A power regulation method and system for photovoltaic power plants

Abstract

The present invention discloses a power control method and system for a photovoltaic power station, which belongs to the field of photovoltaic power generation technology, including step one, setting an expected output power interval for each time period of the photovoltaic power station according to the predicted weather conditions obtained by the meteorological bureau; step two, obtaining relevant parameter information of the photovoltaic power station in real time, and processing and analyzing to obtain the actual output power of the photovoltaic power station; step three, comparing the actual output power obtained with the set expected output power interval, and when the actual output power is not in the expected output power interval, generating an adjustment instruction to adjust the output power. The present invention can judge whether there is a risk of failure in the photovoltaic power station according to the actual output power situation obtained, and once it is judged that there is a risk of failure, a reminder signal can be generated in time to remind the management personnel to check and process the photovoltaic power station accordingly, thereby timely reducing the loss of the photovoltaic power station.

Description

Technical Field

[0001] The present invention belongs to the technical field of photovoltaic power generation, and in particular relates to a power control method and system for a photovoltaic power station. Background Art

[0002] Photovoltaic power station refers to a photovoltaic power generation system that uses solar energy and special materials such as crystalline silicon panels, inverters and other electronic components to connect to the power grid and transmit electricity to the grid. When a photovoltaic power station is connected to the power grid, it needs to follow the operating rules of the power grid to ensure the stable operation of the power grid, so it is necessary to adjust the photovoltaic output power.

[0003] When adjusting the output power of a photovoltaic power station, it is generally adjusted according to the electricity consumption in different seasons and time periods. For example, the power grid dispatching center in a certain area requires reducing the power output between 14:00 and 17:00 every day during a certain period of time. This method is mostly a fixed adjustment. Since the photovoltaic power station is affected by environmental factors, the power generated every day is different, and it is affected by the daily electricity load, its output power will also change. If it is adjusted on a fixed basis, it is easy to cause unstable operation of the power grid. Summary of the invention

[0004] The purpose of the present invention is to provide a power control method and system for a photovoltaic power station, so as to solve the problems faced in the above-mentioned background technology.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A power control method for a photovoltaic power station, the control method comprising:

[0007] Step 1: According to the forecast weather conditions obtained by the Meteorological Bureau, set the expected output power range for each time period of the photovoltaic power station;

[0008] Step 2: Obtain relevant parameter information of the photovoltaic power station in real time, and process and analyze it to obtain the actual output power of the photovoltaic power station;

[0009] Step 3: Compare the actual output power obtained with the set expected output power range. When the actual output power is not within the expected output power range, generate an adjustment instruction to adjust the output power.

[0010] Furthermore, the predicted weather conditions include predicted light intensity, temperature and cloud coverage, and the related parameter information includes acquired real-time light intensity and temperature.

[0011] Furthermore, the method for setting the expected output power range for each time period of the photovoltaic power station in step 1 is:

[0012] According to the weather forecast information of the Meteorological Bureau on the second day, obtain the light intensity of each time period ,temperature and cloud cover fraction C;

[0013] At the same time, find the historical output power of the time period closest to the current light intensity, temperature and cloud coverage from the historical database ;

[0014] By formula Get the expected output power for the current time period ;

[0015] So according to the expected output power Define the expected output power range: ;

[0016] in, as well as is the preset scaling factor, and , To set the optimal working temperature of the photovoltaic panel, is the duration of the current time period, is the power conversion coefficient, as well as is the estimated output power threshold defined, and .

[0017] Furthermore, the method for obtaining the actual output power in step 2 is:

[0018] Divide the time period into N control intervals and obtain the light intensity of each control interval and temperature , so as to formulate the light intensity change curve of each control interval over time And the temperature change curve over time ;

[0019] By formula The actual output power of the control range is obtained ;

[0020] in, is the start time of the control interval, is the end time of the control interval, is the power intensity coefficient, is the power temperature coefficient, is the temperature power coefficient of the photovoltaic power station equipment, It is the standard temperature variation curve of the preset photovoltaic power station equipment during operation.

[0021] Further, the adjustment instruction includes an adjustment-up instruction and a adjustment-down instruction;

[0022] when When , a lowering instruction is generated;

[0023] when When , a height adjustment instruction is generated.

[0024] Furthermore, the method for adjusting the output power according to the generated adjustment instruction in step three is:

[0025] Obtain the load demand Q required for the current control interval and the average historical load demand in the same control interval ;

[0026] When generating a reduction command, the output power range set by the photovoltaic power station is adjusted to ;

[0027] When the increase command is generated, the output power range set by the photovoltaic power station is adjusted to ;

[0028] in, is the preset load demand reference value, It is the power conversion factor of the preset load demand.

[0029] A power control system for a photovoltaic power station, the system is executed by a power control method for a photovoltaic power station, the system comprising:

[0030] A prediction module, which is used to set the expected output power range for each time period of the photovoltaic power station according to the predicted weather conditions obtained by the meteorological bureau;

[0031] A data acquisition module, which is used to obtain relevant parameter information of the photovoltaic power station when it is working;

[0032] A data analysis module, the data analysis module is used to process and analyze the acquired relevant parameter information, generate the actual output power, and compare the acquired actual output power with the set expected output power range to determine whether to generate an adjustment instruction;

[0033] An execution module is used to adjust the output power according to the generated adjustment instruction.

[0034] Furthermore, the data analysis module is also provided with an early warning unit, which is used to determine whether there is a failure risk in the photovoltaic power station according to the actual output power obtained, and the determination method is:

[0035] Get the actual output power obtained in each control interval , ;

[0036] By formula The first stability coefficient ;

[0037] The first stability factor will be obtained The preset first stability coefficient threshold Make a comparison;

[0038] when When , it is considered that there is a risk of failure and an alarm signal is generated;

[0039] At the same time, when it is considered that there is no risk of failure, the average output power of each time period is obtained , so that through the formula Get the difference value of each time period ;

[0040] So through the formula The second stability factor ;

[0041] The second stability factor will be obtained The second stability coefficient threshold value is preset Make a comparison;

[0042] when When , it is considered that there is a risk of failure and an alarm signal is generated;

[0043] in, is the number of time periods to be set. is the gap value of the jth time period, and .

[0044] Beneficial effects of the present invention:

[0045] The present invention first predicts the expected output power of the photovoltaic power station in each time period of the next day according to the predicted weather conditions obtained by the meteorological bureau, so as to define the set expected output power range, so that the output power of each time period can be more accurately and dynamically predicted according to the predicted weather conditions, reducing the subsequent adjustment of the output power; at the same time, the relevant parameter information of the photovoltaic power station when it is working is obtained in real time to process and analyze, and the actual output power of the photovoltaic power station is obtained, so as to compare it with the set expected output power range to determine whether the set output power is reasonable. When it is unreasonable, an adjustment instruction is generated to adjust the output power according to the size of the actual output power and the amount of power load, so that the output power can be accurately adjusted to ensure the stability of the power grid.

[0046] The present invention can determine whether there is a failure risk in the photovoltaic power station based on the actual output power situation obtained. Once it is determined that there is a failure risk, a reminder signal can be generated in time to remind management personnel to conduct corresponding inspections and processing on the photovoltaic power station, thereby timely reducing the losses of the photovoltaic power station.

[0047] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0049] Figure 1 is a flow chart of the method of the present invention;

[0050] Figure 2 It is a system block diagram of the present invention. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] In one embodiment, a power control method for a photovoltaic power station is disclosed. Figure 1 As shown, the control method comprises:

[0053] Step 1: Set the expected output power range for each time period of the photovoltaic power station according to the predicted weather conditions obtained from the Meteorological Bureau. The predicted weather conditions include the predicted light intensity, temperature and cloud coverage;

[0054] Step 2: Real-time acquisition of relevant parameter information of the photovoltaic power station, and processing and analysis to obtain the actual output power of the photovoltaic power station. The relevant parameter information includes the real-time light intensity, temperature and other information;

[0055] Step 3: Compare the actual output power obtained with the set expected output power range. When the actual output power is not within the expected output power range, generate an adjustment instruction to adjust the output power.

[0056] Through the above technical scheme, the present application first predicts the expected output power of the photovoltaic power station in each time period of the next day according to the predicted weather conditions obtained by the Meteorological Bureau, including the predicted light intensity, temperature and cloud coverage, so as to define the set expected output power range. In this way, the output power of each time period can be more accurately predicted according to the predicted weather conditions, reducing the subsequent adjustment of the output power; at the same time, the relevant parameter information of the photovoltaic power station is obtained in real time during operation to process and analyze, and the actual output power of the photovoltaic power station is obtained, which is then compared with the set expected output power range to determine whether the set output power is reasonable. When it is unreasonable, an adjustment instruction is generated to adjust the output power according to the actual output power and the amount of power load. In this way, the output power can be accurately adjusted to ensure the stability of the power grid.

[0057] In one embodiment, the method for setting the expected output power interval for each time period of the photovoltaic power station in step 1 is:

[0058] According to the weather forecast information of the Meteorological Bureau on the second day, obtain the light intensity of each time period ,temperature and cloud cover fraction C;

[0059] At the same time, find the historical output power of the time period closest to the current light intensity, temperature and cloud coverage from the historical database ;

[0060] By formula Get the expected output power for the current time period ;

[0061] So according to the expected output power Define the expected output power range: ;

[0062] in, as well as is the preset scaling factor, and , To set the optimal working temperature of the photovoltaic panel, is the duration of the current time period, is the power conversion coefficient, as well as is the estimated output power threshold defined, and .

[0063] Through the above technical solution, this embodiment provides a specific method for defining the expected output power range for each time period. Since each adjustment of the output power is likely to cause grid fluctuations, which may easily cause grid instability, in order to more accurately set the output power of each time period, the light intensity of each time period is obtained according to the weather forecast information of the next day from the Meteorological Bureau. ,temperature and cloud coverage C, and find the historical output power of the time period closest to the current light intensity, temperature and cloud coverage from the historical database , through the formula Get the expected output power for the current time period In general, the higher the light radiation intensity and the less cloud coverage, the more electricity the photovoltaic panels generate, so the expected output power is also higher. Photovoltaic panels need to work at a suitable temperature. When the temperature is too high or too low, it will affect the work of the photovoltaic panels. Therefore, the formula The predicted output power is obtained. From the formula, it can be seen that when The smaller the value of and C value, or The larger the value, the more output power it generates. In order to make the estimated output power more accurate, find the historical output power of the time period closest to the current light intensity, temperature and cloud coverage from the historical database. , so that through the formula Combine historical data for comprehensive analysis to accurately determine the expected output power for the current time period Since the time period has a certain span, the output power will change during the period. Therefore, according to the estimated output power Define the expected output power range: ,and , so that the output power of the photovoltaic power station can be predicted more accurately.

[0064] In the above technical solution, the preset proportionality coefficient as well as , set the optimal working temperature of photovoltaic panels , power conversion coefficient , the estimated output power threshold as well as Both can be determined based on historical data combined with empirical data, and the duration of the current time period It can be determined artificially according to the actual situation, so I will not elaborate on it here.

[0065] As an implementation mode of the present invention, the method for obtaining the actual output power in step 2 is:

[0066] Divide the time period into N control intervals and obtain the light intensity of each control interval and temperature , so as to formulate the light intensity change curve of each control interval over time And the temperature change curve over time ;

[0067] By formula The actual output power of the control range is obtained ;

[0068] in, is the start time of the control interval, is the end time of the control interval, is the power intensity coefficient, is the power temperature coefficient, is the temperature power coefficient of the photovoltaic power station equipment, It is the standard temperature variation curve of the preset photovoltaic power station equipment during operation.

[0069] Through the above technical solution, this embodiment provides a method for obtaining the actual output power. Due to the influence of environmental factors, the actual output power may be different from the expected output power. Therefore, in order to more accurately obtain the output power, this embodiment divides the time period into N control intervals and obtains the light intensity of each control interval. and temperature , so as to formulate the light intensity change curve of each control interval over time And the temperature change curve over time , and then through the formula The actual output power of the control range is obtained ,formula It is expressed as the power generated by the light intensity. The formula is It is expressed as the power generated by the temperature. Generally speaking, the higher the temperature, the smaller the power generated. It indicates the amount of power consumed by the photovoltaic power station equipment when it is working. Because of the influence of temperature, the power consumed by the equipment is also different. For example, the higher the temperature, the higher the heat dissipation efficiency of the equipment is required to maintain normal operation, so the more power it consumes; so through the formula A comprehensive analysis of light intensity, temperature, and device temperature changes can more accurately determine the actual output power in the control range. , which facilitates the subsequent precise adjustment of power.

[0070] In the above technical solution, the duration of the control interval can be determined manually according to the actual situation, and the power intensity coefficient , the power temperature coefficient is , Temperature power coefficient of photovoltaic power station equipment And the preset standard temperature change curve of photovoltaic power station equipment during operation over time All of them can be determined based on historical data and empirical data, so I will not elaborate on them here.

[0071] As an implementation mode of the present invention, the adjustment instruction includes an adjustment-up instruction and an adjustment-down instruction;

[0072] when When , a lowering instruction is generated;

[0073] when When , a height adjustment instruction is generated.

[0074] The method for adjusting the output power according to the generated adjustment instruction in step 3 is:

[0075] Obtain the load demand Q required for the current control interval and the average historical load demand in the same control interval ;

[0076] When generating a reduction command, the output power range set by the photovoltaic power station is adjusted to ;

[0077] When the increase command is generated, the output power range set by the photovoltaic power station is adjusted to ;

[0078] in, is the preset load demand reference value, It is the power conversion factor of the preset load demand.

[0079] Through the above technical solution, this embodiment provides a specific method for adjusting the output power according to the generated adjustment instruction, and obtaining the actual output power After that, the expected output power range For comparison, when When , it means that the actual output power generated at this time is low, and the set expected output power range is too high. In order to ensure the normal operation of the subsequent power grid, the output power of the photovoltaic power station needs to be lowered; similarly, when When the actual output power generated at this time is high, the set expected output power range is low. In this case, the output power of the photovoltaic power station can be increased. The specific increase method is: when generating a downward adjustment instruction, adjust the output power range set by the photovoltaic power station to ; When the increase command is generated, the output power range set by the photovoltaic power station is adjusted to ; Since the actual output power defaults to the maximum power, the increased or decreased power cannot exceed the actual output power. The increased or decreased output power is also related to the required load charge, that is, the load demand. Therefore, the load demand Q required in the current control interval and the historical load demand average in the same control interval are obtained. The average value of historical load demand in the same control interval can be obtained by averaging the load demand of n same control intervals. Specifically, it is obtained by formula It can be seen from the formula that when the load demand is greater, more output power is needed, so the adjustable output power is less. In this way, the unqualified output power can be adjusted according to the actual output power and the amount of power load. In this way, the output power can be adjusted accurately to ensure the stability of the power grid.

[0080] In the above technical solution, the preset load demand reference value And the power conversion factor of the preset load demand All of them can be determined based on empirical data and historical data, so I will not elaborate on them here.

[0081] In one embodiment, a power control system for a photovoltaic power station is disclosed. The control system is executed by the above-mentioned power control method for a photovoltaic power station. Figure 2 As shown, the regulatory system includes:

[0082] The prediction module is used to set the expected output power range for each time period of the photovoltaic power station according to the predicted weather conditions obtained by the meteorological bureau;

[0083] A data acquisition module is used to obtain relevant parameter information of the photovoltaic power station during operation;

[0084] The data analysis module is used to process and analyze the acquired relevant parameter information, generate the actual output power, and compare the acquired actual output power with the set expected output power range to determine whether to generate an adjustment instruction;

[0085] An execution module, wherein the execution module adjusts the output power according to the generated adjustment instruction;

[0086] The data analysis module is also provided with an early warning unit, which is used to determine whether there is a risk of failure in the photovoltaic power station according to the actual output power obtained. The determination method is:

[0087] Get the actual output power obtained in each control interval , ;

[0088] By formula The first stability coefficient ;

[0089] The first stability factor will be obtained The preset first stability coefficient threshold Make a comparison;

[0090] when When , it is considered that there is a risk of failure and an alarm signal is generated;

[0091] At the same time, when it is considered that there is no risk of failure, the average output power of each time period is obtained , so that through the formula Get the difference value of each time period ;

[0092] So through the formula The second stability factor ;

[0093] The second stability factor will be obtained The second stability coefficient threshold value is preset Make a comparison;

[0094] when When , it is considered that there is a risk of failure and an alarm signal is generated;

[0095] in, is the number of time periods to be set. is the gap value of the jth time period, and .

[0096] Through the above technical scheme, this embodiment provides a power control system for a photovoltaic power station. First, the prediction module is used to set an expected output power range for each time period of the photovoltaic power station according to the predicted weather conditions obtained by the Meteorological Bureau. Then, the data acquisition module is used to obtain relevant parameter information of the photovoltaic power station when it is working. After processing and analysis by the data analysis module, the actual output power is generated, and the actual output power obtained is compared with the set expected output power range to determine whether to generate an adjustment instruction. Finally, the output power is adjusted according to the generated adjustment instruction through the execution module. The data analysis module is also provided with an early warning unit. The early warning unit determines whether there is a risk of failure in the photovoltaic power station according to the actual output power obtained, thereby giving an alarm in time to reduce the loss of the power grid. Specifically, a single time period is analyzed first to obtain the actual output power obtained in each control interval. , through the formula The first stability coefficient Since the time span of each control interval is small, the actual output power generated will not fluctuate too much, so the formula The first stability coefficient , it can be seen that when its value is larger, it can indicate that the gap between the actual output powers of each control interval is larger, indicating that the actual output power is more unstable, indicating that the risk of failure may be greater. Therefore, the first stability coefficient is obtained. The preset first stability coefficient threshold To compare; when When it is considered that there is a risk of failure, an alarm signal is generated to remind the management personnel to carry out maintenance. At the same time, when it is considered that there is no risk of failure, the average output power of each time period is obtained. , so that through the formula Get the difference value of each time period , so that through the formula The second stability factor , since the output power is expected to The average output power in each time period There is generally not a large gap between them. If the gap is large, it indicates that the risk of failure is greater. Therefore, the formula Get the difference value of each time period , then in the formula The second stability factor , when the value of the second stability coefficient is larger, it means that the risk of failure of the photovoltaic power station is greater, so the second stability coefficient The second stability coefficient threshold value is preset For comparison, when In this way, it is possible to determine whether a photovoltaic power station has a risk of failure based on the actual output power obtained. Once it is determined that there is a risk of failure, a reminder signal can be generated in time to remind management personnel to check and handle the photovoltaic power station accordingly, thereby reducing the loss of the photovoltaic power station in a timely manner.

[0097] In the above technical solution, the preset first stability coefficient threshold And the second stability coefficient threshold All can be determined based on empirical data.

[0098] It should be noted that the calculation formulas and various parameters involved in the calculations in the present invention have been dimensionally processed in advance, and the process of dimensionless processing is well known in the industry and will not be described here.

[0099] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A power control method for a photovoltaic power station, characterized in that: The control method comprises: Step 1: setting an expected output power range for each time period of the photovoltaic power station according to the predicted weather conditions obtained by the Meteorological Bureau, wherein the predicted weather conditions include predicted light intensity, temperature and cloud coverage; Step 2: Real-time acquisition of relevant parameter information of the photovoltaic power station, and processing and analysis to obtain the actual output power of the photovoltaic power station, wherein the relevant parameter information includes the acquired real-time light intensity and temperature; Step 3: Compare the actual output power obtained with the set expected output power range. When the actual output power is not within the expected output power range, generate an adjustment instruction to adjust the output power; The method for setting the expected output power range for each time period of the photovoltaic power station in step 1 is: according to the weather forecast information of the meteorological bureau on the second day, obtain the light intensity Lx of each time period f , Temperature T f and cloud cover fraction C; At the same time, find the historical output power P of the time period closest to the current light intensity, temperature and cloud coverage from the historical database hist ; By formula Get the expected output power P for the current time period fcst ; Therefore, according to the expected output power P fcst Define the expected output power range: Wherein, τ1 and τ2 are preset proportional coefficients, and τ1+τ2=1, T th is the optimal working temperature of the photovoltaic panel, tm is the duration of the current time period, R is the power conversion coefficient, as well as is the estimated output power threshold defined, and The method for obtaining the actual output power in step 2 is: dividing the time period into N control intervals, obtaining the light intensity Lx and the temperature T of each control interval, and thus formulating the light intensity versus time curve Lx(t) and the temperature versus time curve T(t) of each control interval; By formula The actual output power P in this control range is obtained act ; Wherein, t1 is the start time of the control interval, t2 is the end time of the control interval, α is the power intensity coefficient, β is the power temperature coefficient, γ is the temperature power coefficient of the photovoltaic power station equipment, and T0(t) is the standard temperature change curve of the preset photovoltaic power station equipment during operation over time; The method for adjusting the output power according to the generated adjustment instruction in step 3 is: the adjustment instruction includes an increase instruction and a decrease instruction. When the command is generated, the lowering instruction is generated. When , a height adjustment instruction is generated; Obtain the load demand Q required for the current control interval and the average historical load demand in the same control interval When generating a reduction command, the expected output power range set by the photovoltaic power station is adjusted to When the increase command is generated, the expected output power range set by the photovoltaic power station is adjusted to Wherein, Q0 is a preset load demand reference value, and W is a preset load demand power conversion coefficient.

2. A power control system for a photovoltaic power station, characterized in that: The system is implemented by the power control method for a photovoltaic power station according to claim 1, and the system comprises: A prediction module, which is used to set the expected output power range for each time period of the photovoltaic power station according to the predicted weather conditions obtained by the meteorological bureau; A data acquisition module, which is used to obtain relevant parameter information of the photovoltaic power station when it is working; A data analysis module, the data analysis module is used to process and analyze the acquired relevant parameter information, generate the actual output power, and compare the acquired actual output power with the set expected output power range to determine whether to generate an adjustment instruction; An execution module is used to adjust the output power according to the generated adjustment instruction.

3. A power control system for a photovoltaic power station according to claim 2, characterized in that: The data analysis module is also provided with an early warning unit, which determines whether the photovoltaic power station has a risk of failure according to the actual output power obtained. The method by which the early warning unit determines whether the photovoltaic power station has a risk of failure according to the actual output power obtained is: Get the actual output power obtained in each control interval By formula The first stability coefficient K is obtained; The obtained first stability coefficient K is compared with the preset first stability coefficient threshold K th Make a comparison; When K>K th When , it is considered that there is a risk of failure and an alarm signal is generated; At the same time, when it is considered that there is no risk of failure, the average output power of each time period is obtained Thus, through the formula B = |P fcst -P V |Get the gap value B for each time period; So through the formula The second stability coefficient Z is obtained; The obtained second stability coefficient Z is compared with the preset second stability coefficient threshold Z th Make a comparison; When Z>Z th When , it is considered that there is a risk of failure and an alarm signal is generated; Among them, M is the number of time periods set, B j is the gap value of the jth time period, and j∈[1,M].

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