Distributed photovoltaic power determination method and device

Abstract

The invention belongs to the technical field of photovoltaic parameter determination, and aims to solve the problems that a conventional measurement mode is time-consuming and labor-consuming, is often not applicable to a large number of distributed photovoltaic measurement processes, and cannot know photovoltaic fault conditions. The distributed photovoltaic power determination method comprises the following steps: setting a data acquisition interval, and acquiring distributed photovoltaic luminous point data based on a sensor; transmitting the luminous point data to a data monitoring terminal, and displaying the distributed photovoltaic power by the data monitoring terminal; the data monitoring terminal judges whether the distributed photovoltaic power value is abnormal or not based on a built-in power evaluation module; and performing warning display on the abnormal distributed photovoltaic power value at the data monitoring terminal. According to the invention, the photovoltaic power generation point data is collected by using the sensor, and the collected data is compared with the normal photovoltaic working value, so that the abnormal or fault condition of the photovoltaic power generation point is judged.

Description

Technical Field

[0001] The present invention belongs to the technical field of photovoltaic parameter determination, and in particular relates to a distributed photovoltaic power determination method and device. Background Art

[0002] Distributed photovoltaics is a power generation system that utilizes dispersed resources, has a small installed capacity, and is deployed near users. The power of distributed photovoltaics is one of the important parameters for judging whether the operation of distributed photovoltaics is normal. Therefore, it is necessary to determine the power of distributed photovoltaics according to preset time intervals to monitor the operation of distributed photovoltaics.

[0003] In the prior art, when monitoring and determining photovoltaic power, the photovoltaic components are generally measured only by directly measuring the current and voltage to determine the power; however, this measurement method is time-consuming and labor-intensive, and is often not applicable in the process of measuring a large number of distributed photovoltaics, and it is impossible to know the fault conditions of the photovoltaics. Summary of the invention

[0004] In order to solve at least one of the above technical problems existing in the prior art, the present invention provides a distributed photovoltaic power determination method and device.

[0005] The present invention is implemented by the following technical solution: a distributed photovoltaic power determination method, comprising the following steps:

[0006] S1: Set the data collection interval to collect the luminous point data of distributed photovoltaic based on the sensor; the luminous point data includes output power, current and voltage values;

[0007] S2: Transmit the above-mentioned light-emitting point data to the data monitoring terminal, and the data monitoring terminal displays the power of the distributed photovoltaic;

[0008] S3: The data monitoring terminal determines whether the power value of the distributed photovoltaic system is abnormal based on the built-in power evaluation module;

[0009] S4: The abnormal distributed photovoltaic power values ​​are displayed as a warning on the data monitoring terminal, and the power values ​​of other distributed photovoltaics are displayed normally.

[0010] Preferably, the data collection interval is 12 hours / time, and the monitoring interval is set and adjusted based on the data monitoring terminal.

[0011] Preferably, the power evaluation module compares the normal photovoltaic power value with the collected light-emitting point power value to determine whether the current distributed photovoltaic power is normal;

[0012] The calculation formula for normal photovoltaic power value is:

[0013] P=A*G*η

[0014] Where P is the power generation, A is the surface area of ​​the photovoltaic panel, G is the solar radiation intensity, and η is the efficiency of the photovoltaic cell;

[0015] The comparison formula between the normal photovoltaic power value and the collected light point power value is:

[0016] K=B1-B2

[0017] Among them, K is the compared data value, B1 is the actually collected data value, and B2 is the standard efficiency value.

[0018] Preferably, the range of K is between 1 and 30, which is an allowable error value;

[0019] If the value of K falls between 1-30, the current distributed photovoltaic power value is normal. If the value of K falls outside 1-30, it means that the current distributed photovoltaic power value is abnormal.

[0020] Preferably, abnormal distributed photovoltaic power values ​​are displayed in red on the data monitoring terminal.

[0021] Preferably, the data monitoring terminal can also predict future photovoltaic power by searching for regularities in historical luminous point data, the steps are as follows:

[0022] By calculating the mean and median of the historical luminous point data, we can understand the trend in the data, and then use the histogram to mark the data to intuitively display the distribution of the data, and find the trend line of the luminous point data by fitting the data points.

[0023] Preferably, the mean is used to describe the center position of the data set, and the calculation formula of the mean is:

[0024]

[0025] Where P0 is the mean, A1 is the data of the first group, A2 is the data of the second group, and An is the data of the nth group;

[0026] The median is used to describe the measurement of the trend of the data set. The mathematical expression of the median is: Suppose there are m numbers, X1, X2...Xm, where if m is an odd number, the median H expression is:

[0027]

[0028] Where X is an array;

[0029] If m is an even number, the expression of the median H is:

[0030]

[0031] The formula is expressed as H in the first Number and The average value of the number.

[0032] The second aspect of the present invention provides a distributed photovoltaic power determination device, including a data monitoring terminal, a power evaluation module is arranged inside the data monitoring terminal, the data monitoring terminal is provided with a network interface, a connection is established with the Internet through the network interface, and the data monitoring terminal is provided with an integrated display screen for feedback information.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The present invention collects photovoltaic power generation point data by using sensors, and compares the collected data with normal photovoltaic working values ​​to determine photovoltaic abnormalities or faults, thereby avoiding the inconvenience caused by direct measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0037] In conjunction with the drawings in the embodiments of the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0038] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so that people familiar with this technology can understand and read them. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention. It should be noted that in this specification, relational terms such as first and second are only used to distinguish one entity from several other entities, and do not necessarily require or imply any actual relationship or order between these entities.

[0039] The present invention provides an embodiment:

[0040] like Figure 1 As shown, a distributed photovoltaic power determination method includes the following steps:

[0041] S1: Set the data collection interval to collect the luminous point data of distributed photovoltaics based on sensors; the luminous point data includes output power, current and voltage values; the data collection interval is 12h / time, and the monitoring interval time is set and adjusted based on the data monitoring terminal;

[0042] S2: Transmit the above-mentioned light-emitting point data to the data monitoring terminal, and the data monitoring terminal displays the power of the distributed photovoltaic;

[0043] S3: The data monitoring terminal determines whether the power value of the distributed photovoltaic system is abnormal based on the built-in power evaluation module;

[0044] S4: The abnormal distributed photovoltaic power values ​​are displayed in red on the data monitoring terminal, and the power values ​​of other distributed photovoltaics are displayed normally.

[0045] In the present invention, the sensor includes a temperature sensor, a voltage sensor and a current sensor, wherein the temperature sensor includes one or more of a thermocouple, a thermistor, a thermal resistor and an infrared thermometer, and the temperature sensor is used to convert the temperature into an electrical signal to monitor the temperature of the photovoltaic device in real time. The current sensor includes one of a shunt, a current transformer, a Hall current sensor, a fluxgate current sensor and a magnetoresistive current sensor, and the current sensor is used for photovoltaic current detection. The voltage sensor includes one of a magnetic balance Hall voltage sensor, a magnetic modulation voltage sensor and a high-resistance isolation voltage sensor, and the voltage sensor is used for photovoltaic voltage detection.

[0046] The sensor transmits data via Ethernet, and the transmission rate calculation formula is:

[0047] R=(1 / T)*log2N

[0048] Where T is the width of the digital pulse signal, N is the effective discrete number of code elements, and R is the data transmission rate;

[0049] Ethernet is a transmission method widely used in local area networks. It uses twisted pair cables as the transmission medium and realizes data transmission between multiple devices through the CSMA / CD protocol.

[0050] The power evaluation module compares the normal photovoltaic power value with the collected light point power value to determine whether the current distributed photovoltaic power is normal;

[0051] The calculation formula for normal photovoltaic power value is:

[0052] P=A*G*η

[0053] Where P is the power generation, A is the surface area of ​​the photovoltaic panel, G is the solar radiation intensity, and η is the efficiency of the photovoltaic cell;

[0054] The comparison formula between the normal photovoltaic power value and the collected light point power value is:

[0055] K=B1-B2

[0056] Among them, K is the compared data value, B1 is the actually collected data value, and B2 is the standard efficiency value.

[0057] The range of K is between 1-30, which is the allowable error value; if the value of K falls between 1-30, the current distributed photovoltaic power value is normal; if the value of K falls outside 1-30, it means that the current distributed photovoltaic power value is abnormal.

[0058] The data monitoring terminal can also predict future photovoltaic power by finding patterns in historical luminous point data. The steps are as follows:

[0059] By calculating the mean and median of the historical luminous point data, we can understand the trend in the data, and then use the histogram to mark the data to intuitively display the distribution of the data, and find the trend line of the luminous point data by fitting the data points.

[0060] The mean is used to describe the center position of the data set. The calculation formula for the mean is:

[0061]

[0062] Where P0 is the mean, A1 is the data of the first group, A2 is the data of the second group, and An is the data of the nth group;

[0063] The median is used to describe the measurement of the trend of the data set. The mathematical expression of the median is: Suppose there are m numbers, X1, X2...Xm, where if m is an odd number, the median H expression is:

[0064]

[0065] Where X is an array;

[0066] If m is an even number, the expression of the median H is:

[0067]

[0068] The formula is expressed as H in the first Number and The average value of the number.

[0069] The second aspect of the present invention provides a distributed photovoltaic power determination device, including a data monitoring terminal, a power evaluation module is provided inside the data monitoring terminal, a network interface is provided in the data monitoring terminal, and a connection is established with the Internet through the network interface. The data monitoring terminal is provided with a comprehensive display screen for feedback information. The comprehensive display screen is used to display the photovoltaic status, the inverter status and the comprehensive status, wherein the comprehensive status includes the number of photovoltaic power stations, the power generated, and the income of the power generation, which are displayed in the form of a bar graph; the photovoltaic status includes the photovoltaic temperature value, and the inverter status includes displaying the parameter status of the inverter.

[0070] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A distributed photovoltaic power determination method, characterized in that: The following steps are involved: S1: Set the data collection interval to collect the luminous point data of distributed photovoltaics based on sensors; the luminous point data includes output power, current and voltage values; S2: Transmit the above-mentioned light-emitting point data to the data monitoring terminal, and the data monitoring terminal displays the power of the distributed photovoltaic; S3: The data monitoring terminal determines whether the power value of the distributed photovoltaic system is abnormal based on the built-in power evaluation module; S4: The abnormal distributed photovoltaic power values ​​are displayed as a warning on the data monitoring terminal, and the power values ​​of other distributed photovoltaics are displayed normally.

2. A distributed photovoltaic power determination method according to claim 1, characterized in that: The data collection interval is 12 hours / time, and the monitoring interval is set and adjusted based on the data monitoring terminal.

3. A distributed photovoltaic power determination method according to claim 1, characterized in that: The power evaluation module compares the normal photovoltaic power value with the collected light point power value to determine whether the current distributed photovoltaic power is normal; The calculation formula for normal photovoltaic power value is: P=A*G*η Where P is the power generation, A is the surface area of ​​the photovoltaic panel, G is the solar radiation intensity, and η is the efficiency of the photovoltaic cell; The comparison formula between the normal photovoltaic power value and the collected light point power value is: K=B1-B2 Among them, K is the compared data value, B1 is the actually collected data value, and B2 is the standard efficiency value.

4. A distributed photovoltaic power determination method according to claim 3, characterized in that: The range of K is between 1-30, which is the allowable error value; If the value of K falls between 1-30, the current distributed photovoltaic power value is normal. If the value of K falls outside 1-30, it means that the current distributed photovoltaic power value is abnormal.

5. A distributed photovoltaic power determination method according to claim 1, characterized in that: Abnormal distributed photovoltaic power values ​​will be displayed in red on the data monitoring terminal.

6. A distributed photovoltaic power determination method according to claim 1, characterized in that: The data monitoring terminal can also predict future photovoltaic power by finding patterns in historical luminous point data. The steps are as follows: By calculating the mean and median of the historical luminous point data, we can understand the trend in the data, and then use the histogram to mark the data to intuitively display the distribution of the data, and find the trend line of the luminous point data by fitting the data points.

7. A distributed photovoltaic power determination method according to claim 6, characterized in that: The mean is used to describe the center position of the data set. The calculation formula for the mean is: Where P0 is the mean, A1 is the data of the first group, A2 is the data of the second group, and An is the data of the nth group; The median is used to describe the measurement of the trend of the data set. The mathematical expression of the median is: Suppose there are m numbers, X1, X2...Xm, where if m is an odd number, the median H expression is: Where X is an array; If m is an even number, the expression of the median H is: The formula is expressed as H in the first Number and The average value of the number.

8. A distributed photovoltaic power determination device, used to implement the distributed photovoltaic power determination method according to any one of claims 1 to 7, characterized in that: It includes a data monitoring terminal, which has a power evaluation module inside, a network interface through which a connection with the Internet is established, and a comprehensive display screen for feeding back information.

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