CN103490402A - Photovoltaic module grounding device, photovoltaic module grounding monitoring device and monitoring method - Google Patents
Photovoltaic module grounding device, photovoltaic module grounding monitoring device and monitoring method Download PDFInfo
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- CN103490402A CN103490402A CN201310398048.8A CN201310398048A CN103490402A CN 103490402 A CN103490402 A CN 103490402A CN 201310398048 A CN201310398048 A CN 201310398048A CN 103490402 A CN103490402 A CN 103490402A
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Abstract
The invention discloses a photovoltaic module grounding device. One end of the photovoltaic module grounding device is connected with a direct-current bus negative electrode of a photovoltaic power generation system, and the other end of the photovoltaic module grounding device is grounded. The photovoltaic module grounding device is of a series connection structure comprising a wire, a resistor, an inductor, another resistor and another inductor or a parallel connection structure comprising the resistors and the inductors. The photovoltaic module grounding device can restrain a potential induced damping (PID) effect of a photovoltaic module. The invention further discloses a photovoltaic module grounding monitoring device which comprises a ground resistor and a current detector; the current detector comprises a leakage current monitoring element, a control unit and a signal transmitting unit, wherein the leakage current monitoring element, the control unit and the signal transmitting unit are connected in sequence; after the photovoltaic module grounding device and the leakage current monitoring element are connected in series, one end of the photovoltaic module grounding device is connected with the direct-current bus negative electrode of the photovoltaic power generation system, and the other end of the photovoltaic module grounding device is grounded. The photovoltaic module grounding monitoring device can monitor a ground fault of the photovoltaic module. The invention further discloses a monitoring method based on the photovoltaic module grounding monitoring device.
Description
Technical field
The present invention relates to a kind of protective circuit device, particularly a kind of photovoltaic module earthing device, to monitoring device and the monitoring method of this earthing device.
Background technology
In photovoltaic generating system, due to photovoltaic module, usually by accessing inverter after series connection, after series connection, output voltage reaches as high as 1000V.And photovoltaic component frame, support consider to need ground connection due to factors such as lightning protection, safeguard protections usually; cause like this in the photovoltaic module of same series connection, have a negative electricity potential difference between the part photovoltaic module electrode (negative potential) that the series connection current potential is lower and module frame (earth potential).This will cause the generation of Leakage Current between electrode and frame in photovoltaic module up to the negative potential of hundreds of volts usually, the existence of Leakage Current will be accelerated the rate of decay of photovoltaic module greatly, the current potential that is photovoltaic module brings out attenuation effect, is called for short the PID(Potential Induced Degradation of photovoltaic module) effect.
In recent years, flourish along with western desert area large-scale ground photovoltaic plant, large-scale ground photovoltaic plant scale and quantity all significantly increase.Because desert photovoltaic plant cable adopts direct-buried mode usually, be subject to the cable insulation destroying infection, photovoltaic array positive and negative electrode earth fault happens occasionally.Once the plus earth fault occurs photovoltaic plant, will be difficult to avoid the generation of photovoltaic module PID effect, and then cause a large amount of decay fast of photovoltaic module, the photovoltaic plant investor is sustained losses severely.
According to above narration, the PID effect of photovoltaic module and earth fault are all to hinder the normal factor of using of photovoltaic system, need to adopt corresponding solution to respond actively.
Summary of the invention
Purpose of the present invention, be to provide a kind of photovoltaic module earthing device, and it can realize the current potential of photovoltaic module is brought out the inhibition of decay (PID) effect.
Another object of the present invention, be to provide a kind of photovoltaic module grounding monitoring device and monitoring method, and it can realize the ground fault detection to photovoltaic module.
In order to reach above-mentioned purpose, solution of the present invention is:
A kind of photovoltaic module earthing device, an end of described earthing device connects photovoltaic generating system DC bus negative pole, other end ground connection, described earthing device adopts wire, resistance, inductance, resistance and the cascaded structure of inductance or the parallel-connection structure of resistance and inductance.
Above-mentioned resistance adopts resistance to be not less than the resistance that 1k Ω and power are not less than 300W.
Above-mentioned resistance adopts the resistance of 6k Ω/300W.
A kind of photovoltaic module grounding monitoring device, comprise earth resistance and current detector, and described current detector comprises leakage current monitoring element, control unit and the signal transmitting unit connected successively; Described earthing device is with after the leakage current monitoring element is connected, and an end connects photovoltaic generating system DC bus negative pole, other end ground connection; Described leakage current monitoring element is sent the actual leakage current monitored into control unit; by control unit, this actual leakage current and the leakage current protection threshold value prestored are compared; and producing the earth fault signal when actual leakage current surpasses threshold value, the control signal transmitting element will be delivered to photovoltaic power station monitoring system on this earth fault signal.
Above-mentioned leakage current protection threshold value is set to 10mA～50mA.
Above-mentioned signal transmitting unit carries out the signal transmission by remote signalling or communication modes and photovoltaic power station monitoring system.
A kind of monitoring method based on foregoing a kind of photovoltaic module grounding monitoring device, comprise the steps:
(1) cross the actual leakage current of earth resistance by leakage current monitoring element monitoring stream;
(2) control unit compares described actual leakage current and leakage current protection threshold value, when described actual leakage current surpasses threshold value, produces the earth fault signal;
(3) signal transmitting unit will be delivered to photovoltaic power station monitoring system on aforementioned earth fault signal.
Above-mentioned signal transmitting unit will be delivered to photovoltaic power station monitoring system on described earth fault signal by remote signalling or communication modes.
Above-mentioned leakage current protection threshold value is set to 10mA～50mA.
After the employing such scheme, the present invention, by adopting earthing device, by technique scheme, by adopting earthing device, achieves a butt joint into the photovoltaic module PID effect inhibit feature of all header box front ends of photovoltaic inverter, and principle is simple, realization is convenient.
Monitoring device of the present invention and monitoring method do not affect the normal operation of photovoltaic DC-to-AC converter, can not reduce photovoltaic power generation quantity, ensure photovoltaic array safety, improve the photovoltaic generating system benefit.
The accompanying drawing explanation
Fig. 1 is the circuit structure diagram of photovoltaic module earthing device of the present invention;
Fig. 2 is the circuit structure diagram of photovoltaic module grounding monitoring device of the present invention.
Embodiment
Below with reference to accompanying drawing, technical scheme of the present invention is elaborated.
The invention provides a kind of photovoltaic module earthing device, in order to suppress the PID effect of photovoltaic module in photovoltaic generating system, one end of described earthing device connects photovoltaic generating system DC bus negative pole, other end ground connection, described earthing device can adopt wire, resistance, inductance, or the serial or parallel connection structure of resistance and inductance; Be the structural representation that adopts resistance shown in Fig. 1, wherein only show the structure that DC bus connects respectively several photovoltaic combiner boxes and photovoltaic DC-to-AC converter (DC/AC), the assemblies such as solar cell are also not shown; One end of resistance connects the DC bus negative pole, and other end ground connection, in actual photovoltaic generating system, can carry out ground connection at header box, DC power distribution cabinet or photovoltaic DC-to-AC converter DC bus.This kind of ground structure can be by the negative pole of potential minimum photovoltaic module in all photovoltaic module cascaded structures of access photovoltaic DC-to-AC converter and the potential difference clamper between the earth below lower magnitude of voltage, and this magnitude of voltage is the basic reason that causes the PID effect.As long as choose suitable resistance value, can effectively avoid between photovoltaic module electrode and ground connection frame forming larger negative bias potential difference, thereby suppress photovoltaic module PID effect.
When the type selecting of resistance need to guarantee that photovoltaic DC-to-AC converter normally moves on the one hand, by photovoltaic DC-to-AC converter direct current negative pole current potential and ground potential clamper, eliminate all photovoltaic module electrodes of access photovoltaic DC-to-AC converter and the negative bias potential difference between the ground connection frame; On the other hand when photovoltaic plus earth fault occurring, resistance can fault current limiting, and can the jam-tolerant electric current and the cause thermal damage problem do not occur, guarantees that the ground connection branch current detects and fault warning function regular event.
Based on above Type Selection Principle, resistance can select resistance to be not less than the resistance that 1k Ω and power are not less than 300W, in the present embodiment, with the resistance of 6k Ω/300W, carries out designing and calculating:
During normal operation, due to the characteristic of semiconductor of solar cell, photovoltaic DC-to-AC converter minus earth branch road leakage current is less than 0.12mA.Take leakage current as 0.12mA calculating, and ohmically pressure drop is:
ΔU=IR=0.12mA×6000Ω=0.72V
Once photovoltaic module plus earth fault occurs, suppose that single photovoltaic group string maximum voltage is 800V, getting other impedances of photovoltaic DC-to-AC converter grounded circuit according to the design of ground system standard is 10 Ω, under the most serious fault state, false voltage drops on photovoltaic DC-to-AC converter direct current minus earth loop, and photovoltaic DC-to-AC converter direct current minus earth branch trouble electric current is:
I=U/R=800V/(6000+10)Ω=133.1mA
Now the maximum power dissipation of resistance is:
P=U
2/R=800
2/6000=106.7W
Therefore, the resistance that is 6k Ω/300W left and right for the type selecting specification has following advantage:
(1), while normally moving, provide the effect of good inhibition photovoltaic module PID effect;
(2), while the plus earth fault occurring, earth resistance can be limited in maximum fault current the 133mA left and right, avoids the grounded circuit overcurrent to cause other device damage;
(3) while the plus earth fault occurring, can not cross cause thermal damage because of resistance and cause the grounded circuit broken string, affect the monitoring function of earth fault.
Structure based on aforementioned employing grounding through resistance, the invention provides a kind of photovoltaic module grounding monitoring device, and this monitoring device comprises earth resistance and current detector, and wherein, an end of earth resistance connects the system DC bus negative pole that photovoltaic is sent out, other end ground connection; Current detector comprises leakage current monitoring element, control unit and the signal transmitting unit connected successively, and the leakage current monitoring element is connected in series with aforementioned earth resistance, the actual leakage current in Monitoring Line, and the leakage data monitored is sent into to control unit; Described control unit compares the aforementioned actual leakage data received and the leakage current protection threshold value prestored; when actual leakage current surpasses this threshold value; produce the earth fault signal, and will on this earth fault signal, deliver to photovoltaic power station monitoring system by signal transmitting unit by remote signalling or communication modes.
This grounding monitoring device that the present embodiment provides, combine ground fault detection and alarm function with photovoltaic module PID effect inhibit feature, avoid overlapping investment, reduces photovoltaic plant operating cost.
Based on aforementioned grounding monitoring device, the present invention also provides a kind of photovoltaic module grounding monitor method, comprises the steps:
(1) cross the actual leakage current of earth resistance by leakage current monitoring element monitoring stream;
(2) size of the actual leakage current of control unit comparison of aforementioned and leakage current protection threshold value, when actual leakage current surpasses the leakage current threshold value, produce the earth fault signal;
(3) signal transmitting unit will be given photovoltaic power station monitoring system on aforementioned earth fault signal.
As shown in Figure 2, photovoltaic DC-to-AC converter DC bus negative pole is by ground resistance earth, and earth fault protection leakage current protection threshold value is set to 10mA～50mA.During normal operation, photovoltaic DC-to-AC converter minus earth branch road leakage current is less than 0.12mA, the inhibiting while of photovoltaic module PID is provided, can not cause the earth fault malfunction.And once earth fault occurs, photovoltaic DC-to-AC converter direct current minus earth loop leakage current will increase, cross earth fault protection leakage current protection threshold value, thus the alarm of triggering earth fault.When monitoring, ground connection branch road leakage current is out-of-limit, can will on the earth fault signal, deliver to photovoltaic power station monitoring system by remote signalling or communication modes, is grounded malfunction monitoring and alarm function.
This grounding monitor method that the present embodiment provides, combine ground fault detection and alarm function with photovoltaic module PID effect inhibit feature, avoid overlapping investment, reduces photovoltaic plant operating cost.
Above embodiment only, for explanation technological thought of the present invention, can not limit protection scope of the present invention with this, every technological thought proposed according to the present invention, and any change of doing on the technical scheme basis, within all falling into protection range of the present invention.
Claims (9)
1. a photovoltaic module earthing device, it is characterized in that: an end of described earthing device connects photovoltaic generating system DC bus negative pole, other end ground connection, described earthing device adopts wire, resistance, inductance, resistance and the cascaded structure of inductance or the parallel-connection structure of resistance and inductance.
2. a kind of photovoltaic module earthing device as claimed in claim 1 is characterized in that: described resistance adopts resistance to be not less than the resistance that 1k Ω and power are not less than 300W.
3. a kind of photovoltaic module earthing device as claimed in claim 2, is characterized in that, described resistance adopts the resistance of 6k Ω/300W.
4. a photovoltaic module grounding monitoring device is characterized in that: comprise earth resistance and current detector, described current detector comprises leakage current monitoring element, control unit and the signal transmitting unit connected successively; Described earthing device is with after the leakage current monitoring element is connected, and an end connects photovoltaic generating system DC bus negative pole, other end ground connection; Described leakage current monitoring element is sent the actual leakage current monitored into control unit; by control unit, this actual leakage current and the leakage current protection threshold value prestored are compared; and producing the earth fault signal when actual leakage current surpasses threshold value, the control signal transmitting element will be delivered to photovoltaic power station monitoring system on this earth fault signal.
5. a kind of photovoltaic module grounding monitoring device as claimed in claim 4 is characterized in that: described leakage current protection threshold value is set to 10mA～50mA.
6. a kind of photovoltaic module grounding monitoring device as described as claim 4 or 5 is characterized in that: described signal transmitting unit carries out the signal transmission by remote signalling or communication modes and photovoltaic power station monitoring system.
7. the monitoring method based on a kind of photovoltaic module grounding monitoring device as claimed in claim 4, is characterized in that comprising the steps:
(1) cross the actual leakage current of earth resistance by leakage current monitoring element monitoring stream;
(2) control unit compares described actual leakage current and leakage current protection threshold value, when described actual leakage current surpasses threshold value, produces the earth fault signal;
(3) signal transmitting unit will be delivered to photovoltaic power station monitoring system on aforementioned earth fault signal.
8. a kind of photovoltaic module grounding monitor method as claimed in claim 7, it is characterized in that: described signal transmitting unit will be delivered to photovoltaic power station monitoring system on described earth fault signal by remote signalling or communication modes.
9. a kind of photovoltaic module grounding monitor method as claimed in claim 7 or 8, it is characterized in that: described leakage current protection threshold value is set to 10mA～50mA.
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103901315A (en) * | 2014-04-21 | 2014-07-02 | 阳光电源股份有限公司 | Monopole grounding system and device and method for grounding protection and fault monitoring |
| CN103983855A (en) * | 2014-05-28 | 2014-08-13 | 阳光电源股份有限公司 | Method and circuit for detecting insulation resistance |
| CN104034994A (en) * | 2014-05-06 | 2014-09-10 | 刘业军 | Novel photovoltaic-used direct current insulation monitoring module |
| CN104267307A (en) * | 2014-10-22 | 2015-01-07 | 重庆市防雷中心 | Remote grounding device and equipotential connection fault monitoring system |
| CN104506130A (en) * | 2014-11-20 | 2015-04-08 | 晶澳(扬州)太阳能光伏工程有限公司 | PID resistant device for solar photovoltaic component using non-isolated inverter |
| CN105743434A (en) * | 2016-04-14 | 2016-07-06 | 特变电工西安电气科技有限公司 | Photovoltaic module earth common-mode voltage suppression system used for photovoltaic power generation system |
| CN111983512A (en) * | 2020-08-18 | 2020-11-24 | 广东电网有限责任公司梅州供电局 | Line grounding device monitoring system and method |
| WO2023284230A1 (en) * | 2021-07-14 | 2023-01-19 | 科华数据股份有限公司 | Multi-channel photovoltaic module ground fault detection device and detection method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020105765A1 (en) * | 2001-02-02 | 2002-08-08 | Canon Kabushiki Kaisha | Apparatus and method of detecting ground fault of solar power generation system |
| CN102842881A (en) * | 2012-07-20 | 2012-12-26 | 江苏兆伏新能源有限公司 | Grounding protection device and thin film battery generating device based on grounding protection device |
| CN103081268A (en) * | 2010-08-20 | 2013-05-01 | 东芝三菱电机产业系统株式会社 | Grounding device |
| CN103248007A (en) * | 2013-05-20 | 2013-08-14 | 中节能东台太阳能发电有限公司 | PID (Potential Induced Degradation)-resistant circuit and monitoring device thereof |
-
2013
- 2013-09-05 CN CN201310398048.8A patent/CN103490402A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020105765A1 (en) * | 2001-02-02 | 2002-08-08 | Canon Kabushiki Kaisha | Apparatus and method of detecting ground fault of solar power generation system |
| CN103081268A (en) * | 2010-08-20 | 2013-05-01 | 东芝三菱电机产业系统株式会社 | Grounding device |
| CN102842881A (en) * | 2012-07-20 | 2012-12-26 | 江苏兆伏新能源有限公司 | Grounding protection device and thin film battery generating device based on grounding protection device |
| CN103248007A (en) * | 2013-05-20 | 2013-08-14 | 中节能东台太阳能发电有限公司 | PID (Potential Induced Degradation)-resistant circuit and monitoring device thereof |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103901315A (en) * | 2014-04-21 | 2014-07-02 | 阳光电源股份有限公司 | Monopole grounding system and device and method for grounding protection and fault monitoring |
| CN104034994A (en) * | 2014-05-06 | 2014-09-10 | 刘业军 | Novel photovoltaic-used direct current insulation monitoring module |
| CN103983855A (en) * | 2014-05-28 | 2014-08-13 | 阳光电源股份有限公司 | Method and circuit for detecting insulation resistance |
| CN103983855B (en) * | 2014-05-28 | 2017-02-15 | 阳光电源股份有限公司 | Method and circuit for detecting insulation resistance |
| CN104267307A (en) * | 2014-10-22 | 2015-01-07 | 重庆市防雷中心 | Remote grounding device and equipotential connection fault monitoring system |
| CN104267307B (en) * | 2014-10-22 | 2017-02-08 | 重庆市防雷中心 | Remote grounding device and equipotential connection fault monitoring system |
| CN104506130A (en) * | 2014-11-20 | 2015-04-08 | 晶澳(扬州)太阳能光伏工程有限公司 | PID resistant device for solar photovoltaic component using non-isolated inverter |
| CN105743434A (en) * | 2016-04-14 | 2016-07-06 | 特变电工西安电气科技有限公司 | Photovoltaic module earth common-mode voltage suppression system used for photovoltaic power generation system |
| CN105743434B (en) * | 2016-04-14 | 2018-03-27 | 特变电工西安电气科技有限公司 | Photovoltaic module common-mode voltage suppression system over the ground in a kind of photovoltaic generating system |
| CN111983512A (en) * | 2020-08-18 | 2020-11-24 | 广东电网有限责任公司梅州供电局 | Line grounding device monitoring system and method |
| WO2023284230A1 (en) * | 2021-07-14 | 2023-01-19 | 科华数据股份有限公司 | Multi-channel photovoltaic module ground fault detection device and detection method |
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