A method for optimizing and reforming existing photovoltaic flat single-axis tracking system

Abstract

The application provides an optimization modification method for existing photovoltaic flat single-axis tracking systems, belongs to the technical field of photovoltaic power generation, and modifies the time of a flat single-axis photovoltaic tracking driving device by using different advance / lag time strategies, so that the flat single-axis photovoltaic tracking driving device outputs different tracking angles, obtains the output power data of photovoltaic modules under the control of the flat single-axis photovoltaic tracking driving device under different advance / lag strategies, compares the output power of the photovoltaic modules under the control of the flat single-axis photovoltaic tracking driving device with the standard time, obtains the optimal advance / lag time optimization strategy of the flat single-axis photovoltaic tracking driving device at each time point, sets the advance / lag time of the flat single-axis photovoltaic tracking driving device through the optimization strategy, adjusts the output inclination angle of the flat single-axis photovoltaic tracking driving device, so that the photovoltaic modules under the control of the flat single-axis photovoltaic tracking driving device all reach the maximum power generation at each time point, thereby improving the power generation of the photovoltaic power generation modules, and finally improving the power generation of the entire photovoltaic system.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of photovoltaic power generation, and relates to a photovoltaic flat single-axis tracking system, in particular to an optimization and reconstruction method for an existing photovoltaic flat single-axis tracking system. BACKGROUND

[0002] In a photovoltaic power station using a tracking system, photovoltaic power generation components can be driven by the tracking system to face the sun at a suitable angle and improve power generation. The main tracking algorithm used in the current photovoltaic tracking system is still the angle calculated by the traditional astronomical algorithm for solar tracking. Solar tracking is to calculate the solar elevation angle and the solar azimuth angle according to the geographical positioning information and the time of the tracking system, and then obtain the projection of the solar radiation in the vertical plane to the axis, so as to obtain the tracking angle. After the tracking system obtains the tracking angle, the driving device controls the photovoltaic power generation components to turn to the tracking angle, so as to obtain the best power generation output power. The photovoltaic components and the inclination sensor are installed on the rotating shaft connected with the tracking system driving device, and the actual tracking angle is fed back to the tracking system by the angle sensor. However, the following problems exist in actual application:

[0003] · Defects and calculation errors in the implementation of the astronomical algorithm of the tracking system;

[0004] · During the installation process and the later operation and maintenance process, the inclination sensor cannot correctly provide the tracking angle of the photovoltaic power generation components, and errors occur.

[0005] The above problems will cause the photovoltaic power generation components to not operate at the best tracking angle for power generation, resulting in a decrease in power generation, and ultimately affecting the overall power generation.

[0006] Therefore, only the astronomical algorithm cannot guarantee that the tracking system can provide accurate tracking angles for a long time to enable the photovoltaic power generation components to obtain the maximum solar radiation. Therefore, it is necessary to make improvements. SUMMARY

[0007] The technical problem solved by the present application is to provide an optimization and reconstruction method for an existing photovoltaic flat single-axis tracking system. The present application is an optimization and reconstruction method for an existing photovoltaic tracking system. Without changing the tracking algorithm of the existing tracking system, the output tracking angle of the tracking system is optimized to be optimal, thereby improving the power generation of the photovoltaic power generation components, and ultimately improving the overall power generation of the photovoltaic system.

[0008] The technical solution adopted by the present application is an optimization and reconstruction method for an existing photovoltaic flat single-axis tracking system, which comprises the following steps:

[0009] A: Strategy optimization: modify the time of the flat single-axis photovoltaic tracking drive device with different lead / lag time strategies, so that the flat single-axis photovoltaic tracking drive outputs different tracking angles, obtains the output power data of the photovoltaic module under the jurisdiction of the flat single-axis photovoltaic tracking drive device under different lead / lag strategies, and compares the output power of the photovoltaic module under the jurisdiction of the flat single-axis photovoltaic tracking drive device with the standard time, to obtain the optimal lead / lag time optimization strategy of the flat single-axis photovoltaic tracking drive at each time point.

[0010] B, Strategy execution: set the lead / lag time of the flat single-axis photovoltaic tracking drive device through the optimization strategy obtained in A, adjust the output inclination angle of the flat single-axis photovoltaic tracking drive device, so that the photovoltaic module under the jurisdiction of the flat single-axis photovoltaic tracking drive device reaches the maximum power generation at each time point.

[0011] As an optional implementation, in the above A, the specific implementation method of strategy optimization is:

[0012] Record the minimum action time interval Δt of the flat single-axis photovoltaic tracking drive device;

[0013] Take the flat single-axis photovoltaic tracking drive device as the statistical object, and statistically obtain the power generation data X of the unit installed capacity and the average value X of X in the photovoltaic production data aver And the standard deviation X stdev ;

[0014] Take 2n+1 flat single-axis photovoltaic tracking drive devices whose power generation data X falls within the interval [X aver -X stdev , X aver +X stdev ] as experimental objects, and label them as Q1~Q 2n+1 , respectively, where n≥3;

[0015] Among the selected 2n+1 objects, take n flat single-axis photovoltaic tracking drive devices to adopt the lead tracking strategy, that is, adjust the time of Q1 device forward by Δt, adjust the time of Q2 device forward by 2Δt, and so on, and finally adjust the time of Q n device backward by nΔt;

[0016] Among the remaining n+1 objects, take n flat single-axis photovoltaic tracking drive devices to adopt the lag tracking strategy, that is, adjust the time of Q n+1 device backward by Δt, adjust the time of Q n+2 device backward by 2Δt, and so on, and finally adjust the time of Q 2n device backward by nΔt;

[0017] Q 2n+1 device adopts the standard time and does not need to be changed;

[0018] Record the real-time power of the photovoltaic power generation assembly under the jurisdiction of the selected 2n+1 flat single-axis photovoltaic tracking drive devices in days as the interval, Δt;

[0019] Draw the Q x(1≤x≤2n+1) of the flat single-axis photovoltaic tracking drive device on the same time / power coordinate axis, respectively, and draw the power curve L of the photovoltaic power generation assembly under the jurisdiction of the flat single-axis photovoltaic tracking drive device, and the maximum power curve L at each recording time point max ;

[0020] and record the curve L max of each point corresponding to the lead-lag strategy of the flat single-axis photovoltaic tracking drive device Q, draw the optimized execution strategy graph S;

[0021] According to the strategy graph S, the time points of frequent lead / lag conversion are gently optimized to avoid frequent adjustment of the lead-lag time of the flat single-axis photovoltaic tracking drive, and an optimized strategy graph S1 is formed;

[0022] According to S1, a single-day execution strategy k is generated, and the single-day execution strategy k contains execution time K t , and lead / lag time strategy S t ;

[0023] Repeat the above steps to generate an annual execution strategy K.

[0024] As an optional implementation, in the above B, during the execution of the strategy, since the change of the solar elevation angle in the sun tracking process presents seasonality and continuity in a year, and the change of the solar azimuth angle only repeats in a day, the single-day execution strategy k also presents seasonality and continuity in a year, therefore, the single-day execution strategy k closest to the execution day can be selected as the execution strategy on the day when the single-day execution strategy k is not generated.

[0025] In the execution strategy, the single-day execution strategy k closest to the execution day is selected as the basis for strategy execution, and the execution time K t of the flat single-axis photovoltaic tracking drive device in k is adjusted according to the execution time K t .

[0026] Compared with the prior art, the present application has the following advantages:

[0027] 1. The scheme modifies the time of the flat single-axis photovoltaic tracking drive device with different advance / lag time strategies, so that the flat single-axis photovoltaic tracking drive outputs different tracking angles, obtains the output power data of the photovoltaic module under the jurisdiction of the flat single-axis photovoltaic tracking drive device under different advance / lag strategies, and compares the output power of the photovoltaic module under the jurisdiction of the flat single-axis photovoltaic tracking drive device with the standard time, obtains the optimal advance / lag time optimization strategy of the flat single-axis photovoltaic tracking drive at each time point, sets the advance / lag time of the flat single-axis photovoltaic tracking drive device through the optimization strategy, adjusts the output inclination angle of the flat single-axis photovoltaic tracking drive device, so that the photovoltaic module under the jurisdiction of the flat single-axis photovoltaic tracking drive device reaches the maximum power generation at each time point. This method optimizes the tracking angle output by the tracking system without changing the existing tracking algorithm, so as to improve the power generation of the photovoltaic power generation component, and finally improve the power generation of the entire photovoltaic system;

[0028] 2. The scheme is a technology for obtaining optimal system power generation with relatively small modification cost, has wide application range, high generalizability, and broad application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is the power generation curve L of the standard tracking mode in the embodiment of the application and the curve of the maximum power generation L max ;

[0030] Figure 2 is the advance / lag strategy diagram corresponding to the maximum power generation in the embodiment of the application;

[0031] Figure 3 is a real-time flow chart of the photovoltaic flat single-axis tracking system optimization modification disclosed in the embodiment of the application. DETAILED DESCRIPTION

[0032] To make the purpose, technical scheme and advantages of the application clearer and more apparent, the following will be combined with specific embodiments and refer to the accompanying drawings Figures 1-3 for further detailed description of the application.

[0033] To achieve the above-mentioned purpose, the embodiment of the application provides an optimization modification method for the existing photovoltaic flat single-axis tracking system, which takes the technical modification of the photovoltaic power plant area adopting the flat single-axis tracking system as an example. The specific implementation method is shown in Figure 3 .

[0034] Record the minimum action time interval Δt of the flat single-axis photovoltaic tracking drive device, and the minimum action time interval Δt of the flat single-axis photovoltaic tracking drive device is 5 minutes;

[0035] Taking the flat single-axis photovoltaic tracking drive device as the statistical object, the power generation data X of the unit installed capacity in the photovoltaic production data and the average value X aver = 300 kWh, the standard deviation X stdev = 11.3;

[0036] Taking 7 flat single-axis photovoltaic tracking drive devices whose power generation data X falls in the interval [X aver -X stdev , X aver + X stdev ] as experimental objects, and marking Q1-Q7;

[0037] Among the selected 7 objects, 3 flat single-axis photovoltaic tracking drive devices adopt the advanced tracking strategy, that is, the time of Q1 device is adjusted forward by Δt, the time of Q2 device is adjusted forward by 2Δt, and the time of Q3 device is adjusted forward by 3Δt;

[0038] Among the remaining 4 objects, 3 flat single-axis photovoltaic tracking drive devices adopt the lag tracking strategy, that is, the time of Q4 device is adjusted backward by Δt, the time of Q5 device is adjusted backward by 2Δt, and the time of Q6 device is adjusted backward by 3Δt;

[0039] The Q7 device adopts the standard time and is not changed;

[0040] Taking March 27 as an example, the real-time power generation of the photovoltaic power generation components under the jurisdiction of the selected 7 flat single-axis photovoltaic tracking drive devices is recorded at intervals of 5 minutes;

[0041] On the time / power coordinate axis, the maximum power generation at each recording time point is plotted as a curve L max , see Figure 1 ;

[0042] The points on the curve L max correspond to the advanced / lag strategy of the flat single-axis photovoltaic tracking drive device Q, and an optimized execution strategy graph S is plotted, see Figure 2 ;

[0043] According to the strategy graph S, the time points where the advanced / lag conversion frequently occurs are gently optimized to avoid the frequent adjustment of the advanced / lag time of the flat single-axis photovoltaic tracking drive, and an optimized strategy graph S1 is formed;

[0044] Based on S1, a single-day execution strategy k of March 27 is generated, containing the execution time K t , and the advanced / lag time strategy S t ;

[0045] On March 28, Q1-Q7 are still used as experimental objects, and the power generation is recorded according to the existing experimental strategy, which is used as the basis for generating the strategy on March 28. The strategy k is executed on March 27, and the execution time K t The time adjustment strategy S is executed on the flat single-axis photovoltaic tracking drive device t The flat single-axis photovoltaic tracking drive device calculates and outputs the tracking angle with the new system time, and obtains the maximum system power generation.

[0046] The method optimizes the tracking angle output by the tracking system to achieve the optimal state without changing the tracking algorithm of the existing tracking system, thereby improving the power generation of the photovoltaic module and ultimately improving the power generation of the entire photovoltaic system. The transformation cost is low, the application range is wide, the promotion is high, and the method has a broad application prospect.

[0047] For those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims should be included in the present application, and any reference signs in the claims should not be regarded as limiting the claims.

[0048] In addition, it should be understood that although the present specification is described in terms of embodiments, each embodiment does not contain only one independent technical solution, and the description manner of the specification is only for clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A method for optimizing and retrofitting an existing photovoltaic flat single-axis tracking system, characterized in that: The method comprises: A: strategy optimization: Record the minimum action time interval Δt of the flat single-axis photovoltaic tracking drive device; With the flat single-axis photovoltaic tracking drive device as the statistical object, the power generation data X of the unit installed capacity and the average value X of the power generation data X are counted in the photovoltaic production data And standard deviation ; Take 2n+1 sets of power generation data X falling in the interval of the flat single-axis photovoltaic tracking drive device as the experimental object, and sequentially mark as , ] interval, and sequentially mark as ~ , wherein n≥3; In the selected 2n+1 objects, take n flat single-axis photovoltaic tracking drive devices to take the lead tracking strategy, that is, to The device time is adjusted forward by Δt, The device time is adjusted forward by 2Δt, and so on, finally The device time is adjusted forward by nΔt; In the remaining n+1 objects, take n flat single-axis photovoltaic tracking drive device to take lag tracking strategy, that is, to The device time is adjusted backward by Δt, The device time is adjusted backward by 2Δt, and so on, finally The device time is adjusted backward by nΔt; The device uses standard time, no changes; Record the real-time power generation of the photovoltaic power generation components under the jurisdiction of the selected 2n+1 flat single-axis photovoltaic tracking drive devices in intervals of Δt in units of days; In the same time / power coordinate axis, the flat single-axis photovoltaic tracking drive device is taken as the object, and the power curve L of the photovoltaic power generation assembly under the jurisdiction of the flat single-axis photovoltaic tracking drive device and the maximum power curve at each recording time point are drawn respectively The power curve L of the photovoltaic power generation assembly under the jurisdiction of the flat single-axis photovoltaic tracking drive device and the maximum power curve at each recording time point are drawn respectively ; And record the curve The corresponding point of each point is the lead-lag strategy of the flat single-axis photovoltaic tracking driving device, and the optimal execution strategy graph S is drawn; According to the strategy diagram S, the time points of frequent leading / lagging conversion are gently optimized to avoid frequent adjustment of the leading / lagging time of the flat single-axis photovoltaic tracking drive, and an optimized strategy diagram S1 is formed; S1 as the basis, generate a single day execution strategy k, single day execution strategy k contains execution time , advance / lag time strategy ; Repeat the above steps to generate the execution strategy K for the whole year; B, strategy execution: set the leading / lagging time of the flat single-axis photovoltaic tracking drive device through the leading / lagging time strategy obtained in A, adjust the output inclination angle of the flat single-axis photovoltaic tracking drive device, and make the photovoltaic components under the jurisdiction of the flat single-axis photovoltaic tracking drive device reach the maximum power generation at each time point.

2. The method for optimizing the reconstruction of an existing photovoltaic flat single-axis tracking system according to claim 1, characterized in that: In the above B, since the change of the solar elevation angle in the sun tracking process presents seasonality and continuity in a year, and the change of the solar azimuth angle only repeats in a day, the single-day execution strategy k also presents seasonality and continuity in a year, therefore, when executing the strategy, the single-day execution strategy k closest to the execution day is selected as the basis for the strategy execution on the date when the single-day execution strategy k is not generated, and the execution time recorded in k is executed according to the execution time recorded in k Performing the lead / lag time strategy on the flat single-axis photovoltaic tracking driving device .

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