CN102478599A - Power grid alternating voltage, and method and device for detecting zero crossing point of power grid alternating voltage - Google Patents
Power grid alternating voltage, and method and device for detecting zero crossing point of power grid alternating voltage Download PDFInfo
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- CN102478599A CN102478599A CN2010105559108A CN201010555910A CN102478599A CN 102478599 A CN102478599 A CN 102478599A CN 2010105559108 A CN2010105559108 A CN 2010105559108A CN 201010555910 A CN201010555910 A CN 201010555910A CN 102478599 A CN102478599 A CN 102478599A
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Abstract
The invention provides a method for detecting a zero crossing point of a power grid alternating voltage. The method comprises the following steps of: sampling the power grid alternating voltage; performing analog-to-digital conversion on the sampled data; judging whether the power grid alternating voltage is positioned near the zero crossing point or not; performing multipoint sampling on the power grid alternating voltage near the zero crossing point and taking the average value; and summarizing the power grid alternating voltage data to acquire the zero crossing point of the power grid alternating voltage. The invention also provides a method for detecting the power grid alternating voltage, the power grid alternating voltage and a device for detecting the zero crossing point of the power grid alternating voltage. According to the invention, the number of the sampling points on other sections of the wave form is reduced by guaranteeing the number of the sampling points near the zero crossing point of the power grid alternating voltage wave form; and the detection precision of the zero crossing point of the power grid alternating voltage is guaranteed under the condition that the total number of the sampling points is limited or at the same data transmission speed.
Description
Technical field
The present invention relates to the photovoltaic sciemtifec and technical sphere, specifically, the present invention relates to a kind of detection method and pick-up unit of grid ac voltage zero crossing, and a kind of detection method of grid ac voltage and pick-up unit.
Background technology
Solar photovoltaic assembly converts sunshine into direct current power.In order to supply the user to use in the electric power input electrical network that produces, need to use solar photovoltaic interconnected inverter to convert the direct current power of photovoltaic module output into alternating electromotive force.When being incorporated into the power networks, the alternating current phases of output must with the alternating voltage phase-locking of electrical network.
In order to reach this purpose, need the zero crossing of detection of grid alternating voltage, it is used to ensure the alternating voltage phase-locking of alternating current phases and electrical network, exports very key so the accurate detection of grid ac voltage zero crossing is incorporated into the power networks for alternating electromotive force.When grid ac voltage zero crossing faults, inverter possibly inject electrical network by error with the alternating electromotive force that produces, and causes the damage of inverter.So it is very high that the accuracy of detection of grid ac voltage zero crossing requires, and the accuracy of detection of other points requires relatively low in the waveform.
In the prior art, the grid ac voltage that sampling is obtained can be converted into digital signal, obtains information such as waveform and zero crossing.Usually exchanging data processor and obtaining between the central processing unit of grid ac voltage information needs to isolate, so use digital optocoupler between to carry out the transmission of data usually.But because the restriction of digital optocoupler transmission speed, the number of grid ac voltage sampled point is restricted.Fig. 1 and Fig. 2 are the sample waveform synoptic diagram of grid ac voltage common in the prior art, and wherein Fig. 1 shows 50 points of sampling in the one-period, and Fig. 2 shows 100 points of sampling in the one-period.It is thus clear that if the number of sampled point is restricted, the precision that the ac grid voltage zero crossing detects also can be affected.
Summary of the invention
Technical matters to be solved by this invention provides a kind of detection method and pick-up unit of grid ac voltage zero crossing; Under the situation that the sampled point number is restricted; Adjust the sampled point number on other section near sampled point number of waveform pass zero point and the waveform, guaranteed the accuracy of detection of grid ac voltage zero crossing.
For solving the problems of the technologies described above, the present invention provides a kind of detection method of grid ac voltage zero crossing, comprises step:
Grid ac voltage is sampled;
Data to being sampled are carried out analog to digital conversion;
Judge whether said grid ac voltage is near zero-crossing point, if, then directly give the zero crossing acquisition module with data transmission, if not, then continue to carry out next step;
The said grid ac voltage that will be near zero-crossing point carries out multiple spot averages, and then gives said zero crossing acquisition module with data transmission;
Gather said grid ac voltage data by said zero crossing acquisition module, obtain the zero crossing of said grid ac voltage.
Alternatively, judge whether said grid ac voltage is near zero-crossing point and comprises that whether the absolute value of judging said grid ac voltage is less than threshold value.
Alternatively, said data are transferred to said zero crossing acquisition module through digital optocoupler.
The present invention also provides a kind of grid alternating current pressure detection method, comprises the detection method of above-mentioned each described grid ac voltage zero crossing.
Correspondingly, the present invention also provides a kind of pick-up unit of grid ac voltage zero crossing, comprising:
The alternating voltage sampling module is used for grid ac voltage is sampled;
Analog-to-digital conversion module is connected with said alternating voltage sampling module, is used for the data of being sampled are carried out analog to digital conversion;
The near zero-crossing point judge module is connected with said analog-to-digital conversion module, is used to judge whether said grid ac voltage is near zero-crossing point;
Alternating voltage multi-point average module is connected with said near zero-crossing point judge module, is used for that the said grid ac voltage that is near zero-crossing point is carried out multiple spot and averages;
The zero crossing acquisition module is connected with said alternating voltage multi-point average module with said near zero-crossing point judge module respectively, is used to gather said grid ac voltage data, obtains the zero crossing of said grid ac voltage.
Alternatively, judge whether said grid ac voltage is near zero-crossing point and comprises that whether the absolute value of judging said grid ac voltage is less than threshold value.
Alternatively, said zero crossing acquisition module is connected with said alternating voltage multi-point average module with said near zero-crossing point judge module respectively through digital optocoupler.
The present invention also provides a kind of pick-up unit of grid ac voltage, comprises the pick-up unit of above-mentioned each described grid ac voltage zero crossing.
Compared with prior art, the present invention has the following advantages:
The present invention reduces the sampled point number on other section in the waveform through guaranteeing near the sampled point number the grid ac voltage waveform pass zero point; Be restricted under the situation of perhaps identical data rate at overall sampled point number, guaranteed the accuracy of detection of grid ac voltage zero crossing.
Description of drawings
Above-mentioned and other characteristic, character and advantage of the present invention will become more obvious through the description below in conjunction with accompanying drawing and embodiment, wherein:
Fig. 1～Fig. 2 is the sample waveform synoptic diagram of grid ac voltage common in the prior art;
Fig. 3 is the detection method process flow diagram of the grid ac voltage zero crossing of one embodiment of the invention;
Fig. 4 is the sample waveform synoptic diagram of the grid ac voltage of one embodiment of the invention;
Fig. 5 is the waveform synoptic diagram after the processing of grid ac voltage of one embodiment of the invention;
Fig. 6 is the synoptic diagram of pick-up unit of the grid ac voltage zero crossing of one embodiment of the invention.
Embodiment
Below in conjunction with specific embodiment and accompanying drawing the present invention is described further, but should limit protection scope of the present invention with this.
Fig. 3 is the detection method process flow diagram of the grid ac voltage zero crossing of one embodiment of the invention.As shown in the figure, this detection method can comprise:
Execution in step S101 samples to grid ac voltage;
Fig. 4 is the sample waveform synoptic diagram of the grid ac voltage of one embodiment of the invention.As shown in the figure, it shows 200 points of sampling in the one-period.
Execution in step S102 carries out analog to digital conversion to the data of being sampled;
Execution in step S103 judges whether grid ac voltage is near zero-crossing point, and whether the absolute value of for example judging grid ac voltage is less than threshold value; If; Then directly give the zero crossing acquisition module with data transmission through digital optocoupler, if not, execution in step S104 then continued;
Execution in step S104, the grid ac voltage that will be near zero-crossing point carries out multiple spot averages, and then gives the zero crossing acquisition module through digital optocoupler with data transmission;
Execution in step S105 gathers the grid ac voltage data by the zero crossing acquisition module, obtains the zero crossing of grid ac voltage.
Fig. 5 is the waveform synoptic diagram after the processing of grid ac voltage of one embodiment of the invention.As shown in the figure, keep former sampled point near zero-crossing point, outside this, multiple spot is averaged.In Fig. 5, the dot spacing of near zero-crossing point is T/200, outside this, 5 is averaged, and its dot spacing is T/40.Comparison diagram 4 and Fig. 5, the total sampling number among Fig. 4 is 200, the total sampling number among Fig. 5 then is reduced to 63.Because the minimizing of sampling number, its data rate becomes faster; And, because near both dot spacings waveform pass zero point are identical, do not influence near the sampling precision of waveform pass zero point.In addition,, also can realize detection, so the present invention can the detection of grid alternating voltage to the grid ac voltage amplitude because the present invention has also carried out not influencing the reservation of averaging of sampling precision to the sampled point except near zero-crossing point.
Fig. 6 is the synoptic diagram of pick-up unit of the grid ac voltage zero crossing of one embodiment of the invention.As shown in the figure, this pick-up unit 600 can comprise:
Alternating voltage sampling module 601 is used for grid ac voltage is sampled;
Analog-to-digital conversion module 603 is connected with alternating voltage sampling module 601, is used for the data of being sampled are carried out analog to digital conversion;
Near zero-crossing point judge module 605 is connected with analog-to-digital conversion module 603, is used to judge whether grid ac voltage is near zero-crossing point, and whether the absolute value of for example judging grid ac voltage is less than threshold value;
Alternating voltage multi-point average module 607 is connected with near zero-crossing point judge module 605, is used for that the grid ac voltage that is near zero-crossing point is carried out multiple spot and averages;
Zero crossing acquisition module 609 is connected with alternating voltage multi-point average module 607 with near zero-crossing point judge module 605 respectively through digital optocoupler, is used to gather the grid ac voltage data, obtains the zero crossing of grid ac voltage.In the present embodiment, zero crossing acquisition module 609 can be realized by central processing unit (CPU).
The present invention reduces the sampled point number on other section in the waveform through guaranteeing near the sampled point number the grid ac voltage waveform pass zero point; Be restricted under the situation of perhaps identical data rate at overall sampled point number, guaranteed the accuracy of detection of grid ac voltage zero crossing.
Though the present invention with preferred embodiment openly as above; But it is not to be used for limiting the present invention; Any those skilled in the art are not breaking away from the spirit and scope of the present invention; Can make possible change and modification, so protection scope of the present invention should be as the criterion with the scope that claim of the present invention was defined.
Claims (8)
1. the detection method of a grid ac voltage zero crossing is characterized in that, comprises step:
Grid ac voltage is sampled;
Data to being sampled are carried out analog to digital conversion;
Judge whether said grid ac voltage is near zero-crossing point, if, then directly give the zero crossing acquisition module with data transmission, if not, then continue to carry out next step;
The said grid ac voltage that will be near zero-crossing point carries out multiple spot averages, and then gives said zero crossing acquisition module with data transmission;
Gather said grid ac voltage data by said zero crossing acquisition module, obtain the zero crossing of said grid ac voltage.
2. detection method according to claim 1 is characterized in that, judges whether said grid ac voltage is near zero-crossing point and comprises that whether the absolute value of judging said grid ac voltage is less than threshold value.
3. detection method according to claim 1 and 2 is characterized in that, said data are transferred to said zero crossing acquisition module through digital optocoupler.
4. a grid alternating current pressure detection method is characterized in that, comprises the detection method of each described grid ac voltage zero crossing in the claim 1 to 3.
5. the pick-up unit of a grid ac voltage zero crossing is characterized in that, comprising:
The alternating voltage sampling module is used for grid ac voltage is sampled;
Analog-to-digital conversion module is connected with said alternating voltage sampling module, is used for the data of being sampled are carried out analog to digital conversion;
The near zero-crossing point judge module is connected with said analog-to-digital conversion module, is used to judge whether said grid ac voltage is near zero-crossing point;
Alternating voltage multi-point average module is connected with said near zero-crossing point judge module, is used for that the said grid ac voltage that is near zero-crossing point is carried out multiple spot and averages;
The zero crossing acquisition module is connected with said alternating voltage multi-point average module with said near zero-crossing point judge module respectively, is used to gather said grid ac voltage data, obtains the zero crossing of said grid ac voltage.
6. pick-up unit according to claim 5 is characterized in that, judges whether said grid ac voltage is near zero-crossing point and comprises that whether the absolute value of judging said grid ac voltage is less than threshold value.
7. according to claim 5 or 6 described pick-up units, it is characterized in that said zero crossing acquisition module is connected with said alternating voltage multi-point average module with said near zero-crossing point judge module respectively through digital optocoupler.
8. the pick-up unit of a grid ac voltage is characterized in that, comprises the pick-up unit of each described grid ac voltage zero crossing in the claim 5 to 7.
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| CN2010105559108A CN102478599A (en) | 2010-11-22 | 2010-11-22 | Power grid alternating voltage, and method and device for detecting zero crossing point of power grid alternating voltage |
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| CN2010105559108A CN102478599A (en) | 2010-11-22 | 2010-11-22 | Power grid alternating voltage, and method and device for detecting zero crossing point of power grid alternating voltage |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103197129A (en) * | 2013-04-10 | 2013-07-10 | 安徽节源节能科技有限公司 | Electric power signal zero crossing point detection method |
| CN104767549A (en) * | 2015-03-23 | 2015-07-08 | 瑞斯康微电子（深圳）有限公司 | Asynchronous transmission method for power line carrier communication on basis of zero-passage transmission mode |
| CN107490720A (en) * | 2017-09-21 | 2017-12-19 | 源初（广州）科技有限公司 | The Digital Detecting device and detection method of a kind of voltage zero-crossing point of power grid |
| CN112129993A (en) * | 2019-06-24 | 2020-12-25 | 天地融科技股份有限公司 | Zero crossing point signal output and power line data sending method and equipment |
| CN114814343A (en) * | 2022-04-06 | 2022-07-29 | 上海正泰智能科技有限公司 | Method for detecting zero crossing point based on dual waveform capture |
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103197129A (en) * | 2013-04-10 | 2013-07-10 | 安徽节源节能科技有限公司 | Electric power signal zero crossing point detection method |
| CN103197129B (en) * | 2013-04-10 | 2015-12-02 | 安徽节源节能科技有限公司 | Electric power signal zero-crossing examination method |
| CN104767549A (en) * | 2015-03-23 | 2015-07-08 | 瑞斯康微电子（深圳）有限公司 | Asynchronous transmission method for power line carrier communication on basis of zero-passage transmission mode |
| CN107490720A (en) * | 2017-09-21 | 2017-12-19 | 源初（广州）科技有限公司 | The Digital Detecting device and detection method of a kind of voltage zero-crossing point of power grid |
| CN112129993A (en) * | 2019-06-24 | 2020-12-25 | 天地融科技股份有限公司 | Zero crossing point signal output and power line data sending method and equipment |
| CN112129993B (en) * | 2019-06-24 | 2023-09-12 | 天地融科技股份有限公司 | Zero crossing signal output and power line data transmission method and device |
| CN114814343A (en) * | 2022-04-06 | 2022-07-29 | 上海正泰智能科技有限公司 | Method for detecting zero crossing point based on dual waveform capture |
| CN114814343B (en) * | 2022-04-06 | 2023-12-12 | 上海正泰智能科技有限公司 | Method for detecting zero crossing point based on double waveform capture |
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Application publication date: 20120530 |