CN114372228A - Calculation method of theoretical output power of photovoltaic module - Google Patents

Abstract

A method for calculating theoretical output power of a photovoltaic module belongs to the technical field of snow melting of solar power stations, and particularly relates to a method for calculating the theoretical output power of the photovoltaic module. The invention provides a method for calculating theoretical output power of a photovoltaic module. The method for calculating the theoretical output power of the photovoltaic module comprises the following steps: p_thIs the theoretical output power (unit W), P of the photovoltaic module_stcIs rated power, R, of the photovoltaic module under a standard test environment_acReal-time irradiation intensity (unit W/m) for photovoltaic module surface²），R_stcThe irradiation intensity (unit W/m) under the standard test environment is adopted²），T_bIs the temperature (unit ℃) of a photovoltaic module back plate, T_stcThe temperature of a component battery (unit ℃) in a standard test environment, gamma is a power temperature coefficient (unit%/° c, gamma is a negative number) of the photovoltaic component, and Y is the number of years that the photovoltaic component has operated (the number of days that the photovoltaic component operates is divided by 365, namely the yearNumber, result accurate to 3 bits after decimal point).

Description

Calculation method of theoretical output power of photovoltaic module

Technical Field

The invention belongs to the technical field of snow melting of solar power stations, and particularly relates to a method for calculating theoretical output power of a photovoltaic module.

Background

In the middle and high latitude areas, the accumulated snow in winter can cover the surface of the photovoltaic assembly, and the power generation amount of the photovoltaic power station is greatly reduced. The power generation capacity of the photovoltaic power station can be effectively improved if the accumulated snow on the surface of the photovoltaic module is melted, but the snow melting technology of the photovoltaic power station is still required to be further improved at present, and a calculation method of the theoretical output power of the photovoltaic module is required.

Disclosure of Invention

The invention aims at the problems and provides a method for calculating the theoretical output power of a photovoltaic module.

In order to achieve the purpose, the invention adopts the following technical scheme that the calculation method of the theoretical output power of the photovoltaic module comprises the following steps:

P_this the theoretical output power (unit W), P of the photovoltaic module_stcIs rated power, R, of the photovoltaic module under a standard test environment_acReal-time irradiation intensity (unit W/m) for photovoltaic module surface²)，R_stcThe irradiation intensity (unit W/m) under the standard test environment is adopted²)，T_bIs the temperature (unit ℃) of a photovoltaic module back plate, T_stcThe temperature of a component battery (unit ℃) in a standard test environment, gamma is a power temperature coefficient (unit%/° C, gamma is a negative number) of the photovoltaic component, Y is the number of years that the photovoltaic component has operated (the number of years is obtained by dividing the number of days that the photovoltaic component operates by 365, and the result is accurate to 3 bits after decimal point), A is₁Power decay Rate (% in units) for the first year of operation of a photovoltaic Module A_VThe linear power attenuation rate (unit%) of the photovoltaic module every year_dThe dust influence coefficient of the surface of the component.

When Y ≦ 1, the amount of the catalyst,

Y>when the pressure of the mixture is 1, the pressure is lower,

in the formula, K_dThe specific value of (A) requires a radiation intensity R at 12 pm per day_ac>500W/m²Under the conditions ofK is calculated according to the following formula_dReal-time value of (a), the calculated K_dThe real-time value as the time to the next time meets the above calculation condition (12 am and irradiation intensity R)_ac>500W/m²) Between moments in time in the above calculation P_thK used in the formula_dThe value is obtained. The next time the above calculation conditions are met (12 am and irradiation intensity R)_ac>500W/m²) Then, K is recalculated according to the following formula_dBy the new calculated K_dValue replacing previously calculated K_dValue calculation P_th。

When Y ≦ 1, the amount of the catalyst,

Y>when the pressure of the mixture is 1, the pressure is lower,

in the formula, P_acIs the real-time output power (unit W), R of the photovoltaic module_stc＝1000W/m²，T_stc＝25℃,P_stc、γ、A₁、A_VAnd providing specific parameter values by a photovoltaic module manufacturer according to different types of photovoltaic modules.

The invention has the beneficial effects.

Compared with the conventional method for calculating the theoretical output power of the photovoltaic module, the calculation method is different in that:

(1) the traditional algorithm multiplies a fixed coefficient of power attenuation along with time in the calculation when the attenuation characteristic of the photovoltaic module along with time is calculated, and the algorithm considers the characteristics that the attenuation characteristics of the output power of the photovoltaic module along with time are completely different after the first year and the second year. The first year power attenuation is large, and the second year and later power attenuation is small and linear, so the algorithm separately calculates the theoretical output power of the first year and later. In the first year of assembly use, the time-induced power decay scaling factor is (1-YxA)₁) (ii) a The power attenuation proportionality coefficient caused by time is [1-A ] in the second and later years of the assembly use₁-(Y-1)×A_v]. The theoretical output power value of the photovoltaic module obtained through calculation is more accurate than that of the previous algorithm.

(2) Because the photovoltaic power station is influenced by factors such as the installation inclination angle of the photovoltaic module, fine particles of soil and sand caused by wind, whether factory-discharged smoke dust exists around the photovoltaic power station, whether rainwater is washed away, whether measures for regularly removing dust from the photovoltaic module exist, and the like, the dust thickness on the surface of the photovoltaic module and the influence of the dust thickness on the power generation efficiency of the photovoltaic module are changed, so that the influence coefficient of the dust on the surface of the module is changed.

In the past, when the theoretical output power of the photovoltaic module is calculated by an algorithm, the surface dust influence coefficient multiplied in the calculation is a fixed value (the fixed value usually selected in the calculation is 97-85%), the dynamic change of the surface dust influence coefficient of the module is not considered, and the accuracy of the theoretical output power value of the photovoltaic module obtained through calculation is reduced. The patent proposes a calculation method for calculating the irradiation intensity R at a point of time when a certain condition is met (12 am)_ac>500W/m²) Then, according to the real-time output power P of the photovoltaic module_acY number of operating years of the photovoltaic module and real-time irradiation intensity R of surface of the photovoltaic module_acCalculating the isoparametric parameters to obtain the real-time surface dust influence coefficient K_dAnd at intervals of time, to K_dDynamically updating the value with the newly calculated K_dValue replacing previously calculated K_dThe theoretical output power value of the photovoltaic module is calculated more accurately.

Drawings

The invention is further described with reference to the following figures and detailed description. The scope of the invention is not limited to the following expressions.

FIG. 1 is a design diagram of a photovoltaic module with transverse 'king' shaped cooling fins mounted on the back surface.

Fig. 2 is a diagram of the positions of snow depth detection points of a certain photovoltaic module (all values in the diagram are in mm).

Fig. 3 is a dimension chart of the fin (all values in mm in the figure).

Fig. 4 is a diagram of the back side mounting position of the heat sink on the photovoltaic module (all values in mm in the figure).

Fig. 5 is a schematic side view of the snow depth detection sensor and the photovoltaic module.

Fig. 6 is a schematic top view of a snow depth detection sensor and a photovoltaic module.

Fig. 7 is a schematic diagram of a snow melting controller for a photovoltaic module.

FIG. 8 is a flowchart of a control procedure.

Fig. 9 is a specific circuit schematic a of the present invention.

Fig. 10 a detailed circuit schematic b of the invention.

Fig. 11 a detailed circuit schematic c of the invention.

Fig. 12 a detailed circuit schematic d of the invention.

Fig. 13 a detailed circuit schematic e of the invention.

Fig. 14 a detailed circuit schematic f of the invention.

Fig. 15 is a detailed circuit schematic g of the present invention.

Detailed Description

As shown in the figure, the photovoltaic module radiating fin comprises a transverse strip-shaped rectangular plate, a plurality of vertical strip-shaped rectangular plates are uniformly distributed along the length direction of the transverse strip-shaped rectangular plate, the front vertical edge of the front-end vertical strip-shaped rectangular plate is the front edge of the radiating fin, and the rear vertical edge of the rear-end vertical strip-shaped rectangular plate is the rear edge of the radiating fin; the center line along the length direction of the transverse strip-shaped rectangular plate passes through the center of the vertical strip-shaped rectangular plate; the heat radiating fins are provided with transverse strip-shaped electric tracing bands, the central lines of the transverse strip-shaped electric tracing bands in the length direction are overlapped with the central lines of the transverse strip-shaped rectangular plates in the length direction, the front ends of the transverse strip-shaped electric tracing bands are flush with the front ends of the heat radiating fins, and the rear ends of the transverse strip-shaped electric tracing bands are flush with the rear ends of the heat radiating fins.

The transverse heat dissipation fin in the shape of the Chinese character 'wang' is used for effectively transferring heat energy emitted by the electric tracing band to the photovoltaic module, so that the snow melting speed of each part on the surface of the photovoltaic module is more uniform. In addition, compared with the radiating fins fully paved on the photovoltaic module back plate, the designed transverse 'king' shaped radiating fin can greatly reduce the consumption of radiating fin materials and remarkably reduce the cost.

The number of the vertical strip-shaped rectangular plates is four.

The width of the transverse strip-shaped electric tracing band is smaller than that of the transverse strip-shaped rectangular plate.

The plurality of radiating fins are uniformly distributed along the length direction of the photovoltaic module; the length direction of the radiating fin is vertical to the length direction of the photovoltaic module; the front ends of the radiating fins are in the same vertical direction; in the horizontal direction, the heat sink is centered on the back side of the photovoltaic module.

The number of the radiating fins is six.

And a detection point is arranged between the adjacent radiating fins.

The center of a rectangular area defined by every four adjacent vertical strip-shaped rectangular plates is a detection point.

And selecting x multiplied by y detection points at the photovoltaic module back plate according to the uniform distance, wherein x is the number of transverse detection points, and y is the number of longitudinal detection points. Transverse 'king' shaped radiating fins are designed to surround each detection point, as shown in figure 1. And 1 electric tracing band is arranged at the central line position of each radiating fin, and the transverse central line of the radiating fin is superposed with the transverse central line of the electric tracing band.

m is the length (unit mm) of the photovoltaic module, n is the width (unit mm) of the photovoltaic module, k is the transverse distance (unit mm) of the detection points, p is the longitudinal distance (unit mm) of the detection points, q is the longitudinal distance (unit mm) of the heat tracing band, a is the width (unit mm) of the radiating fins, e is the length (unit mm) of the radiating fins, b is the width (unit mm) of the vertical strip-shaped rectangular plates, and c is the width (unit mm) of the transverse strip-shaped rectangular plates;

0.8n < e, 60mm < b < 100mm, 60mm < c < 100mm, 250mm < a < p, k n/(x +1), p m/(y +1), q p, the electrical heat trace length being equal to the fin length e; in the horizontal direction, the radiating fin is centered on the back side of the photovoltaic module, the distance between the left edge of the photovoltaic module and the left edge of the radiating fin is (n-e)/2, and the distance between the right edge of the photovoltaic module and the right edge of the radiating fin is (n-e)/2; the thickness of the radiating fin is between 0.8mm and 1.5 mm.

The power supply control loops of the heat tracing bands installed on each photovoltaic module are mutually independent. The power supply control loops of the heat tracing bands installed on each photovoltaic module are mutually independent. When snow is accumulated on the surface of the photovoltaic module, all the electric tracing bands are not started to melt snow, but only the upper and lower adjacent electric tracing bands at the positions where the detection points with the accumulated snow are identified are powered and heated, so that only the positions with the accumulated snow are heated, and the positions without the accumulated snow are not heated, therefore, electric energy can be greatly saved, and snow melting cost is reduced.

The photovoltaic module is 2094mm in length, and 1038mm in width.

The radiating fins are made of aluminum.

Taking a photovoltaic module with model number YL450D-40d1/2 manufactured by British energy (Chinese) limited as an example, the module is 2094mm in length and 1038mm in width. 15 detection points (5 rows by 3 columns) are selected at a uniform pitch on the photovoltaic module back sheet as shown in fig. 2. The transverse king-shaped aluminum radiating fins are designed, the size of each radiating fin is as shown in figure 3, the 15 points are surrounded, and each photovoltaic module uses 6 radiating fins. 1 electric tracing band is installed at the central line position of each radiating fin, the installation position is shown in figure 4, and the solar panel uses 6 electric tracing bands in total. Taking the photovoltaic module of the model as an example, if the aluminum radiating fins are fully paved on the back surface, the thickness of the radiating fins is 1mm according to the aluminum density of 2700kg/m³The aluminum material used was calculated to be 5.8686444 kg. If the designed transverse king-shaped aluminum radiating fin is used, 2.356776kg of aluminum material is needed, and the aluminum material consumption is 40.16% of that of the radiating fin fully paved on the back plate.

The cooling fin designed by the invention can be used for detecting the snow depth of the detection point, and the method for detecting the snow depth of the detection point of the photovoltaic module comprises the following steps:

the snow depth detection sensor is arranged on a numerical control electric holder, the snow depth detection sensor is controlled by the holder to rotate horizontally and in a pitching mode, and the holder is fixed on an upright post vertical to the horizontal plane. The stand is installed at the extension line direction of No. 1 photovoltaic module central line. f is the distance (unit mm) between the stand column and the photovoltaic module No. 1 in the center line direction of the photovoltaic module No. 1, h is the height (unit mm) from the horizontal plane where the front edge of the photovoltaic module No. 1 is located to the horizontal plane where the snow depth detection sensor is located on the stand column, m is the length (unit mm) of the photovoltaic module, n is the width (unit mm) of the photovoltaic module, j is the distance (unit mm) of the photovoltaic module, beta is the horizontal rotation angle (unit DEG) of the snow depth detection sensor probe, d1 is the snow depth (unit mm) detected in the direction indicated by the snow depth detection sensor, d2 is the snow depth (unit mm) projected to the overlooking center line direction of the photovoltaic module by d1, d is the snow depth (unit mm) projected to the normal line direction of the photovoltaic module by d2, theta is the included angle (unit DEG) between the photovoltaic module and the horizontal plane, and delta is the pitching rotation angle (unit DEG) of the snow depth detection sensor probe.

In order to obtain an accumulated snow depth value d of a certain detection point of the photovoltaic module, a horizontal rotation angle beta and a pitching rotation angle delta when the snow depth detection sensor points to the detection point are calculated, the snow depth detection sensor is rotated to the angle by controlling the numerical control electric holder, and then the snow depth detection sensor carries out accumulated snow depth detection. Finally, the snow depth d1 detected by the snow depth detection sensor in the direction is converted into the snow depth d in the normal direction of the photovoltaic module through an algorithm (the following algorithm). Taking 5 typical points in fig. 6 as an example (the snow depth algorithm of other points can be obtained by taking the snow depth algorithm of the 5 typical points as a reference), the snow depth calculation method is as follows.

(1) Algorithm for detecting snow depth at No. 1 point

Firstly, the angle delta of the numerical control electric pan-tilt which needs to rotate in a pitching mode and the angle beta of the numerical control electric pan-tilt which needs to rotate in a horizontal mode are calculated, and the calculation is as follows.

By

To obtain

By

To obtain

Then, the snow depth d1 detected by the snow depth detection sensor in the direction pointed by the numerical control electric pan-tilt is converted into the snow depth d in the normal direction of the photovoltaic module, and the calculation is as follows.

By

D2 ═ d1 × cos β

By

D2 × sin (θ + δ) ═ d1 × cos β × sin (θ + δ)

(2) Algorithm for detecting snow depth at No. 2 detection point

The detection point No. 2 is located on the center line of the photovoltaic module No. 1, so the horizontal rotation angle beta is 0 degree, and d1 is d 2. The angle delta of the numerical control electric pan-tilt required to rotate in pitch is calculated as follows.

By

To obtain

The snow depth d1 detected by the snow depth detection sensor in the direction pointed by the numerical control electric pan-tilt is converted into the snow depth d in the normal direction of the photovoltaic module, and the calculation is as follows.

By

And d1 d2 d1 × sin (θ + δ)

(3) Algorithm for detecting snow depth at No. 3 detection point

Firstly, the angle delta of the numerical control electric pan-tilt which needs to rotate in a pitching mode and the angle beta of the numerical control electric pan-tilt which needs to rotate in a horizontal mode are calculated, and the calculation is as follows.

By

To obtain

By

To obtain

Then, the snow depth d1 detected by the snow depth detection sensor in the direction pointed by the numerical control electric pan-tilt is converted into the snow depth d in the normal direction of the photovoltaic module, and the calculation is as follows.

By

D2 ═ d1 × cos β

By

D2 × sin (θ + δ) ═ d1 × cos β × sin (θ + δ)

(4) Algorithm for detecting snow depth at No. 4 detection point

The No. 4 detection point is located on the No. 2 photovoltaic module, so the physical quantity j of the spacing between the photovoltaic modules needs to be included in the calculation. Firstly, the angle delta of the numerical control electric pan-tilt which needs to rotate in a pitching mode and the angle beta of the numerical control electric pan-tilt which needs to rotate in a horizontal mode are calculated, and the calculation is as follows.

By

To obtain

By

To obtain

Then, the snow depth d1 detected by the snow depth detection sensor in the direction pointed by the numerical control electric pan-tilt is converted into the snow depth d in the normal direction of the photovoltaic module, and the calculation is as follows.

By

D2 ═ d1 × cos β

By

D2 × sin (θ + δ) ═ d1 × cos β × sin (θ + δ)

(5) Algorithm for detecting snow depth at No. 5 detection point

Firstly, the angle delta of the numerical control electric pan-tilt which needs to rotate in a pitching mode and the angle beta of the numerical control electric pan-tilt which needs to rotate in a horizontal mode are calculated, and the calculation is as follows.

By

To obtain

By

To obtain

Then, the snow depth d1 detected by the snow depth detection sensor in the direction pointed by the numerical control electric pan-tilt is converted into the snow depth d in the normal direction of the photovoltaic module, and the calculation is as follows.

By

D2 ═ d1 × cos β

By

D2 × sin (θ + δ) d1 × cos β × sin (θ + δ) is obtained.

The invention discloses a method for calculating theoretical output power of a photovoltaic module and a method for judging snow melting, which comprises the following steps:

1) calculation method of theoretical output power of photovoltaic module

The invention provides a method for calculating a theoretical output power value of a photovoltaic module.

The calculation process is as follows, wherein P_thIs the theoretical output power (unit W), P of the photovoltaic module_stcIs rated power, R, of the photovoltaic module under a standard test environment_acReal-time irradiation intensity (unit W/m) for photovoltaic module surface²)，R_stcThe irradiation intensity (unit W/m) under the standard test environment is adopted²)，T_bIs the temperature (unit ℃) of a photovoltaic module back plate, T_stcThe temperature of a component battery (unit ℃) in a standard test environment, gamma is a power temperature coefficient (unit%/° C, gamma is a negative number) of the photovoltaic component, Y is the number of years that the photovoltaic component has operated (the number of years is obtained by dividing the number of days that the photovoltaic component operates by 365, and the result is accurate to 3 bits after decimal point), A is₁Power decay Rate (% in units) for the first year of operation of a photovoltaic Module A_VThe linear power attenuation rate (unit%) of the photovoltaic module every year_dThe dust influence coefficient of the surface of the component.

When Y ≦ 1, the amount of the catalyst,

Y>when the pressure of the mixture is 1, the pressure is lower,

in the formula, K_dThe specific value of (A) requires a radiation intensity R at 12 pm per day_ac>500W/m²Under the condition of (1), K is calculated according to the following formula_dReal-time value of (a), the calculated K_dThe real-time value as the time to the next time meets the above calculation condition (12 am and irradiation intensity R)_ac>500W/m²) Between moments in time in the above calculation P_thK used in the formula_dThe value is obtained. The next time the above calculation conditions are met (12 am and irradiation intensity R)_ac>500W/m²) Then, recalculated according to the following formulaK_dBy the new calculated K_dValue replacing previously calculated K_dValue calculation P_th。

When Y ≦ 1, the amount of the catalyst,

Y>when the pressure of the mixture is 1, the pressure is lower,

in the formula, P_acIs the real-time output power (unit W), R of the photovoltaic module_stc＝1000W/m²，T_stc＝25℃,P_stc、γ、A₁、A_VAnd providing specific parameter values by a photovoltaic module manufacturer according to different types of photovoltaic modules.

Compared with the conventional method for calculating the theoretical output power of the photovoltaic module, the calculation method is different in that:

(1) the traditional algorithm multiplies a fixed coefficient of power attenuation along with time in the calculation when the attenuation characteristic of the photovoltaic module along with time is calculated, and the algorithm considers the characteristics that the attenuation characteristics of the output power of the photovoltaic module along with time are completely different after the first year and the second year. The first year power attenuation is large, and the second year and later power attenuation is small and linear, so the algorithm separately calculates the theoretical output power of the first year and later. In the first year of assembly use, the time-induced power decay scaling factor is (1-YxA)₁) (ii) a The power attenuation proportionality coefficient caused by time is [1-A ] in the second and later years of the assembly use₁-(Y-1)×A_v]. The theoretical output power value of the photovoltaic module obtained through calculation is more accurate than that of the previous algorithm.

(2) Because the photovoltaic power station is influenced by factors such as the installation inclination angle of the photovoltaic module, fine particles of soil and sand caused by wind, whether factory-discharged smoke dust exists around the photovoltaic power station, whether rainwater is washed away, whether measures for regularly removing dust from the photovoltaic module exist, and the like, the dust thickness on the surface of the photovoltaic module and the influence of the dust thickness on the power generation efficiency of the photovoltaic module are changed, so that the influence coefficient of the dust on the surface of the module is changed.

In the past, when the theoretical output power of the photovoltaic module is calculated by an algorithm, the surface dust influence coefficient multiplied in the calculation is a fixed value (the fixed value usually selected in the calculation is 97-85%), the dynamic change of the surface dust influence coefficient of the module is not considered, and the accuracy of the theoretical output power value of the photovoltaic module obtained through calculation is reduced. The patent proposes a calculation method for calculating the irradiation intensity R at a point of time when a certain condition is met (12 am)_ac>500W/m²) Then, according to the real-time output power P of the photovoltaic module_acY number of operating years of the photovoltaic module and real-time irradiation intensity R of surface of the photovoltaic module_acCalculating the isoparametric parameters to obtain the real-time surface dust influence coefficient K_dAnd at intervals of time, to K_dDynamically updating the value with the newly calculated K_dValue replacing previously calculated K_dThe theoretical output power value of the photovoltaic module is calculated more accurately.

2) Method for judging start of snow melting

The snow melting system needs to determine two preconditions before starting the snow melting function: firstly, whether the surface of the photovoltaic module is covered by snow or not. Second, whether the snowing has ended. When both conditions are met, the snow melting function can be started.

If the snow melting function is started under the condition of no snow cover, the snow melting system can run in an idle state, so that the electric energy is consumed, and the service life of equipment such as a numerical control electric holder is shortened. If the snow melting function is started when the snowing is not finished, the electric energy consumed by the heat tracing band is greatly increased, because the snow on the surface of the component can slide off the surface of the component (when the installation inclination angle of the photovoltaic component is not 0 ℃) or a part of the snow is blown off by natural wind when the snow covers a certain thickness during the snowing process. Therefore, after snowing is completely finished, the electric energy consumed for snow melting is the least when the snow accumulation amount on the surface of the photovoltaic module is fixed.

The automatic snow melting system of the photovoltaic power station is safe and reliable, saves electric energy and has high intelligent degree.

The invention adopts the following method to confirm the two preconditions, and judges whether to start snow melting on the assembly on the basis.

(1) Method for judging whether snow covers on surface of photovoltaic module

If the surface of the photovoltaic assembly is covered by snow, the real-time output power of the photovoltaic assembly is greatly lower than the theoretical output power, and whether the surface of the photovoltaic assembly is covered by the snow can be judged according to the difference value of the two powers.

Calculating the difference value P between the theoretical output power and the actual output power of the photovoltaic module_dif(unit W).

P_dif＝P_th-P_ac

Wherein the theoretical output power P of the photovoltaic module_thAs previously described, the real-time output power P of the photovoltaic module_acThe calculation formula of (unit W) is as follows.

P_ac＝U×I

U is the voltage (unit V) at the output end of the photovoltaic module, and I is the current (unit A) at the output end of the photovoltaic module.

Setting a power threshold P_d(unit W) in which P_d＝0.3×P_th. If P is_dif>P_dAnd then, the situation that the surface of the photovoltaic module is covered with snow can be judged.

(2) Method for judging whether snowing is finished

Whether snowing is finished or not needs to be judged according to whether the snow depth on the surface of the photovoltaic module is increased in unit time or not, and the specific method is as follows.

Selecting a photovoltaic module at the central position of the photovoltaic array, detecting the snow depth of all detection points on the surface of the photovoltaic module every 10 minutes, and calculating the average snow depth value d of the detection points_p(unit mm).

In the formula d_iThe depth value (unit mm) of accumulated snow at the ith detection point on the surface of the photovoltaic module is 1-g, and g is the depth value of accumulated snow on the surface of the photovoltaic moduleThe number of accumulated snow depth detection points.

If average accumulated snow depth value d_pIf the increase is not continued for 30 minutes, it is judged that the snowfall has ended.

The method for controlling the snow melting speed of the surface of the photovoltaic module comprises the following steps:

generally, the snow accumulation amount of each part on the surface of the photovoltaic module is inconsistent, namely the snow accumulation depth of each part is different. If the same electric heating quantity is provided for all snow accumulation parts in unit time, the parts with smaller snow accumulation depth can realize complete snow melting in a shorter time, and the snow melting time of the parts with larger snow accumulation depth is relatively longer. The photovoltaic module has the characteristic of generating electricity, so long as a small part of the surface of the photovoltaic module is shielded by real shadows, the photovoltaic module does not generate electricity or the generated power is greatly reduced, and a hot spot effect is generated when the photovoltaic module is serious, so that the photovoltaic module is permanently damaged. If more electric heating quantity is provided for the position with larger snow depth in unit time, and less electric heating quantity is provided for the position with smaller snow depth in unit time, the difference of snow melting time of each position on the surface of the photovoltaic module can be reduced, and the snow melting speed of each position of the photovoltaic module can be controlled.

The invention provides a snow melting speed control method, which realizes that different electric heating amounts are supplied to parts with different snow depths on the surface of a photovoltaic assembly in unit time.

Collecting snow depth values of all detection points on the surface of a single photovoltaic module, and calculating d_a1，d_a2，...d_ayWherein d is_a1～d_ayThe average value (unit mm) of snow depths of all detection points on the same horizontal height of the photovoltaic module from bottom to top is obtained, and y is the number of longitudinal detection points.

Average depth d of accumulated snow_aThe depth interval is divided into 3 depth intervals: (1)0mm<d_a≦15mm；(2)15mm<d_a≦30mm；(3)d_a>30 mm. The power supply modes of upper and lower adjacent electric tracing bands at a detection point with accumulated snow are divided into 3 types: the duty ratio of the heating time is 50%, and the heating period is 2 s; heating timeThe space ratio is 75%, and the heating period is 4 s; and thirdly, continuous heating.

The power supply mode adopted by the electric tracing band according to different snow depth conditions of the photovoltaic module is as follows.

1. When d is_a1～d_ayThe snow accumulation depth conditions of all 3 depth intervals are included, a power supply mode is adopted for the upper adjacent electric tracing band and the lower adjacent electric tracing band corresponding to the detection point of the depth interval (1), a power supply mode is adopted for the upper adjacent electric tracing band and the lower adjacent electric tracing band corresponding to the detection point of the depth interval (2), and a power supply mode is adopted for the upper adjacent electric tracing band and the lower adjacent electric tracing band corresponding to the detection point of the depth interval (3).

2. When d is_a1～d_ayThe snow accumulation depth conditions of the depth section (2) and the depth section (3) are included, a power supply mode II is adopted corresponding to the upper and lower adjacent electric tracing bands at the detection point of the depth section (2), and a power supply mode III is adopted corresponding to the upper and lower adjacent electric tracing bands at the detection point of the depth section (3).

3. When d is_a1～d_ayThe snow accumulation depth conditions of the depth section (1) and the depth section (2) are included, a power supply mode II is adopted corresponding to the upper and lower adjacent electric tracing bands at the detection point of the depth section (1), and a power supply mode III is adopted corresponding to the upper and lower adjacent electric tracing bands at the detection point of the depth section (2).

4. When d is_a1～d_ayThe snow accumulation depth conditions of the depth section (1) and the depth section (3) are included, a power supply mode (I) is adopted corresponding to the upper and lower adjacent electric tracing bands at the detection point of the depth section (1), and a power supply mode (III) is adopted corresponding to the upper and lower adjacent electric tracing bands at the detection point of the depth section (3).

5. When d is_a1～d_ayOnly the snow depth condition of the depth section (1) is included, and a power supply mode (c) is adopted corresponding to the upper and lower adjacent electric tracing bands of the detection point of the depth section (1).

6. When d is_a1～d_ayOnly the snow depth condition of the depth section (2) is included, and a power supply mode (c) is adopted corresponding to the upper and lower adjacent electric tracing bands of the detection point of the depth section (2).

7. When d is_a1～d_ayOnly the snow depth condition of the depth section (3) is included, and a power supply mode (c) is adopted corresponding to the upper and lower adjacent electric tracing bands of the detection point of the depth section (3).

8. When the snow depth of the upper and lower adjacent detection points of a certain heat tracing band belongs to different depth intervals, the power supply mode of the heat tracing band works according to the power supply mode of the detection point with the larger snow depth value.

The optimization method of the snow melting system comprises the following steps:

1) optimized according to heating time

Because the specific position and the environment of each photovoltaic module are different, for example, some photovoltaic modules are shielded by shadows, some components are not communicated with air, some components are provided with heating sources nearby, and the like, the conditions can cause different heating time required by each component and each part of the component for melting snow. The patent proposes a method for reducing the difference of heating time of each heat tracing band, and the specific method is as follows.

(1) Counting the time T of each heat tracing band from heating to stopping heating after snow melting is finished in the snow melting system of the photovoltaic module after 3 times of snowing_i1、T_i2、T_i3、(T_i1、T_i2、T_i3Respectively representing the working time of the ith heat tracing band in the 1 st, the 2 nd and the 3 rd snow melting systems, wherein i is 1 to v, and v is the total amount of the heat tracing bands used by the snow melting system). (the method is not limited to counting the data of the snow melting process for 3 times, and the obtained result is more accurate if more data are counted in practical application)

(2) Calculating the total working time T of each tracing band_i＝T_i1+T_i2+T_i3。

(3) Calculating the average value of the total working time of all the heat tracing bands of the system

(4) Calculating the difference D between the total working time of each heat tracing band and the average time_i＝T_i-T_av。

(5) Calculating the ratio of the time difference value and the average time value of each heat tracing band

(6) Screening S_i>0.1 of heat tracing band, the heat tracing band meeting the condition is replaced by the heat tracing band with higher power value, and the power value of the heat tracing band before replacement is set as P_iThe power value of the replaced heat tracing band is (1+ S)_i)×P_i。

(7) Screening S_i<A heating tape of 0.1, wherein the heating tape meeting the condition is replaced by the heating tape with lower power value, and the power value of the heating tape before replacement is P_iThe power value of the replaced heat tracing band is (1+ S)_i)×P_i。

2) Optimizing according to heating electric quantity

Gaps or falling between the heat tracing band and the heat radiating fins and between the heat radiating fins and the assembly back plate can occur due to construction quality problems or aging problems after the photovoltaic snow melting system is used for a period of time in the installation process. This results in a substantial reduction in the heat conducted by the heat tracing band to the photovoltaic module, not only is electrical energy lost, but the snow melting effect is also affected. This patent proposes a method by which components that have suffered from this problem can be found, as follows.

(1) Counting the electric quantity E consumed by each component in the snow melting process_i(i 1-w, w is the total number of photovoltaic modules, E_iRepresenting the amount of power consumed by the ith photovoltaic module to melt snow).

E_i＝E_i1+E_i2+…+E_iz

Wherein z is the total number of the heat tracing bands for mounting the photovoltaic module back plate, E_i1Represents the electric quantity consumed by the 1 st heat tracing band on the i-th photovoltaic module back plate in the snow melting project, E_i2And the electric quantity consumed by the 2 nd heat tracing band on the ith photovoltaic module back plate in the snow melting project is represented, and the like.

(2) Calculating the average value of the power consumption of all the components in the snow melting process

(3) Calculating the difference F between the average consumed electric quantity value and the consumed electric quantity value of each component_i＝E_i-E_av

(4) Calculating the ratio of the electric quantity difference value of each component to the average consumed electric quantity value

(5) Screening of Q_i>And 0.2, carrying out on-site inspection on the photovoltaic module meeting the condition to solve the problem of the heat tracing band part and carrying out maintenance.

The invention relates to a photovoltaic component snow melting controller which comprises a CPU circuit, a heat tracing band control circuit, a photovoltaic component voltage detection circuit, a current detection circuit, an irradiation detection circuit, a keyboard and liquid crystal screen circuit, a GPRS communication circuit, a numerical control pan-tilt control circuit, a snow depth detection circuit, an angle detection circuit and a temperature detection circuit, wherein a signal transmission port of the CPU circuit is respectively connected with a signal transmission port of the heat tracing band control circuit, a signal transmission port of the voltage detection circuit, a signal transmission port of the current detection circuit, a signal transmission port of the irradiation detection circuit, a signal transmission port of the keyboard and liquid crystal screen circuit, a signal transmission port of the GPRS communication circuit, a signal transmission port of the numerical control pan-tilt control circuit, a signal transmission port of the snow depth detection circuit, a signal transmission port of the angle detection circuit and a signal transmission port of the temperature detection circuit, a control signal output port of the heat tracing band control circuit is connected with an electric heat tracing band, a detection signal input port of the current detection circuit is connected with a current transformer (a junction box on the back of the photovoltaic component outputs two wires which are respectively the positive output and the negative output of the photovoltaic component, a round hole is arranged in the center of the current transformer, the wire with the diameter of 13.6mm can penetrate through the round hole to the maximum, and the positive wire or the negative wire of the photovoltaic component can penetrate through the hole to detect the current value output by the photovoltaic component); and a detection signal output port of the snow depth sensor is connected with a detection signal input port of the snow depth detection circuit.

The CPU circuit is the core of the controller, and the completed work comprises the steps of collecting various physical signals, controlling the rotation of the numerical control electric pan-tilt, calculating the accumulated snow depth of the detected point on the surface of the photovoltaic module, and judging which electric tracing bands need to be powered and heated, which power supply modes are adopted by the electric tracing bands, and the like.

The snow depth detection circuit detects the snow depth in real time through the snow depth sensor, converts 485 signals output by the snow depth sensor into serial TTL (transistor-transistor logic) signals through the level signal conversion circuit to communicate with the CPU (central processing unit), and realizes the electrical isolation of the controller circuit and the snow depth sensor through the power isolation circuit.

The numerical control cradle head control circuit realizes horizontal rotation and pitching rotation of the cradle head through real-time control of the CPU on the cradle head, 485 signals output by the cradle head are converted into serial TTL (transistor-transistor logic) signals through the level signal conversion circuit to be communicated with the CPU, and electric isolation between the controller circuit and the numerical control electric cradle head is realized through the power isolation circuit.

The angle detection circuit detects the angles of the photovoltaic module and the snow depth sensor in real time through the angle sensor, converts a 485 signal output by the angle sensor into a serial TTL signal through the level signal conversion circuit to communicate with the CPU, and realizes the electrical isolation of the controller circuit and the angle sensor through the power isolation circuit.

The irradiation detection circuit detects the irradiation intensity in real time through the irradiation sensor, the irradiation sensor outputs the irradiation intensity through a current signal, the current signal is changed into a voltage signal through the signal conditioning circuit, and the voltage signal is changed into a digital signal through the AD conversion module in the CPU.

The current detection circuit samples the current output by the photovoltaic module in proportion through the current sensor and outputs a corresponding voltage signal, and the voltage signal is converted into a digital signal through an AD conversion module in the CPU after passing through the signal conditioning circuit.

The voltage detection circuit samples the voltage output by the photovoltaic module in proportion through the voltage transformer and outputs a corresponding current signal, the current signal is changed into a voltage signal through the signal conditioning circuit, and the voltage signal is changed into a digital signal through the AD conversion module in the CPU.

The temperature sensor in the temperature detection circuit converts the temperature of the photovoltaic module backboard into a digital signal, communicates with the CPU in a single data bus mode, and sends the temperature information of the photovoltaic module backboard to the CPU.

The CPU in the keyboard and liquid crystal screen circuit identifies the trigger key in an external interruption and scanning mode, and the CPU communicates with the liquid crystal screen module in a serial synchronous communication mode and controls the liquid crystal screen to display contents. The keyboard and the liquid crystal display circuit have the functions of setting system control parameters and checking the working state of the system.

The heat tracing band control circuit outputs a control signal from an IO port of the CPU, and controls whether the coil at the control end of the relay supplies power or not after optical coupling isolation, thereby controlling whether each heat tracing band supplies power or not for heating. The 24V power supply at the control end of the relay is electrically isolated from the 24V power supply in the controller circuit through the power isolation circuit.

And the CPU in the GPRS communication circuit is communicated with the GPRS wireless transparent transmission module through a serial asynchronous communication interface, and remote wireless communication is realized through a GPRS network.

The snow depth detection circuit, the numerical control holder control circuit, the angle detection circuit, the irradiation detection circuit, the current detection circuit, the voltage detection circuit, the temperature detection circuit, the keyboard and liquid crystal display circuit, the heat tracing band control circuit and the GPRS communication circuit are all connected with the CPU circuit.

When the snow depth detection device is used, the snow depth detection sensor is arranged on the numerical control electric cradle head, the cradle head controls the snow depth detection sensor to rotate horizontally and in a pitching mode, the cradle head is fixed on an upright post perpendicular to the horizontal plane, and the upright post is arranged in the extension line direction of the center line of the No. 1 photovoltaic module. An angle sensor is mounted on the snow depth detecting sensor for detecting an angle at which the snow depth detecting sensor is directed. And the other angle sensor is arranged on the photovoltaic module and used for detecting the included angle between the photovoltaic module and the horizontal plane. The output lead of the photovoltaic module passes through a round hole in the center of the current sensor (in fig. 6, 3 photovoltaic modules are connected in series electrically); and respectively connecting the positive and negative electrodes of the output ends of the 3 photovoltaic modules to a PV + pin and a PV-pin of a voltage signal input port connector in the voltage detection circuit. And fixing the temperature sensor on the area, far away from the heat tracing band and the covering area of the heat radiating fin, on the back plate of the photovoltaic assembly. And fixing the irradiation sensor on a plane with the same inclination angle as the photovoltaic module, wherein the irradiation sensor cannot be shielded by a shadow. And fixing the heat radiating fins on the photovoltaic module back plate according to the position requirement of the invention, and fixing the heat tracing bands at the horizontal center line position of the heat radiating fins.

As shown in fig. 8, when the present invention starts to work, in the first step, various known physical parameters including the rated power of the component, the temperature coefficient of the power of the component, the power attenuation rate of the photovoltaic component during the first year of operation, the linear power attenuation rate of the photovoltaic component after the first year of operation, etc. are input by the keyboard, and initial parameters including the polling period and the power threshold P are set_dSnow melting duration, etc., and then into the cyclic program step. And secondly, acquiring the irradiation intensity of the surface of the photovoltaic module and the temperature of a back plate of the photovoltaic module, and calculating the theoretical output power of the photovoltaic module according to the parameters of the running years and the like of the module and the algorithm provided by the invention. Thirdly, collecting the voltage and current values of the output end of the photovoltaic module, calculating the actual output power of the photovoltaic module, and calculating the difference value P between the actual output power and the theoretical output power_dif. Comparison P_difAnd P_dMagnitude of value, if P_difNot more than P_dAnd returning to the second step to circularly execute the calculation process. If P is_difGreater than P_dThen the fourth step is entered. Fourthly, detecting the snow depth of all detection points on a typical photovoltaic assembly, and calculating the average snow depth value d of the surface of the assembly_pEvery 10 minutes, detected and counted. If d is_pIf the increase is not generated within 30 minutes, entering the fifth step; if d is_pIncreasing within 30 minutes, the fourth step is repeated. Fifthly, controlling the holder to rotate to enable the snow depth sensor to sequentially detect all set detection points, and calculating the snow depth of each detection point according to the algorithm provided by the invention. And sixthly, according to the snow depth situation of each detection point of the photovoltaic module, heating and melting the snow for each heat tracing band by adopting a corresponding power supply mode according to the snow melting speed control method provided by the invention, and then entering the snow melting duration time for waiting. And seventhly, detecting the snow depth of all detection points again. And judging whether the snow depth of all the detection points is zero or not, returning to the fifth step to continue the snow melting step if the snow depth is not zero, stopping heating if the snow depth is zero, returning to the second step after the waiting time of the inspection period, and repeating the steps of the circulating program.

The CPU circuit adopts a MM32F3273D7P chip U1, pins 1-4 of U1 are correspondingly connected with +3.3V, LCD-A0, LCD-RST and LCD-CS respectively, pin 5 of U1 is connected with one end of a resistor R1, one end of a crystal oscillator X1 and one end of a capacitor C1 respectively, the other end of C1 is connected with ground and one end of a capacitor C2 respectively, the other end of C2 is connected with the other end of X1, the other end of R1 and pin 6 of U1 respectively, pins 7-12 of U1 are connected with RST, RD2, RD3, SCL, UART and GND respectively, pin 12 of U1 is connected with the positive pole of a capacitor C3 and one end of a capacitor C4 respectively, the negative pole of C3 is connected with the other end of C4 and pin 13 of U1, pins 14-32 of U1 are connected with UART, 1-TX, 1-RX, ADC 1-1, GND, ADC 1-RX, ADC 1-1, ADC 1-72, ADC 1-RX, ADC 1-72, ADC 1-RX, ADC1, UART-RX, UART-RX-3, ADC, GND, +3.3V are correspondingly connected, pins 18 and 19 of U1 are connected with two ends of C5, and pins 31 and 32 of U1 are connected with two ends of C6;

pins 33-64 of U1 are correspondingly connected with pins L6-L1, pins LE 3-LE 1, pins UART1-RX, pins UART1-TX, pins RD1, pins INT3, pins JTMS, pins GND, +3.3V, pins JTCK, pins ROW 5-ROW 1, pins COL 5-COL 1, pins GND, pins RD4, pins T-DQ, pins GND and pins +3.3V respectively;

the 3 pin of the BM117-3.3 chip P1 is connected with +15V, the 2 pin of the P1 is connected with +3.3V, one end of a switch SW1 is respectively connected with the ground and one end of a capacitor C13, the other end of the SW1 is respectively connected with one end of a resistor R2, the other end of the RST and the other end of the capacitor C13, and the other end of the R2 is connected with + 3.3V.

The CPU is 32-bit microcontroller produced by Shanghai flexible microelectronics Limited, and the model is MM32F3273D 7P. The communication module is an embedded GPRS wireless transparent transmission module produced by Jinan people Internet of things technology Limited, and the model is USR-GPRS232-7S 3. The liquid crystal screen module is made of a product produced by Shenzhen crystal union electronics Limited, and the model is JLX 12864G-183-BN. The relay is a low-power-consumption micro relay produced by Ningbo Vitaceae New epoch electric appliances Limited, the model is HK4100F-DC24V-SDAG, the coil voltage is 24V, and the coil power consumption is 0.15W. The 24V power isolation module is made of a product produced by Shenzhen Henlike electronics Limited, and has the model number of HLK-10D 2424B. The 3.3V power supply module is a product produced by Shanghai Baili microelectronics Inc., and the model is BM 1117-3.3. The voltage transformer is a product produced by Nanjing Hodgkin technologies, Inc., and has a model number of VSM 025A/10. The current sensor is a product produced by Jojoba sensing technology Limited in Jiangsu, and the model is HDIB-CE-10P2O 2.

The snow depth detection circuit comprises a common-mode inductor LDM1, wherein the first end of an LDM1 is connected with +24V, the second end of an LDM1 is connected with one end of an inductor L1, the other end of the L1 is connected with a pin 1 of a P2 of an HLK-10D2424B chip, a pin 2 of the P2 is connected with the third end of the LDM1, and the fourth end of the LDM1 is grounded; the 4 pin of the P2 is connected with +24V-HM31 through an inductor L2, and the 3 pin of the P2 is connected with GND-HM31 through an inductor L3;

the 1 pin of a ST3485 chip U2 is connected with UART1-RX, the 2 and 3 pins of U2 are connected with RD1, the 4 pin of U2 is connected with UART1-TX, the 5 pin of U2 is respectively connected with ground and one end of a capacitor C21, the other end of C21 is respectively connected with 8 pins of +3.3V, U2, the 6 pin of U2 is respectively connected with one end of a resistor R5, one end of a resistor R6 and one end of a resistor R7, the other end of R6 is connected with +3.3V, the other end of R7 is connected with RS485-A1, the other end of R5 is respectively connected with the 7 pin of U2, one end of a resistor R3 and one end of a resistor R4, the other end of R3 is grounded, and the other end of R4 is connected with RS 485-B1.

The snow depth sensor is a laser snow depth sensor produced by Austrian SOMMER company, the model is HM31, and the snow depth measuring range is 0-15 m. The numerical control electric pan-tilt adopts a worm and gear light pan-tilt produced by Sichuan convergent optical communication Limited, the model is HY-LW18-01B, the horizontal rotation angle range is 0-360 degrees, the pitching angle range is-60 degrees, and the positioning precision is 0.1 degrees. An angle sensor is mounted on the snow depth detection sensor to detect the angle pointed by the snow depth detection sensor. An angle sensor is arranged on a photovoltaic module backboard to detect an included angle between the photovoltaic module and the horizontal plane, the angle sensor is a double-shaft inclination angle sensor produced by Shenzhen Weite Intelligent science and technology Limited, the model is SINDT02-485, and the angle sensor is an angle sensorThe accuracy of the degree detection is 0.1 degree. The temperature sensor adopts a wide temperature measuring range single-bus temperature measuring chip manufactured by Beijing seven-core Zhongchuang science and technology Limited, the model is QT18B20, the temperature measuring range is-55 ℃ to +125 ℃, the maximum error is +/-0.5 ℃ in the range of-10 ℃ to +85 ℃, and the maximum error is +/-1.5 ℃ in the full temperature range. The irradiation sensor is a product produced by Wuhan cloud technology Limited, the model is YGC-TBQ-KV-A2, and the irradiation detection range is 0-2000W/m². The electric tracing band is made of glass fiber constant power electric tracing band produced by Anhui Huanrei electric heating appliances, the model is RDP2-J4-60, 220V is used for supplying power, the heating power is 60W/m, and the width of the electric tracing band is 9.5 mm.

The numerical control holder control circuit comprises a common-mode inductor LDM2, wherein the first end of an LDM2 is connected with +24V, the second end of an LDM2 is connected with one end of an inductor L4, the other end of the L4 is connected with a pin 1 of a P3 of an HLK-10D2424B chip, a pin 2 of the P3 is connected with the third end of the LDM2, and the fourth end of the LDM2 is grounded; the 4 pins of the P3 are connected with +24V-HY through an inductor L5, and the 3 pins of the P3 are connected with GND-HY through an inductor L6;

the 1 pin of a ST3485 chip U3 is connected with UART2-RX, the 2 and 3 pins of U3 are connected with RD2, the 4 pin of U3 is connected with UART2-TX, the 5 pin of U3 is respectively connected with ground and one end of a capacitor C29, the other end of C29 is respectively connected with 8 pins of +3.3V, U3, the 6 pin of U3 is respectively connected with one end of a resistor R10, one end of a resistor R11 and one end of a resistor R12, the other end of R11 is connected with +3.3V, the other end of R12 is connected with RS485-A2, the other end of R10 is respectively connected with the 7 pin of U3, one end of a resistor R8 and one end of a resistor R9, the other end of R8 is grounded, and the other end of R9 is connected with RS 485-B2.

The temperature detection circuit adopts a QT18B20 chip PE3, and pins 1, 2 and 3 of the PE3 are respectively connected with T-GND, T-DQ and T-3.3V.

The angle detection circuit comprises a common-mode inductor LDM3, wherein the first end of an LDM3 is connected with +24V, the second end of an LDM3 is connected with one end of an inductor L7, the other end of the L7 is connected with a pin 1 of a P4 of an HLK-10D2424B chip, a pin 2 of the P4 is connected with the third end of the LDM3, and the fourth end of an LDM3 is grounded; the pin 4 of the P4 is connected with the +24V-SINDT through an inductor L8, and the pin 3 of the P4 is connected with the GND-SINDT through an inductor L9;

a pin 1 of a ST3485 chip U4 is connected with UART3-RX, pins 2 and 3 of U4 are connected with RD3, a pin 4 of U4 is connected with UART3-TX, a pin 5 of U4 is respectively connected with the ground and one end of a capacitor C38, the other end of C38 is respectively connected with a pin 8 of +3.3V, U4, a pin 6 of U4 is respectively connected with one end of a resistor R16, one end of a resistor R17 and one end of a resistor R18, the other end of R17 is connected with +3.3V, the other end of R18 is connected with RS485-A3, the other end of R16 is respectively connected with a pin 7 of U4, one end of a resistor R14 and one end of a resistor R15, the other end of R14 is grounded, and the other end of R15 is connected with RS 485-B3;

the 1 pin of a ST3485 chip U5 is connected with UART4-RX, the 2 and 3 pins of U5 are connected with RD4, the 4 pin of U5 is connected with UART4-TX, the 5 pin of U5 is respectively connected with ground and one end of a capacitor C39, the other end of C39 is respectively connected with 8 pins of +3.3V, U5, the 6 pin of U5 is respectively connected with one end of a resistor R21, one end of a resistor R22 and one end of a resistor R23, the other end of R22 is connected with +3.3V, the other end of R23 is connected with RS485-A4, the other end of R21 is respectively connected with the 7 pin of U5, one end of a resistor R19 and one end of a resistor R20, the other end of R19 is grounded, and the other end of R20 is connected with RS 485-B4.

The irradiation detection circuit comprises an LM324 chip CA1A, a pin 3 of CA1A is connected with a CURRENT, a pin 2 of CA1A is respectively connected with a pin 1 of CA1A and one end of a resistor R25, and the other end of R25 is connected with an ADC5 through a resistor R26.

Pins 1, 2 and 3 of the PE6 of the YGC-TBQ-KV-A2 chip are correspondingly connected with +24V, GND and CURRENT respectively.

The current detection circuit comprises an LM324 chip CA1B, wherein a pin 5 of CA1B is respectively connected with one end of a resistor R29 and one end of a resistor R30, the other end of R29 is respectively connected with the other end of R30 and the ground, a pin 6 of CA1B is respectively connected with one end of a resistor R27 and one end of a resistor R28, the other end of R27 is connected with an S-CUR, the other end of R28 is respectively connected with a pin 7 of CA1B and one end of a resistor R31, the other end of R31 is respectively connected with a pin 9 of LM324 chip CA1C and one end of a resistor R32, a pin 10 of CA1C is grounded through a resistor R33, the other end of R32 is respectively connected with a pin 8 of CA1C and one end of a resistor R34, and the other end of R34 is connected with an ADC4 through a resistor R35;

pins 5-8 of a PE7 chip HDIB-CE-10P2O2 are correspondingly connected with a +24V pin, a GND pin, an S-CUR pin and a GND pin respectively.

The voltage detection circuit comprises a VSM025A/10 chip U6, wherein a pin 1 of U6 is connected with PV + through parallel resistors R36 and R37, a pin 2 of U6 is connected with PV-, a pin 5 of U6 is connected with a pin 3 of LM324 chip CA2A through a resistor R39, a pin 2 of CA2A is respectively connected with a pin 1 of CA2A and one end of a resistor R40, and the other end of R40 is connected with an ADC 1;

a pin 1 of a VSM025A/10 chip U7, a pin 1 of U7 is connected with PV + through parallel resistors R41 and R42, a pin 2 of U7 is connected with PV-, a pin 5 of U7 is connected with a pin 5 of a LM324 chip CA2B through a resistor R44, a pin 6 of CA2B is respectively connected with a pin 7 of CA2B and one end of a resistor R45, and the other end of R45 is connected with an ADC 2;

the VSM025A/10 chip U8, 1 pin of U8 connects PV + through parallel resistance R46, R47, 2 pins of U8 connects PV-, 5 pins of U8 connects 10 pins of LM324 chip CA2C through resistance R49, 9 pins of CA2C connect 8 pins of CA2C, one end of resistance R50 separately, another end of R50 connects ADC 3.

The keyboard and liquid crystal screen circuit comprises a 74LV08A chip U9 and a JLX12864G-183-BN chip U10, wherein 1, 2, 5, 8, 9 and 12 pins of the U9 are respectively and correspondingly connected with COL1, COL2, COL3, INT3, COL5 and COL 4;

the 8-12 pins of the U10 are correspondingly connected with the SDA, the SCL, the LCD-A0, the LCD-RST and the LCD-CS respectively.

The heat tracing band control circuit comprises a common mode inductor LDM4, wherein the first end of an LDM4 is connected with +24V, the second end of an LDM4 is connected with one end of an inductor L10, the other end of the L10 is connected with a pin 1 of a P5 of an HLK-10D2424B chip, a pin 2 of the P5 is connected with the third end of the LDM4, and the fourth end of the LDM4 is grounded; the 4 pins of the P5 are connected with +24V-RELAY through an inductor L11, and the 3 pins of the P5 are connected with GND-RELAY through an inductor L12;

pins 3, 4, 7, 8, 13 and 14 of a U11 chip 74LVC373ADB chip are correspondingly connected with pins L1-L6 respectively, pin 11 of U11 is connected with pin LE1, and pins 2, 5, 6, 9, 12 and 15 of U11 are correspondingly connected with pins L1-1-L1-6 respectively;

pins 2, 4, 6 and 8 of the TLP521-4 chip U12 are correspondingly connected with pins L1-1-L1-4 respectively; pins 2 and 4 of the TLP521-2 chip U13 are correspondingly connected with pins L1-5 and L1-6 respectively; the 15, 13, 11 and 9 feet of U12 are correspondingly connected with KM1-1, KM1-2, KM1-3 and KM1-4 respectively, and the 7 and 5 feet of U13 are correspondingly connected with KM1-5 and KM1-6 feet respectively;

pins 2, 4, 6 and 8 of the TLP521-4 chip U15 are correspondingly connected with pins L2-1-L2-4 respectively; pins 2 and 4 of the TLP521-2 chip U16 are correspondingly connected with pins L2-5 and L2-6 respectively; the 15, 13, 11 and 9 feet of U15 are correspondingly connected with KM2-1, KM2-2, KM2-3 and KM2-4 respectively, and the 7 and 5 feet of U16 are correspondingly connected with KM2-5 and KM2-6 feet respectively;

pins 3, 4, 7, 8, 13 and 14 of a U14 chip 74LVC373ADB chip are correspondingly connected with pins L1-L6 respectively, pin 11 of U14 is connected with pin LE2, and pins 2, 5, 6, 9, 12 and 15 of U14 are correspondingly connected with pins L2-1-L2-6 respectively;

pins 2, 4, 6 and 8 of the TLP521-4 chip U18 are correspondingly connected with pins L3-1-L3-4 respectively; pins 2 and 4 of the TLP521-2 chip U19 are correspondingly connected with pins L3-5 and L3-6 respectively; the 15, 13, 11 and 9 feet of U18 are correspondingly connected with KM3-1, KM3-2, KM3-3 and KM3-4 respectively, and the 7 and 5 feet of U19 are correspondingly connected with KM3-5 and KM3-6 feet respectively;

pins 3, 4, 7, 8, 13 and 14 of a 74LVC373ADB chip U17 are correspondingly connected with pins L1-L6 respectively, pin 11 of U17 is connected with pin LE3, and pins 2, 5, 6, 9, 12 and 15 of U17 are correspondingly connected with pins L3-1-L3-6 respectively.

The GPRS communication circuit comprises a USR-GPRS232-7S3 chip U20, pins 6 and 7 of U20 are correspondingly connected with a USR-TX and a USR-RX respectively, a pin 10 of U20 is connected with a PWR, and a pin 15 of U20 is connected with a G-LINK;

pin 1 of a TPS79328DBVR chip P6 is respectively connected with +3.3V, one end of a capacitor C64 and one end of a resistor R74, the other end of R74 is connected with pin 3 of P6, the other end of C64 is respectively connected with ground and pin 2 of P6, pin 4 of P6 is respectively connected with ground and one end of a capacitor C65 through a capacitor C66, and the other end of C65 is connected with pin 5 of P6;

the base electrode of an NPN triode Q1 is respectively connected with one end of a resistor R75 and one end of a resistor R76, the other end of the R75 is connected with a USR-TX, the other end of the R76 is respectively connected with +2.8V and one end of a resistor R77, the other end of the R77 is respectively connected with the collector electrode of the Q1 and the base electrode of the NPN triode Q2, the emitter electrodes of the Q1 and the Q2 are grounded, the collector electrode of the Q2 is respectively connected with one end of the resistor R78 and the UART5-RX, and the other end of the R78 is connected with + 3.3V;

a pin 1 of the TLP521-1 chip U21 is connected with a GPRS-PWR through a resistor R83, a pin 2 of the U21 is grounded, a pin 4 of the U21 is connected with +3.3V, a pin 3 of the U21 is respectively connected with one end of a resistor R84, one end of a capacitor C67 and one end of a resistor R85, and the other end of the R84 is respectively connected with the other end of a capacitor C67 and the ground; the other end of the R85 is connected with the base electrode of an NPN triode Q5, the emitter electrode of Q5 is grounded, and the collector electrode of Q5 is connected with PWR;

the base electrode of an NPN triode Q3 is respectively connected with one end of a resistor R79 and one end of a resistor R80, the other end of the R79 is connected with UART5-TX, the other end of the R80 is respectively connected with +3.3V and one end of a resistor R81, the other end of the R81 is respectively connected with the collector electrode of the Q3 and the base electrode of an NPN triode Q4, the emitter electrodes of the Q3 and the Q4 are grounded, the collector electrode of the Q4 is respectively connected with one end of a resistor R82 and the USR-RX, and the other end of the R82 is connected with + 2.8V;

the base electrode of an NPN triode Q6 is connected with G-LINK through a resistor R86, the collector electrode of Q6 is respectively connected with one end of a resistor R88 and the +4V end through a light-emitting diode LED1 and a resistor R87 in sequence, and the other end of R88 is respectively connected with the emitter electrode of the Q6 and the ground through a light-emitting diode LED 2;

a pin 1 of a P7 of the MP2303 chip is connected with an MP-BS, a pin 2 of the P7 is respectively connected with a cathode of a diode D11 and one end of a resistor R89, an anode of D11 is connected with +15V, and the other end of R89 is connected with a pin 7 of a P7; the 3 pins of the P7 are respectively connected with +4V, one end of a capacitor C72, one end of an inductor L13, one end of a capacitor C73, one end of a capacitor C74 and one end of a resistor R90, the other end of the C72 is respectively connected with the MP-BS and the cathode of a diode D12, the anode of the D12 is connected with the other end of the L13, the other end of the R90 is respectively connected with the 5 pin of the P7 and one end of the resistor R91, the other end of the R91 is respectively connected with the ground and one end of the resistor R92, and the other end of the R92 is connected with the 6 pin of the P7 through the capacitor C75.

Wherein P1 is a 3.3V power module, and the maximum output current is 1A, which supplies power for the electronic components in the controller that need 3.3V power supply. The P2-P5 are 24V direct current power supply isolation modules, have the maximum output power of 10W, are used for realizing the electrical isolation between the controller and various external devices and preventing the influence of electromagnetic interference and surge caused by the external devices on the controller. P6 is a 2.8V power supply module, has a maximum output current of 200mA, and supplies power for a communication level conversion circuit in the GPRS communication circuit. P7 is a 4V power module, and the maximum output current is 3A, and the power is supplied to the GPRS wireless transparent transmission module in the GPRS communication circuit.

PE 1-PE 7 are external devices and are connected with a controller circuit board through connectors, so that power supply and data transmission are achieved. Wherein PE1 is a snow depth sensor with model HM31, and is connected with the circuit board through connector J3; PE2 is a numerical control electric holder, has model number of HY-LW18-01B, and is connected with the circuit board through a connector J4; PE3 is a temperature sensor, the model is QT18B20, and is connected with the circuit board through a connector J5; PE4 is an angle detection sensor installed on the snow depth sensor, is of type SINDT02-485, and is connected with the circuit board through a connector J6; the PE5 is an angle detection sensor installed on the photovoltaic module backboard, is of a model number of SINDT02-485, and is connected with the circuit board through a connector J7; the PE6 is an irradiation sensor with the model of YGC-TBQ-KV-A2, and is connected with the circuit board through a connector J8; PE7 is a current sensor, model HDIB-CE-10P2O2, and is connected with the circuit board through a connector J9.

The connectors J10, J11 and J12 are voltage signal input ports of the photovoltaic module. A pin 1 of the connector J10 is connected with the positive output end of the No. 1 photovoltaic module, and a pin 2 of the connector J10 is connected with the negative output end of the No. 1 photovoltaic module. Pin 1 of connector J11 is connected with No. 2 photovoltaic module's anodal output, and connector J11's pin 2 is connected with No. 2 photovoltaic module's negative pole output. Pin 1 of the connector J12 is connected with the positive output end of the No. 3 photovoltaic module, and pin 2 of the connector J12 is connected with the negative output end of the No. 3 photovoltaic module.

A pin 1 of the connector J14 is connected with a live wire of an alternating current 220V power supply, and a pin 2 of the connector J14 is connected with a zero wire of the alternating current 220V power supply. The pins 1, 3, 5, 7, 9 and 11 of the connector J15 are connected with one end of the 6 heat tracing bands of the No. 1 photovoltaic module, and the pins 2, 4, 6, 8, 10 and 12 of the J15 are connected with the other end of the 6 heat tracing bands of the No. 1 photovoltaic module back plate. The pins 1, 3, 5, 7, 9 and 11 of the connector J16 are connected with one end of the 6 heat tracing bands of the No. 2 photovoltaic module backboard, and the pins 2, 4, 6, 8, 10 and 12 of the J16 are connected with the other end of the 6 heat tracing bands of the No. 2 photovoltaic module. The pins 1, 3, 5, 7, 9 and 11 of the connector J17 are connected with one end of the 6 heat tracing bands of the No. 3 photovoltaic module backboard, and the pins 2, 4, 6, 8, 10 and 12 of the J17 are connected with the other end of the 6 heat tracing bands of the No. 3 photovoltaic module.

In addition, the connector J1 is a DC power supply interface of the controller, the connector J2 is a program downloading interface of the CPU, and the connector J13 is connected with a 5 × 5 keyboard.

R24 is a 1% precision resistor with a resistance of 150 Ω. R38, R43, R48 are precision resistors of 1% precision and have a resistance of 130 Ω. R90 is a precision resistor with 1% precision and has a resistance of 40.2K omega. R91 is a 1% precision resistor with a resistance of 10K Ω.

The light emitting diode LED1 (green) is a GPRS communication network status indicator lamp, and indicates that the GPRS network connection is established when the light emitting diode LED1 is turned on, and indicates that the GPRS network connection is disconnected when the light emitting diode LED1 is turned off. The light emitting diode LED2 (red) is a power indicator lamp of the GPRS wireless transparent transmission module, and when the power indicator lamp is turned on, the power indicator lamp indicates that the GPRS wireless transparent transmission module is powered on, and when the power indicator lamp is turned off, the power indicator lamp indicates that the GPRS wireless transparent transmission module stops supplying power.

LDM 1-LDM 4 are common mode inductors for suppressing common mode electromagnetic interference signals in the power supply, and the inductance value is 10 mH.

The invention adopts MM32F3273D7P chip as CPU of controller, the number of general purpose input/output ports of the chip is 52, if more electric tracing bands need to be controlled, the invention can be realized by selecting the chip with more general purpose input/output ports as CPU or adding input/output port expansion circuit.

It should be understood that the detailed description of the present invention is only for illustrating the present invention and is not limited by the technical solutions described in the embodiments of the present invention, and those skilled in the art should understand that the present invention can be modified or substituted equally to achieve the same technical effects; as long as the use requirements are met, the method is within the protection scope of the invention.

Claims (1)

1. The method for calculating the theoretical output power of the photovoltaic module is characterized in that P_thIs the theoretical output power (unit W), P of the photovoltaic module_stcIs rated power, R, of the photovoltaic module under a standard test environment_acReal-time irradiation intensity (unit W/m) for photovoltaic module surface²)，R_stcThe irradiation intensity (unit W/m) under the standard test environment is adopted²)，T_bIs the temperature (unit ℃) of a photovoltaic module back plate, T_stcThe temperature of a component battery (unit ℃) in a standard test environment, gamma is a power temperature coefficient (unit%/° C, gamma is a negative number) of the photovoltaic component, Y is the number of years that the photovoltaic component has operated (the number of years is obtained by dividing the number of days that the photovoltaic component operates by 365, and the result is accurate to 3 bits after decimal point), A is₁Power decay Rate (% in units) for the first year of operation of a photovoltaic Module A_VThe linear power attenuation rate (unit%) of the photovoltaic module every year_dThe influence coefficient of dust on the surface of the component is;

when Y ≦ 1, the amount of the catalyst,

Y>when the pressure of the mixture is 1, the pressure is lower,

in the formula, K_dThe specific value of (A) requires a radiation intensity R at 12 pm per day_ac>500W/m²Under the condition of (1), K is calculated according to the following formula_dReal-time value of (a), the calculated K_dThe real-time value as the time to the next time meets the above calculation condition (12 am and irradiation intensity R)_ac>500W/m²) Between moments in time in the above calculation P_thK used in the formula_dA value; the next time the above calculation conditions are met (12 am and irradiation intensity R)_ac>500W/m²) Then, K is recalculated according to the following formula_dBy the new calculated K_dValue replacing previously calculated K_dValue calculation P_th；

When Y ≦ 1, the amount of the catalyst,

Y>when the pressure of the mixture is 1, the pressure is lower,

in the formula, P_acIs the real-time output power (unit W), R of the photovoltaic module_stc＝1000W/m²，T_stc＝25℃,P_stc、γ、A₁、A_VAnd providing specific parameter values by a photovoltaic module manufacturer according to different types of photovoltaic modules.

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