CN113567748B - Converter direct current capacitance detection method, life prediction method and system - Google Patents
Converter direct current capacitance detection method, life prediction method and system Download PDFInfo
- Publication number
- CN113567748B CN113567748B CN202010349754.3A CN202010349754A CN113567748B CN 113567748 B CN113567748 B CN 113567748B CN 202010349754 A CN202010349754 A CN 202010349754A CN 113567748 B CN113567748 B CN 113567748B
- Authority
- CN
- China
- Prior art keywords
- current
- converter
- voltage
- direct current
- phase
- 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
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/26—Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants ; Measuring impedance or related variables
- G01R27/2605—Measuring capacitance
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
Abstract
The invention discloses a converter direct current capacitance detection method, a life prediction method and a system, wherein the direct current capacitance detection method comprises the following steps: s1, injecting alternating current detection voltage with preset frequency and amplitude on a direct current bus of a converter to be detected; s2, detecting and acquiring input voltage and input current on a direct current bus of the converter, and detecting and acquiring phase current of an alternating current output end of the converter; calculating to obtain a first current of a direct current capacitor according to the input current and the phase current; s3, extracting a voltage component with the preset frequency from the input voltage, and extracting a current component with the preset frequency from the first current; and S4, calculating and determining the capacitance value of the direct current capacitor according to the voltage component and the current component. The device has the advantages of simple structure, low cost, convenient implementation, on-line detection and the like.
Description
Technical Field
The invention relates to the technical field of converters, in particular to a converter direct-current capacitor detection method, a converter direct-current capacitor service life prediction method and a converter direct-current capacitor service life prediction system.
Background
The development of power electronic technology enables electrical equipment containing direct-current bus support capacitors, such as uninterruptible power supplies, frequency converters, current transformers and the like, to be widely applied. The direct current bus support capacitor is used as a key energy storage element and mainly has the functions of buffering direct energy exchange between the power grid side and a load, stabilizing the bus voltage and inhibiting the direct current bus voltage from greatly fluctuating due to sudden change of the load.
The typical structure of a photovoltaic power generation system is shown in fig. 1, a photovoltaic power generation panel generates direct current, the direct current is converted into alternating current through a converter, and the alternating current is filtered and transformed and then output to a power grid for users to use. In a photovoltaic power generation system, a converter bears conversion work from direct current to alternating current, and is a core unit in the photovoltaic power generation system, and the stability of the photovoltaic power generation system is determined to a great extent by the stable state of the converter. In order to improve the working stability of the converter in the photovoltaic power generation system, the requirements on the aspects of fault diagnosis, health management and the like of the converter are higher and higher. The direct current support capacitor (capacitor C in fig. 1) is used as a key energy storage element in the converter and is also an element with a high fault rate in the converter, so that the running state and the residual life of the converter can be predicted, problems can be found in advance, and health maintenance prompt can be timely carried out, and the direct current support capacitor has very important significance.
Among the prior art, in order to detect the electric capacity life-span, adopt off-line detection scheme more, detect after regularly tearing down the electric capacity from the converter promptly, however direct current supports electric capacity and generally by a plurality of small capacity electric capacity series-parallel connection group cluster electric capacity subassemblies, and it is inconvenient to dismantle, must cut off the power supply and stop equipment operation moreover and just can operate, has a great deal of inconvenience among the practical application. In addition, some technologies collect the temperature and the voltage and the current of the capacitor, and then estimate the service life of the capacitor based on an Arrhenius empirical formula, or estimate the service life of the capacitor after capacitance value calculation based on a capacitance charge-discharge principle.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: aiming at the technical problems in the prior art, the invention provides a converter direct current capacitance detection method, a converter direct current capacitance service life prediction method and a converter direct current capacitance service life prediction system which are simple in structure, low in cost, convenient to implement and capable of conducting online detection.
In order to solve the technical problems, the technical scheme provided by the invention is as follows: a converter direct current capacitance detection method comprises the following steps:
s1, injecting alternating current detection voltage with preset frequency and amplitude into a direct current bus of a tested converter;
s2, detecting and acquiring input voltage and input current on a direct current bus of the converter, and detecting and acquiring phase current of an alternating current output end of the converter; calculating to obtain a first current of a direct current capacitor according to the input current and the phase current;
s3, extracting a voltage component with the preset frequency from the input voltage, and extracting a current component with the preset frequency from the first current;
and S4, calculating and determining the capacitance value of the direct current capacitor according to the voltage component and the current component.
Further, in step S1, the preset frequency is smaller than a disturbance frequency generated by the switching operation of the converter on the dc current and smaller than an ac-side voltage fundamental frequency of the converter.
Furthermore, the value range interval of the preset frequency is [0.1X, 0.5X ], and X is the fundamental frequency of the alternating-current side voltage of the converter.
Further, in step S2, detecting and obtaining a switching tube state of each phase of the ac output end of the converter; when the upper tube of the switching tube of the phase is in a conducting state, the phase outputs current; when the lower tube of the switching tube of the phase is conducted, the phase has no output current.
Further, the first current is determined by subtracting the phase current from the input current in step S2.
Further, step S3 specifically includes filtering the input voltage and the first current at a preset filtering frequency interval, taking the filtered input voltage as a voltage component, and taking the filtered input current as a current component.
A method for predicting the service life of a direct current capacitor of a converter comprises the steps of determining the capacitance value of the direct current capacitor according to the method for detecting the direct current capacitor of the converter, judging whether the ratio of a capacitance error value to the nominal capacitance value of the direct current capacitor is larger than a preset threshold value, if so, judging that the service life of the direct current capacitor is limited, and otherwise, judging that the direct current capacitor is effective; the capacitance error value is a difference between the capacitance value and a nominal capacitance value of the dc capacitor.
A converter direct current capacitance detection system comprises a detection voltage injection module, an input end electric energy detection module, an output end electric energy detection module and an analysis processing module; the voltage injection module, the input end electric energy detection module and the output end electric energy detection module are respectively connected with the analysis processing module;
the detection voltage injection module is connected with a direct current bus of the converter and used for injecting alternating current detection voltage with preset frequency and preset amplitude into the direct current bus;
the input end electric energy detection module is used for detecting and acquiring input voltage and input current on a direct current bus of the converter;
the output end electric energy detection module is used for detecting and acquiring phase current of the alternating current output end of the converter;
the analysis processing module is used for calculating to obtain a first current of a direct current capacitor according to the input current and the phase current, extracting a voltage component with the preset frequency from the input voltage, extracting a current component with the preset frequency from the first current, and calculating and determining a capacitance value of the direct current capacitor according to the voltage component and the current component.
Furthermore, the output end electric energy detection module also comprises a switching tube state detection submodule;
the switching tube state detection submodule is used for detecting and acquiring the state of a switching tube of each phase of the alternating current output end of the converter; when the upper tube of the switching tube of the phase is in a conducting state, the output end electric energy detection module outputs the current of the phase; when the lower tube of the switching tube of the phase is conducted, the output end electric energy detection module outputs no current of the phase.
Further, the analysis processing module further includes a filtering submodule, where the filtering submodule is configured to filter the input voltage and the first current in a preset filtering frequency interval, and use the input voltage obtained after filtering as a voltage component and the input current obtained after filtering as a current component.
Compared with the prior art, the invention has the advantages that:
1. the invention can complete the detection of the direct current capacitor by utilizing the hardware equipment of the current transformer only by adding the detection voltage injection module for injecting the alternating current detection voltage to the current transformer, and has the advantages of simple structure, convenient implementation, low cost and the like.
2. According to the invention, in the process of detecting the direct-current capacitor, the direct-current capacitor can be detected in the running process without stopping and powering off the power generation system and the converter, namely, the detection process can be carried out on line, and the detection convenience is good.
3. According to the invention, the capacitance value of the direct current capacitor can be calculated by injecting the alternating current detection voltage into the direct current bus and extracting the component with the frequency of the alternating current detection voltage from the input voltage and the first current, and the detection speed is high, the efficiency is high, and the accuracy is good; meanwhile, the frequency of the injected alternating current detection voltage is low, the duration is short, the normal operation of the converter cannot be influenced, and the converter can work continuously, stably and reliably.
Drawings
Fig. 1 is a schematic diagram of a typical structure of a photovoltaic power generation system in the prior art.
Fig. 2 is a schematic diagram of a detection process according to an embodiment of the present invention.
FIG. 3 is a schematic diagram of a current situation according to an embodiment of the present invention.
Fig. 4 is a schematic structural diagram of a detection system according to an embodiment of the present invention.
Detailed Description
The invention is further described below with reference to the drawings and specific preferred embodiments of the description, without thereby limiting the scope of protection of the invention.
As shown in fig. 2, the method for detecting the dc capacitance of the current transformer of the present embodiment includes: s1, injecting alternating current detection voltage with preset frequency and amplitude into a direct current bus of a tested converter; s2, detecting and acquiring input voltage and input current on a direct current bus of the converter, and detecting and acquiring phase current of an alternating current output end of the converter; calculating to obtain a first current of a direct current capacitor according to the input current and the phase current; s3, extracting a voltage component with the preset frequency from the input voltage, and extracting a current component with the preset frequency from the first current; and S4, calculating and determining the capacitance value of the direct current capacitor according to the voltage component and the current component.
In this embodiment, in step S1, the preset frequency is preferably smaller than a disturbance frequency generated by the switching operation of the inverter on the dc current and smaller than an ac-side voltage fundamental wave frequency of the inverter. Further preferably, the range of the preset frequency is [0.1X, 0.5X ], where X is the fundamental frequency of the ac-side voltage of the converter.
In this embodiment, preferably, in step S2, the method further includes detecting and acquiring a switching tube state of each phase of the ac output end of the converter; when the upper tube of the switching tube of the phase is in a conducting state, the phase outputs current; when the lower tube of the switching tube of the phase is conducted, the phase has no output current. The first current is determined by subtracting the phase current from the input current in step S2.
In this embodiment, preferably, the step S3 specifically includes filtering the input voltage and the first current in a preset filtering frequency interval, taking the filtered input voltage as a voltage component, and taking the filtered input current as a current component.
A method for predicting the service life of a direct current capacitor of a converter comprises the steps of determining the capacitance value of the direct current capacitor according to the method for detecting the direct current capacitor of the converter, judging whether the ratio of a capacitance error value to the nominal capacitance value of the direct current capacitor is larger than a preset threshold value, if so, judging that the service life of the direct current capacitor is limited, and otherwise, judging that the direct current capacitor is effective; the capacitance error value is a difference between the capacitance value and a nominal capacitance value of the dc capacitor.
A converter direct current capacitance detection system is shown in figure 4 and comprises a detection voltage injection module, an input end electric energy detection module, an output end electric energy detection module and an analysis processing module; the voltage injection module, the input end electric energy detection module and the output end electric energy detection module are respectively connected with the analysis processing module; the detection voltage injection module is connected with a direct current bus of the converter and used for injecting alternating current detection voltage with preset frequency and preset amplitude into the direct current bus; the input end electric energy detection module is used for detecting and acquiring input voltage and input current on a direct current bus of the converter; the output end electric energy detection module is used for detecting and acquiring phase current of the alternating current output end of the converter; the analysis processing module is used for calculating to obtain a first current of a direct current capacitor according to the input current and the phase current, extracting a voltage component with the preset frequency from the input voltage, extracting a current component with the preset frequency from the first current, and calculating and determining a capacitance value of the direct current capacitor according to the voltage component and the current component.
In this embodiment, preferably, the output end electric energy detection module further includes a switching tube state detection submodule; the switching tube state detection submodule is used for detecting and acquiring the state of a switching tube of each phase of the alternating current output end of the converter; when the upper tube of the switching tube of the phase is in a conducting state, the output end electric energy detection module outputs the current of the phase; when the lower tube of the switching tube of the phase is conducted, the output end electric energy detection module outputs no current of the phase.
In this embodiment, preferably, the analysis processing module further includes a filtering submodule, where the filtering submodule is configured to filter the input voltage and the first current in a preset filtering frequency interval, and use the input voltage obtained after filtering as a voltage component and the input current obtained after filtering as a current component.
In this embodiment, a specific detection process is taken as an example to describe the operation process of the method and the system, and as shown in fig. 3, a photovoltaic power station converts generated direct current electric energy into three-phase alternating current through a converter and outputs the three-phase alternating current to a power grid, and the converter converts the direct current into power frequency alternating current with a frequency of 50 Hz. The converter is controlled by the on-off of the switch tubeThe direct current is changed into the alternating current, the disturbance frequency generated by the action of the switch tube is mainly distributed above 100Hz, therefore, in the embodiment, the frequency of the alternating current detection voltage injected into the direct current bus of the converter is 20Hz, the voltage is 20V, and the preferable frequency range is [5Hz, 25Hz ]]Preferably, the voltage range is [0.02Y, 0.05Y ]]And Y is the converter dc bus voltage, and the converter dc bus operating voltage in this embodiment is about 600V, so as to ensure that the voltage component and the current component required for calculating the capacitance value of the dc capacitor C can be conveniently detected, and the normal operation of the converter is not affected. The injected ac detection voltage can be expressed as: vinfF × sin (2 × pi × H × t), H being a predetermined frequency and F being a predetermined amplitude, a party according to the present embodiment, i.e., Vinf＝20×sin(2×π×20×t)。
In this embodiment, the voltage between the positive and negative electrodes of the dc bus can be detected by the voltage sensor to be VdcThe current value of the positive level of the direct current bus can be detected to be I through the current sensorin. Meanwhile, the current sensors arranged on the output ends of the current transformer can detect the output currents I of the three phases of the current transformer A, B, Ca、Ib、IcThen, the output current of the converter is Ia+Ib+IcThen, the first current on the DC capacitor C can be calculated as Icap＝Iin-(Ia+Ib+Ic). In this embodiment, considering the influence of the switching state of the switching tube on the output current, it is preferable to further obtain the state of the switching tube, and in the same two switching tubes, when the upper tube is turned on, it is considered that the phase has current output, and when the lower tube is turned on, it is considered that the phase has no current output, that is, the output current is 0, the upper tube is the switching tube connected to the positive electrode of the dc bus, and the lower tube is the switching tube connected to the negative electrode of the dc bus. In the present embodiment, a state parameter S of the switch tube is definedx＝a,b,cIs provided with
a, b, and C represent phases of the output, the first current on the dc capacitor C can be obtained as: i iscap＝Iin-(Ia×Sa+Ib×Sb+Ic×Sc)。
In the present embodiment, the input voltage V is obtaineddcAnd a first current IcapThen, the filter frequency interval is preset [15Hz, 25Hz ]]Filtering to obtain voltage component required for calculating capacitance value and current component required for calculating capacitance value, and passing through
The capacitance of the dc capacitor can be calculated, where I is the current component, V is the voltage component, and f is the frequency of the injected ac detection voltage. In this embodiment, f is 20.
In this embodiment, the predetermined filtering frequency interval is determined according to a predetermined frequency of the ac detection voltage, preferably [ f- λ, f + λ ], preferably λ is less than 10, and f + λ is less than a disturbance frequency generated by the switching tube action.
The foregoing is considered as illustrative of the preferred embodiments of the invention and is not to be construed as limiting the invention in any way. Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention shall fall within the protection scope of the technical solution of the present invention, unless the technical essence of the present invention departs from the content of the technical solution of the present invention.
Claims (10)
1. A method for detecting a direct current capacitor of a converter is characterized by comprising the following steps:
s1, injecting alternating current detection voltage with preset frequency and amplitude into a direct current bus of a tested converter;
s2, detecting and acquiring input voltage and input current on a direct current bus of the converter, and detecting and acquiring phase current of an alternating current output end of the converter; calculating to obtain a first current of a direct current capacitor according to the input current and the phase current;
s3, extracting a voltage component with the preset frequency from the input voltage, and extracting a current component with the preset frequency from the first current;
and S4, calculating and determining the capacitance value of the direct current capacitor according to the voltage component and the current component.
2. The converter direct current capacitance detection method according to claim 1, characterized in that: in step S1, the preset frequency is smaller than a disturbance frequency generated by a switching operation of the converter on the dc current and smaller than an ac-side voltage fundamental frequency of the converter.
3. The converter direct current capacitance detection method according to claim 1, characterized in that: the value range interval of the preset frequency is [0.1X, 0.5X ], and X is the fundamental frequency of the alternating-current side voltage of the converter.
4. The converter direct current capacitance detection method according to claim 2, characterized in that: step S2, detecting and acquiring the state of a switch tube of each phase of the alternating current output end of the converter; when the upper tube of the switching tube of the phase is in a conducting state, the phase outputs current; when the lower tube of the switching tube of the phase is conducted, the phase has no output current.
5. The converter direct current capacitance detection method according to claim 4, characterized in that: the first current is determined by subtracting the phase current from the input current in step S2.
6. The converter direct current capacitance detection method according to claim 4, characterized in that: step S3 specifically includes filtering the input voltage and the first current at a preset filtering frequency interval, taking the filtered input voltage as a voltage component, and taking the filtered input current as a current component.
7. A method for predicting the service life of a direct current capacitor of a converter is characterized by comprising the following steps: the converter DC capacitor detection method according to any one of claims 1 to 6, determining a capacitance value of a DC capacitor, determining whether a ratio of a capacitance error value to a nominal capacitance value of the DC capacitor is greater than a preset threshold, if so, determining that the DC capacitor has reached a lifetime limit, otherwise, determining that the DC capacitor is valid; the capacitance error value is a difference between the capacitance value and a nominal capacitance value of the dc capacitor.
8. A converter direct current capacitance detection system which characterized in that: the device comprises a detection voltage injection module, an input end electric energy detection module, an output end electric energy detection module and an analysis processing module; the voltage injection module, the input end electric energy detection module and the output end electric energy detection module are respectively connected with the analysis processing module;
the detection voltage injection module is connected with a direct current bus of the converter and used for injecting alternating current detection voltage with preset frequency and preset amplitude into the direct current bus;
the input end electric energy detection module is used for detecting and acquiring input voltage and input current on a direct current bus of the converter;
the output end electric energy detection module is used for detecting and acquiring phase current of the alternating current output end of the converter;
the analysis processing module is used for calculating to obtain a first current of a direct current capacitor according to the input current and the phase current, extracting a voltage component with the preset frequency from the input voltage, extracting a current component with the preset frequency from the first current, and calculating and determining a capacitance value of the direct current capacitor according to the voltage component and the current component.
9. The converter dc capacitance detection system of claim 8, wherein: the output end electric energy detection module also comprises a switching tube state detection submodule;
the switching tube state detection submodule is used for detecting and acquiring the state of a switching tube of each phase of the alternating current output end of the converter; when the upper tube of the switching tube of the phase is in a conducting state, the output end electric energy detection module outputs the current of the phase; when the lower tube of the switching tube of the phase is conducted, the output end electric energy detection module outputs no current of the phase.
10. The converter dc capacitance detection system of claim 9, wherein: the analysis processing module further comprises a filtering submodule, wherein the filtering submodule is used for filtering the input voltage and the first current in a preset filtering frequency interval, the input voltage obtained after filtering is used as a voltage component, and the input current obtained after filtering is used as a current component.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010349754.3A CN113567748B (en) | 2020-04-28 | 2020-04-28 | Converter direct current capacitance detection method, life prediction method and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010349754.3A CN113567748B (en) | 2020-04-28 | 2020-04-28 | Converter direct current capacitance detection method, life prediction method and system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113567748A CN113567748A (en) | 2021-10-29 |
| CN113567748B true CN113567748B (en) | 2022-05-31 |
Family
ID=78157954
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010349754.3A Active CN113567748B (en) | 2020-04-28 | 2020-04-28 | Converter direct current capacitance detection method, life prediction method and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113567748B (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013004019A1 (en) * | 2011-07-07 | 2013-01-10 | City University Of Hong Kong | Dc link module for reducing dc link capacitance |
| CN102969730A (en) * | 2012-11-16 | 2013-03-13 | 上海交通大学 | Control method of double stage chain type energy storage converter |
| CN105044470A (en) * | 2015-06-30 | 2015-11-11 | 同济大学 | Method for detecting DC capacity of current transformer based on resonance principles |
| CN105158577A (en) * | 2015-07-28 | 2015-12-16 | 苏州汇川技术有限公司 | Unit series-connected high-voltage frequency converter and bus capacitance online monitoring method thereof |
| CN109387701A (en) * | 2017-08-02 | 2019-02-26 | 台达电子工业股份有限公司 | Three-phase converter plant and capacitor evaluation method |
| CN109459618A (en) * | 2018-11-16 | 2019-03-12 | 哈尔滨工业大学 | The online capacitance detection method of the standard of electric drive system for electric vehicles dc-link capacitance |
| CN110086369A (en) * | 2019-05-06 | 2019-08-02 | 阳光电源股份有限公司 | The selection method and appraisal procedure and its application apparatus of dc-link capacitance |
| CN110957715A (en) * | 2018-09-26 | 2020-04-03 | 株洲中车时代电气股份有限公司 | Method, device and medium for obtaining grid-side power supply voltage of single-phase grid-side converter |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10620247B2 (en) * | 2017-09-27 | 2020-04-14 | Quanta Computer Inc. | System and method to detect capacitance of a power supply unit |
-
2020
- 2020-04-28 CN CN202010349754.3A patent/CN113567748B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013004019A1 (en) * | 2011-07-07 | 2013-01-10 | City University Of Hong Kong | Dc link module for reducing dc link capacitance |
| CN102969730A (en) * | 2012-11-16 | 2013-03-13 | 上海交通大学 | Control method of double stage chain type energy storage converter |
| CN105044470A (en) * | 2015-06-30 | 2015-11-11 | 同济大学 | Method for detecting DC capacity of current transformer based on resonance principles |
| CN105158577A (en) * | 2015-07-28 | 2015-12-16 | 苏州汇川技术有限公司 | Unit series-connected high-voltage frequency converter and bus capacitance online monitoring method thereof |
| CN109387701A (en) * | 2017-08-02 | 2019-02-26 | 台达电子工业股份有限公司 | Three-phase converter plant and capacitor evaluation method |
| CN110957715A (en) * | 2018-09-26 | 2020-04-03 | 株洲中车时代电气股份有限公司 | Method, device and medium for obtaining grid-side power supply voltage of single-phase grid-side converter |
| CN109459618A (en) * | 2018-11-16 | 2019-03-12 | 哈尔滨工业大学 | The online capacitance detection method of the standard of electric drive system for electric vehicles dc-link capacitance |
| CN110086369A (en) * | 2019-05-06 | 2019-08-02 | 阳光电源股份有限公司 | The selection method and appraisal procedure and its application apparatus of dc-link capacitance |
Non-Patent Citations (3)
| Title |
|---|
| "A Real-Time Predictive-Maintenance System of Aluminum Electrolytic Capacitors Used in Uninterrupted Power Supplies";Karim Abdennadher;《IEEE Transactions on Industry Applications》;20101231;全文 * |
| "AC-DC-AC变频器直流支撑电容电流计算及分析";刘海涛;《大功率交流技术》;20120430;全文 * |
| "电压型PWM整流器直流链支撑电容的容值设计";刘刚;《船舰电子对抗》;20170226;第40卷(第1期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113567748A (en) | 2021-10-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5605548B2 (en) | Grid interconnection device | |
| EP3024134B1 (en) | Parallel inverter system, and shutdown control method and shutdown control device for parallel inverter system | |
| CN101944746B (en) | Island detection method, device and system of photovoltaic grid-connected power generating system | |
| US11056907B2 (en) | Uninterruptible power supply device | |
| CN107121611A (en) | The method for monitoring the failure of DCMBoostPFC converters output capacitance | |
| CN104569716A (en) | Method for diagnosing bridge arm IGBT open-circuit fault of energy storage converter exteriorly | |
| CN103384958B (en) | Power conversion device | |
| CN105098832A (en) | System and method for controlling low voltage ride through of multi-machine grid-connected power converter | |
| CN102253278B (en) | Startup condition detection method suitable for photovoltaic inverter with DC/DC (direct current/direct current) | |
| CN106058930A (en) | Automatic detecting system and automatic detecting method for capacitance of photovoltaic grid-connected inverter bus capacitor | |
| TWI487653B (en) | Elevator electrical energy feedback device, feedback method and elevator | |
| Li et al. | Online condition monitoring of DC-link capacitor for AC/DC/AC PWM converter | |
| CN202886481U (en) | Capacitor capacity detection circuit of solar energy inverter | |
| CN103475024A (en) | Electric energy quality serial connection compensation control method and system based on solar photovoltaic power generation | |
| CN109120013B (en) | Method and device for detecting injection disturbance quantity of power grid adaptability detection device | |
| CN104467016B (en) | A kind of five level photovoltaic inverter precharge control methods and system | |
| CN113567748B (en) | Converter direct current capacitance detection method, life prediction method and system | |
| CN102185291B (en) | Island detection method and island detection system | |
| CN204231007U (en) | The electric power system of air conditioner and air conditioner | |
| CN112713755B (en) | Quick turn-off method and system for bidirectional thyristor | |
| TW202219500A (en) | Impedance monitoring of a modular electrolysis system | |
| CN103515981B (en) | Grid-connected photovoltaic power generation system and self-action phase shift island phenomenon detection method thereof | |
| CN104345217B (en) | Detection method and device for capacitance value | |
| CN105591533A (en) | PWM convertor circuit and frequency converter comprising same | |
| CN104283302A (en) | Air conditioner and power supply system of air conditioner |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |