CN209784459U - Monitoring device of wind power converter - Google Patents
Monitoring device of wind power converter Download PDFInfo
- Publication number
- CN209784459U CN209784459U CN201920483767.2U CN201920483767U CN209784459U CN 209784459 U CN209784459 U CN 209784459U CN 201920483767 U CN201920483767 U CN 201920483767U CN 209784459 U CN209784459 U CN 209784459U
- Authority
- CN
- China
- Prior art keywords
- wind power
- power converter
- target wind
- ripple
- monitoring device
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000012806 monitoring device Methods 0.000 title claims abstract description 41
- 238000003860 storage Methods 0.000 claims abstract description 6
- 238000000034 method Methods 0.000 abstract description 17
- 238000010248 power generation Methods 0.000 abstract description 16
- 230000008569 process Effects 0.000 abstract description 11
- 230000000246 remedial effect Effects 0.000 abstract description 6
- 238000010586 diagram Methods 0.000 description 10
- 239000003990 capacitor Substances 0.000 description 7
- 239000011104 metalized film Substances 0.000 description 4
- 238000001514 detection method Methods 0.000 description 3
- 230000006870 function Effects 0.000 description 3
- 238000012544 monitoring process Methods 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000010408 film Substances 0.000 description 1
- 239000004973 liquid crystal related substance Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
Landscapes
- Control Of Eletrric Generators (AREA)
Abstract
The application discloses monitoring devices of wind power converter includes: the storage is used for storing the resonance angular frequency of the direct current bus of the target wind power converter; the detector is used for detecting the ripple current of the target wind power converter in real time; and the processor is respectively connected with the memory and the detector and is used for outputting a ripple resonance judgment result of the target wind power converter according to the ripple current and the resonance angular frequency. Whether ripple resonance occurs to the target wind power converter can be detected through the monitoring device, and therefore when the monitoring device judges that the ripple resonance occurs to the target wind power converter, a worker can take corresponding remedial measures to process the ripple resonance occurring to the target wind power converter, and therefore the economic loss caused by a wind power generation system when the ripple resonance occurs to the target wind power converter can be reduced.
Description
Technical Field
The utility model relates to a wind power generation technical field, in particular to monitoring devices of wind-powered electricity generation converter.
Background
With the rapid development of wind power technology, the safety requirements of the power system on the wind turbine generator and the components thereof are higher and higher. The capacitor is widely applied to a direct current link of the wind power converter as an energy storage device, and mainly plays a role in balancing the power of the converter at the machine side and the converter at the grid side, stabilizing the voltage of a bus at the direct current side and absorbing alternating current components in the two-stage converter, so that the fluctuation value of the voltage of the bus at the direct current side can be controlled within an allowable range. The film capacitor has the advantages of high working voltage, long service life, strong ripple resistance, low stray inductance and the like, so most of the direct current side capacitor of the wind power converter is a metalized film capacitor.
in practical application, the influence of ripple current is reduced to the multiunit metallized film electric capacity that generally needs to connect in parallel in wind power converter, but, when carrying out parallelly connected use with multiunit metallized film electric capacity, can make wind power converter take place the ripple resonance, and when the ripple resonance takes place for wind power converter, can make the metallized film electric capacity in the wind power converter frequently overheat and take place to damage. However, in the prior art, a monitoring device capable of monitoring the ripple resonance of the wind power converter has not been found, so that when the ripple resonance of the wind power converter occurs, a worker cannot take corresponding remedial measures, and huge economic loss is caused to the wind power generation system.
Therefore, what kind of monitoring device of wind power converter is provided to can monitor ripple resonance that wind power converter takes place in the operation in real time is the problem that technical staff in this field await solution urgently.
SUMMERY OF THE UTILITY MODEL
In view of this, the utility model aims at providing a monitoring devices of wind power converter to can the ripple resonance that the wind power converter takes place at the operation in-process of real-time supervision. The specific scheme is as follows:
A monitoring device of a wind power converter comprises:
The storage is used for storing the resonance angular frequency of the direct current bus of the target wind power converter;
The detector is used for detecting the ripple current of the target wind power converter in real time;
and the processor is respectively connected with the memory and the detector and is used for outputting a ripple resonance judgment result of the target wind power converter according to the ripple current and the resonance angular frequency.
Preferably, the detector is embodied as a current sensor.
preferably, the method further comprises the following steps:
And the display is connected with the processor and used for displaying the spectrogram of the ripple current.
preferably, the display is an oscilloscope.
preferably, the memory is specifically an EEPROM.
Preferably, the method further comprises the following steps:
And the alarm is connected with the processor and used for prompting the target wind power converter to generate the ripple resonance.
Preferably, the method further comprises the following steps:
And the temperature sensor is connected with the processor and used for detecting the temperature information of the target wind power converter.
preferably, the method further comprises the following steps:
And the controller is connected with the processor and used for switching off the target wind power converter when the ripple resonance occurs in the target wind power converter.
preferably, the controller is a single chip microcomputer or an MCU or a DSP chip.
Therefore, in the monitoring device of the wind power converter provided by the utility model, when the detector detects the ripple current of the target wind power converter in real time, the detector can send the detected ripple current of the target wind power converter to the processor, so that the processor can detect the ripple current of the target wind power converter according to the detector, and the resonance angular frequency of the direct current bus of the target wind power converter stored in the memory is used for outputting the judgment result of the ripple resonance of the target wind power converter, when the processor judges that the ripple resonance occurs in the target wind power converter, the staff can take corresponding remedial measures to process the ripple resonance occurring in the target wind power converter, therefore, the economic loss of the wind power generation system caused by the ripple resonance of the target wind power converter can be reduced.
drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be 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 structural diagram of a monitoring device of a wind power converter provided in an embodiment of the present invention;
Fig. 2 is an equivalent model diagram of a wind power generation system provided in an embodiment of the present invention;
Fig. 3 is a simplified equivalent diagram of a wind power generation system according to an embodiment of the present invention;
Fig. 4 is a schematic diagram of a target wind power converter provided by an embodiment of the present invention when ripple resonance occurs;
Fig. 5 is a structural diagram of another monitoring device of a wind power converter provided in an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
fig. 1 is the embodiment of the utility model provides a monitoring devices's of wind power converter structure chart, please refer to fig. 1, this monitoring devices of wind power converter includes:
A memory 11 for storing the resonant angular frequency of the dc bus of the target wind power converter;
A detector 12 for detecting the ripple current of the target wind power converter in real time;
and the processor 13 is respectively connected with the memory 11 and the detector 12 and is used for outputting a ripple resonance judgment result of the target wind power converter according to the ripple current and the resonance angular frequency.
In order to make those skilled in the art better understand the technical solution provided by the present application, first, a simple description is given below to the calculation process of the angular frequency of the dc bus of the target wind power converter. Fig. 2 is an equivalent model diagram of a wind power generation system according to an embodiment of the present invention, please refer to fig. 2, in which the wind power generation system includes a machine side rectification module, a direct current side and a grid side inversion module. The influence of bus stray parameters and capacitance stray parameters is considered in the equivalent model, wherein RDCand LDCrespectively representing the stray resistance and the stray inductance, L, of the DC busESL、RESRAnd C are eachThe equivalent series inductance and the equivalent series resistance of the thin film capacitor in the target wind power converter and the nominal value of the capacitor are shown.
Since the ripple current of the target wind power converter is mainly formed by overlapping the ac component of the grid-side converter and the ac component of the machine-side converter, in this embodiment, it is assumed that the ripple current contains the frequency w0and only one branch satisfies in the equivalent model
That is, if the natural resonant frequency of one branch in the equivalent model is equal to the current frequency of a specific frequency of the ripple current, at this time, the whole circuit will present a low impedance, but in practical applications, since the branch current will be affected by the series-parallel connection of other branches, and there are more branches connected in series-parallel connection in the target wind power converter, if the other branches excluding the branch do not resonate at this frequency point, the whole circuit will not present a low impedance situation.
Therefore, in practical application, a direct current component on a bus of the target converter can be omitted, ripple currents generated by the grid-side inverter module and the machine-side rectifier module are superposed to be equivalent to a ripple source for analysis, and a simplified equivalent diagram of the wind power generation system can be obtained. Referring to fig. 3, fig. 3 is a simplified equivalent diagram of a wind power generation system according to an embodiment of the present invention, in fig. 3, AC is an equivalent ripple source, and R is an equivalent ripple sourceDC＝RDC0+RDC1，LDC＝LDC0+LDC1；
At this time, the equivalent impedance of the wind power generation system can be expressed as:
The method is simplified and can be obtained:
From the equation, the simplified wind power generation system is a standard RLC series circuit, and then, when the imaginary part of the equivalent impedance Z is set to zero, the natural resonant angular frequency of the wind power generation system, that is, the resonant angular frequency of the dc bus of the target wind power converter, can be obtained:
That is to say that the first and second electrodes,
therefore, in this embodiment, in order to enable the monitoring device of the wind power converter to monitor whether ripple resonance occurs in the target wind power converter during operation, the memory 11, the detector 12 and the processor 13 are disposed in the monitoring device of the wind power converter, and the resonant angular frequency of the dc bus of the target wind power converter is stored in the memory 11 in advance, it is conceivable that, when the monitoring device is monitoring the target wind power converter, the ripple current of the target wind power converter is detected in real time by the detector 12, then the resonant angular frequency of the dc bus of the target wind power converter and the ripple current of the target wind power converter are input into the processor 13, and finally, the processor 13 outputs a determination result of whether the target wind power converter will generate ripple resonance, that is, the processor 13 outputs the ripple current of the target wind power converter detected by the detector 12 and the ripple current of the target wind power converter stored in the memory 11 And comparing the resonance angular frequency of the direct current bus of the electric converter to judge whether the target wind power converter generates ripple resonance.
fig. 4 is the schematic diagram of the target wind power converter when ripple resonance occurs, as can be seen from fig. 4, if ripple resonance occurs in the target wind power converter, a large current peak appears on the frequency spectrum diagram of the ripple current, and under this condition, the processor 13 can determine that ripple resonance occurs in the target wind power converter.
It can be considered that, if the processor 13 determines that the ripple resonance occurs in the target wind power converter, the staff may take corresponding remedial measures to process the ripple resonance occurring in the target wind power converter, so that the economic loss suffered by the wind power generation system can be relatively reduced.
In addition, in practical applications, the memory 11 may be configured as any device having a storage function, such as: hard disk, magnetic disk, memory, ram, etc., the detector 12 may be configured as a current sensor, hall sensor, or current tester, and the processor 13 may be configured as any chip with logic computation function, such as: the single chip microcomputer or the CPU is not particularly limited as long as it can achieve the purpose of practical application.
It can be seen that, in the monitoring device for a wind power converter provided in this embodiment, when the detector detects the ripple current of the target wind power converter in real time, the detector may send the detected ripple current of the target wind power converter to the processor, so that the processor may output the result of determining the ripple resonance of the target wind power converter according to the ripple current of the target wind power converter detected by the detector and the resonance angular frequency of the dc bus of the target wind power converter stored in the memory. When the processor judges that the target wind power converter has ripple resonance, the staff can take corresponding remedial measures to process the ripple resonance generated by the target wind power converter, so that the economic loss of the wind power generation system caused by the ripple resonance generated by the target wind power converter can be reduced.
Based on the above embodiments, the present embodiment further describes and optimizes the technical solution, and as a preferred implementation, the detector 12 is specifically a current sensor.
specifically, the detector 12 can be set as a current sensor, because the current on the direct current side of the target wind power converter is large, and the current sensor has the advantages of high detection sensitivity, strong anti-interference energy and stable and reliable working performance, so that when the detector 12 is set as the current sensor, the ripple current of the target wind power converter can be measured more accurately and stably.
Specifically, in practical application, the current sensor may be configured as a resistor shunt, a current transformer, or a fluxgate current sensor, and the like.
Therefore, through the technical scheme provided by the embodiment, the safety and the reliability of the ripple current of the target wind power converter in the detection process are ensured.
Based on above-mentioned embodiment, this embodiment does further explanation and optimization to technical scheme, and fig. 5 is the embodiment of the utility model provides a monitoring devices's of another kind of wind power converter structure chart, it is concrete, above-mentioned wind power converter's monitoring devices still includes:
And a display 14 connected to the processor 13 for displaying a spectrogram of the ripple current.
It can be understood that, the processor 13 generally analyzes by analyzing a frequency spectrogram of ripple current when determining whether the target wind power converter has ripple resonance, so in this embodiment, a display 14 connected to the processor 13 and configured to display the frequency spectrogram of ripple current of the target wind power converter is further disposed in the monitoring device of the wind power converter.
It can be thought that, the ripple current of the target wind power converter is displayed through the display 14, so that the worker can more visually and accurately observe the ripple current of the target wind power converter, and thus, the worker can more accurately judge whether the ripple resonance occurs in the target wind power converter. Specifically, in practical application, the display 14 may be a liquid crystal display, or the display 14 may be an LED display, as long as the purpose of displaying the ripple current of the target wind power converter can be achieved.
Obviously, through the technical scheme provided by the embodiment, the staff can more intuitively and accurately check the frequency spectrogram of the ripple current of the target wind power converter, and therefore the accuracy and the reliability of the ripple resonance judgment result are improved.
As a preferred embodiment, the display 14 is embodied as an oscilloscope.
The oscilloscope serving as a common electronic measuring instrument can convert some electric signals which cannot be seen by people in daily life into image information for displaying, so that the oscilloscope is used for displaying the ripple current of the target wind power converter, and the frequency spectrogram of the ripple current of the target wind power converter can be displayed more accurately.
Specifically, the oscilloscope can perform FFT (fast fourier transform) analysis on the ripple current of the target wind power converter, observe whether the ripple current of the target wind power converter at the resonance angular frequency is significantly amplified, and indicate that ripple resonance occurs in the target wind power converter if significant amplification occurs.
In addition, the oscilloscope can be used for displaying the ripple current of the target wind power converter, and can also be used for measuring parameters such as voltage, frequency and phase difference of the target wind power converter in the actual operation process. Therefore, when observing the ripple current of the target wind power converter, a worker can observe the change conditions of other parameters of the target wind power converter in the operation process in real time, and the data result obtained by measurement of the oscilloscope is more accurate and comprehensive. In practical applications, the oscilloscope may be set to Tektronix MDO 4104C.
Therefore, by the technical scheme provided by the embodiment, the frequency spectrum graph of the ripple current of the target wind power converter can be displayed more clearly, visually and accurately.
Based on the above embodiments, the present embodiment further describes and optimizes the technical solution, and as a preferred implementation, the memory is specifically an EEPROM.
In this embodiment, in order to avoid the loss of data stored in the Memory, the Memory is an EEPROM (Electrically Erasable Programmable Read Only Memory). Because the EEPROM is a storage chip in which stored data cannot be lost under the condition of power failure, even if the monitoring device of the wind power converter is powered off, the data stored in the EEPROM cannot be influenced, and therefore, when the resonant angular frequency of the direct current bus of the target wind power converter is stored in the EEPROM, the safety of the resonant angular frequency of the direct current bus of the target wind power converter in the storage process can be further ensured.
Based on the above embodiments, the present embodiment further describes and optimizes the technical solution, please refer to fig. 5, and the monitoring device of the wind power converter further includes:
And the alarm 15 is connected with the processor 13 and used for prompting the target wind power converter to generate ripple resonance.
It can be thought that if the target wind power converter generates ripple resonance, not only the normal operation of the target wind power converter is affected, but also the normal operation of the wind power generation system where the target wind power converter is located is affected. Therefore, in the embodiment, the alarm 15 for prompting the target wind power converter to generate ripple resonance is further arranged in the monitoring device of the wind power converter, so that a worker can take corresponding remedial measures for the target wind power converter according to the early warning information prompted by the alarm 15, and the probability of safety accidents of the target wind power converter is reduced. In practical applications, the alarm 15 may be configured as an audible and visual alarm, or the alarm 15 may be configured as a buzzer, or the alarm 15 may be configured as a voice prompt, which is not limited herein.
therefore, by the technical scheme provided by the embodiment, not only can the workers timely know the real-time running state of the target wind power converter, but also the probability of safety accidents of the target wind power converter can be reduced.
Based on the above embodiments, the present embodiment further describes and optimizes the technical solution, please refer to fig. 5, and the monitoring device of the wind power converter further includes:
and the temperature sensor 16 is connected with the processor 13 and is used for detecting the temperature information of the target wind power converter.
It can be understood that, if the target wind power converter fails, most of the reasons are that the target wind power converter is damaged due to frequent overheating of a capacitor in the target wind power converter, so in this embodiment, the temperature sensor 16 can be used for detecting the temperature information of the target wind power converter, and the temperature information of the target wind power converter is monitored to achieve the purpose of monitoring the target wind power converter in real time.
specifically, if the temperature of the target wind power converter monitored by the temperature sensor 16 is too high, it may be determined that the target wind power converter is in an abnormal operation state, and if the temperature of the target wind power converter monitored by the temperature sensor 16 is within a normal range, it may be determined that the target wind power converter is in a normal operation state.
Obviously, through the technical scheme provided by this embodiment, the detection means of the target wind power converter can be more flexible and various, and thus the monitoring device of the wind power converter provided by the application can be applied to more actual scenes.
Based on the above embodiments, the present embodiment further describes and optimizes the technical solution, please refer to fig. 5, and the monitoring device of the wind power converter further includes:
And the controller 17 is connected with the processor 13 and is used for switching off the target wind power converter when the target wind power converter generates ripple resonance.
in this embodiment, in order to ensure the safety of the target wind power converter in the operation process, a controller 17 is further arranged in the monitoring device of the wind power converter, and the controller 17 is used for controlling the target wind power converter to be turned on or off. Therefore, when the processor 13 judges that the target wind power converter has ripple resonance, the target wind power converter can be turned off through the controller 17, so that safety accidents are avoided.
In addition, it should be noted that, in practical application, the controller 17 and the processor 13 may be disposed in the same chip, so that not only the manufacturing cost of the monitoring device of the wind power converter may be reduced, but also the occupied space of the monitoring device of the wind power converter may be relatively reduced.
Therefore, the technical scheme provided by the embodiment further ensures the safety and reliability of the target wind power converter in the operation process.
as a preferred embodiment, the controller 17 is specifically a single chip microcomputer or an MCU or DSP chip.
In practical application, the controller 17 can be set as a single chip microcomputer or an MCU or a DSP chip, and because the single chip microcomputer or the MCU or the DSP chip is a programmable logic device with a calculation processing function, the target wind power converter can be controlled by using the single chip microcomputer or the MCU or the DSP chip.
Specifically, the DSP chip can be set to TMS320F28335, because TMS320F28335 is not only lower in cost, but also has the advantages of low power consumption and fast data processing speed, so that the turn-off speed of the controller 17 to the target wind power converter can be relatively shortened. In addition, the TMS320F28335 is small in size, so that the space occupation of the monitoring device of the wind power converter by the controller 17 can be further reduced.
Therefore, the technical scheme provided by the embodiment can enable the setting mode of the controller to be more flexible and diversified.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (9)
1. a monitoring device of a wind power converter is characterized by comprising:
The storage is used for storing the resonance angular frequency of the direct current bus of the target wind power converter;
the detector is used for detecting the ripple current of the target wind power converter in real time;
And the processor is respectively connected with the memory and the detector and is used for outputting a ripple resonance judgment result of the target wind power converter according to the ripple current and the resonance angular frequency.
2. The monitoring device according to claim 1, wherein the detector is in particular a current sensor.
3. The monitoring device of claim 1, further comprising:
and the display is connected with the processor and used for displaying the spectrogram of the ripple current.
4. The monitoring device according to claim 3, wherein the display is embodied as an oscilloscope.
5. the monitoring device according to claim 1, wherein the memory is in particular an EEPROM.
6. The monitoring device of claim 1, further comprising:
And the alarm is connected with the processor and used for prompting the target wind power converter to generate the ripple resonance.
7. The monitoring device of claim 1, further comprising:
And the temperature sensor is connected with the processor and used for detecting the temperature information of the target wind power converter.
8. the monitoring device of any one of claims 1 to 7, further comprising:
and the controller is connected with the processor and used for switching off the target wind power converter when the ripple resonance occurs in the target wind power converter.
9. The monitoring device of claim 8, wherein the controller is a single chip microcomputer or an MCU or a DSP chip.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920483767.2U CN209784459U (en) | 2019-04-09 | 2019-04-09 | Monitoring device of wind power converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920483767.2U CN209784459U (en) | 2019-04-09 | 2019-04-09 | Monitoring device of wind power converter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN209784459U true CN209784459U (en) | 2019-12-13 |
Family
ID=68802232
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201920483767.2U Active CN209784459U (en) | 2019-04-09 | 2019-04-09 | Monitoring device of wind power converter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN209784459U (en) |
-
2019
- 2019-04-09 CN CN201920483767.2U patent/CN209784459U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105699825B (en) | A kind of automobile quiescent current detection device and method | |
| JP3379298B2 (en) | Device for determining the life of sealed lead-acid batteries | |
| RU2534457C2 (en) | Control method and device of equipment energy efficiency parameters | |
| US20100161259A1 (en) | Aging status diagnostic apparatus for power conversion system, and method their of | |
| CN105954632A (en) | Zinc oxide lightning arrester on-line monitoring and diagnostic method | |
| CN106152980B (en) | A kind of deformation of transformer winding detection method and system | |
| CN110031703A (en) | A kind of the unusual service condition method of discrimination and system of super extra-high voltage transformer | |
| CN112816909A (en) | Method and device for monitoring leakage current of solar photovoltaic inverter | |
| CN111257618A (en) | Cubical switchboard contact current measurement ring with from function of getting electricity | |
| CN209784459U (en) | Monitoring device of wind power converter | |
| CN103135063A (en) | Detection and monitoring method of lead-acid storage battery | |
| CN211121602U (en) | Three-phase capacitor voltage transformer state monitoring system | |
| CN103176095B (en) | Earth detector and method | |
| CN100460883C (en) | Detection method for testing current in resistance property of lightning arrester | |
| CN104977479B (en) | Three-phase electricity condition detection apparatus, method and electric system | |
| CN217718079U (en) | Mutual inductor state monitoring circuit | |
| CN216956221U (en) | Non-invasive AC-DC line conductor current sensing device | |
| CN105445674A (en) | AC/DC power supply fault analyzing device and detection method thereof | |
| CN211348414U (en) | Induction electricity-taking electric temperature monitoring device | |
| CN211123194U (en) | Battery internal resistance measuring device | |
| CN206757008U (en) | A kind of DC charging motor ripple monitoring device | |
| CN107037362A (en) | A kind of DC charging motor ripple monitoring device | |
| CN204439820U (en) | Once-through type lightning arrester on-Line Monitor Device detector | |
| CN113466730A (en) | Storage battery internal resistance flash measurement device and method | |
| KR100550360B1 (en) | Apparatus for diagnosing status of electric power converter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |