Methods, devices, computer equipment, and storage media for monitoring the health status of reactive power compensation devices.

Abstract

This application relates to a method, apparatus, computer equipment, and storage medium for monitoring the health status of a reactive power compensation device. The method involves determining the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance of the target capacitor branch during operation. Based on these parameters, the fundamental voltage of the first bus after the target capacitor branch is put into operation, and the harmonic voltages of the first bus corresponding to each harmonic order, the fundamental capacitor current flowing into the target capacitor branch and the harmonic currents corresponding to each harmonic order are determined. An overcurrent coefficient is determined based on the fundamental capacitor current, each harmonic current, and the rated current of the target capacitor branch. The health status of the target capacitor branch is then monitored based on the overcurrent coefficient and a preset current coefficient threshold. This application accurately reflects the actual overcurrent state of a single capacitor branch through the overcurrent coefficient and the preset current coefficient threshold, avoiding the concealment of overcurrent risks in a single capacitor branch by the normal total current.

Description

Technical Field

[0001] This application relates to the field of electronic technology, and in particular to a method, apparatus, computer equipment, and storage medium for monitoring the health status of a reactive power compensation device. Background Technology

[0002] The loads in low-voltage power distribution systems are mainly resistive and inductive, requiring a large amount of reactive power to support their operation. Configuring reactive power compensation devices is the primary way to address this reactive power demand. Reactive power compensation devices are grouped according to the reactive power requirements of the load. A single reactive power compensation device often includes multiple capacitor branches, with each capacitor branch consisting of harmonic suppression reactors and capacitors.

[0003] In actual operation, the number of capacitor banks to be connected is determined based on the real-time reactive power of the low-voltage power distribution system, thus determining the capacitor banks that need to be connected. However, there is currently a lack of means to monitor the operational health status of the capacitor banks connected in the low-voltage reactive power compensation device. Summary of the Invention

[0004] Therefore, it is necessary to provide a method, device, computer equipment, and storage medium for monitoring the health status of a reactive power compensation device that can monitor the operational health status of the capacitor branch in operation, in order to address the aforementioned technical problems.

[0005] Firstly, this application provides a method for monitoring the health status of a reactive power compensation device, including:

[0006] Determine the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance of the target capacitor branch in the reactive power compensation device during operation; the target capacitor branch is the capacitor branch that the reactive power compensation device is currently put into operation.

[0007] Based on the equivalent fundamental inductive reactance, the equivalent fundamental capacitive reactance, the first bus fundamental voltage after the target capacitor branch is put into operation, and the first bus harmonic voltage corresponding to each harmonic order, the capacitor fundamental current flowing into the target capacitor branch and the capacitor harmonic current corresponding to each harmonic order are determined.

[0008] The overcurrent coefficient is determined based on the fundamental current of the capacitor, the harmonic current of each capacitor, and the rated current of the target capacitor branch.

[0009] The health status of the target capacitor branch is monitored based on the overcurrent coefficient and the preset current coefficient threshold.

[0010] In one embodiment, the method further includes:

[0011] Based on the equivalent fundamental capacitance, determine the equivalent harmonic capacitance corresponding to each harmonic order;

[0012] The fundamental voltage of the target capacitor branch is determined based on the fundamental current of the capacitor and the equivalent fundamental capacitive reactance, and the harmonic voltage of each capacitor is determined based on the harmonic current and equivalent harmonic capacitive reactance of each harmonic order.

[0013] The overvoltage coefficient is determined based on the fundamental voltage of the capacitor, the harmonic voltages of each capacitor, and the rated voltage of the target capacitor branch.

[0014] The health status of the target capacitor branch is monitored based on the overvoltage coefficient and the preset voltage coefficient threshold.

[0015] In one embodiment, determining the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance of the target capacitor branch in the reactive power compensation device during operation includes:

[0016] Based on the first bus voltage and the first incoming current after the target capacitor branch is put into operation, determine the first equivalent fundamental impedance and the first target harmonic impedance of the incoming line of the reactive power compensation device.

[0017] The second bus voltage and the second incoming current before the target capacitor branch is put into operation are obtained, and the second equivalent fundamental impedance and the second target harmonic impedance of the incoming line are determined based on the second bus voltage and the second incoming current.

[0018] The equivalent fundamental inductive reactance and the equivalent fundamental capacitive reactance are determined based on the first equivalent fundamental impedance, the first target harmonic impedance, the second equivalent fundamental impedance, and the second target harmonic impedance.

[0019] In one embodiment, determining the second equivalent fundamental impedance and the second target harmonic impedance of the incoming line based on the second bus voltage and the second incoming line current includes:

[0020] Based on the second bus voltage, determine the second bus fundamental voltage and the second bus harmonic voltage corresponding to each harmonic order of the reactive power compensation device;

[0021] Based on the second incoming current, determine the incoming fundamental current and the incoming harmonic current corresponding to each harmonic order before the target capacitor branch is put into operation.

[0022] The second equivalent fundamental impedance is determined based on the ratio of the second bus fundamental voltage to the incoming line fundamental current.

[0023] The second target harmonic impedance is determined based on the harmonic voltage of each of the second busbars and the harmonic current of each of the incoming lines.

[0024] In one embodiment, determining the second target harmonic impedance based on each of the second bus harmonic voltages and each of the incoming line harmonic currents includes:

[0025] The target harmonic order is determined based on the reactance of the target capacitor branch.

[0026] The second target harmonic impedance is determined based on the ratio of the second bus harmonic voltage to the incoming line harmonic current corresponding to the same harmonic order as the target harmonic order.

[0027] In one embodiment, determining the equivalent fundamental inductive reactance and the equivalent fundamental capacitive reactance based on the first equivalent fundamental impedance, the first target harmonic impedance, the second equivalent fundamental impedance, and the second target harmonic impedance includes:

[0028] Based on the first equivalent fundamental impedance, determine the first equivalent fundamental reactance after the target capacitor branch is put into operation;

[0029] Based on the first target harmonic impedance, determine the first equivalent harmonic reactance after the target capacitor branch is put into operation;

[0030] Based on the second equivalent fundamental impedance, determine the second equivalent fundamental reactance of the target capacitor branch before it is put into operation;

[0031] Based on the second target harmonic impedance, determine the second equivalent harmonic reactance of the target capacitor branch before it is put into operation;

[0032] The equivalent fundamental inductive reactance and the equivalent fundamental capacitive reactance are determined based on the target harmonic order, the first equivalent fundamental reactance, the first equivalent harmonic reactance, the second equivalent fundamental reactance, and the second equivalent harmonic reactance.

[0033] In one embodiment, obtaining the second bus voltage and second incoming current before the target capacitor branch is put into operation includes:

[0034] If the operating time of the capacitor branch that was last put into operation is greater than or equal to a preset time, the second bus voltage and the second incoming current for the preset time prior to the current moment are obtained.

[0035] Secondly, this application also provides a health status monitoring device for a reactive power compensation device, comprising:

[0036] The first determining module is used to determine the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance of the target capacitor branch in the reactive power compensation device during operation; the target capacitor branch is the capacitor branch that the reactive power compensation device is currently put into operation.

[0037] The second determining module is used to determine the capacitor fundamental current flowing into the target capacitor branch and the capacitor harmonic current corresponding to each harmonic number based on the equivalent fundamental inductive reactance, the equivalent fundamental capacitive reactance, the first bus fundamental voltage after the target capacitor branch is put into operation, and the first bus harmonic voltage corresponding to each harmonic number.

[0038] The third determining module is used to determine the overcurrent coefficient based on the fundamental current of the capacitor, the harmonic current of each capacitor, and the rated current of the target capacitor branch.

[0039] The fourth determining module is used to monitor the health status of the target capacitor branch based on the overcurrent coefficient and the preset current coefficient threshold.

[0040] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method steps provided in the first aspect.

[0041] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method steps provided in the first aspect.

[0042] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the method steps provided in the first aspect.

[0043] The aforementioned method, device, computer equipment, and storage medium for monitoring the health status of a reactive power compensation device determine the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance of the target capacitor branch during operation. Based on the equivalent fundamental inductive reactance, equivalent fundamental capacitive reactance, the fundamental voltage of the first bus after the target capacitor branch is put into operation, and the first harmonic voltage corresponding to each harmonic order, the fundamental current flowing into the target capacitor branch and the harmonic current corresponding to each harmonic order are determined. Based on the fundamental current, each harmonic current, and the rated current of the target capacitor branch, an overcurrent coefficient is determined. Based on the overcurrent coefficient and a preset current coefficient threshold, the health status of the target capacitor branch is monitored. The target capacitor branch is the capacitor branch that the reactive power compensation device is currently putting into operation. This embodiment of the application, by determining the overcurrent coefficient of the target capacitor branch that the reactive power compensation device is currently putting into operation, and by comparing the overcurrent coefficient with a preset current coefficient threshold, achieves health status monitoring of the target capacitor branch. This can accurately reflect the actual overcurrent state of a single capacitor branch and avoid the hidden risk of overcurrent in a single capacitor branch being masked by the normal total current. Moreover, the overcurrent coefficient is determined based on the fundamental current of the capacitor and the harmonic current of each capacitor, which is suitable for the power distribution system operating conditions with increased and more complex background harmonics, and fully considers the superposition effect of harmonic currents. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is an application environment diagram of a method for monitoring the health status of a reactive power compensation device in one embodiment.

[0046] Figure 2 This is a flowchart illustrating a method for monitoring the health status of a reactive power compensation device in one embodiment.

[0047] Figure 3 This is a flowchart illustrating a method for monitoring the health status of a reactive power compensation device in another embodiment.

[0048] Figure 4 This is a flowchart illustrating the method for determining the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance in one embodiment.

[0049] Figure 5 This is a flowchart illustrating a method for determining the second equivalent fundamental impedance and the second target harmonic impedance in one embodiment.

[0050] Figure 6 This is a flowchart illustrating the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance in another embodiment;

[0051] Figure 7 This is a structural block diagram of a health status monitoring device for a reactive power compensation device in one embodiment.

[0052] Figure 8 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0054] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0055] Low-voltage power distribution system loads are mainly resistive and inductive, requiring a large amount of reactive power to support operation. Configuring reactive power compensation devices is the primary way to address this reactive power demand. The DL / T2114-2020 Technical Guidelines for Reactive Power Compensation Configuration in Power Grids stipulate that the capacity of reactive power compensation devices in distribution networks should be configured at 10% to 30% of the transformer capacity. Therefore, the market capacity for low-voltage reactive power compensation devices is enormous.

[0056] Reactive power compensation devices often include multiple capacitor branches, with each capacitor branch consisting of a reactor and a capacitor. With the increasing coverage of urban cabling and the widespread use of nonlinear equipment, the background harmonics in low-voltage power distribution systems are becoming increasingly amplified and complex. The equivalent impedance of the connected capacitor branches can easily cause background harmonic amplification or even resonance, leading to prolonged overcurrent and overvoltage operation of the capacitors in the connected capacitor branches.

[0057] Operating a capacitor under overvoltage conditions increases the internal electric field strength, accelerates the aging of the capacitor's insulation, and also accelerates internal dielectric losses, leading to thermal aging and mechanical deformation, shortening its service life. In severe cases, it can cause partial discharge, casing bulging, seal rupture, oil leakage, and even internal insulation breakdown, resulting in explosions and other serious operational accidents. GB / T12747.1-2017, "Self-healing Parallel Capacitors for AC Power Systems with Nominal Voltage of 1000V and Below - Part 1: General Performance, Testing and Rating Safety Requirements, Installation and Operation Guidelines," specifies the maximum operating voltage requirements for low-voltage capacitors. To ensure the long-term safe and stable operation of capacitors, necessary operational monitoring and corresponding protection measures are required for reactive power compensation devices. Therefore, this application proposes a method for monitoring the health status of reactive power compensation devices that can solve the above-mentioned technical problems.

[0058] The method for monitoring the health status of reactive power compensation devices provided in this application embodiment can be applied to, for example... Figure 1 The application environment shown includes a controller 100 and a reactive power compensation device 200. The reactive power compensation device 200 includes m groups of capacitor branches, namely C1, C2, ..., Ci, Cm. Each group of capacitor branches includes a series reactor X. L and capacitor XC The controller 100 acquires the bus voltage u(t) and incoming current i(t) of the reactive power compensation device 200, including the second bus voltage and second incoming current before the target capacitor branch Ci is put into operation, and the first bus voltage and first incoming current after the target capacitor branch is put into operation. Based on the second bus voltage, second incoming current, first bus voltage, and first incoming current, the controller 100 determines the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance of the target capacitor branch during operation. Therefore, based on the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance, the controller 100 determines the capacitor fundamental current I flowing into the target capacitor branch Ci. Ci,1 The capacitor harmonic current I corresponding to each harmonic order Ci,n The overcurrent coefficient is determined based on the fundamental current of the capacitor, the harmonic current of each capacitor, and the rated current of the target capacitor branch. The health status of the capacitor branch of the reactive power compensation device 200 is then monitored based on the overcurrent coefficient.

[0059] In one exemplary embodiment, such as Figure 2 As shown, a method for monitoring the health status of a reactive power compensation device is provided, which can be applied to... Figure 1 The controller in the example is used for illustration, including the following steps S201 to S204. Wherein:

[0060] S201, determine the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance of the target capacitor branch in the reactive power compensation device during operation; the target capacitor branch is the capacitor branch that the reactive power compensation device is currently put into operation.

[0061] In this embodiment, the first bus voltage and first incoming current after the target capacitor branch is put into operation can be obtained, and the first equivalent fundamental impedance and first target harmonic impedance of the incoming line can be determined based on the first bus voltage and first incoming current. The second bus voltage and second incoming current before the target capacitor branch is put into operation can be obtained, and the second equivalent fundamental impedance and second target harmonic impedance of the incoming line of the reactive power compensation device can be determined based on the second bus voltage and second incoming current. Furthermore, the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance can be determined based on the first equivalent fundamental impedance, the first target harmonic impedance, the second equivalent fundamental impedance, and the second target harmonic impedance.

[0062] In one possible implementation, the factory-rated parameters of the target capacitor branch can also be obtained, including the capacitor's rated voltage, first rated capacity, rated reactance rate of the reactor, and second rated capacity. Based on the rated voltage and first rated capacity, the rated fundamental capacitive reactance is calculated; based on the rated reactance rate and second rated capacity, the rated fundamental inductive reactance is calculated. Based on the operating parameters of the target capacitor branch after it is put into operation, inductive reactance correction factors and capacitive reactance correction factors are determined. The rated fundamental inductive reactance is corrected using the inductive reactance correction factor to obtain the equivalent fundamental inductive reactance; the rated fundamental capacitive reactance is corrected using the capacitive reactance correction factor to obtain the equivalent fundamental capacitive reactance.

[0063] S202, based on the equivalent fundamental inductive reactance, the equivalent fundamental capacitive reactance, the fundamental voltage of the first bus after the target capacitor branch is put into operation, and the first harmonic voltage of each harmonic order, determine the fundamental current of the capacitor flowing into the target capacitor branch and the harmonic current of each harmonic order.

[0064] In this embodiment, the fundamental current flowing into the target capacitor branch is calculated using the following formula. Harmonic currents of capacitors corresponding to each harmonic order :

[0065]

[0066] in, The fundamental voltage of the first bus after the target capacitor branch Ci is put into operation. Let n be the harmonic voltage of the first bus corresponding to each harmonic order after the target capacitor branch Ci is put into operation, where n is the harmonic order (n is greater than or equal to 2) and j is an imaginary number. For equivalent fundamental wave impedance, This is the equivalent fundamental frequency capacitive reactance.

[0067] S203. Determine the overcurrent coefficient based on the fundamental current of the capacitor, the harmonic current of each capacitor, and the rated current of the target capacitor branch.

[0068] In this embodiment of the application, taking a harmonic frequency of 2-25 as an example, the fundamental current of the capacitor and the harmonic current of each capacitor are squared and summed. The square root of the sum is then obtained, and the ratio of this sum to the rated current of the target capacitor branch is used as the overcurrent coefficient. That is, the overcurrent coefficient can be calculated using the following formula. :

[0069]

[0070] in, The rated current of the target capacitor branch.

[0071] S204 monitors the health status of the target capacitor branch based on the overcurrent coefficient and the preset current coefficient threshold.

[0072] Optionally, the preset current coefficient threshold can be one or more.

[0073] In this embodiment, if the overcurrent coefficient is greater than a preset current coefficient threshold, the capacitor in the target capacitor branch is considered to have an overcurrent condition. For example, when the overcurrent coefficient is less than or equal to 1.3, it is determined that the capacitor has no overcurrent; when the overcurrent coefficient is greater than 1.3 and less than or equal to 2, it is determined that the capacitor has a slight overcurrent and an alarm signal is output; when the overcurrent coefficient is greater than 2, it is determined that the capacitor has a severe overcurrent and a trip signal is output.

[0074] It should be noted that if the controller determines that three sets of capacitor branches need to be put into operation, the health status of the first set of capacitor branches will be monitored when they are put into operation. After the health status monitoring of the first set of capacitor branches is completed, the health status monitoring of the second set of capacitor branches will be put into operation, and so on.

[0075] In the aforementioned method for monitoring the health status of a reactive power compensation device, the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance of the target capacitor branch during operation are determined. Based on the equivalent fundamental inductive reactance, equivalent fundamental capacitive reactance, the fundamental voltage of the first bus after the target capacitor branch is put into operation, and the harmonic voltage of the first bus corresponding to each harmonic order, the fundamental current flowing into the target capacitor branch and the harmonic current corresponding to each harmonic order are determined. Based on the fundamental current, each harmonic current, and the rated current of the target capacitor branch, the overcurrent coefficient is determined. Based on the overcurrent coefficient and a preset current coefficient threshold, the health status of the target capacitor branch is monitored. The target capacitor branch is the capacitor branch that the reactive power compensation device is currently putting into operation. This embodiment of the application, by determining the overcurrent coefficient of the target capacitor branch that the reactive power compensation device is currently putting into operation, and by comparing the overcurrent coefficient with a preset current coefficient threshold, achieves health status monitoring of the target capacitor branch. This can accurately reflect the actual overcurrent status of a single capacitor branch and avoid the hidden risk of overcurrent in a single capacitor branch being masked by the normal total current. Moreover, the overcurrent coefficient is determined based on the fundamental current of the capacitor and the harmonic current of each capacitor, which is suitable for the power distribution system operating conditions with increased and more complex background harmonics, and fully considers the superposition effect of harmonic currents.

[0076] Figure 3 Another embodiment is a schematic diagram of the health status monitoring process of the reactive power compensation device, such as... Figure 3 As shown, it includes the following steps:

[0077] S301, determine the equivalent harmonic capacitance corresponding to each harmonic order based on the equivalent fundamental capacitance.

[0078] In this embodiment, the ratio of the equivalent fundamental capacitance to the harmonic order is used as the equivalent harmonic capacitance corresponding to that harmonic order. For example, if the harmonic order is 3, the ratio of the equivalent fundamental capacitance to 3 is used as the equivalent harmonic capacitance corresponding to the 3rd harmonic order; if the harmonic order is 5, the ratio of the equivalent fundamental capacitance to 5 is used as the equivalent harmonic capacitance corresponding to the 5th harmonic order.

[0079] S302, determine the fundamental voltage of the target capacitor branch based on the fundamental current and equivalent fundamental capacitive reactance of the capacitor, and determine the harmonic voltage of each capacitor based on the harmonic current and equivalent harmonic capacitive reactance of each harmonic order.

[0080] In this embodiment, the product of the capacitor's fundamental current and its equivalent fundamental capacitive reactance is used as the capacitor's fundamental voltage. The capacitor harmonic currents of each harmonic order and the corresponding equivalent harmonic capacitive reactance are calculated. The product of these values ​​is used as the harmonic voltage of each capacitor. Specifically, it can be expressed as:

[0081]

[0082] S303 determines the overvoltage coefficient based on the fundamental voltage of the capacitor, the harmonic voltages of each capacitor, and the rated voltage of the target capacitor branch.

[0083] In this embodiment, the fundamental voltage of the capacitor and the harmonic voltages of each capacitor are summed, and the summation result is compared with the rated voltage. The ratio of the two values ​​is used as the overvoltage coefficient. Specifically, it can be expressed as:

[0084]

[0085] S304 monitors the health status of the target capacitor branch based on the overvoltage coefficient and the preset voltage coefficient threshold.

[0086] In this embodiment of the application, as in S204 above, the preset voltage coefficient threshold can be multiple or one. For example, when the overvoltage coefficient is less than or equal to 1.1, it is determined that the capacitor in the target capacitor branch has no overvoltage; when the overvoltage coefficient is greater than 1.1 and less than 1.3, it is determined that the capacitor has a slight overvoltage and an alarm signal is output; when the overvoltage coefficient is greater than 1.3, it is determined that the capacitor has a severe overvoltage and a trip signal is output.

[0087] Optionally, the overvoltage coefficient and overcurrent coefficient can be combined simultaneously to monitor the health status of the target capacitor branch.

[0088] In this embodiment, the equivalent harmonic capacitive reactance corresponding to each harmonic order is determined based on the equivalent fundamental capacitive reactance; the fundamental voltage of the target capacitor branch is determined based on the fundamental current and the equivalent fundamental capacitive reactance; and the harmonic voltage of each capacitor is determined based on the harmonic current and the equivalent harmonic capacitive reactance corresponding to each harmonic order; the overvoltage coefficient is determined based on the fundamental voltage of the capacitor, the harmonic voltage of each capacitor, and the rated voltage of the target capacitor branch; and the health status of the target capacitor branch is monitored based on the overvoltage coefficient and a preset voltage coefficient threshold. This embodiment effectively solves the technical problem of inaccurate monitoring of capacitor terminal overvoltage in the prior art through the overvoltage coefficient. Building upon the overcurrent monitoring of a single capacitor branch, it further achieves accurate overvoltage monitoring of the capacitor terminal, accurately reflecting the actual voltage value borne by the capacitor body. This solves the monitoring blind spot where the bus voltage is normal but overvoltage occurs at the capacitor terminal due to harmonic amplification, forming a comprehensive monitoring system of overcurrent and overvoltage in two dimensions. This system comprehensively covers the two core failure risks of long-term overcurrent thermal aging and long-term overvoltage insulation aging of capacitors, significantly improving the operational safety of the reactive power compensation device.

[0089] Figure 4 This is a flowchart illustrating a method for determining the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance in one embodiment, as shown below. Figure 4 As shown, this application embodiment relates to a possible implementation of how to determine the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance of the target capacitor branch in a reactive power compensation device during operation, including the following steps:

[0090] S401, based on the first bus voltage and the first incoming current after the target capacitor branch is put into operation, determine the first equivalent fundamental impedance and the first target harmonic impedance of the incoming line of the reactive power compensation device.

[0091] S402, obtain the second bus voltage and the second incoming current before the target capacitor branch is put into operation, and determine the second equivalent fundamental impedance and the second target harmonic impedance of the incoming line based on the second bus voltage and the second incoming current.

[0092] In cases where the operating time of the capacitor branch that was last put into operation is greater than or equal to a preset time, the second bus voltage and the second incoming current for the preset time prior to the current moment are obtained.

[0093] If the operating time of the capacitor branch that was last put into operation is greater than or equal to a preset time, the second bus voltage and the second incoming current for the preset time prior to the current moment are obtained. Based on the second bus voltage and the second incoming current, multiple initial equivalent fundamental impedances and multiple initial harmonic impedances are obtained. For the multiple initial equivalent fundamental impedances, the average value of the remaining values ​​after removing the maximum and minimum values ​​is taken to obtain the second equivalent fundamental impedance. Similarly, for the multiple initial harmonic impedances, the average value of the remaining values ​​after removing the maximum and minimum values ​​is taken to obtain the second target harmonic impedance.

[0094] Optionally, if the operating time of the capacitor branch last put into operation is greater than or equal to a preset time, multiple second equivalent fundamental impedances and second target harmonic impedances are obtained. Any one of these second equivalent fundamental impedances and second target harmonic impedances can be used as the final required impedance, or the most recent second equivalent fundamental impedance and second target harmonic impedance can be used as the final required impedance. For example, if the last operation occurred at time A, with a preset time T, the second bus voltage and second incoming current from time A to A+T can be obtained at time A+T to obtain the corresponding second equivalent fundamental impedance and second target harmonic impedance. Similarly, the second bus voltage and second incoming current from time A+T to A+2T can be obtained at time A+2T to obtain the corresponding second equivalent fundamental impedance and second target harmonic impedance. The second equivalent fundamental impedance and second target harmonic impedance obtained later are used to cover the previous one, and so on. In other words, the second equivalent fundamental impedance and second target harmonic impedance most recently obtained before the target capacitor branch was put into operation are used as the final required impedance.

[0095] To ensure data accuracy, it is recommended that the sampling rate of the first bus voltage, the second bus voltage, the first incoming current, and the second incoming current be 6.4kHz or higher.

[0096] In this embodiment of the application, taking the target capacitor branch before it is put into operation as an example, the fundamental voltage of the second bus of the reactive power compensation device and the harmonic voltage of the second bus corresponding to each harmonic order can be determined according to the second bus voltage. The fundamental current of the incoming line and the harmonic current of the incoming line corresponding to each harmonic order before the target capacitor branch is put into operation can be determined according to the second incoming current. The second equivalent fundamental impedance can be determined according to the ratio of the fundamental voltage of the second bus to the fundamental current of the incoming line. The second target harmonic impedance can be determined according to each harmonic voltage of the second bus and each harmonic current of the incoming line.

[0097] After the target capacitor branch is put into operation, the first equivalent fundamental impedance and the first target harmonic impedance are obtained in the same way.

[0098] S403, determine the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance based on the first equivalent fundamental impedance, the first target harmonic impedance, the second equivalent fundamental impedance, and the second target harmonic impedance.

[0099] In this embodiment, the first equivalent fundamental reactance after the target capacitor branch is put into operation can be determined based on the first equivalent fundamental impedance, the first equivalent harmonic reactance after the target capacitor branch is put into operation can be determined based on the first target harmonic impedance, the second equivalent fundamental reactance before the target capacitor branch is put into operation can be determined based on the second equivalent fundamental impedance, the second equivalent harmonic reactance before the target capacitor branch is put into operation can be determined based on the second target harmonic impedance, and the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance can be determined based on the target harmonic order, the first equivalent fundamental reactance, the first equivalent harmonic reactance, the second equivalent fundamental reactance and the second equivalent harmonic reactance.

[0100] In one possible implementation, the first equivalent fundamental impedance, the first target harmonic impedance, the second equivalent fundamental impedance, and the second target harmonic impedance can all be treated as complex impedances (including real resistance and imaginary reactance). The parallel complex impedance law can be directly used, combined with the reactance frequency characteristics of the target harmonic order, to establish a two-variable linear equation and directly solve for the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance of the target capacitor branch.

[0101] In this embodiment, based on the first bus voltage and first incoming current after the target capacitor branch is put into operation, the first equivalent fundamental impedance and first target harmonic impedance of the incoming line of the reactive power compensation device are determined. The second bus voltage and second incoming current before the target capacitor branch is put into operation are obtained. Based on the second bus voltage and second incoming current, the second equivalent fundamental impedance and second target harmonic impedance of the incoming line are determined. Based on the first equivalent fundamental impedance, the first target harmonic impedance, the second equivalent fundamental impedance, and the second target harmonic impedance, the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance are determined. This embodiment, through the combined data of fundamental impedance and target harmonic impedance, can simultaneously solve for the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance of the target capacitor branch, improving parameter solution efficiency. Furthermore, this method is applicable to any group of capacitor branches in the reactive power compensation device, without requiring adjustments to the calculation logic for branches with different capacities and reactance rates. It is adaptable to application scenarios with multiple groups of capacitor branches and possesses good versatility.

[0102] Figure 5 This is a flowchart illustrating a method for determining the second equivalent fundamental impedance and the second target harmonic impedance in one embodiment, as shown below. Figure 5 As shown, this application embodiment relates to a possible implementation of how to determine the second equivalent fundamental impedance and the second target harmonic impedance of the incoming line based on the second bus voltage and the second incoming line current, including the following steps:

[0103] S501, based on the second bus voltage, determine the second bus fundamental voltage of the reactive power compensation device and the second bus harmonic voltage corresponding to each harmonic order.

[0104] S502, based on the second incoming current, determine the incoming fundamental current and the incoming harmonic current corresponding to each harmonic order before the target capacitor branch is put into operation.

[0105] In this embodiment, the acquired second incoming line current can be converted from the time domain to the frequency domain using Fast Fourier Transform (FFT) to obtain the corresponding fundamental current (i.e., the incoming line harmonic current corresponding to harmonic order 1) and the incoming line harmonic current corresponding to each harmonic order. Optionally, a window width of 10 cycles is recommended for the FFT, and the harmonic order is 2-25.

[0106] The second bus voltage is subjected to a fast Fourier transform in the same way to obtain the fundamental voltage of the second bus and the harmonic voltage of the second bus corresponding to each harmonic order.

[0107] S503. Determine the second equivalent fundamental impedance based on the ratio of the second bus fundamental voltage to the incoming fundamental current.

[0108] In this embodiment of the application, the fundamental voltage of the second bus is... and incoming fundamental current The ratio of the two is used as the second equivalent fundamental impedance. Specifically, it can be expressed as:

[0109]

[0110] S504, determine the second target harmonic impedance based on the harmonic voltage of each second bus and the harmonic current of each incoming line.

[0111] In this embodiment of the application, the target harmonic order can be determined based on the reactance of the target capacitor branch, and the ratio of the second bus harmonic voltage to the incoming line harmonic current corresponding to the same harmonic order as the target harmonic order can be determined as the second target harmonic impedance.

[0112] In one possible implementation, the ratio of each second bus harmonic voltage to the corresponding incoming line harmonic current can also be obtained, and the average value of each ratio can be used as the second target harmonic impedance.

[0113] In this embodiment, the fundamental voltage of the second bus and the harmonic voltages of the second bus corresponding to each harmonic order of the reactive power compensation device are determined based on the second bus voltage. The fundamental current of the incoming line before the target capacitor branch is put into operation and the harmonic currents of each harmonic order are determined based on the second incoming line current. The second equivalent fundamental impedance is determined based on the ratio of the second bus fundamental voltage to the incoming fundamental current. The second target harmonic impedance is determined based on each second bus harmonic voltage and each incoming harmonic current. This embodiment achieves accurate separation and extraction of the second equivalent fundamental impedance and the second target harmonic impedance, avoiding calculation errors caused by the superposition of fundamental and harmonic parameters. It improves the calculation accuracy of the incoming line equivalent impedance from the data source, laying a reliable data foundation for the accurate solution of subsequent branch reactance parameters.

[0114] In an exemplary embodiment, determining the second target harmonic impedance based on each second bus harmonic voltage and each incoming line harmonic current includes: determining the target harmonic order based on the reactance of the target capacitor branch; and determining the second target harmonic impedance based on the ratio of the second bus harmonic voltage to the incoming line harmonic current corresponding to the same harmonic order as the target harmonic order.

[0115] In this embodiment, the target harmonic order is recommended to be the nearest odd harmonic higher than the tuning point in the target capacitor branch. This frequency is the key frequency at which harmonic amplification and resonance are most likely to occur after the target capacitor branch is put into operation. Calculating the impedance at this frequency allows subsequent current and voltage calculations to fully consider the harmonic impact of the resonance risk point, improving the monitoring scheme's ability to predict overcurrent and overvoltage accidents caused by resonance. For example, for a target capacitor branch with a series reactance of 6%, if the square root of the reciprocal of the reactance rate yields a tuning point of 4.08, then the target harmonic order is selected as the 5th order. If the tuning point corresponding to another reactance rate is 5.08, then the target harmonic order is selected as the 7th order.

[0116] Obtain the second bus harmonic voltage corresponding to the harmonic order that is the same as the target harmonic order h. The second target harmonic voltage and the corresponding incoming line harmonic current are then compared. The ratio of these values ​​is used as the second target harmonic impedance. Specifically, it can be expressed as:

[0117]

[0118] In this embodiment, the target harmonic order is determined based on the reactance of the target capacitor branch; the second target harmonic impedance is determined based on the ratio of the second bus harmonic voltage to the incoming harmonic current corresponding to the same harmonic order as the target harmonic order. This embodiment determines the target harmonic order based on the reactance of the target branch capacitor, fully considering the tuning characteristics of the capacitor branch and avoiding impedance calculation anomalies caused by selecting frequencies near the tuning point. This ensures the effectiveness and accuracy of the second target harmonic impedance. Furthermore, only the harmonic impedance corresponding to the target harmonic order is extracted, eliminating the need for individual calculation and analysis of harmonic impedances across the entire frequency band, significantly reducing the controller's computational load and adapting to the real-time computational requirements of industrial controllers.

[0119] Figure 6 This is a flowchart illustrating the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance in another embodiment, as shown below. Figure 6 As shown, this application embodiment relates to a possible implementation of how to determine the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance based on the first equivalent fundamental impedance, the first target harmonic impedance, the second equivalent fundamental impedance, and the second target harmonic impedance, including the following steps:

[0120] S601, based on the first equivalent fundamental impedance, determine the first equivalent fundamental reactance after the target capacitor branch is put into operation.

[0121] S602, based on the first target harmonic impedance, determine the first equivalent harmonic reactance after the target capacitor branch is put into operation.

[0122] S603, based on the second equivalent fundamental impedance, determine the second equivalent fundamental reactance of the target capacitor branch before it is put into operation.

[0123] S604, based on the second target harmonic impedance, determine the second equivalent harmonic reactance before the target capacitor branch is put into operation.

[0124] S605, determine the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance based on the target harmonic order, the first equivalent fundamental reactance, the first equivalent harmonic reactance, the second equivalent fundamental reactance and the second equivalent harmonic reactance.

[0125] In this embodiment of the application, the second equivalent fundamental impedance before the target capacitor branch is put into operation Second target harmonic impedance And the first equivalent fundamental impedance after the target capacitor branch is put into operation. First target harmonic impedance The following relationship must be satisfied:

[0126]

[0127] in, The equivalent fundamental impedance of the target capacitor branch, The equivalent harmonic impedance corresponding to the target harmonic order of the target capacitor branch.

[0128] The equivalent impedance is determined based on the equivalent reactance and equivalent resistance. Given the load characteristics of the target capacitor branch, its equivalent reactance is much greater than its equivalent resistance. To simplify the calculation, the resistance value is ignored for the equivalent impedance. The above formula can be simplified to:

[0129]

[0130] in, The second equivalent fundamental reactance before the target capacitor branch is put into operation. The second equivalent harmonic reactance before the target capacitor branch is put into operation. The first equivalent fundamental reactance after the target capacitor branch is put into operation. The first equivalent harmonic reactance after the target capacitor branch is put into operation. The equivalent fundamental reactance of the target capacitor branch before it is put into operation. The equivalent harmonic reactance is the value corresponding to the target harmonic order before the target capacitor branch is put into operation.

[0131] The equivalent fundamental reactance and the equivalent harmonic reactance corresponding to the target harmonic order after the target capacitor branch is put into operation can be expressed by the following formula:

[0132]

[0133] in, The equivalent fundamental inductive reactance after the target capacitor branch is put into operation. h represents the equivalent fundamental capacitive reactance corresponding to the commissioning of the target capacitor branch, and h represents the target harmonic order.

[0134] Combining the two formulas above, we can obtain the equivalent fundamental inductive reactance after the target capacitor branch is put into operation. and equivalent fundamental wave capacitance Specifically, it can be expressed as:

[0135]

[0136] In this embodiment, the first equivalent fundamental reactance after the target capacitor branch is put into operation is determined based on the first equivalent fundamental impedance; the first equivalent harmonic reactance after the target capacitor branch is put into operation is determined based on the first target harmonic impedance; the second equivalent fundamental reactance before the target capacitor branch is put into operation is determined based on the second equivalent fundamental impedance; the second equivalent harmonic reactance before the target capacitor branch is put into operation is determined based on the second target harmonic impedance; and the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance are determined based on the target harmonic order, the first equivalent fundamental reactance, the first equivalent harmonic reactance, the second equivalent fundamental reactance, and the second equivalent harmonic reactance. This embodiment fully considers the engineering reality that the equivalent reactance of the capacitor branch is much larger than the equivalent resistance, simplifying the complex impedance calculation to a pure reactance real number calculation. While ensuring calculation accuracy, this significantly reduces the computational complexity of the controller, improving the computational efficiency and real-time performance of the entire health monitoring solution.

[0137] To better illustrate the method proposed in this application, the above process will be explained in detail below with specific examples, as follows:

[0138] A company's distribution transformer has a capacity of 2.5 MVA and is equipped with a 360 kvar reactive power compensation device, including 12 capacitor branches, each with the same capacity. The capacitors in each branch have a rated voltage of 0.525 kV, a rated capacity of 60 kvar, and a rated current of 66 A. The corresponding series reactor in the capacitor branch has a reactance rate of 7% and a rated capacity of 3.5 kvar. Switching is controlled by a reactive power compensation controller, which is connected to the bus voltage and total incoming current (for controlling the switching of capacitor branches) and the incoming current of the reactive power compensation device (for online health monitoring). The rated parameters of each capacitor branch are set in the controller.

[0139] During the operation of the reactive power compensation device: the voltage of the second bus and the current of the second incoming line connected to the reactive power compensation device are detected synchronously. Based on the above steps, the fundamental voltage of the second bus, the fundamental current of the incoming line, and the harmonic voltage and current of the second bus from the 2nd to the 25th harmonics are calculated in real time. The reactance of the capacitor branch of this reactive power compensation device is 7%, and the tuning point is 3.78. Therefore, the target harmonic order is selected as the 5th order. Taking one operating state (target capacitor branch) as an example, the two operating states before and after the fifth group of capacitor branches are put into operation last for 50 and 70 seconds respectively. Assuming the preset duration is 30 seconds, the state before the fifth group of capacitor branches is put into operation saves the second equivalent fundamental impedance and the 5th harmonic impedance (i.e., the second target harmonic impedance). The state after the fifth group of capacitor branches is put into operation saves the first equivalent fundamental impedance and the 5th harmonic impedance (i.e., the first target harmonic impedance).

[0140] Second equivalent fundamental impedance before the fifth capacitor branch is put into operation and 5th harmonic impedance The impedances are 1.395Ω and 0.195Ω, respectively. The first equivalent fundamental impedance after the fifth group of capacitors is put into operation. and 5th harmonic impedance The equivalent fundamental inductive reactance of the reactor in the fifth capacitor branch is 0.327Ω, and the equivalent fundamental capacitive reactance of the capacitor in the fifth capacitor branch is 4.497Ω.

[0141] Based on the calculated equivalent fundamental inductive reactance of the reactors and equivalent fundamental capacitive reactance of the capacitors in the fifth capacitor branch, as well as the corresponding fundamental voltage of the first bus and the 2nd to 25th harmonic voltages of the first bus, the fundamental current and the 2nd to 25th harmonic currents flowing into the fifth capacitor branch are calculated. Therefore, the fundamental voltage and harmonic voltages of each capacitor are calculated based on the fundamental current and the 2nd to 25th harmonic currents. The results are shown in Table 1.

[0142] Table 1

[0143]

[0144] Based on the fundamental voltage and 2nd to 25th harmonic voltages of the capacitor branch in the table above, as well as the fundamental current and 2nd to 25th harmonic currents flowing into this group of capacitor branches, and in conjunction with the set rated voltage and rated current of the capacitors, calculate the overvoltage coefficient of the capacitors during the operation of the fifth group of capacitor branches. The value is 0.92, which is less than the preset voltage coefficient threshold (1.1), and the overcurrent coefficient is... The value is 0.83, which is less than the preset current coefficient threshold (1.3). This indicates that the fifth capacitor branch is operating healthily at this moment.

[0145] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0146] Based on the same inventive concept, this application also provides a health status monitoring device for a reactive power compensation device used to implement the aforementioned method for monitoring the health status of a reactive power compensation device. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more embodiments of the health status monitoring device for a reactive power compensation device provided below can be found in the limitations of the health status monitoring method for a reactive power compensation device described above, and will not be repeated here.

[0147] In one exemplary embodiment, such as Figure 7 As shown, a health status monitoring device for a reactive power compensation device is provided, comprising: a first determining module 11, a second determining module 12, a third determining module 13, and a fourth determining module 14, wherein:

[0148] The first determining module 11 is used to determine the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance of the target capacitor branch in the reactive power compensation device during operation; the target capacitor branch is the capacitor branch that the reactive power compensation device is currently put into operation.

[0149] The second determining module 12 is used to determine the capacitor fundamental current flowing into the target capacitor branch and the capacitor harmonic current corresponding to each harmonic number based on the equivalent fundamental inductive reactance, the equivalent fundamental capacitive reactance, the first bus fundamental voltage after the target capacitor branch is put into operation, and the first bus harmonic voltage corresponding to each harmonic number.

[0150] The third determining module 13 is used to determine the overcurrent coefficient based on the fundamental current of the capacitor, the harmonic current of each capacitor, and the rated current of the target capacitor branch.

[0151] The fourth determination module 14 is used to monitor the health status of the target capacitor branch based on the overcurrent coefficient and the preset current coefficient threshold.

[0152] In one exemplary embodiment, the device further includes:

[0153] The fifth determining module is used to determine the equivalent harmonic capacitance corresponding to each harmonic order based on the equivalent fundamental capacitance.

[0154] The sixth determining module is used to determine the fundamental voltage of the target capacitor branch based on the fundamental current and equivalent fundamental capacitive reactance of the capacitor, and to determine the harmonic voltage of each capacitor based on the harmonic current and equivalent harmonic capacitive reactance of the capacitor corresponding to each harmonic order.

[0155] The seventh determining module is used to determine the overvoltage coefficient based on the fundamental voltage of the capacitor, the harmonic voltage of each capacitor, and the rated voltage of the target capacitor branch.

[0156] The eighth determination module is used to monitor the health status of the target capacitor branch based on the overvoltage coefficient and the preset voltage coefficient threshold.

[0157] In an exemplary embodiment, the first determining module 11 is specifically configured to determine the first equivalent fundamental impedance and the first target harmonic impedance of the incoming line of the reactive power compensation device based on the first bus voltage and the first incoming line current after the target capacitor branch is put into operation; obtain the second bus voltage and the second incoming line current before the target capacitor branch is put into operation, and determine the second equivalent fundamental impedance and the second target harmonic impedance of the incoming line based on the second bus voltage and the second incoming line current; and determine the equivalent fundamental inductive reactance and the equivalent fundamental capacitive reactance based on the first equivalent fundamental impedance, the first target harmonic impedance, the second equivalent fundamental impedance and the second target harmonic impedance.

[0158] In an exemplary embodiment, the first determining module 11 is specifically configured to: determine the fundamental voltage of the second bus of the reactive power compensation device and the harmonic voltage of the second bus corresponding to each harmonic order based on the second bus voltage; determine the fundamental current of the incoming line corresponding to the target capacitor branch before it is put into operation and the harmonic current of the incoming line corresponding to each harmonic order based on the second incoming line current; determine the second equivalent fundamental impedance based on the ratio of the fundamental voltage of the second bus to the fundamental current of the incoming line; and determine the second target harmonic impedance based on each harmonic voltage of the second bus and each harmonic current of the incoming line.

[0159] In an exemplary embodiment, the first determining module 11 is specifically used to determine the target harmonic order based on the reactance of the target capacitor branch; and to determine the second target harmonic impedance based on the ratio of the second bus harmonic voltage to the incoming harmonic current corresponding to the same harmonic order as the target harmonic order.

[0160] In an exemplary embodiment, the first determining module 11 is specifically configured to: determine the first equivalent fundamental reactance after the target capacitor branch is put into operation based on the first equivalent fundamental impedance; determine the first equivalent harmonic reactance after the target capacitor branch is put into operation based on the first target harmonic impedance; determine the second equivalent fundamental reactance before the target capacitor branch is put into operation based on the second equivalent fundamental impedance; determine the second equivalent harmonic reactance before the target capacitor branch is put into operation based on the second target harmonic impedance; and determine the equivalent fundamental inductive reactance and the equivalent fundamental capacitive reactance based on the target harmonic order, the first equivalent fundamental reactance, the first equivalent harmonic reactance, the second equivalent fundamental reactance and the second equivalent harmonic reactance.

[0161] In an exemplary embodiment, the first determining module 11 is specifically used to obtain the second bus voltage and the second incoming current for a preset duration prior to the current moment, if the operating time of the capacitor branch that was last put into operation is greater than or equal to a preset duration.

[0162] Each module in the aforementioned reactive power compensation device's health status monitoring device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the computer device's memory as software, so that the processor can call and execute the corresponding operations of each module.

[0163] In one exemplary embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 8 As shown, the computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores relevant data for status monitoring. The I / O interfaces are used for information exchange between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a method for monitoring the health status of a reactive power compensation device.

[0164] Those skilled in the art will understand that Figure 8 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0165] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of any of the above method embodiments.

[0166] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the above method embodiments.

[0167] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps of any of the above method embodiments.

[0168] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0169] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0170] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0171] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for monitoring the health status of a reactive power compensation device, characterized in that, The method includes: Determine the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance of the target capacitor branch in the reactive power compensation device during operation; the target capacitor branch is the capacitor branch that the reactive power compensation device is currently put into operation. Based on the equivalent fundamental inductive reactance, the equivalent fundamental capacitive reactance, the first bus fundamental voltage after the target capacitor branch is put into operation, and the first bus harmonic voltage corresponding to each harmonic order, the capacitor fundamental current flowing into the target capacitor branch and the capacitor harmonic current corresponding to each harmonic order are determined. The overcurrent coefficient is determined based on the fundamental current of the capacitor, the harmonic current of each capacitor, and the rated current of the target capacitor branch. The health status of the target capacitor branch is monitored based on the overcurrent coefficient and the preset current coefficient threshold.

2. The method according to claim 1, characterized in that, The method further includes: Based on the equivalent fundamental capacitance, determine the equivalent harmonic capacitance corresponding to each harmonic order; The fundamental voltage of the target capacitor branch is determined based on the fundamental current of the capacitor and the equivalent fundamental capacitive reactance, and the harmonic voltage of each capacitor is determined based on the harmonic current and equivalent harmonic capacitive reactance of each harmonic order. The overvoltage coefficient is determined based on the fundamental voltage of the capacitor, the harmonic voltages of each capacitor, and the rated voltage of the target capacitor branch. The health status of the target capacitor branch is monitored based on the overvoltage coefficient and the preset voltage coefficient threshold.

3. The method according to claim 1, characterized in that, The determination of the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance of the target capacitor branch in the reactive power compensation device during operation includes: Based on the first bus voltage and the first incoming current after the target capacitor branch is put into operation, determine the first equivalent fundamental impedance and the first target harmonic impedance of the incoming line of the reactive power compensation device. The second bus voltage and the second incoming current before the target capacitor branch is put into operation are obtained, and the second equivalent fundamental impedance and the second target harmonic impedance of the incoming line are determined based on the second bus voltage and the second incoming current. The equivalent fundamental inductive reactance and the equivalent fundamental capacitive reactance are determined based on the first equivalent fundamental impedance, the first target harmonic impedance, the second equivalent fundamental impedance, and the second target harmonic impedance.

4. The method according to claim 3, characterized in that, The step of determining the second equivalent fundamental impedance and the second target harmonic impedance of the incoming line based on the second bus voltage and the second incoming line current includes: Based on the second bus voltage, determine the second bus fundamental voltage and the second bus harmonic voltage corresponding to each harmonic order of the reactive power compensation device; Based on the second incoming current, determine the incoming fundamental current and the incoming harmonic current corresponding to each harmonic order before the target capacitor branch is put into operation. The second equivalent fundamental impedance is determined based on the ratio of the second bus fundamental voltage to the incoming line fundamental current. The second target harmonic impedance is determined based on the harmonic voltage of each of the second busbars and the harmonic current of each of the incoming lines.

5. The method according to claim 4, characterized in that, The step of determining the second target harmonic impedance based on the harmonic voltages of each of the second busbars and the harmonic currents of each of the incoming lines includes: The target harmonic order is determined based on the reactance of the target capacitor branch. The second target harmonic impedance is determined based on the ratio of the second bus harmonic voltage to the incoming line harmonic current corresponding to the same harmonic order as the target harmonic order.

6. The method according to claim 5, characterized in that, The step of determining the equivalent fundamental inductive reactance and the equivalent fundamental capacitive reactance based on the first equivalent fundamental impedance, the first target harmonic impedance, the second equivalent fundamental impedance, and the second target harmonic impedance includes: Based on the first equivalent fundamental impedance, determine the first equivalent fundamental reactance after the target capacitor branch is put into operation; Based on the first target harmonic impedance, determine the first equivalent harmonic reactance after the target capacitor branch is put into operation; Based on the second equivalent fundamental impedance, determine the second equivalent fundamental reactance of the target capacitor branch before it is put into operation; Based on the second target harmonic impedance, determine the second equivalent harmonic reactance of the target capacitor branch before it is put into operation; The equivalent fundamental inductive reactance and the equivalent fundamental capacitive reactance are determined based on the target harmonic order, the first equivalent fundamental reactance, the first equivalent harmonic reactance, the second equivalent fundamental reactance, and the second equivalent harmonic reactance.

7. The method according to claim 4, characterized in that, The step of obtaining the second bus voltage and second incoming current before the target capacitor branch is put into operation includes: If the operating time of the capacitor branch that was last put into operation is greater than or equal to a preset time, the second bus voltage and the second incoming current for the preset time prior to the current moment are obtained.

8. A health status monitoring device for a reactive power compensation device, characterized in that, The device includes: The first determining module is used to determine the equivalent fundamental inductive reactance and equivalent fundamental capacitive reactance of the target capacitor branch in the reactive power compensation device during operation; the target capacitor branch is the capacitor branch that the reactive power compensation device is currently put into operation. The second determining module is used to determine the capacitor fundamental current flowing into the target capacitor branch and the capacitor harmonic current corresponding to each harmonic number based on the equivalent fundamental inductive reactance, the equivalent fundamental capacitive reactance, the first bus fundamental voltage after the target capacitor branch is put into operation, and the first bus harmonic voltage corresponding to each harmonic number. The third determining module is used to determine the overcurrent coefficient based on the fundamental current of the capacitor, the harmonic current of each capacitor, and the rated current of the target capacitor branch. The fourth determining module is used to monitor the health status of the target capacitor branch based on the overcurrent coefficient and the preset current coefficient threshold.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method described in any one of claims 1-7.

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