CN113064102A - Fault detection method, device, equipment and medium - Google Patents
Fault detection method, device, equipment and medium Download PDFInfo
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- 238000001514 detection method Methods 0.000 title claims abstract description 43
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- 238000004590 computer program Methods 0.000 claims description 11
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- 239000003990 capacitor Substances 0.000 description 6
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- 238000009434 installation Methods 0.000 description 3
- 238000012423 maintenance Methods 0.000 description 3
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- 230000002159 abnormal effect Effects 0.000 description 2
- 230000032683 aging Effects 0.000 description 2
- 230000007257 malfunction Effects 0.000 description 2
- 238000010248 power generation Methods 0.000 description 2
- 241000238631 Hexapoda Species 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/56—Testing of electric apparatus
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
- G01R19/16566—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533
- G01R19/16576—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533 comparing DC or AC voltage with one threshold
- G01R19/1658—AC voltage or recurrent signals
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
- G01R29/16—Measuring asymmetry of polyphase networks
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/001—Measuring interference from external sources to, or emission from, the device under test, e.g. EMC, EMI, EMP or ESD testing
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Abstract
The application discloses a fault detection method, which comprises the following steps: when the photovoltaic inverter breaks down, detecting the operation data of the photovoltaic inverter; if the target device is determined to be not in accordance with the first preset standard according to the operation data, judging that the target device fails; if the fact that the data of the input end of the photovoltaic inverter do not accord with the second preset standard is determined according to the operation data, the fact that the fault occurs on the direct current side of the photovoltaic inverter is determined; and if the data of the output end of the photovoltaic inverter are determined to be not in accordance with the third preset standard according to the operation data, judging that the alternating current side of the photovoltaic inverter has a fault. Obviously, when the photovoltaic inverter fails, the method can be used for positioning the position of the photovoltaic inverter where the photovoltaic inverter fails, so that the user experience of a user when the photovoltaic inverter is used can be remarkably improved. Correspondingly, the fault detection device, the equipment and the medium have the beneficial effects.
Description
Technical Field
The invention relates to the technical field of photovoltaic power generation, in particular to a fault detection method, a fault detection device, equipment and a medium.
Background
A photovoltaic inverter is a power conversion device capable of converting direct current of a photovoltaic module into alternating current of a power grid, and occupies a very important position in a photovoltaic system. Among them, many factors in the photovoltaic system can influence the normal operation of the photovoltaic inverter, such as: the number of photovoltaic modules on the direct current side of the photovoltaic inverter, the aging of devices of the photovoltaic inverter, the operation condition of a power grid connected to the alternating current side of the photovoltaic inverter and the like.
However, in the prior art, when a photovoltaic inverter in a photovoltaic system fails, a user generally cannot locate the position where the photovoltaic inverter fails, so that user experience of the user when using the photovoltaic inverter is greatly reduced. At present, no effective solution exists for the technical problem.
Therefore, how to locate the position of the photovoltaic inverter where the photovoltaic inverter fails when the photovoltaic inverter fails to improve the user experience of a user when the user uses the photovoltaic inverter is a technical problem to be solved by those skilled in the art.
Disclosure of Invention
In view of this, the present invention provides a method, an apparatus, a device, and a medium for detecting a fault, so as to locate a fault location of a photovoltaic inverter when the photovoltaic inverter fails, and improve user experience when a user uses the photovoltaic inverter. The specific scheme is as follows:
a fault detection method is applied to a photovoltaic inverter in a photovoltaic system and comprises the following steps:
when the photovoltaic inverter breaks down, detecting the operation data of the photovoltaic inverter;
if the target device is determined to be not in accordance with the first preset standard according to the operation data, judging that the target device fails; wherein the target device is a device specified in the photovoltaic inverter according to a preset rule;
if the fact that the data of the input end of the photovoltaic inverter do not accord with a second preset standard is determined according to the operation data, the fact that a fault occurs on the direct current side of the photovoltaic inverter is determined;
and if the fact that the data of the output end of the photovoltaic inverter do not accord with a third preset standard is determined according to the operation data, judging that the alternating current side of the photovoltaic inverter has a fault.
Preferably, if it is determined according to the operation data that the input terminal data of the photovoltaic inverter does not meet a second preset standard, the process of determining that a fault occurs on the dc side of the photovoltaic inverter includes:
if the fact that the direct-current voltage input by the photovoltaic inverter is not within the preset direct-current voltage range is determined according to the operation data, the fact that undervoltage or overvoltage occurs on the direct-current side of the photovoltaic inverter is determined;
if the fact that the direct current voltage input by the photovoltaic inverter is higher than a first preset threshold value is determined according to the operation data, the fact that the number of photovoltaic modules connected to the direct current side of the photovoltaic inverter exceeds the bearing range of the photovoltaic inverter is determined;
if the direct current voltage input by the photovoltaic inverter is determined to be a negative value according to the operation data, determining that the positive electrode and the negative electrode of a photovoltaic module connected with the photovoltaic inverter are reversely connected;
and if the fact that the power of the photovoltaic inverter exceeds the preset power is determined according to the operation data, judging that the photovoltaic inverter has an overload phenomenon.
Preferably, after the process of determining that the undervoltage or the overvoltage occurs on the dc side of the photovoltaic inverter, the method further includes:
and adjusting the number of photovoltaic modules connected with the photovoltaic inverter.
Preferably, if it is determined according to the operation data that the data at the output end of the photovoltaic inverter does not meet a third preset standard, the process of determining that a fault occurs at the ac side of the photovoltaic inverter includes:
if the alternating-current voltage output by the photovoltaic inverter is determined not to be within the preset alternating-current voltage range according to the operation data, determining that undervoltage or overvoltage occurs on the alternating-current side of the photovoltaic inverter;
if the frequency of the alternating-current voltage output by the photovoltaic inverter is determined not to be within a preset frequency range according to the operation data, determining that the power grid frequency of a power grid connected with the photovoltaic inverter is not within the preset frequency range;
if the fact that the alternating-current voltage output by the photovoltaic inverter is in phase failure is determined according to the operation data, it is determined that a circuit breaker connected with the photovoltaic inverter is in fault;
if the fact that the waveform of the alternating voltage output by the photovoltaic inverter does not meet the preset condition is determined according to the operation data, it is determined that the photovoltaic inverter is incompatible with a power grid connected with the photovoltaic inverter;
if the current or the resistance between the photovoltaic inverter and the grounding wire is determined to not meet the preset grounding standard according to the operation data, judging that the grounding wire has a fault;
and if the temperature of the connection part of the photovoltaic inverter and the alternating current cable is determined to be higher than a second preset threshold value according to the operation data, judging that the connection part of the photovoltaic inverter and the alternating current cable is loosened.
Preferably, after the process of determining that the ac side of the photovoltaic inverter has the undervoltage or the overvoltage, the method further includes:
and adjusting the alternating voltage protection range of the photovoltaic inverter.
Preferably, after the process of determining that the photovoltaic inverter is incompatible with the grid to which the photovoltaic inverter is connected, the method further includes:
and adjusting the number of the grid-connected inverters connected between the photovoltaic inverter and the power grid.
Correspondingly, the invention also discloses a fault detection device applied to a photovoltaic inverter in a photovoltaic system, which comprises:
the data detection module is used for detecting the operation data of the photovoltaic inverter when the photovoltaic inverter fails;
the first judgment module is used for judging that the target device fails if the target device is determined to be not in accordance with a first preset standard according to the operation data; wherein the target device is a device specified in the photovoltaic inverter according to a preset rule;
the second judgment module is used for judging that the direct current side of the photovoltaic inverter has a fault if the operation data determine that the input end data of the photovoltaic inverter does not accord with a second preset standard;
and the third judging module is used for judging that the alternating current side of the photovoltaic inverter has a fault if the data of the output end of the photovoltaic inverter is determined to be not in accordance with a third preset standard according to the operation data.
Correspondingly, the invention also discloses a fault detection device, which comprises:
a memory for storing a computer program;
a processor for implementing the steps of a fault detection method as disclosed in the foregoing when executing said computer program.
Accordingly, the present invention also discloses a computer readable storage medium having stored thereon a computer program which, when being executed by a processor, realizes the steps of a fault detection method as disclosed in the foregoing.
Therefore, in the invention, when the photovoltaic inverter in the photovoltaic system has a fault, the operation data of the photovoltaic inverter is detected; if the target device in the photovoltaic inverter is determined to be not in accordance with the first preset standard according to the operation data of the photovoltaic inverter, the target device in the photovoltaic inverter is indicated to be in fault; if the data of the input end of the photovoltaic inverter is determined to be not in accordance with the second preset standard according to the operation data of the photovoltaic inverter, the direct current side of the photovoltaic inverter is indicated to have a fault; and if the output end data of the photovoltaic inverter is determined to be not in accordance with the third preset standard according to the operation data of the photovoltaic inverter, indicating that the alternating current side of the photovoltaic inverter has a fault. Obviously, when the photovoltaic inverter fails, the method can be used for positioning the position of the photovoltaic inverter where the photovoltaic inverter fails, so that the user experience of a user when the photovoltaic inverter is used can be remarkably improved. Correspondingly, the fault detection device, the equipment and the medium provided by the invention also have the beneficial effects.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
Fig. 1 is a flowchart of a fault detection method according to an embodiment of the present invention;
fig. 2 is a structural diagram of a fault detection apparatus according to an embodiment of the present invention;
fig. 3 is a structural diagram of a fault detection device according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1, fig. 1 is a flowchart of a fault detection method according to an embodiment of the present invention, where the fault detection method is applied to a photovoltaic inverter in a photovoltaic system, and the fault detection method includes:
step S11: when the photovoltaic inverter breaks down, detecting the operation data of the photovoltaic inverter;
step S12: if the target device is determined to be not in accordance with the first preset standard according to the operation data, judging that the target device fails;
wherein the target device is a device specified in the photovoltaic inverter according to a preset rule;
step S13: if the fact that the data of the input end of the photovoltaic inverter do not accord with the second preset standard is determined according to the operation data, the fact that the fault occurs on the direct current side of the photovoltaic inverter is determined;
step S14: and if the data of the output end of the photovoltaic inverter are determined to be not in accordance with the third preset standard according to the operation data, judging that the alternating current side of the photovoltaic inverter has a fault.
In this embodiment, a fault detection method applied to a photovoltaic inverter in a photovoltaic system is provided, by which a location where the photovoltaic inverter fails can be located when the photovoltaic inverter fails, and thus user experience of a user when using the photovoltaic inverter is improved.
Specifically, when a photovoltaic inverter in the photovoltaic system fails, the operation data of the photovoltaic inverter is obtained, and the operation data of the photovoltaic inverter is detected. It can be understood that, in practical applications, since the operation state of the pv inverter is interfered by factors such as the installation location of the pv inverter, the operation environment, the wear and the aging degree, some installation components in the pv inverter may malfunction more frequently than other components in the pv inverter, and the normal operation of the pv inverter is affected. Therefore, in the present embodiment, the components that are prone to failure in the photovoltaic inverter are summarized according to manual operation experience, and some target devices that are prone to failure are specified in the photovoltaic inverter according to preset rules. The target devices comprise vulnerable devices such as a protection circuit, a fan, a piezoresistor, a safety capacitor and the like in the photovoltaic inverter.
When the photovoltaic inverter breaks down, firstly, a target device in the photovoltaic inverter is detected according to the operation data of the photovoltaic inverter, whether the target device meets a first preset standard or not is judged, and if the target device does not meet the first preset standard, the fact that the normal operation of the photovoltaic inverter is influenced because the target device breaks down is shown.
When a pv inverter is installed in a poorly ventilated location, it often results in the over-temperature protection circuit in the pv inverter being activated and thus in faulty operation of the pv inverter. Therefore, when the inverter temperature is determined to be not in accordance with the first preset standard according to the operation data of the photovoltaic inverter, it is indicated that the photovoltaic inverter is abnormal due to over-temperature. In this case, the photovoltaic inverter should be installed at a position where ventilation conditions are good to avoid the above-mentioned situation.
When the fan in the photovoltaic inverter is blocked due to leaves, insects, stones or frost and the like, the photovoltaic inverter can not normally operate. Therefore, when the abnormal air outlet is judged according to the operation data of the photovoltaic inverter, the normal operation of the photovoltaic inverter is influenced due to the fault of the fan, and under the condition, the aim of fault maintenance of the photovoltaic inverter can be fulfilled only by cleaning or replacing the fan.
In practical application, the piezoresistor and the safety capacitor are the most seriously damaged devices in the photovoltaic inverter, and when the piezoresistor and the safety capacitor are in failure, the normal operation of the photovoltaic inverter is also influenced. Therefore, when the piezoresistor and the safety capacitor in the photovoltaic inverter are determined to be not in accordance with the first preset standard according to the operation data of the photovoltaic inverter, the normal operation of the photovoltaic inverter is influenced due to the fault of the piezoresistor and/or the safety capacitor. When the fault occurs, the aim of maintaining the fault of the photovoltaic inverter can be fulfilled only by maintaining or replacing the piezoresistor and/or the safety capacitor in the photovoltaic inverter by a worker.
It can be understood that, besides the normal operation of the photovoltaic inverter can be affected by the device problem of the photovoltaic inverter itself, the normal operation of the photovoltaic inverter can also be affected by the failure of some devices or lines on the direct current side and the alternating current side of the photovoltaic inverter. The operation data of the photovoltaic inverter can represent the operation condition of the photovoltaic inverter on the direct current side and the operation condition of the photovoltaic inverter on the alternating current side, so that the position of the photovoltaic inverter with a fault can be judged to be on the direct current side of the photovoltaic inverter or on the alternating current side of the photovoltaic inverter according to the operation data of the photovoltaic inverter.
That is, when it is determined that the data of the input end of the photovoltaic inverter does not meet the second preset standard according to the operation data of the photovoltaic inverter, it is determined that a fault occurs on the direct current side of the photovoltaic inverter; and when the data of the output end of the photovoltaic inverter is determined to be not in accordance with the third preset standard according to the operation data of the photovoltaic inverter, the AC side of the photovoltaic inverter is indicated to have a fault.
In addition, the problems occurring on the ac side of the pv inverter are more than the problems occurring on the dc side of the pv inverter, and the problems occurring on the dc side of the pv inverter are more than the problems occurring on the pv inverter itself. Therefore, in practical applications, in order to improve the efficiency and speed of fault detection of the photovoltaic inverter, when the photovoltaic inverter fails, a target device in the photovoltaic inverter may be detected first, if the target device has no problem, the data at the input end of the photovoltaic inverter may be detected, and if the data at the input end of the photovoltaic inverter has no problem, the data at the output end of the photovoltaic inverter may be detected.
As can be seen, in the present embodiment, when a photovoltaic inverter in a photovoltaic system fails, the operation data of the photovoltaic inverter is detected; if the target device in the photovoltaic inverter is determined to be not in accordance with the first preset standard according to the operation data of the photovoltaic inverter, the target device in the photovoltaic inverter is indicated to be in fault; if the data of the input end of the photovoltaic inverter is determined to be not in accordance with the second preset standard according to the operation data of the photovoltaic inverter, the direct current side of the photovoltaic inverter is indicated to have a fault; and if the output end data of the photovoltaic inverter is determined to be not in accordance with the third preset standard according to the operation data of the photovoltaic inverter, indicating that the alternating current side of the photovoltaic inverter has a fault. Obviously, when the photovoltaic inverter fails, the method can be used for positioning the position of the photovoltaic inverter where the photovoltaic inverter fails, so that the user experience of a user when the photovoltaic inverter is used can be remarkably improved.
Based on the above embodiments, this embodiment further describes and optimizes the technical solution, and as a preferred implementation, the above steps: if the input end data of the photovoltaic inverter are determined to be not in accordance with the second preset standard according to the operation data, the process of judging that the direct current side of the photovoltaic inverter has a fault comprises the following steps:
if the direct-current voltage input by the photovoltaic inverter is determined not to be within the preset direct-current voltage range according to the operation data, determining that undervoltage or overvoltage occurs on the direct-current side of the photovoltaic inverter;
if the fact that the direct current voltage input by the photovoltaic inverter is higher than a first preset threshold value is determined according to the operation data, the fact that the number of photovoltaic modules connected to the direct current side of the photovoltaic inverter exceeds the bearing range of the photovoltaic inverter is determined;
if the direct current voltage input by the photovoltaic inverter is determined to be a negative value according to the operation data, determining that the positive electrode and the negative electrode of the photovoltaic module connected with the photovoltaic inverter are reversely connected;
and if the power of the photovoltaic inverter is determined to exceed the preset power according to the operation data, judging that the photovoltaic inverter has an overload phenomenon.
In this embodiment, a method for determining whether a fault occurs on a dc side of a photovoltaic inverter is provided, where the cause of the fault on the dc side of the photovoltaic inverter includes: overvoltage or undervoltage occurs on the direct current side of the photovoltaic inverter, a cable is damaged, a connector fails, the positive electrode and the negative electrode of the photovoltaic module are reversely connected, the photovoltaic inverter is overloaded, and the like.
Specifically, in practical applications, due to the limitation of the installation area of the photovoltaic system, the number of photovoltaic modules in the photovoltaic system is often too large or too small, and in this case, the dc voltage input by the photovoltaic inverter is not within the preset range, and thus the photovoltaic inverter cannot normally operate. Therefore, when the direct-current voltage input by the photovoltaic inverter is determined not to be within the preset direct-current voltage range according to the operation data of the photovoltaic inverter, the phenomenon that the direct-current side of the photovoltaic inverter is under-voltage or over-voltage is indicated.
When the direct current side of the photovoltaic inverter is determined to have undervoltage or overvoltage, the faults of the photovoltaic inverter can be maintained by adjusting the number of photovoltaic modules connected with the photovoltaic inverter. That is, when the direct current side of the photovoltaic inverter has an undervoltage, the fault of the photovoltaic inverter can be maintained by increasing the number of photovoltaic modules connected with the photovoltaic inverter; when overvoltage occurs on the direct current side of the photovoltaic inverter, the faults of the photovoltaic inverter can be maintained by reducing the number of photovoltaic modules connected with the photovoltaic inverter.
In the actual operation process, sometimes, the phenomena of water inflow of a connector between the photovoltaic module and the photovoltaic inverter and damage of a connecting cable occur, so that the direct-current insulation of the photovoltaic inverter is too low, the direct-current voltage is too high, and the photovoltaic inverter cannot be normally started. Therefore, when the direct current voltage input by the photovoltaic inverter is determined to be higher than the first preset threshold value according to the operation data of the photovoltaic inverter, the fact that the number of the photovoltaic modules connected to the direct current side of the photovoltaic inverter exceeds the bearing range of the photovoltaic inverter is indicated. If the above situation occurs, the above problem can be detected and repaired.
When the fact that the direct-current voltage input by the photovoltaic inverter is a negative value is determined according to the operation data of the photovoltaic inverter, it is indicated that the photovoltaic inverter is reversely connected with the photovoltaic module, and the photovoltaic inverter cannot be normally started due to the fact that the photovoltaic inverter is reversely connected with the photovoltaic module. In this case, the photovoltaic inverter can be subjected to fault maintenance by detecting the positive and negative electrodes of the photovoltaic module.
In addition, in practical application, the direct current power of the photovoltaic inverter often exceeds 1.1 to 1.2 times of the normal operation power of the photovoltaic inverter, so that the photovoltaic inverter can obtain higher power generation benefit under the condition of low irradiation, but when the irradiation is particularly good, the photovoltaic inverter can be frequently started and cannot normally operate under the condition of high irradiation. Therefore, when the power of the photovoltaic inverter is determined to exceed the preset power according to the operation data of the photovoltaic inverter, the phenomenon of overload of the photovoltaic inverter is indicated, and at the moment, the number of photovoltaic modules in the photovoltaic system can be reduced by workers to maintain the faults of the photovoltaic inverter. Of course, in the actual operation process, the user can also receive the alarm, because the operation mode relatively improves the benefit of the user in the overall view.
Obviously, the technical scheme provided by the embodiment can further ensure the comprehensiveness and integrity of the DC side fault of the photovoltaic inverter in the detection process.
Based on the above embodiments, this embodiment further describes and optimizes the technical solution, and as a preferred implementation, the above steps: if the fact that the data of the output end of the photovoltaic inverter do not accord with the third preset standard is determined according to the operation data, the process that the fault occurs on the alternating current side of the photovoltaic inverter is judged, and the process comprises the following steps:
if the alternating voltage output by the photovoltaic inverter is determined not to be within the preset alternating voltage range according to the operation data, determining that the alternating side of the photovoltaic inverter has undervoltage or overvoltage;
if the frequency of the alternating voltage output by the photovoltaic inverter is determined not to be within the preset frequency range according to the operation data, determining that the power grid frequency of a power grid connected with the photovoltaic inverter is not within the preset frequency range;
if the fact that the alternating-current voltage output by the photovoltaic inverter is in phase failure is determined according to the operation data, the fact that a circuit breaker connected with the photovoltaic inverter breaks down is determined;
if the fact that the waveform of the alternating voltage output by the photovoltaic inverter does not meet the preset condition is determined according to the operation data, it is determined that the photovoltaic inverter is incompatible with a power grid connected with the photovoltaic inverter;
if the current or the resistance between the photovoltaic inverter and the grounding wire is determined to not meet the preset grounding standard according to the operation data, judging that the grounding wire has a fault;
and if the temperature of the joint of the photovoltaic inverter and the alternating current cable is higher than a second preset threshold value according to the operation data, judging that the joint of the photovoltaic inverter and the alternating current cable is loosened.
In this embodiment, a method for determining whether a fault occurs on an ac side of a photovoltaic inverter is provided, where the cause of the fault on the ac side of the photovoltaic inverter includes: overvoltage or undervoltage occurs on the alternating current side of the photovoltaic inverter, the grid frequency of a power grid connected with the photovoltaic inverter fluctuates greatly, alternating current is in phase failure, an alternating current cable is not firmly connected, problems occur on a grounding wire and the like.
It can be understood that, because a transformer in the photovoltaic system is close to or far away from the photovoltaic inverter, the ac voltage of the photovoltaic grid-connected point is too high or too low, and thus the photovoltaic inverter cannot be normally started. Therefore, when the alternating-current voltage output by the photovoltaic inverter is determined not to be within the preset alternating-current voltage range according to the operation data of the photovoltaic inverter, the alternating-current side of the photovoltaic inverter is indicated to have undervoltage or overvoltage. At this time, in order to enable the photovoltaic inverter to operate normally, the ac voltage protection range of the photovoltaic inverter may be adjusted to avoid the above situation.
And when the frequency of the alternating-current voltage output by the photovoltaic inverter is determined to be not in the preset range according to the operation data of the photovoltaic inverter, indicating that the frequency of the power grid connected with the photovoltaic inverter is not in the preset range. That is, the frequency of the grid to which the photovoltaic inverter is connected fluctuates, and thus the photovoltaic inverter cannot be normally started. In this case, the fault state of the photovoltaic inverter can be repaired by adjusting the ac frequency protection range of the photovoltaic inverter. Specifically, in practical application, the frequency of the ac voltage output by the photovoltaic inverter may be detected by a power analyzer or an oscilloscope.
If the fact that the alternating-current voltage output by the photovoltaic inverter is in phase failure is determined according to the operation data of the photovoltaic inverter, the fact that a breaker connected with the photovoltaic inverter has a fault is indicated, and the photovoltaic inverter cannot normally operate due to the fact that the breaker has the fault. Obviously, when this occurs, the fault of the photovoltaic inverter can be repaired by replacing the circuit breaker.
In practical application, the photovoltaic inverter sometimes needs to be connected to the weak grid, but due to the influence of the property characteristics of the weak grid, the number of the grid-connected inverters connected to the weak grid is limited. Meanwhile, harmonic components of the grid-connected point voltage can be increased due to the existence of the weak power grid, so that the waveform of the three-phase alternating-current voltage is seriously distorted, and the photovoltaic inverter cannot normally operate. Therefore, when the waveform of the alternating-current voltage output by the photovoltaic inverter is determined to not meet the preset condition according to the operation data of the photovoltaic inverter, the photovoltaic inverter is incompatible with a power grid connected with the photovoltaic inverter.
In order to solve the above problem, the number of grid-connected inverters connected between the photovoltaic inverter and the grid may be adjusted to repair the failure of the photovoltaic inverter. Specifically, when the above situation occurs, the number of grid-connected inverters can be reduced to repair the malfunction of the photovoltaic inverter.
It should be noted that, due to the parasitic capacitance between the photovoltaic system and the ground, when the parasitic capacitance, the photovoltaic system and the power grid form a loop, the loop voltage is loaded on the parasitic capacitance. At this time, if the loop impedance is small, the leakage current between the pv inverter and the ground will increase, and if this phenomenon occurs, the pv inverter may not be started normally. Meanwhile, since the grounding resistance of the photovoltaic inverter is usually required to be less than 4 ohms, if the grounding of the photovoltaic inverter is poor, the photovoltaic inverter can not be started normally. Therefore, when the current or the resistance between the photovoltaic inverter and the grounding wire is determined to not meet the preset grounding standard according to the operation data of the photovoltaic inverter, the grounding wire of the photovoltaic inverter is indicated to be in fault. In order to solve this problem, it is necessary to detect the ground line and ensure the correct grounding of the ground line.
In addition, because the alternating current cable is thick and hard, the operation is not easy, the situation that the alternating current cable is not firmly connected sometimes can occur, the phenomenon that the inverter cannot be normally started can also be caused, and when the alternating current cable is not firmly connected, the situation that the temperature of the alternating current cable is overheated can occur. Therefore, when the temperature of the connection part of the photovoltaic inverter and the alternating current cable is determined to be higher than the second preset threshold value according to the operation data of the photovoltaic inverter, the connection part of the photovoltaic inverter and the alternating current cable is loosened, and at the moment, the photovoltaic inverter and the alternating current cable can be screwed down to carry out fault maintenance on the photovoltaic inverter.
Or when the situation that the voltage of the alternating current output by the photovoltaic inverter is disconnected and switched on is determined according to the operation data of the photovoltaic inverter, the situation that the connection part of the photovoltaic inverter and the alternating current cable is loosened and the photovoltaic inverter cannot be normally started can be caused. Specifically, in the actual operation process, an infrared thermometer may be used to detect a temperature value between the photovoltaic inverter and the ac cable, and a voltmeter may be used to measure the ac voltage output by the photovoltaic inverter.
Obviously, according to the technical scheme provided by the embodiment, the fault detection result of the photovoltaic inverter can be more accurate and reliable.
Referring to fig. 2, fig. 2 is a structural diagram of a fault detection apparatus according to an embodiment of the present invention, the fault detection apparatus includes:
the data detection module 21 is configured to detect operation data of the photovoltaic inverter when the photovoltaic inverter fails;
the first judging module 22 is configured to judge that the target device fails if it is determined that the target device does not meet the first preset standard according to the operation data; wherein the target device is a device specified in the photovoltaic inverter according to a preset rule;
the second determination module 23 is configured to determine that a fault occurs on the dc side of the photovoltaic inverter if it is determined that the input end data of the photovoltaic inverter does not meet the second preset standard according to the operation data;
and a third determining module 24, configured to determine that a fault occurs on the ac side of the photovoltaic inverter if it is determined that the data at the output end of the photovoltaic inverter does not meet a third preset standard according to the operation data.
The fault detection device provided by the embodiment of the invention has the beneficial effects of the fault detection method disclosed by the embodiment of the invention.
Referring to fig. 3, fig. 3 is a structural diagram of a fault detection device according to an embodiment of the present invention, where the fault detection device includes:
a memory 31 for storing a computer program;
a processor 32 for implementing the steps of a fault detection method as disclosed in the foregoing when executing the computer program.
The fault detection equipment provided by the embodiment of the invention has the beneficial effects of the fault detection method disclosed by the embodiment of the invention.
Correspondingly, the embodiment of the invention also discloses a computer readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the fault detection method as disclosed in the foregoing are realized.
The embodiment of the invention also provides a computer readable storage medium, which has the beneficial effects of the fault detection method disclosed in the foregoing.
The embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same or similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.
Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The above detailed description is provided for a fault detection method, apparatus, device and medium provided by the present invention, and the principle and implementation of the present invention are explained in this document by applying specific examples, and the description of the above examples is only used to help understanding the method and core idea of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.
Claims (9)
1. A fault detection method is applied to a photovoltaic inverter in a photovoltaic system, and comprises the following steps:
when the photovoltaic inverter breaks down, detecting the operation data of the photovoltaic inverter;
if the target device is determined to be not in accordance with the first preset standard according to the operation data, judging that the target device fails; wherein the target device is a device specified in the photovoltaic inverter according to a preset rule;
if the fact that the data of the input end of the photovoltaic inverter do not accord with a second preset standard is determined according to the operation data, the fact that a fault occurs on the direct current side of the photovoltaic inverter is determined;
and if the fact that the data of the output end of the photovoltaic inverter do not accord with a third preset standard is determined according to the operation data, judging that the alternating current side of the photovoltaic inverter has a fault.
2. The method according to claim 1, wherein the step of determining that the dc side of the pv inverter has failed if it is determined from the operation data that the input data of the pv inverter does not meet the second predetermined criteria comprises:
if the fact that the direct-current voltage input by the photovoltaic inverter is not within the preset direct-current voltage range is determined according to the operation data, the fact that undervoltage or overvoltage occurs on the direct-current side of the photovoltaic inverter is determined;
if the fact that the direct current voltage input by the photovoltaic inverter is higher than a first preset threshold value is determined according to the operation data, the fact that the number of photovoltaic modules connected to the direct current side of the photovoltaic inverter exceeds the bearing range of the photovoltaic inverter is determined;
if the direct current voltage input by the photovoltaic inverter is determined to be a negative value according to the operation data, determining that the positive electrode and the negative electrode of a photovoltaic module connected with the photovoltaic inverter are reversely connected;
and if the fact that the power of the photovoltaic inverter exceeds the preset power is determined according to the operation data, judging that the photovoltaic inverter has an overload phenomenon.
3. The method according to claim 2, wherein the step of determining whether an undervoltage or an overvoltage occurs on the dc side of the photovoltaic inverter is followed by:
and adjusting the number of photovoltaic modules connected with the photovoltaic inverter.
4. The method according to claim 1, wherein the step of determining that the ac side of the pv inverter has failed if it is determined from the operation data that the output data of the pv inverter does not meet a third predetermined criterion includes:
if the alternating-current voltage output by the photovoltaic inverter is determined not to be within the preset alternating-current voltage range according to the operation data, determining that undervoltage or overvoltage occurs on the alternating-current side of the photovoltaic inverter;
if the frequency of the alternating-current voltage output by the photovoltaic inverter is determined not to be within a preset frequency range according to the operation data, determining that the power grid frequency of a power grid connected with the photovoltaic inverter is not within the preset frequency range;
if the fact that the alternating-current voltage output by the photovoltaic inverter is in phase failure is determined according to the operation data, it is determined that a circuit breaker connected with the photovoltaic inverter is in fault;
if the fact that the waveform of the alternating voltage output by the photovoltaic inverter does not meet the preset condition is determined according to the operation data, it is determined that the photovoltaic inverter is incompatible with a power grid connected with the photovoltaic inverter;
if the current or the resistance between the photovoltaic inverter and the grounding wire is determined to not meet the preset grounding standard according to the operation data, judging that the grounding wire has a fault;
and if the temperature of the connection part of the photovoltaic inverter and the alternating current cable is determined to be higher than a second preset threshold value according to the operation data, judging that the connection part of the photovoltaic inverter and the alternating current cable is loosened.
5. The method according to claim 4, wherein the step of determining whether an undervoltage or an overvoltage occurs on the ac side of the photovoltaic inverter is followed by:
and adjusting the alternating voltage protection range of the photovoltaic inverter.
6. The fault detection method of claim 4, wherein the process of determining that the photovoltaic inverter is incompatible with a grid to which the photovoltaic inverter is connected further comprises:
and adjusting the number of the grid-connected inverters connected between the photovoltaic inverter and the power grid.
7. A fault detection device, applied to a photovoltaic inverter in a photovoltaic system, includes:
the data detection module is used for detecting the operation data of the photovoltaic inverter when the photovoltaic inverter fails;
the first judgment module is used for judging that the target device fails if the target device is determined to be not in accordance with a first preset standard according to the operation data; wherein the target device is a device specified in the photovoltaic inverter according to a preset rule;
the second judgment module is used for judging that the direct current side of the photovoltaic inverter has a fault if the operation data determine that the input end data of the photovoltaic inverter does not accord with a second preset standard;
and the third judging module is used for judging that the alternating current side of the photovoltaic inverter has a fault if the data of the output end of the photovoltaic inverter is determined to be not in accordance with a third preset standard according to the operation data.
8. A fault detection device, comprising:
a memory for storing a computer program;
processor for implementing the steps of a method of fault detection as claimed in any one of claims 1 to 6 when executing said computer program.
9. A computer-readable storage medium, characterized in that a computer program is stored on the computer-readable storage medium, which computer program, when being executed by a processor, carries out the steps of a fault detection method as claimed in any one of the claims 1 to 6.
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108362981A (en) * | 2018-01-09 | 2018-08-03 | 复旦大学 | A kind of photovoltaic system DC Line Fault arc method for measuring that active/passive detection combines |
| CN110838822A (en) * | 2019-11-21 | 2020-02-25 | 上海电气富士电机电气技术有限公司 | Fault information acquisition system and method for photovoltaic inverter |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108362981A (en) * | 2018-01-09 | 2018-08-03 | 复旦大学 | A kind of photovoltaic system DC Line Fault arc method for measuring that active/passive detection combines |
| CN110838822A (en) * | 2019-11-21 | 2020-02-25 | 上海电气富士电机电气技术有限公司 | Fault information acquisition system and method for photovoltaic inverter |
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