CN203249968U - A real-time detecting circuit for detecting the earth insulation impedance of a photovoltaic grid-connected inverter - Google Patents
A real-time detecting circuit for detecting the earth insulation impedance of a photovoltaic grid-connected inverter Download PDFInfo
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- CN203249968U CN203249968U CN 201320281517 CN201320281517U CN203249968U CN 203249968 U CN203249968 U CN 203249968U CN 201320281517 CN201320281517 CN 201320281517 CN 201320281517 U CN201320281517 U CN 201320281517U CN 203249968 U CN203249968 U CN 203249968U
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Abstract
The utility model belongs to a detecting circuit of a photovoltaic grid-connected inverter and especially designs a real-time detecting circuit and a detecting method which are used for detecting the earth insulation impedance of a photovoltaic grid-connected inverter. The real-time detecting circuit comprises a positive pole of the photovoltaic inverter, a negative pole of the photovoltaic inverter, and a grounding point of the photovoltaic inverter. A positive insulation impedance device is connected between the positive pole of the photovoltaic inverter and the grounding point of the photovoltaic inverter. A negative insulation impedance device is connected between the negative pole of the photovoltaic inverter and the grounding point of the photovoltaic inverter. A DSP detecting controller is disposed between the negative pole and the grounding point. A first auxiliary resistor is arranged between the positive pole and the grounding point. A second auxiliary resistor is arranged between the negative pole and the grounding point. A first relay is connected between the positive pole and the grounding point and controls whether to access the first auxiliary resistor. A second relay is connected between the negative pole and the grounding point and controls whether to access the second auxiliary resistor. The real-time detecting circuit is capable of accurately detecting the earth impedance of the photovoltaic grid-connected inverter in real time and accurately determining the value of the earth impedance.
Description
Technical field
The utility model belongs to the testing circuit of photovoltaic combining inverter, special design a kind of real-time detection circuit and detection method for detection of photovoltaic combining inverter insulation against ground impedance.
Background technology
In photovoltaic generating system, in order to prevent solar panel owing to decreasing insulating is brought Danger Electric shock risk, require photovoltaic combining inverter to have the function of direct current insulation against ground impedance detection.And inverter in the market all be only before start, detect once or accuracy of detection low.
Under normal circumstances, the negative or positive electrode of photovoltaic DC-to-AC converter insulation impedance over the ground is all more than 2M Ω, and as shown in Figure 1, R1 is during for test and the equivalent resistance between positive pole and ground.The newest standards of a lot of relevant authentication mechanisms requires negative or positive electrode and upward namely reports disorderly closedown less than the resistance of 30K Ω, and still can normally move greater than the resistance of 37K Ω.This has just had very high requirement to the detection measure of precision of insulation impedance.General inverter all is that (PE) or negative pole (SN) voltage VPE over the ground judge whether inverter ground connection is normal over the ground for positive pole (SP) by detecting photovoltaic combining inverter.But because 2M Ω is very big with respect to 30K Ω, to such an extent as to and the VPE during upper 30K Ω and and the VPE during upper 37K Ω differ very little, add because the existence of sampling error, can't directly judge the accurate scope of insulation impedance by VPE at all.
Summary of the invention
The utility model is for the deficiencies in the prior art; designed a kind of can be in real time and accurately detect the testing circuit of photovoltaic combining inverter earth impedance; detection that can be real-time; and can judge accurately the size of earth impedance; effectively guaranteed operating personnel's safety; also can reduce simultaneously the number of times of photovoltaic DC-to-AC converter newspaper machine halt trouble, guarantee the normal operation of equipment.
The utility model is achieved through the following technical solutions:
The real-time detection circuit of the insulation against ground impedance of photovoltaic combining inverter, the positive pole that comprises photovoltaic DC-to-AC converter, negative pole and earth point, be connected with anodal insulation impedance between the positive pole of photovoltaic DC-to-AC converter and the earth point, be connected with the negative pole insulation impedance between the negative pole of photovoltaic DC-to-AC converter and the earth point, it is characterized in that: be provided with DSP between described negative pole and the earth point and detect controller, be provided with the first auxiliary resistance between described positive pole and the earth point, be provided with the second auxiliary resistance between negative pole and the earth point, also be connected with the first relay whether control the first auxiliary resistance accesses between positive pole and the earth point, also be connected with the second relay whether control the second auxiliary resistance accesses between negative pole and the earth point.
The detection method of photovoltaic combining inverter insulation against ground impedance is characterized in that: may further comprise the steps:
A) user detects the upper limit RH that controller arranges the insulation against ground impedance according to actual behaviour in service by DSP, and the lower limit RL of insulation against ground impedance is set, and the voltage between the positive and negative end is VDC, and anodal insulation impedance is RZ, and the negative pole insulation impedance is RF; The first auxiliary resistance R1F, the second auxiliary resistance are R2F;
B) when having between small resistor R1 access positive pole and the earth point, the resistance value of R1 is preset as 1.2RH, the R1 of this moment with the resistance in parallel of anodal insulation impedance is
Resistance R between positive pole and the negative pole is negative pole insulation impedance and R12 sum, and this moment, the calculating voltage at negative pole insulation impedance two ends was
DSP detects the voltage VPE that controller detects negative pole insulation impedance two ends, when VPE greater than V
RFThe time, then explanation has the resistance less than R1 to access between positive pole and earth point,
C) at this moment, DSP detects controller and controls the second cut-off, and in the second auxiliary resistance place in circuit, this moment, the resistance value of fiducial value R2 was preset as
R2 with the resistance in parallel of anodal insulation impedance is
The second auxiliary resistance resistance in parallel with the negative pole insulation impedance is
The calculating voltage at negative pole insulation impedance two ends is
DSP detects the voltage VPE that controller detects negative pole insulation impedance two ends, when VPE greater than V
RFIn ' time, then be determined with between the resistance access positive pole and earth point less than R2, and DSP detection this moment controller sends alerting signal, otherwise VPE is less than V
RF', then be determined with at R2 and access between positive pole and earth point to the resistance of resistance between the 1.2RH;
Above-mentioned determination methods also can be used for the detection of the insulation against ground impedance between negative pole and the earth point.
In sum, the utility model for the precision of the detection of photovoltaic DC-to-AC converter insulation against ground impedance in the prior art not and the relatively poor problem of real-time, the utility model designed a kind of can be in real time and accurately detect the testing circuit of photovoltaic DC-to-AC converter insulation against ground impedance, provided simultaneously and judged whether the insulation against ground impedance reports the detection method of fault, the utility model has realized that photovoltaic DC-to-AC converter insulation against ground impedance detects in real time, can be convenient to the situation that people in time understand photovoltaic DC-to-AC converter insulation against ground impedance, detection method described in the utility model can accurately be judged the scope at resistance place of the insulation against ground impedance of both positive and negative polarity and earth point in addition, the cost of testing circuit described in the utility model is low, is convenient to carry out marketing.
Description of drawings
Fig. 1 is the composition diagram of testing circuit of the present utility model;
1 is the second auxiliary resistance among the figure, and 2 is the second relay, and 3 is the first auxiliary resistance, and 4 is the first relay, and 5 is anodal, and 6 is anodal insulation impedance, and 7 is earth point, and 8 for DSP detects controller, and 9 is negative pole, and 10 is the negative pole insulation impedance.
Embodiment
Below in conjunction with accompanying drawing the utility model is described further.
The real-time detection circuit of the insulation against ground impedance of photovoltaic combining inverter, the positive pole 5 that comprises photovoltaic DC-to-AC converter, negative pole 9 and earth point 7, be connected with anodal insulation impedance 6 between the positive pole of photovoltaic DC-to-AC converter and the earth point, be connected with negative pole insulation impedance 10 between the negative pole of photovoltaic DC-to-AC converter and the earth point, it is characterized in that: be provided with DSP between described negative pole and the earth point and detect controller 8, described anodal 5 and earth point 7 between be provided with the first auxiliary resistance 3, be provided with the second auxiliary resistance 1 between negative pole 9 and the earth point 7, also be connected with the first relay 4 whether control the first auxiliary resistance 3 accesses between positive pole and the earth point, also be connected with the second relay 2 whether control the second auxiliary resistance 1 accesses between negative pole and the earth point.
The detection method of photovoltaic combining inverter insulation against ground impedance is characterized in that: may further comprise the steps:
A) user detects the upper limit RH that controller arranges the insulation against ground impedance according to actual behaviour in service by DSP, and the lower limit RL of insulation against ground impedance is set, and the voltage between the positive and negative end is VDC, and anodal insulation impedance is RZ, and the negative pole insulation impedance is RF; The first auxiliary resistance R1F, the second auxiliary resistance are R2F;
B) when having between small resistor R1 access positive pole and the earth point, the resistance value of R1 is preset as 1.2RH, the R1 of this moment with the resistance in parallel of anodal insulation impedance is
Resistance R between positive pole and the negative pole is negative pole insulation impedance and R12 sum, and this moment, the calculating voltage at negative pole insulation impedance two ends was
DSP detects the voltage VPE that controller detects negative pole insulation impedance two ends, when VPE greater than V
RFThe time, then explanation has the resistance less than R1 to access between positive pole and earth point,
C) at this moment, DSP detects controller and controls the second cut-off, and in the second auxiliary resistance place in circuit, this moment, the resistance value of fiducial value R2 was preset as
R2 with the resistance in parallel of anodal insulation impedance is
The second auxiliary resistance resistance in parallel with the negative pole insulation impedance is
The calculating voltage at negative pole insulation impedance two ends is
DSP detects the voltage VPE that controller detects negative pole insulation impedance two ends, when VPE greater than V
RFIn ' time, then be determined with between the resistance access positive pole and earth point less than R2, and DSP detection this moment controller sends alerting signal, otherwise VPE is less than V
RF', then be determined with at R2 and access between positive pole and earth point to the resistance of resistance between the 1.2RH;
Above-mentioned determination methods also can be used for the detection of the insulation against ground impedance between negative pole and the earth point.
In sum, the utility model for the precision of the detection of photovoltaic DC-to-AC converter insulation against ground impedance in the prior art not and the relatively poor problem of real-time, the utility model designed a kind of can be in real time and accurately detect the testing circuit of photovoltaic DC-to-AC converter insulation against ground impedance, provided simultaneously and judged whether the insulation against ground impedance reports the detection method of fault, the utility model has realized that photovoltaic DC-to-AC converter insulation against ground impedance detects in real time, can be convenient to the situation that people in time understand photovoltaic DC-to-AC converter insulation against ground impedance, detection method described in the utility model can accurately be judged the scope at resistance place of the insulation against ground impedance of both positive and negative polarity and earth point in addition, the cost of testing circuit described in the utility model is low, is convenient to carry out marketing.
Claims (1)
1. the real-time detection circuit of the insulation against ground impedance of photovoltaic combining inverter, the positive pole that comprises photovoltaic DC-to-AC converter, negative pole and earth point, be connected with anodal insulation impedance between the positive pole of photovoltaic DC-to-AC converter and the earth point, be connected with the negative pole insulation impedance between the negative pole of photovoltaic DC-to-AC converter and the earth point, it is characterized in that: be provided with DSP between described negative pole and the earth point and detect controller, be provided with the first auxiliary resistance between described positive pole and the earth point, be provided with the second auxiliary resistance between negative pole and the earth point, also be connected with the first relay whether control the first auxiliary resistance accesses between positive pole and the earth point, also be connected with the second relay whether control the second auxiliary resistance accesses between negative pole and the earth point.
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| Application Number | Priority Date | Filing Date | Title |
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| CN 201320281517 CN203249968U (en) | 2013-05-21 | 2013-05-21 | A real-time detecting circuit for detecting the earth insulation impedance of a photovoltaic grid-connected inverter |
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| CN 201320281517 CN203249968U (en) | 2013-05-21 | 2013-05-21 | A real-time detecting circuit for detecting the earth insulation impedance of a photovoltaic grid-connected inverter |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103323674A (en) * | 2013-05-21 | 2013-09-25 | 江苏宝丰新能源科技有限公司 | Circuit and method for real-time detection of ground insulation impedance of photovoltaic grid-connected inverter |
| CN106324359A (en) * | 2015-06-24 | 2017-01-11 | 中兴通讯股份有限公司 | Insulation impedance detection method and device of photovoltaic inverter |
| CN107305224A (en) * | 2016-04-19 | 2017-10-31 | 台达电子企业管理（上海）有限公司 | Insulation resistance detection circuit, detection method and the photovoltaic DC-to-AC converter of photovoltaic DC-to-AC converter |
| CN112083230A (en) * | 2020-09-07 | 2020-12-15 | 爱士惟新能源技术(江苏)有限公司 | Ground insulation impedance detection circuit and method of grid-connected inverter |
-
2013
- 2013-05-21 CN CN 201320281517 patent/CN203249968U/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103323674A (en) * | 2013-05-21 | 2013-09-25 | 江苏宝丰新能源科技有限公司 | Circuit and method for real-time detection of ground insulation impedance of photovoltaic grid-connected inverter |
| CN103323674B (en) * | 2013-05-21 | 2016-08-03 | 江苏宝丰新能源科技有限公司 | The real-time detection circuit of the ground insulation resistance of photovoltaic combining inverter and detection method |
| CN106324359A (en) * | 2015-06-24 | 2017-01-11 | 中兴通讯股份有限公司 | Insulation impedance detection method and device of photovoltaic inverter |
| CN106324359B (en) * | 2015-06-24 | 2019-11-19 | 中兴通讯股份有限公司 | The insulation impedance detection method and device of photovoltaic DC-to-AC converter |
| CN107305224A (en) * | 2016-04-19 | 2017-10-31 | 台达电子企业管理（上海）有限公司 | Insulation resistance detection circuit, detection method and the photovoltaic DC-to-AC converter of photovoltaic DC-to-AC converter |
| US10411479B2 (en) | 2016-04-19 | 2019-09-10 | Delta Electronics (Shanghai) Co., Ltd | Detection circuit and detection method for detecting insulation resistance of photovoltaic inverter, and photovoltaic inverter |
| CN112083230A (en) * | 2020-09-07 | 2020-12-15 | 爱士惟新能源技术(江苏)有限公司 | Ground insulation impedance detection circuit and method of grid-connected inverter |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20131023 Termination date: 20180521 |