Capacitor fault early warning method and device, electronic equipment and storage medium

Abstract

The invention discloses a capacitor fault early warning method and device, electronic equipment and a storage medium. The method comprises the steps that the three-phase voltage of a bus connected with a capacitor bank and the three-phase current of the capacitor bank collected according to a preset sampling frequency within observation time are acquired; calculating an inter-phase current ratio at each sampling time point according to the three-phase current; according to the two voltages with the maximum voltage difference in the three-phase voltages at each sampling time point, the bus voltage unbalance rate at each sampling point is calculated; and when it is determined that the inter-phase current ratio is not within the preset safety threshold interval and the bus voltage unbalance rate is not smaller than the preset voltage balance threshold, an alarm signal is sent out. According to the invention, the operation safety of the capacitor bank can be improved.

Description

Technical Field

[0001] The present invention relates to the field of data processing technology, and in particular to a capacitor fault early warning method, device, electronic equipment and storage medium. Background Art

[0002] As a key reactive power compensation device in the power system, capacitors play an important role in improving power quality, enhancing power factor and system voltage stability. By properly configuring capacitor banks, reactive power compensation can be performed on the system under different load conditions, thereby optimizing system voltage quality, reducing line losses and ensuring safe and stable operation of the power grid. However, due to the dynamic changes in reactive power demand in the power system, capacitor banks need to be switched frequently, which increases the risk of breakdown and other failures in the capacitor banks. In addition, capacitors may experience dielectric aging problems during long-term operation, which will gradually weaken the insulation performance of the capacitor, increase the frequency of breakdown failures, and may cause serious safety accidents such as explosions or fires. Therefore, monitoring the health status of capacitors and early warning of failures are crucial to preventing the expansion of faults, reducing equipment damage and ensuring the safe and stable operation of power systems.

[0003] Existing capacitor fault diagnosis methods mainly include pole-to-shell insulation detection, capacitance value measurement, and dielectric loss measurement. However, these detection methods usually require regular routine tests after the capacitor bank is powered off, but this method has many limitations. First, the power outage test requires a large number of equipment to be powered off, which not only increases the workload of operation and maintenance personnel, but also brings higher safety risks. For occasions with large equipment operation and maintenance, it is usually difficult to provide sufficient power outage windows during peak power consumption, resulting in some routine test cycles may be delayed. In addition, the detection cycle is generally six years, which is a long period, which makes it impossible to monitor the equipment in real time, making it difficult to detect problems in time at the early stage of failure. Summary of the invention

[0004] The embodiments of the present invention provide a capacitor fault early warning method, device, electronic device and storage medium. By implementing the present invention, early warning of capacitor faults can be performed without power outages for maintenance, thereby improving the operational safety of capacitor banks.

[0005] An embodiment of the present invention provides a capacitor fault early warning method, comprising: obtaining a three-phase voltage of a bus connected to a capacitor bank and a three-phase current of the capacitor bank collected at a preset sampling frequency within an observation time;

[0006] According to the three-phase current, calculating the phase current ratio at each sampling time point;

[0007] Calculate the bus voltage unbalance rate at each sampling point according to the two voltages with the largest voltage difference among the three-phase voltages at each sampling time point;

[0008] When it is determined that the phase-to-phase current ratio is not within the preset safety threshold range and the bus voltage unbalance rate is not less than the preset voltage balance threshold, an alarm signal is issued.

[0009] Furthermore, the calculating of the phase current ratio at each sampling time point according to the three-phase current includes:

[0010] The current ratios between the three-phase currents are calculated at each sampling time point to obtain the phase current ratios at each sampling time point.

[0011] Furthermore, the calculation of the bus voltage unbalance rate at each sampling point according to the two voltages with the largest voltage difference among the three-phase voltages at each sampling time point includes:

[0012] Calculate the average value of the three-phase voltage at each sampling time point as the voltage average value at the corresponding sampling time point;

[0013] According to the voltage average value and the two voltages with the largest voltage difference among the three-phase voltages, the bus voltage unbalance rate at each sampling point is calculated by the following formula:

[0014]

[0015] Among them, UB is the bus voltage unbalance rate; U1 and U2 are the two voltages with the largest voltage difference among the three-phase voltages; is the average voltage.

[0016] Furthermore, the safety threshold interval is calculated in the following way:

[0017] Obtain the qualified range standard of capacitance value and rated reactance ratio;

[0018] Calculate the qualified change rate of the capacitor according to the qualified range standard and the rated reactance rate;

[0019] According to the qualified change rate of the capacitor, the safety threshold range is calculated and generated.

[0020] Based on the above method embodiment, the present invention provides a corresponding device embodiment.

[0021] An embodiment of the present invention provides a capacitor fault warning device, comprising: an observation data acquisition module, a phase current ratio calculation module, a bus voltage unbalance rate calculation module and a fault warning module.

[0022] The observation data acquisition module is used to acquire the three-phase voltage of the bus connected to the capacitor bank and the three-phase current of the capacitor bank collected at a preset sampling frequency during the observation time.

[0023] The phase current ratio calculation module is used to calculate the phase current ratio at each sampling time point according to the three-phase current.

[0024] The bus voltage unbalance rate calculation module is used to calculate the bus voltage unbalance rate at each sampling point according to the two voltages with the largest voltage difference among the three-phase voltages at each sampling time point.

[0025] The fault warning module is used to send out an alarm signal when it is determined that the phase current ratio is not within a preset safety threshold range and the bus voltage imbalance rate is not less than a preset voltage balance threshold.

[0026] Furthermore, the bus voltage unbalance rate calculation module calculates the bus voltage unbalance rate at each sampling point according to the two voltages with the largest voltage difference among the three-phase voltages at each sampling time point, including:

[0027] Calculate the average value of the three-phase voltage at each sampling time point as the voltage average value at the corresponding sampling time point;

[0028] According to the voltage average value and the two voltages with the largest voltage difference among the three-phase voltages, the bus voltage unbalance rate at each sampling point is calculated by the following formula:

[0029]

[0030] Among them, UB is the bus voltage unbalance rate; U1 and U2 are the two voltages with the largest voltage difference among the three-phase voltages; is the average voltage.

[0031] Furthermore, the phase current ratio calculation module calculates the phase current ratio at each sampling time point according to the three-phase current, including:

[0032] The current ratios between the three-phase currents are calculated at each sampling time point to obtain the phase current ratios at each sampling time point.

[0033] Furthermore, in the fault warning module, the safety threshold interval is calculated in the following manner:

[0034] Obtain the qualified range standard of capacitance value and rated reactance ratio;

[0035] Calculate the qualified change rate of the capacitor according to the qualified range standard and the rated reactance rate;

[0036] According to the qualified change rate of the capacitor, the safety threshold range is calculated and generated.

[0037] Based on the above method embodiment, the present invention provides a corresponding electronic device embodiment.

[0038] An embodiment of the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the capacitor fault warning method described in any one of the above method embodiments can be implemented.

[0039] Based on the above method item embodiments, the present invention provides a corresponding storage medium item embodiment.

[0040] An embodiment of the present invention provides a storage medium on which a computer program is stored. When the computer program is executed by a processor, the capacitor fault warning method described in any one of the above method embodiments can be implemented.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] The embodiment of the present invention provides a capacitor fault warning method, device, electronic device and storage medium. The method relies on the technical premise that capacitor failure will cause capacitor capacitance changes, which will then affect the overall impedance change of the capacitor group, and ultimately cause three-phase current imbalance. By monitoring this unbalanced current, the present invention can identify changes in the capacitance value of the capacitor group, and then judge the health status of the capacitor group. Specifically, the present invention calculates the phase current ratio and the bus voltage imbalance rate by analyzing the three-phase voltage of the bus connected to the capacitor group and the three-phase current of the capacitor group, and by judging whether the phase current ratio and the bus voltage imbalance rate are within the safety threshold, it can effectively identify the signs of capacitor failure and issue a fault warning signal in time. This method can detect the problem of capacitor capacitance attenuation in real time, and solves the problem that the existing fault diagnosis method cannot detect faults early due to the long detection cycle and complex power outage operation, thereby improving the operating safety of the capacitor group and enhancing the stability of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a flow chart of a capacitor fault early warning method provided by an embodiment of the present invention.

[0044] Figure 2 It is a simulation circuit diagram of a capacitor bank and a series reactor provided by an embodiment of the present invention.

[0045] Figure 3 It is a schematic diagram of a power supply abc three-phase vector provided by an embodiment of the present invention.

[0046] Figure 4 It is a structural schematic diagram of a capacitor fault warning device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] like Figure 1 As shown, an embodiment of the present invention provides a capacitor fault early warning method, which at least includes the following steps:

[0049] Step S1, obtaining the three-phase voltage of the bus connected to the capacitor bank and the three-phase current of the capacitor bank collected at a preset sampling frequency within an observation time.

[0050] Specifically, by deploying voltage and current sensors on the bus side of the capacitor bank and the input end of the capacitor bank, the system operation status is monitored in real time, and the three-phase voltage signal and the three-phase current signal are synchronously collected at a predetermined sampling frequency (here, the sampling frequency is 15 minutes). After these signals are acquired, they will be converted into digital signals and stored in the data acquisition device or the host computer system for subsequent analysis and processing. The observation time here can be 2 hours, that is, sampling is performed every 15 minutes for 2 consecutive hours, and subsequent processing is performed based on the sampling results to determine whether the capacitor may be in a fault state and issue an alarm signal in time.

[0051] In addition, to ensure the accuracy and completeness of the collected data, the sampling equipment should be pre-calibrated and the interference problem in the signal transmission process should be checked to reduce the impact of external noise on the measurement results. At the same time, according to the needs of the actual application scenario, the sampling frequency can be adjusted to meet the different requirements for signal accuracy and time domain resolution. Through this step, the original electrical data of the capacitor bank under the operating state can be obtained, laying the foundation for subsequent fault diagnosis.

[0052] Step S2: Calculate the phase current ratio at each sampling time point according to the three-phase current.

[0053] In an optional embodiment, calculating the phase current ratio at each sampling time point according to the three-phase current includes:

[0054] The current ratios between the three-phase currents are calculated at each sampling time point to obtain the phase current ratios at each sampling time point.

[0055] Specifically, for example, for each sampling time point, the instantaneous value I of the three-phase current is extracted respectively. A ,I B and I C , and calculate the current ratio between the three phases according to the following ratio formula:

[0056]

[0057] Among them, R AB For I A with I B The ratio of BC For I B with I C The ratio of CA For I C with I A The ratio of

[0058] These interphase current ratios reflect the balance relationship between the three-phase currents. Under ideal conditions, the three-phase currents should be symmetrical, and their ratios are close to 1. However, in actual operation, these ratios may deviate from the ideal values ​​due to internal faults of the capacitor bank or external environmental factors. The present invention detects the current ratios to identify whether the capacitor has a fault at this time, and issues an alarm signal in time.

[0059] Step S3: Calculate the bus voltage unbalance rate at each sampling point according to the two voltages with the largest voltage difference among the three-phase voltages at each sampling time point.

[0060] In a preferred embodiment, the calculation of the bus voltage unbalance rate at each sampling point according to the two voltages with the largest voltage difference among the three-phase voltages at each sampling time point includes:

[0061] Calculate the average value of the three-phase voltage at each sampling time point as the voltage average value at the corresponding sampling time point;

[0062] According to the voltage average value and the two voltages with the largest voltage difference among the three-phase voltages, the bus voltage unbalance rate at each sampling point is calculated by the following formula:

[0063]

[0064] Among them, UB is the bus voltage unbalance rate; U1 and U2 are the two voltages with the largest voltage difference among the three-phase voltages; is the average voltage.

[0065] Step S4: When it is determined that the phase current ratio is not within the preset safety threshold range and the bus voltage imbalance rate is not less than the preset voltage balance threshold, an alarm signal is issued.

[0066] In a preferred embodiment, the safety threshold interval is calculated in the following manner:

[0067] Obtain the qualified range standard of capacitance value and rated reactance ratio;

[0068] Calculate the qualified change rate of the capacitor according to the qualified range standard and the rated reactance rate;

[0069] According to the qualified change rate of the capacitor, the safety threshold range is calculated and generated.

[0070] Specifically, the safety threshold interval is set to a value between 0.9755 and 1.0231. The voltage balance threshold is set to a value of 0.02.

[0071] In a preferred embodiment, the capacitor bank and the series reactor circuit are as follows Figure 2 As shown, the rated reactance is x, the capacitance is C, the power system frequency is ω, and the capacitor reactance is The reactance of the reactor is The impedance of the two in series is The equivalent capacitance of three phases a, b and c is

[0072] According to Kirchhoff's current law, the equation is:

[0073]

[0074] in, They are the phase voltages of the three-phase power supply a, b, and c respectively. is the voltage at the neutral point n.

[0075] Since capacitor banks are generally three-phase balanced, that is, C a =C b =C c , assuming that the capacitance value of phase a after the fault occurs is C a changes to k times of the original value, and the voltage of the neutral point after the fault can be obtained:

[0076]

[0077] According to the system power three-phase balance Formula (4) can be simplified as:

[0078]

[0079] According to the capacitor voltage-current relationship I a =U a ωC a And formula (5), we can get the phase a current after the fault:

[0080]

[0081] Among them, I′ a is the modulus of the current when the capacitance of phase a is unbalanced.

[0082] like Figure 3 As shown, point O is the neutral point of the power supply before the fault, and point N is the neutral point that shifts after the a-phase fault. Because only the a-phase capacitance value changes, the neutral point only shifts in the direction of Oa. According to the cosine theorem, we can get:

[0083]

[0084] Among them, U bn is the voltage of phase b after the capacitance changes; U n is the voltage of the neutral point N after the capacitance changes; U a is the voltage of phase a before the capacitance changes; U b is the voltage of phase b before the capacitance changes;

[0085] According to formula (5) and formula (7), we can get:

[0086]

[0087] Combining equation (6) and equation (8), we can get:

[0088]

[0089]

[0090] From formula (10), it can be concluded that when the capacitance value of phase a changes to k times of the original value, the ratio of the phase current of the fault phase a to the normal phase b is I ab for

[0091] Most capacitor banks in power grids are frame-type capacitor banks. Assuming that each phase has n capacitor units, when the value of a single capacitor unit changes by 5%, the capacitance value of a single-phase capacitor becomes k times the original value:

[0092]

[0093] According to formula (6), the current change multiple after the single-phase capacitance changes is Calculate; According to the relevant provisions of the test regulations, the qualified range of capacitance value is ±5%, assuming that the reactance rate x = 5%, according to It can be concluded that the qualified change rate of the capacitor is: 5%*(1-5%), that is, the reasonable range of k is 1-5%*(1-5%) to 1+5%*(1-5%), that is, 95.25%~104.75%. According to the ratio of the phase current of the fault phase a to the normal phase b, I ab for The normal range of the corresponding current ratio is 0.9755 to 1.0231, so monitoring the three-phase current ratio can monitor the change of the capacitance value of the capacitor. In addition, in order to avoid the current ratio error caused by the bus voltage imbalance, it is necessary to obtain the three-phase voltage of the bus where the capacitor group is located through the bus voltage online monitoring device, and monitor the imbalance. When it exceeds a certain threshold, an early warning is issued, and then the monitoring data is analyzed and judged manually. The recommended threshold is set to 2%.

[0094] In a preferred embodiment, data is collected according to an observation time of 2 hours and a sampling frequency of 15 minutes, and the phase current ratio and bus voltage unbalance rate at each sampling time point are calculated. When it is determined that each phase current ratio is not within the preset safety threshold range, and each bus voltage unbalance rate is not less than the preset voltage balance threshold, an alarm signal is issued.

[0095] In another preferred embodiment, data is collected according to an observation time of 2 hours and a sampling frequency of 15 minutes, and the phase current ratio and bus voltage unbalance rate at each sampling time point are calculated. When it is determined that the phase current ratio is not within the preset safety threshold range and the bus voltage unbalance rate is not less than the preset voltage balance threshold, an alarm signal is issued.

[0096] Based on the above method embodiment, the present invention provides a corresponding device embodiment.

[0097] like Figure 4 As shown, an embodiment of the present invention provides a capacitor fault warning device, including: an observation data acquisition module, a phase current ratio calculation module, a bus voltage unbalance rate calculation module and a fault warning module.

[0098] The observation data acquisition module is used to acquire the three-phase voltage of the bus connected to the capacitor bank and the three-phase current of the capacitor bank collected at a preset sampling frequency during the observation time;

[0099] The phase current ratio calculation module is used to calculate the phase current ratio at each sampling time point according to the three-phase current;

[0100] The bus voltage unbalance rate calculation module is used to calculate the bus voltage unbalance rate at each sampling point according to the two voltages with the largest voltage difference among the three-phase voltages at each sampling time point;

[0101] The fault warning module is used to send out an alarm signal when it is determined that the phase current ratio is not within a preset safety threshold range and the bus voltage imbalance rate is not less than a preset voltage balance threshold.

[0102] In a preferred embodiment, the bus voltage unbalance rate calculation module calculates the bus voltage unbalance rate at each sampling point according to the two voltages with the largest voltage difference among the three-phase voltages at each sampling time point, including:

[0103] Calculate the average value of the three-phase voltage at each sampling time point as the voltage average value at the corresponding sampling time point;

[0104] According to the voltage average value and the two voltages with the largest voltage difference among the three-phase voltages, the bus voltage unbalance rate at each sampling point is calculated by the following formula:

[0105]

[0106] Among them, UB is the bus voltage unbalance rate; U1 and U2 are the two voltages with the largest voltage difference among the three-phase voltages; is the average voltage.

[0107] In a preferred embodiment, the phase current ratio calculation module calculates the phase current ratio at each sampling time point according to the three-phase current, including:

[0108] The current ratios between the three-phase currents are calculated at each sampling time point to obtain the phase current ratios at each sampling time point.

[0109] In a preferred embodiment, in the fault warning module, the safety threshold interval is calculated in the following manner:

[0110] Obtain the qualified range standard of capacitance value and rated reactance ratio;

[0111] Calculate the qualified change rate of the capacitor according to the qualified range standard and the rated reactance rate;

[0112] According to the qualified change rate of the capacitor, the safety threshold range is calculated and generated.

[0113] It should be noted that the embodiments of the device described above correspond to the above embodiments of the present invention, and can implement any of the methods described above in the present invention. In addition, the embodiments of the above-mentioned device are merely schematic, wherein the modules described as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the drawings of the device embodiments provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which can be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art can understand and implement it without paying any creative work.

[0114] Based on the above method embodiment of the present invention, a corresponding electronic device embodiment is provided.

[0115] An embodiment of the present invention provides an electronic device, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, the capacitor fault warning method described in any one of the present invention is implemented, or when the processor executes the computer program, the functions of the modules in the above-mentioned device embodiments are implemented.

[0116] Exemplarily, the computer program may be divided into one or more modules, which are stored in the memory and executed by the processor to implement the present invention. The one or more modules may be a series of computer program instruction segments capable of implementing specific functions, which are used to describe the execution process of the computer program in the terminal device.

[0117] The terminal device may be a computing device such as a desktop computer, a notebook, a PDA, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0118] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the terminal device, and uses various interfaces and lines to connect various parts of the entire terminal device.

[0119] The memory can be used to store the computer program and / or module, and the processor realizes various functions of the terminal device by running or executing the computer program and / or module stored in the memory, and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application required for a function, etc.; the data storage area can store data created according to the use of the mobile phone, etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (SecureDigital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0120] Based on the above method embodiment, the present invention provides a storage medium embodiment;

[0121] Another embodiment of the present invention provides a storage medium, wherein the storage medium includes a stored computer program, wherein when the computer program is executed, the device where the storage medium is located is controlled to execute any one of the above capacitor fault early warning methods of the present invention.

[0122] The storage medium is a computer-readable storage medium, and the computer program includes computer program code, which may be in source code form, object code form, executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable medium may be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0123] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0124] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A capacitor failure early warning method, characterized in that: include: Obtaining the three-phase voltage of the bus connected to the capacitor bank and the three-phase current of the capacitor bank collected at a preset sampling frequency during the observation time; According to the three-phase current, calculating the phase current ratio at each sampling time point; Calculate the bus voltage unbalance rate at each sampling point according to the two voltages with the largest voltage difference among the three-phase voltages at each sampling time point; When it is determined that the phase-to-phase current ratio is not within the preset safety threshold range and the bus voltage unbalance rate is not less than the preset voltage balance threshold, an alarm signal is issued.

2. The capacitor failure early warning method according to claim 1, characterized in that: The calculating the phase current ratio at each sampling time point according to the three-phase current includes: The current ratios between the three-phase currents are calculated at each sampling time point to obtain the phase current ratios at each sampling time point.

3. The capacitor failure early warning method according to claim 2, characterized in that: The calculating the bus voltage unbalance rate at each sampling point according to the two voltages with the largest voltage difference among the three-phase voltages at each sampling time point includes: Calculate the average value of the three-phase voltage at each sampling time point as the voltage average value at the corresponding sampling time point; According to the voltage average value and the two voltages with the largest voltage difference among the three-phase voltages, the bus voltage unbalance rate at each sampling point is calculated by the following formula: Among them, is the bus voltage unbalance rate; and are the two voltages with the largest voltage difference among the three-phase voltages; is the average voltage.

4. The capacitor failure early warning method according to claim 3, characterized in that: The safety threshold interval is calculated in the following way: Obtain the qualified range standard of capacitance value and rated reactance ratio; Calculate the qualified change rate of the capacitor according to the qualified range standard and the rated reactance rate; According to the qualified change rate of the capacitor, the safety threshold range is calculated and generated.

5. A capacitor fault warning device, characterized in that: include: Observation data acquisition module, phase current ratio calculation module, bus voltage imbalance rate calculation module and fault warning module; The observation data acquisition module is used to acquire the three-phase voltage of the bus connected to the capacitor bank and the three-phase current of the capacitor bank collected at a preset sampling frequency during the observation time; The phase current ratio calculation module is used to calculate the phase current ratio at each sampling time point according to the three-phase current; The bus voltage unbalance rate calculation module is used to calculate the bus voltage unbalance rate at each sampling point according to the two voltages with the largest voltage difference among the three-phase voltages at each sampling time point; The fault warning module is used to send out an alarm signal when it is determined that the phase current ratio is not within a preset safety threshold range and the bus voltage imbalance rate is not less than a preset voltage balance threshold.

6. The capacitor failure warning device according to claim 5, characterized in that: The bus voltage unbalance rate calculation module calculates the bus voltage unbalance rate at each sampling point according to the two voltages with the largest voltage difference among the three-phase voltages at each sampling time point, including: Calculate the average value of the three-phase voltage at each sampling time point as the voltage average value at the corresponding sampling time point; According to the voltage average value and the two voltages with the largest voltage difference among the three-phase voltages, the bus voltage unbalance rate at each sampling point is calculated by the following formula: Among them, is the bus voltage unbalance rate; and are the two voltages with the largest voltage difference among the three-phase voltages; is the average voltage.

7. The capacitor failure warning device according to claim 6, characterized in that: The phase current ratio calculation module calculates the phase current ratio at each sampling time point according to the three-phase current, including: The current ratios between the three-phase currents are calculated at each sampling time point to obtain the phase current ratios at each sampling time point.

8. The capacitor failure warning device according to claim 7, characterized in that: Fault warning module, the safety threshold interval is calculated by: Obtain the qualified range standard of capacitance value and rated reactance ratio; Calculate the qualified change rate of the capacitor according to the qualified range standard and the rated reactance rate; According to the qualified change rate of the capacitor, the safety threshold range is calculated and generated.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the capacitor failure early warning method according to any one of claims 1 to 4 can be implemented.

10. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the capacitor failure early warning method described in any one of claims 1 to 4 can be implemented.

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