CN202872325U - Direct current grounding detection protection device used for photovoltaic power generation system - Google Patents
Direct current grounding detection protection device used for photovoltaic power generation system Download PDFInfo
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- CN202872325U CN202872325U CN201220496535.9U CN201220496535U CN202872325U CN 202872325 U CN202872325 U CN 202872325U CN 201220496535 U CN201220496535 U CN 201220496535U CN 202872325 U CN202872325 U CN 202872325U
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Abstract
The utility model discloses a direct current grounding detection protection device used for a photovoltaic power generation system. The direct current grounding detection protection device comprises the following components of: a selection module which receives selection commands making an positive pole or negative pole grounded and generates selection signals; a grounding current detection module which is connected with the selection module, detects grounding current of a positive pole grounding branch circuit or negative pole grounding branch circuit according to the selection signals, and generates detection signals; a direct current grounding protection module which performs direct current grounding protection on the positive pole grounding branch circuit and the negative pole grounding branch circuit; and a control module which controls the photovoltaic power generation system and stops the operation of the photovoltaic power generation system, and starts up the direct current grounding protection module when the control module determines a grounding fault existing in the photovoltaic power generation system according to the detection signals. When grounding faults occur, the direct current grounding detection protection device can accurately detect the faults, and detect the magnitude of direct current grounding current; and the direct current grounding detection protection device has the advantages of simple structure and stable performance.
Description
Technical field
The utility model relates to the photovoltaic combining inverter technical field, and particularly a kind of DC earthing for photovoltaic generating system detects protective device.
Background technology
Current, the contact of the Back-contact(back of the body is being installed) domestic consumer's generator unit of cell panel and thin-film solar cell panel, considering the Surface Polarization phenomenon of Back-contact cell panel needs cell panel to be over the ground negative polarity, occur with the blocking-up leakage current, improve generating efficiency.And for the hull cell plate, for the performance that do not affect cell panel itself (such as corrosion etc.), then need cell panel to be over the ground positive polarity.Therefore, need to be the anode of cell panel or negativing ending grounding.
Yet in the electric equipment of the photovoltaic generating system energising course of work, if the electric current of dc terminal between over the ground surpasses prescribed limit, there is fault in system earth, and earth current will be excessive, and this moment, contact will injure human-body safety.So must have the DC earthing circuit in the photovoltaic generating system, must have DC earthing to detect protective circuit simultaneously, so that can whether have earth fault in the detection system.
Traditional DC earthing detects protective circuit and only has a kind of earthing mode, namely only has plus earth or only has minus earth.When connecting different photovoltaic panels, the earthing mode of requirement also may be different, so if DC earthing detects earthing mode that protective circuit allows to be only had when a kind of, the applicability of inverter just is restricted so.If traditional DC earthing detects protective circuit earthing failure (when having earth fault), inverter can be out of service, is because earth fault unusually but inverter itself can not detect the machine appearance.
The utility model content
The purpose of this utility model is intended to solve at least to a certain extent one of above-mentioned technological deficiency.
For this reason; the utility model need to propose a kind of DC earthing for photovoltaic generating system and detect protective device, its can plus earth also can minus earth, and when ground connection is broken down; this fault can be detected accurately, and the size of DC earthing electric current can be detected.In addition, it is simple in structure that this DC earthing detects protective device, stable performance.
The DC earthing that is used for photovoltaic generating system that the utility model proposes detects protective device, comprising: select module, described selection module receives the selection instruction with negative or positive electrode ground connection, and signal is selected in generation; The checking for grounded current module, described checking for grounded current module links to each other with described selection module, and described checking for grounded current module is according to the earth current of described selection input plus earth branch road or minus earth branch road, and the generation detection signal; The DC earthing protection module, described DC earthing protection module carries out the DC earthing protection to described plus earth branch road and described minus earth branch road; Control module; described control module links to each other with described DC earthing protection module with described checking for grounded current module respectively; when described control module judges that according to described detection signal there is earth fault in photovoltaic generating system; it is out of service to control described photovoltaic generating system, and described DC earthing protection module starts.
Detect protective device according to the DC earthing that is used for photovoltaic generating system that the utility model proposes; can select plus earth or minus earth according to actual conditions by selecting module; and can detect exactly the size of DC earthing electric current; simultaneously can also be by the DC earthing electric current be carried out real-time detection; when exceeding prescribed limit, sends in the DC earthing electric current guard signal with the protection machine; so both reduce the spoilage of fuse, strengthened again the reliability of machine.In addition, it is simple in structure that this DC earthing detects protective device, and stable performance can be judged exactly photovoltaic generating system and whether have earth fault.
The aspect that the utility model is additional and advantage in the following description part provide, and part will become obviously from the following description, or recognize by practice of the present utility model.
Description of drawings
Above-mentioned and/or the additional aspect of the utility model and advantage are from obviously and easily understanding becoming the description of embodiment below in conjunction with accompanying drawing, wherein:
Fig. 1 is the block diagram that detects protective device according to the DC earthing that is used for photovoltaic generating system of the utility model embodiment;
Fig. 2 is the structural representation that is used for the inverter of photovoltaic generating system according to the DC earthing detection protective device of the utility model embodiment;
Fig. 3 is the circuit theory diagrams that detect protective device according to the DC earthing that is used for photovoltaic generating system of the utility model embodiment;
Fig. 4 is the schematic diagram of the DC earthing that is used for photovoltaic generating system according to the utility model embodiment when detecting protective device plus earth; And
Fig. 5 is the schematic diagram of the DC earthing that is used for photovoltaic generating system according to the utility model embodiment when detecting the protective device minus earth.
Embodiment
The below describes embodiment of the present utility model in detail, and the example of described embodiment is shown in the drawings, and wherein identical or similar label represents identical or similar element or the element with identical or similar functions from start to finish.Be exemplary below by the embodiment that is described with reference to the drawings, only be used for explaining the utility model, and can not be interpreted as restriction of the present utility model.
Disclosing hereinafter provides many different embodiment or example to be used for realizing different structure of the present utility model.Of the present utility model open in order to simplify, hereinafter parts and the setting of specific examples are described.Certainly, they only are example, and purpose does not lie in restriction the utility model.In addition, the utility model can be in different examples repeat reference numerals and/or letter.This repetition is in order to simplify and purpose clearly, itself not indicate the relation between the various embodiment that discuss of institute and/or the setting.In addition, the various specific technique that the utility model provides and the example of material, but those of ordinary skills can recognize the property of can be applicable to of other techniques and/or the use of other materials.In addition, First Characteristic described below Second Characteristic it " on " structure can comprise that the first and second Characteristics creations are the direct embodiment of contact, also can comprise the embodiment of other Characteristics creation between the first and second features, such the first and second features may not be direct contacts.
In description of the present utility model, need to prove, unless otherwise prescribed and limit, term " installation ", " linking to each other ", " connection " should be done broad understanding, for example, can be mechanical connection or electrical connection, also can be the connection of two element internals, can be directly to link to each other, and also can indirectly link to each other by intermediary, for the ordinary skill in the art, can understand as the case may be the concrete meaning of above-mentioned term.
With reference to following description and accompanying drawing, with these and other aspects of clear embodiment of the present utility model.In these descriptions and accompanying drawing, specifically disclose some particular implementation among the embodiment of the present utility model, represent to implement some modes of the principle of embodiment of the present utility model, but should be appreciated that the scope of embodiment of the present utility model is not limited.On the contrary, embodiment of the present utility model comprises spirit and interior all changes, modification and the equivalent of intension scope that falls into additional claims.
Describe with reference to the accompanying drawings the DC earthing that is used for photovoltaic generating system that proposes according to the utility model embodiment and detect protective device.
As shown in Figure 1, this DC earthing detection protective device comprises selection module 101, checking for grounded current module 102, DC earthing protection module 103 and control module 104.
Wherein, select module 101 to be used for reception with the selection instruction of negative or positive electrode ground connection, and generate the selection signal.Checking for grounded current module 102 links to each other with selecting module 101, and checking for grounded current module 102 is used for according to the earth current of selecting input plus earth branch road or minus earth branch road, and the generation detection signal.103 pairs of plus earth branch roads of DC earthing protection module and minus earth branch road carry out the DC earthing protection.Control module 104 links to each other with DC earthing protection module 103 with checking for grounded current module 102 respectively; when control module 104 judges that according to detection signal there is earth fault in photovoltaic generating system; it is out of service to control this photovoltaic generating system, and simultaneously DC earthing protection module 103 startups are protected this photovoltaic generating system.
That is to say; in the present embodiment; as shown in Figure 2; when above-mentioned DC earthing detection protective device is used for the isolated inverter of this photovoltaic generating system; DC earthing protection module 103 itself also can be selected plus earth or minus earth (namely having the function of selecting module 101), can directly may be selected to be plus earth or minus earth according to the cell panel type when connecting this circuit.Namely say; select as required plus earth or minus earth; if there is not earth fault in the system; earth current is less; DC earthing protection module 103 will be with current signal transfer to control module 104 DSP(Digital Signal Processor for example; digital signal processor); DSP can judge this electric current and not exist unusually; simultaneously; checking for grounded current module 102 also can work; and detected signal is transferred to control module 104, DSP also can judge ground connection and not have fault.If when having earth fault in the system; earth current can be very large; for protection system; ground connection insurance F1 or F2 can fuse; DC earthing protection module 103 can be with this current signal transfer to control module 104, and checking for grounded current module 102 can detect also that this is unusual simultaneously, and the abnormal signal that detects is transferred to control module; it is unusual that DSP will judge this ground connection, and DC earthing protection module 103 starts so that machine is carried out real-time guard.
Further, in an embodiment of the present utility model, as shown in Figure 3, checking for grounded current module 102 comprises sampling submodule 301, switching submodule 302, anodal branch submodule 303, negative pole branch submodule 304 and output sub-module 305.
Wherein, sampling submodule 301 generates sampled signal according to the earth current of plus earth branch road or minus earth branch road.Switching submodule 302 links to each other with sampling submodule 301, and switching submodule 302 is distributed sampled signal according to the selection signal of selecting module 101.Anodal branch submodule 303 links to each other with switching submodule 302 respectively according to actual needs with negative pole branch submodule 304, switching submodule 302 is sent to anodal branch submodule 303 or negative pole branch submodule 304 according to the selection signal with sampled signal, and anodal branch submodule 303 or negative pole branch submodule 304 generate respectively the first detection signal or the second detection signal according to sampled signal.Output sub-module 305 and anodal branch submodule 303 link to each other with negative pole branch submodule 304, and output sub-module is exported the first detection signal or the second detection signal as detection signal.
In an example of the present utility model, switching submodule 302 is wire jumper.Sampling submodule 301 can be linked to each other with anodal branch submodule 303 by wire jumper, the submodule 301 of perhaps will sampling links to each other with negative pole branch submodule 304.
Particularly, checking for grounded current module 102 can be gone here and there on the branch road of the branch road of plus earth and minus earth, also can go here and there on the ground connection total loop.Preferably, in the present embodiment so that checking for grounded current module 102 string is described as example at the ground connection total loop.
In the present embodiment, to shown in Figure 5, sampling submodule 301 specifically comprises the first resistance R 1, the second resistance R 2, the 3rd resistance R 3, the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6, the 7th resistance R 7 and the first comparator U1 such as Fig. 3.Wherein, the first resistance R 1, the 4th resistance R 4 and the 5th resistance R 5 all are chosen in the M ohm level.
Extremely shown in Figure 5 such as Fig. 3, the first resistance R 1, the second resistance R 2, the 3rd resistance R 3 and the 4th resistance R 4 are connected in series mutually, has first node (voltage is V1) between the first resistance R 1 and the second resistance R 2, has Section Point (voltage is V3) between the second resistance R 2 and the 3rd resistance R 3, has the 3rd node (voltage is V2) between the 3rd resistance R 3 and the 4th resistance R 4, and the first resistance R 1 links to each other with anodal PV+, and the 4th resistance R 4 links to each other with negative pole PV-.One end of the 5th resistance R 5 links to each other with DC earthing protection module 103, and the other end of the 5th resistance R 5 links to each other with Section Point.One end of the 6th resistance R 6 links to each other with first node, and an end of the 7th resistance R 7 links to each other with the 3rd node.The positive input terminal of the first comparator U1 links to each other with the other end of the 6th resistance R 6, and the negative input end of the first comparator U1 links to each other with the other end of the 7th resistance R 7.
And in the present embodiment, to shown in Figure 5, sampling submodule 301 also comprises filter 306, and filter 306 is connected between the 6th resistance R 6 and the first comparator U1 such as Fig. 3.Filter 306 comprises the first capacitor C 1 and the tenth resistance R 10 in parallel.
In addition, in the present embodiment, to shown in Figure 5, sampling submodule 301 also comprises the 8th resistance R 8 and the 9th resistance R 9 such as Fig. 3.Wherein, the 8th resistance R 8 is connected between the negative input end and output of the first comparator U1, and an end of the 9th resistance R 9 links to each other with the output of the first comparator U1, and the other end of the 9th resistance R 9 is the output of sampling submodule 301.
In sum, the situation of DC earthing detection protective device when work of embodiment proposition of the present utility model is as follows:
As shown in Figure 3 and Figure 4, anodal PV+ and negative pole PV-are the dc terminal input voltage ,+VCC1 ,-VCC1 ,+VCC2 is accessory power supply.When plus earth, U2-0 links to each other with U2-3, and the 5th resistance R 5 is in parallel with the first resistance R 1 and the second resistance R 2, be R5//(R1+R2), the * R10/R6 of the output end vo of the first comparator U1=(V1-V2), this moment, U2-0 was connected to the positive input terminal of first window comparator U2A by wire jumper.The voltage of U2A positive input terminal is (VCC2-Vo) * R9/(R9+R16), U2A negative input end voltage is Vdc*R14/(R13+R14), positive input terminal voltage is lower than negative input end voltage, U2A output low level then, triode Q 1 does not have open-minded, the voltage at test point 1 place is high level, and voltage transmission herein is to control module 104, and DSP can judge and not have earth fault.If there is earth fault in system; fuse F1 can blow damage; this moment, the positive input terminal voltage of first window comparator U2A was higher than negative input end voltage; U2A exports high level; the Q1 conducting, then the voltage at test point 1 place is low level, this low level is transferred to control module 104; DSP can judge earth fault, and DC earthing protection module 103 starts so that machine is carried out real-time guard simultaneously.Checking for grounded current module 102 detected current signals also can send control module 104 to, the size of DSP meeting read current.
Such as Fig. 3 and shown in Figure 5, when minus earth, U2-0 links to each other with U2-6, the 5th resistance R 5 is in parallel with the first resistance R 3 and the second resistance R 4, be R5//(R3+R4), the * R10/R6 of the output end vo of the first comparator U1=(V1-V2), this moment, U2-0 was connected to the negative input end of Second Window comparator U2B by wire jumper, the voltage of the negative input end of U2B is Vo*R15/(R15+R9), the positive input terminal voltage of U2B is Vdc*R14/(R13+R14), positive input terminal voltage is lower than negative input end voltage, Second Window comparator U2B output low level then, not conducting of triode Q1, the voltage at test point 1 place is high level, and voltage transmission herein is to control module 104, and DSP can judge and not have earth fault.If there is earth fault in system, fuse F2 can blow damage, and the positive input terminal voltage of Second Window comparator U2B is higher than negative input end voltage, and then U2B exports high level, the Q1 conducting, and then the voltage at test point 1 place is low level.This low level is transferred to control module 104, and DSP can judge earth fault, and DC earthing protection module 103 starts so that machine is carried out real-time guard simultaneously.Checking for grounded current module 102 detected current signals also can send control module 104 to, the size of DSP meeting read current.
Detect protective device according to the DC earthing that is used for photovoltaic generating system that the utility model proposes; can select plus earth or minus earth according to actual conditions by selecting module 101; and can detect exactly the size of DC earthing electric current; simultaneously can also be by the DC earthing electric current be carried out real-time detection; when exceeding prescribed limit, sends in the DC earthing electric current guard signal with the protection machine; so both reduce the spoilage of fuse, strengthened again the reliability of machine.In addition, it is simple in structure that this DC earthing detects protective device, and stable performance can be judged exactly photovoltaic generating system and whether have earth fault.
In the description of this specification, the description of reference term " embodiment ", " some embodiment ", " example ", " concrete example " or " some examples " etc. means to be contained at least one embodiment of the present utility model or the example in conjunction with specific features, structure, material or the characteristics of this embodiment or example description.In this manual, the schematic statement of above-mentioned term not necessarily referred to identical embodiment or example.And the specific features of description, structure, material or characteristics can be with suitable mode combinations in any one or more embodiment or example.
Although illustrated and described embodiment of the present utility model, for the ordinary skill in the art, be appreciated that in the situation that does not break away from principle of the present utility model and spirit and can carry out multiple variation, modification, replacement and modification to these embodiment that scope of the present utility model is by claims and be equal to and limit.
Claims (7)
1. a DC earthing that is used for photovoltaic generating system detects protective device, it is characterized in that, comprising:
Select module, described selection module receives the selection instruction with negative or positive electrode ground connection, and generates the selection signal;
The checking for grounded current module, described checking for grounded current module links to each other with described selection module, and described checking for grounded current module is according to the earth current of described selection input plus earth branch road or minus earth branch road, and the generation detection signal;
The DC earthing protection module, described DC earthing protection module carries out the DC earthing protection to described plus earth branch road and described minus earth branch road;
Control module; described control module links to each other with described DC earthing protection module with described checking for grounded current module respectively; when described control module judges that according to described detection signal there is earth fault in photovoltaic generating system; it is out of service to control described photovoltaic generating system, and described DC earthing protection module starts.
2. DC earthing as claimed in claim 1 detects protective device, it is characterized in that described checking for grounded current module further comprises:
The sampling submodule, described sampling submodule generates sampled signal according to the earth current of described plus earth branch road or minus earth branch road;
Switching submodule, described switching submodule links to each other with described sampling submodule, and described switching submodule is distributed described sampled signal according to described selection signal;
Anodal branch's submodule and negative pole branch submodule, described anodal branch submodule links to each other with described switching submodule with negative pole branch submodule, described switching submodule is sent to described anodal branch submodule or negative pole branch submodule according to described selection signal with described sampled signal, and described anodal branch submodule or negative pole branch submodule generate respectively the first detection signal or the second detection signal according to described sampled signal; And
Output sub-module, described output sub-module and described anodal branch submodule link to each other with negative pole branch submodule, and described output sub-module is exported described the first detection signal or the second detection signal as described detection signal.
3. DC earthing as claimed in claim 2 detects protective device, it is characterized in that described switching submodule is wire jumper.
4. DC earthing as claimed in claim 2 detects protective device, it is characterized in that described sampling submodule further comprises:
The first resistance to the four resistance of mutually connecting, wherein, has first node between described the first resistance and the second resistance, has Section Point between described the second resistance and the 3rd resistance, has the 3rd node between described the 3rd resistance and the 4th resistance, described the first resistance links to each other with described positive pole, and described the 4th resistance links to each other with described negative pole;
The 5th resistance, an end of described the 5th resistance links to each other with described DC earthing protection module, and the other end of described the 5th resistance links to each other with described Section Point;
The 6th resistance, an end of described the 6th resistance links to each other with described first node;
The 7th resistance, an end of described the 7th resistance links to each other with described the 3rd node;
The first comparator, the positive input terminal of described the first comparator links to each other with the other end of described the 6th resistance, and the negative input end of described the first comparator links to each other with the other end of described the 7th resistance.
5. DC earthing as claimed in claim 4 detects protective device, it is characterized in that described sampling submodule also comprises:
Filter, described filter are connected between described the 6th resistance and described the first comparator.
6. DC earthing as claimed in claim 4 detects protective device, it is characterized in that described sampling submodule also comprises:
The 8th resistance, described the 8th resistance is connected between the negative input end and output of described the first comparator.
7. DC earthing as claimed in claim 4 detects protective device, it is characterized in that described sampling submodule also comprises:
The 9th resistance, an end of described the 9th resistance links to each other with the output of described the first comparator, and the other end of described the 9th resistance is the output of described sampling submodule.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201220496535.9U CN202872325U (en) | 2012-09-26 | 2012-09-26 | Direct current grounding detection protection device used for photovoltaic power generation system |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201220496535.9U CN202872325U (en) | 2012-09-26 | 2012-09-26 | Direct current grounding detection protection device used for photovoltaic power generation system |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
| CN103792444A (en) * | 2013-08-20 | 2014-05-14 | 深圳市金霆科技有限公司 | Direct-current remote supply power input grounding detection circuit and detection method thereof |
| CN104034956A (en) * | 2014-05-30 | 2014-09-10 | 杭州电子科技大学 | Positive/negative voltage measuring circuit |
| CN110554279A (en) * | 2019-09-09 | 2019-12-10 | 南京南瑞继保工程技术有限公司 | Device and method for detecting internal fault of control winding of magnetic control type controllable reactor |
-
2012
- 2012-09-26 CN CN201220496535.9U patent/CN202872325U/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
| CN103792444A (en) * | 2013-08-20 | 2014-05-14 | 深圳市金霆科技有限公司 | Direct-current remote supply power input grounding detection circuit and detection method thereof |
| CN103792444B (en) * | 2013-08-20 | 2016-12-28 | 深圳市金霆科技有限公司 | Direct-current remote feeding power input grounding testing circuit and detection method thereof |
| CN104034956A (en) * | 2014-05-30 | 2014-09-10 | 杭州电子科技大学 | Positive/negative voltage measuring circuit |
| CN104034956B (en) * | 2014-05-30 | 2017-02-15 | 杭州电子科技大学 | Positive/negative voltage measuring circuit |
| CN110554279A (en) * | 2019-09-09 | 2019-12-10 | 南京南瑞继保工程技术有限公司 | Device and method for detecting internal fault of control winding of magnetic control type controllable reactor |
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