the power capacitor bank; calculating the difference between the total current value of each phase and the sum of the current monitoring values ​​corresponding to all capacitor units in that phase; if the difference exceeds a set threshold, then performing accuracy verification processing on the miniature current sensor.

[0020] This invention also provides a power capacitor bank operation monitoring device, including a current monitoring module, a distance calculation module, a reference value acquisition module, a deviation value calculation module, and a fault judgment module; wherein:

[0021] The current monitoring module is used to monitor the current monitoring values ​​corresponding to all capacitor units of the power capacitor bank.

[0022] The distance calculation module is used to calculate the sum of distances between each current monitoring value and its corresponding center;

[0023] The reference value acquisition module is used to obtain the minimum value of the distance and the sum as the reference value of the corresponding center;

[0024] The deviation value calculation module is used to calculate the deviation value of each capacitor unit based on the reference value;

[0025] The fault diagnosis module is used to diagnose faults in the capacitor unit based on the deviation value, thereby enabling operational monitoring of the capacitor unit.

[0026] Furthermore, the deviation value calculation module is used to calculate the deviation value of each capacitor unit based on the reference value, specifically: the expression for the deviation value of each capacitor unit is as follows:

[0027]

[0028] Where: m i I represents the deviation value of the i-th capacitor unit; i This represents the current monitoring value of the i-th capacitor cell; I k This represents the current value of the capacitor cell at the kth center.

[0029] Furthermore, the current monitoring module is used to monitor the current monitoring values ​​corresponding to all capacitor units of the power capacitor bank. Specifically, the current monitoring module uses a miniature current sensor to monitor the current monitoring values ​​corresponding to all capacitor units of the power capacitor bank.

[0030] Furthermore, the system also includes an accuracy verification module; the accuracy verification module is used to collect the total current value of each phase of the power capacitor bank, and to perform accuracy verification processing on the miniature current sensor based on the current value and the current monitoring value corresponding to all capacitor units of that phase.

[0031] Furthermore, the accuracy verification module is used to collect the total current value of each phase of the power capacitor bank, and to perform accuracy verification processing on the miniature current sensor based on the current value and the current monitoring value corresponding to all capacitor units. Specifically, it collects the total current value of each phase of the power capacitor bank; calculates the difference between the total current value of each phase and the sum of the current monitoring values ​​corresponding to all capacitor units in that phase; if the difference exceeds a set threshold, the miniature current sensor is subjected to accuracy verification processing. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of a power capacitor bank operation monitoring method according to an embodiment of the present invention;

[0033] Figure 2This is a schematic diagram of the module connection of a power capacitor bank operation monitoring device in one embodiment of the present invention. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Please see Figure 1 A method for monitoring the operation of a power capacitor bank includes the following steps:

[0036] S1: Monitors the current and temperature of all capacitor units in the power capacitor bank;

[0037] S2: Using each current monitoring value as the center, calculate the sum of the distances between other current monitoring values ​​and that center;

[0038] S3: Obtain the minimum value of the distance and use it as the baseline value for monitoring;

[0039] S4: Calculate the deviation value of each capacitor unit based on the reference value;

[0040] S5: Based on the deviation value, the capacitor unit is fault-determined to realize the operation monitoring of the capacitor unit.

[0041] This embodiment calculates the deviation value of each capacitor unit by monitoring the current monitoring value corresponding to the capacitor unit, so as to form a judgment on the degree of current concentration and deviation of each phase of the power capacitor bank. It can directly diagnose the fault of the capacitor unit without monitoring the voltage value of the capacitor unit, which greatly reduces the monitoring cost and improves the monitoring efficiency of the power capacitor bank.

[0042] It should be noted that since some capacitor devices do not have suitable interfaces for monitoring the voltage of each phase of the capacitor, this method can quickly meet the on-site monitoring needs, greatly reduce monitoring costs, and improve monitoring efficiency.

[0043] Furthermore, the calculation of the deviation value of each capacitor unit based on the reference value specifically involves: the expression for the deviation value of each capacitor unit is as follows:

[0044]

[0045] Where: m i I represents the deviation value of the i-th capacitor unit; i This represents the current monitoring value of the i-th capacitor cell; Ik This represents the current value of the capacitor cell at the kth center.

[0046] In this embodiment, by calculating the deviation value of each capacitor unit, a judgment can be made on the degree of concentration and deviation of the current values ​​of each phase of the power capacitor bank. This avoids the need to monitor the voltage value of the capacitor unit during the monitoring process, thus saving monitoring costs and improving monitoring efficiency.

[0047] Furthermore, the monitoring of the current monitoring values ​​corresponding to all capacitor units of the power capacitor bank specifically involves using a miniature current sensor to monitor the current monitoring values ​​corresponding to all capacitor units of the power capacitor bank.

[0048] Furthermore, after monitoring the current monitoring values ​​corresponding to all capacitor units of the power capacitor bank, the method further includes: collecting the total current value of each phase of the power capacitor bank, and performing accuracy verification processing on the miniature current sensor based on the current value and the current monitoring values ​​corresponding to all capacitor units of each phase.

[0049] In this embodiment, it is necessary to maintain the accuracy of monitoring at all times during the monitoring of the power capacitor bank. Therefore, by collecting the total current value of each phase of the power capacitor bank and comparing it with the current monitoring value monitored by each micro current sensor, it is possible to directly obtain whether each micro current sensor is in normal working condition and with normal accuracy, thus ensuring the accuracy of monitoring.

[0050] Furthermore, the process of collecting the total current value of each phase of the power capacitor bank and performing accuracy verification processing on the miniature current sensor based on the current value and the current monitoring value corresponding to all capacitor units in each phase is as follows: collecting the total current value of each phase of the power capacitor bank; calculating the difference between the total current value of each phase and the sum of the current monitoring values ​​corresponding to all capacitor units in that phase; if the difference exceeds a set threshold, then performing accuracy verification processing on the miniature current sensor.

[0051] In this embodiment, if the difference exceeds a set threshold, such as 1% to 2%, the sensor accuracy is considered to have decreased, and an alarm is triggered indicating abnormal sensor accuracy. If the deviation does not exceed the set threshold, the sensor accuracy is considered to be normal.

[0052] Furthermore, fault diagnosis of the capacitor unit based on the deviation value can achieve operational monitoring of the capacitor unit, which can be achieved as follows:

[0053] If the deviation exceeds the preset value, such as 5% or 3%, the corresponding capacitor unit is directly judged to be faulty.

[0054] Please see Figure 2This embodiment provides a power capacitor bank operation monitoring device for implementing a power capacitor bank operation monitoring method, which includes a current monitoring module, a distance calculation module, a reference value acquisition module, a deviation value calculation module, and a fault judgment module; wherein:

[0055] The current monitoring module is used to monitor the current monitoring values ​​corresponding to several capacitor units of the power capacitor bank.

[0056] The distance calculation module is used to calculate the sum of distances between each current monitoring value and its corresponding center;

[0057] The reference value acquisition module is used to obtain the minimum value of the distance and the sum as the reference value of the corresponding center;

[0058] The deviation value calculation module is used to calculate the deviation value of each capacitor unit based on the reference value;

[0059] The fault diagnosis module is used to diagnose faults in the capacitor unit based on the deviation value, thereby enabling operational monitoring of the capacitor unit.

[0060] This embodiment calculates the deviation value of each capacitor unit by monitoring the current monitoring value corresponding to the capacitor unit, so as to form a judgment on the degree of current concentration and deviation of each phase of the power capacitor bank. It can directly diagnose the fault of the capacitor unit without monitoring the voltage value of the capacitor unit, which greatly reduces the monitoring cost and improves the monitoring efficiency of the power capacitor bank.

[0061] Furthermore, the deviation value calculation module is used to calculate the deviation value of each capacitor unit based on the reference value, specifically: the expression for the deviation value of each capacitor unit is as follows:

[0062]

[0063] Where: m i I represents the deviation value of the i-th capacitor unit; i This represents the current monitoring value of the i-th capacitor cell; I k This represents the current value of the capacitor cell at the kth center.

[0064] In this embodiment, by calculating the deviation value of each capacitor unit, a judgment can be made on the degree of concentration and deviation of the current values ​​of each phase of the power capacitor bank. This avoids the need to monitor the voltage value of the capacitor unit during the monitoring process, thus saving monitoring costs and improving monitoring efficiency.

[0065] Furthermore, the current monitoring module is used to monitor the current monitoring values ​​corresponding to all capacitor units of the power capacitor bank. Specifically, the current monitoring module uses a miniature current sensor to monitor the current monitoring values ​​corresponding to all capacitor units of the power capacitor bank.

[0066] Furthermore, the system also includes an accuracy verification module; the accuracy verification module is used to collect the total current value of each phase of the power capacitor bank, and to perform accuracy verification processing on the miniature current sensor based on the current value and the current monitoring value corresponding to all capacitor units of that phase.

[0067] In this embodiment, it is necessary to maintain the accuracy of monitoring at all times during the monitoring of the power capacitor bank. Therefore, by collecting the total current value of the power capacitor bank and comparing it with the current monitoring value detected by each micro current sensor, it is possible to directly determine whether each micro current sensor is working normally and with normal accuracy, thus ensuring the accuracy of monitoring.

[0068] Furthermore, the accuracy verification module is used to collect the total current value of each phase of the power capacitor bank, and to perform accuracy verification processing on the miniature current sensor based on the current value and the current monitoring value corresponding to all capacitor units. Specifically, it collects the total current value of each phase of the power capacitor bank; calculates the difference between the total current value of each phase and the sum of the current monitoring values ​​corresponding to all capacitor units in that phase; if the difference exceeds a set threshold, the miniature current sensor is subjected to accuracy verification processing.

[0069] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for monitoring the operation of a power capacitor bank, characterized in that, Includes the following steps: Monitor the current values ​​corresponding to all capacitor units in the power capacitor bank; Using each current monitoring value as the center, calculate the sum of the distances between other current monitoring values ​​and that center; The minimum value of the distance and the sum is used as the baseline value for monitoring; The deviation value of each capacitor unit is calculated based on the reference value; The capacitor unit is fault-detected based on the deviation value, thereby enabling the monitoring of the capacitor unit's operation. Specifically, the calculation of the deviation value of each capacitor unit based on the reference value is as follows: the expression for the deviation value of each capacitor unit is as follows: In the formula: This represents the deviation value of the i-th capacitor unit; This represents the current monitoring value of the i-th capacitor unit; This represents the current value of the capacitor cell at the kth center. After monitoring the current values ​​corresponding to all capacitor units of the power capacitor bank, the total current value of each phase of the power capacitor bank is collected, and the accuracy of the miniature current sensor is verified based on the current value and the current monitoring values ​​corresponding to all capacitor units of each phase. The process involves collecting the total current value of each phase of the power capacitor bank, and then performing accuracy verification on the miniature current sensor based on this current value and the corresponding current monitoring values ​​of all capacitor units in that phase. Specifically: Collect the total current value of each phase of the power capacitor bank; Calculate the difference between the total current value of each phase and the sum of the current monitoring values ​​corresponding to all capacitor units in that phase; If the difference exceeds the set threshold, the micro current sensor will undergo accuracy verification.

2. The method for monitoring the operation of a power capacitor bank according to claim 1, characterized in that, The current monitoring values ​​corresponding to all capacitor units of the monitored power capacitor bank are specifically as follows: Miniature current sensors are used to monitor the current values ​​of all capacitor cells in a power capacitor bank.

3. A power capacitor bank operation monitoring device, characterized in that, It includes a current monitoring module, a distance calculation module, a reference value acquisition module, a deviation value calculation module, and a fault diagnosis module; among which: The current monitoring module is used to monitor the current monitoring values ​​corresponding to all capacitor units of the power capacitor bank. The distance calculation module is used to calculate the sum of distances between each current monitoring value and its corresponding center; The reference value acquisition module is used to obtain the minimum value of the distance and the sum as the reference value of the corresponding center; The deviation value calculation module is used to calculate the deviation value of each capacitor unit based on the reference value; The fault judgment module is used to judge the fault of the capacitor unit according to the deviation value, so as to realize the operation monitoring of the capacitor unit. The deviation calculation module is used to calculate the deviation value of each capacitor unit based on the reference value. Specifically, the expression for the deviation value of each capacitor unit is as follows: In the formula: Indicates the first i The deviation value of each capacitor unit; Indicates the first i Current monitoring values ​​of each capacitor unit; Indicates the first k The current value of the capacitor unit at the center; The power capacitor bank operation monitoring device also includes an accuracy verification module; the accuracy verification module is used to collect the total current value of each phase of the power capacitor bank, and to perform accuracy verification processing on the miniature current sensor based on the current value and the current monitoring value corresponding to all capacitor units of that phase. Specifically, the process of collecting the current values ​​of each phase of the power capacitor bank and performing accuracy verification on the miniature current sensor based on these current values ​​and the corresponding current monitoring values ​​of all capacitor units in that phase involves: Collect the total current value of each phase of the power capacitor bank; Calculate the difference between the total current value of each phase and the sum of the current monitoring values ​​corresponding to all capacitor units in that phase; If the difference exceeds the set threshold, the micro current sensor will undergo accuracy verification.

4. The power capacitor bank operation monitoring device according to claim 3, characterized in that, The current monitoring module is used to monitor the current monitoring values ​​corresponding to all capacitor units of the power capacitor bank, specifically: The current monitoring module uses a miniature current sensor to monitor the current values ​​corresponding to all capacitor units in the power capacitor bank.

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