Photovoltaic module detection device

Abstract

The photovoltaic module detection device belongs to the technical field of solar power station snow melting, and particularly relates to a photovoltaic module detection device. The photovoltaic module detection device has good use effect. The photovoltaic module detection device comprises a photovoltaic module voltage detection circuit, a current detection circuit, an irradiation detection circuit, a snow depth detection circuit, an angle detection circuit and a temperature detection circuit, wherein the signal transmission port of the CPU circuit is connected with the signal transmission port of the voltage detection circuit, the signal transmission port of the current detection circuit, the signal transmission port of the irradiation detection circuit, the signal transmission port of the snow depth detection circuit, the signal transmission port of the angle detection circuit and the signal transmission port of the temperature detection circuit; the detection signal input port of the current detection circuit is connected with the current transformer; and the detection signal input port of the irradiation detection circuit is connected with the detection signal output port of the irradiation sensor.

Description

Technical Field

[0001] This invention belongs to the field of solar power plant snow melting technology, and particularly relates to a photovoltaic module testing device. Background Technology

[0002] In mid-to-high latitude regions, winter snow cover can significantly reduce the power generation of photovoltaic (PV) modules. Melting the snow on the PV module surface could effectively increase power generation, but current snow-melting technologies for PV power plants require further improvement. (Invention Content)

[0003] The present invention addresses the above-mentioned problems by providing a photovoltaic module testing device with good performance.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: the photovoltaic module testing device of the present invention includes a photovoltaic module voltage detection circuit, a current detection circuit, an irradiation detection circuit, a snow depth detection circuit, an angle detection circuit, and a temperature detection circuit. The CPU circuit's signal transmission port is connected to the signal transmission ports of the voltage detection circuit, current detection circuit, irradiation detection circuit, snow depth detection circuit, angle detection circuit, and temperature detection circuit, respectively. The current detection circuit's detection signal input port is connected to a current transformer. The irradiation detection circuit's detection signal input port is connected to the irradiation sensor's detection signal output port. A snow depth sensor and a gimbal angle sensor are disposed on the upper end of the CNC pan-tilt unit. A photovoltaic module angle sensor is disposed on the photovoltaic module. The detection signal output ports of the pan-tilt unit angle sensor and the photovoltaic module angle sensor are respectively connected to the detection signal input port of the angle detection circuit. The snow depth sensor's detection signal output port is connected to the snow depth detection circuit's detection signal input port.

[0005] As a preferred embodiment, the snow depth detection circuit of the present invention includes a common-mode inductor LDM1. The first terminal of LDM1 is connected to +24V, the second terminal of LDM1 is connected to one end of inductor L1, the other end of L1 is connected to pin 1 of HLK-10D2424B chip P2, pin 2 of P2 is connected to the third terminal of LDM1, and the fourth terminal of LDM1 is grounded. Pin 4 of P2 is connected to +24V-HM31 through inductor L2, and pin 3 of P2 is connected to GND-HM31 through inductor L3.

[0006] Pin 1 of ST3485 chip U2 is connected to UART1-RX, pins 2 and 3 of U2 are connected to RD1, pin 4 of U2 is connected to UART1-TX, pin 5 of U2 is connected to ground and one end of capacitor C21, the other end of C21 is connected to +3.3V and pin 8 of U2, pin 6 of U2 is connected to one end of resistor R5, one end of resistor R6 and one end of resistor R7, the other end of R6 is connected to +3.3V, the other end of R7 is connected to RS485-A1, the other end of R5 is connected to pin 7 of U2, one end of resistor R3 and one end of resistor R4, the other end of R3 is grounded, and the other end of R4 is connected to RS485-B1.

[0007] As another preferred embodiment, the temperature detection circuit of the present invention uses a QT18B20 chip PE3, with pins 1, 2, and 3 of PE3 connected to T-GND, T-DQ, and T-3.3V, respectively.

[0008] As another preferred embodiment, the angle detection circuit of the present invention includes a common-mode inductor LDM3. The first terminal of LDM3 is connected to +24V, the second terminal of LDM3 is connected to one end of inductor L7, the other end of L7 is connected to pin 1 of P4 of HLK-10D2424B chip, pin 2 of P4 is connected to the third terminal of LDM3, and the fourth terminal of LDM3 is grounded; pin 4 of P4 is connected to +24V-SINDT through inductor L8, and pin 3 of P4 is connected to GND-SINDT through inductor L9.

[0009] Pin 1 of ST3485 chip U4 is connected to UART3-RX; pins 2 and 3 of U4 are connected to RD3; pin 4 of U4 is connected to UART3-TX; pin 5 of U4 is connected to ground and one end of capacitor C38; the other end of C38 is connected to +3.3V and pin 8 of U4; pin 6 of U4 is connected to one end of resistor R16, one end of resistor R17, and one end of resistor R18; the other end of R17 is connected to +3.3V; the other end of R18 is connected to RS485-A3; the other end of R16 is connected to pin 7 of U4, one end of resistor R14, and one end of resistor R15; the other end of R14 is grounded; the other end of R15 is connected to RS485-B3.

[0010] Pin 1 of ST3485 chip U5 is connected to UART4-RX, pins 2 and 3 of U5 are connected to RD4, pin 4 of U5 is connected to UART4-TX, pin 5 of U5 is connected to ground and one end of capacitor C39, the other end of C39 is connected to +3.3V and pin 8 of U5, pin 6 of U5 is connected to one end of resistor R21, one end of resistor R22, and one end of resistor R23, the other end of R22 is connected to +3.3V, the other end of R23 is connected to RS485-A4, the other end of R21 is connected to pin 7 of U5, one end of resistor R19, and one end of resistor R20, the other end of R19 is grounded, and the other end of R20 is connected to RS485-B4.

[0011] Secondly, the irradiation detection circuit of the present invention includes an LM324 chip CA1A. Pin 3 of CA1A is connected to CURRENT. Pin 2 of CA1A is connected to pin 1 of CA1A and one end of resistor R25, respectively. The other end of R25 is connected to ADC5 through resistor R26.

[0012] In addition, the current detection circuit of the present invention includes an LM324 chip CA1B. Pin 5 of CA1B is connected to one end of resistor R29 and one end of resistor R30. The other end of R29 is connected to the other end of R30 and ground. Pin 6 of CA1B is connected to one end of resistor R27 and one end of resistor R28. The other end of R27 is connected to S-CUR. The other end of R28 is connected to pin 7 of CA1B and one end of resistor R31. The other end of R31 is connected to pin 9 of the LM324 chip CA1C and one end of resistor R32. Pin 10 of CA1C is grounded through resistor R33. The other end of R32 is connected to pin 8 of CA1C and one end of resistor R34. The other end of R34 is connected to ADC4 through resistor R35.

[0013] Pins 5 to 8 of the HDIB-CE-10P2O2 chip PE7 are connected to +24V, GND, S-CUR, and GND respectively.

[0014] The voltage detection circuit includes a VSM025A / 10 chip U6. Pin 1 of U6 is connected to PV+ through parallel resistors R36 and R37. Pin 2 of U6 is connected to PV-. Pin 5 of U6 is connected to pin 3 of the LM324 chip CA2A through resistor R39. Pin 2 of CA2A is connected to pin 1 of CA2A and one end of resistor R40. The other end of R40 is connected to ADC1.

[0015] VSM025A / 10 chip U7, pin 1 of U7 is connected to PV+ through parallel resistors R41 and R42, pin 2 of U7 is connected to PV-, pin 5 of U7 is connected to pin 5 of LM324 chip CA2B through resistor R44, pin 6 of CA2B is connected to pin 7 of CA2B and one end of resistor R45, and the other end of R45 is connected to ADC2;

[0016] The VSM025A / 10 chip U8 has pin 1 connected to PV+ via parallel resistors R46 and R47, pin 2 connected to PV-, and pin 5 connected to pin 10 of the LM324 chip CA2C via resistor R49. Pin 9 of CA2C is connected to pin 8 of CA2C and one end of resistor R50, with the other end of R50 connected to ADC3.

[0017] The beneficial effects of this invention.

[0018] The snow depth detection circuit detects the snow depth in real time through a snow depth sensor, converts the 485 signal output by the snow depth sensor into a serial TTL signal through a level signal conversion circuit to communicate with the CPU, and achieves electrical isolation between the controller circuit and the snow depth sensor through a power isolation circuit.

[0019] The angle detection circuit uses an angle sensor to detect the angles of the photovoltaic module and the snow depth sensor in real time. The 485 signal output by the angle sensor is converted into a serial TTL signal through a level signal conversion circuit to communicate with the CPU. The power isolation circuit realizes the electrical isolation between the controller circuit and the angle sensor.

[0020] The irradiation detection circuit detects the irradiation intensity in real time through an irradiation sensor. The irradiation sensor outputs the irradiation intensity as a current signal. The current signal is converted into a voltage signal by a signal conditioning circuit. The voltage signal is converted into a digital signal by an AD conversion module inside the CPU.

[0021] The current detection circuit samples the current output by the photovoltaic module proportionally through a current sensor and outputs a corresponding voltage signal. The voltage signal is then converted into a digital signal by the AD conversion module inside the CPU after passing through the signal conditioning circuit.

[0022] The voltage detection circuit samples the voltage output by the photovoltaic module proportionally through a voltage transformer and outputs a corresponding current signal. The current signal is converted into a voltage signal by a signal conditioning circuit, and the voltage signal is converted into a digital signal by an AD conversion module inside the CPU.

[0023] In the temperature detection circuit, the temperature sensor converts the temperature of the photovoltaic module backsheet into a digital signal and communicates with the CPU via a single data bus to send the module backsheet temperature information to the CPU.

[0024] The snow depth detection circuit, CNC gimbal control circuit, angle detection circuit, irradiation detection circuit, current detection circuit, voltage detection circuit, temperature detection circuit, keyboard and LCD screen circuit, heat tracing control circuit, and GPRS communication circuit are all connected to the CPU circuit. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The scope of protection of the present invention is not limited to the following description.

[0026] Figure 1 Schematic diagram of a photovoltaic module snow melting controller.

[0027] Figure 2 Control program flowchart.

[0028] Figure 3 The specific circuit schematic diagram a of the present invention.

[0029] Figure 4 Specific circuit schematic diagram b of the present invention.

[0030] Figure 5 Specific circuit schematic diagram c of the present invention.

[0031] Figure 6 Specific circuit schematic diagram d of the present invention.

[0032] Figure 7 Specific circuit schematic diagram e of the present invention.

[0033] Figure 8 Specific circuit schematic diagram f of the present invention.

[0034] Figure 9 Specific circuit schematic diagram g of the present invention.

[0035] Figure 10 Design drawing of the horizontal "king" - shaped heat sink installed on the back of the photovoltaic module.

[0036] Figure 11 Location map of snow depth detection points on a certain photovoltaic module (all numerical units in the figure are mm).

[0037] Figure 12 Size drawing of the heat sink (all numerical units in the figure are mm).

[0038] Figure 13 Installation location drawing of the heat sink on the back of the photovoltaic module (all numerical units in the figure are mm).

[0039] Figure 14 Side view schematic diagram of the snow depth detection sensor and the photovoltaic module.

[0040] Figure 15 Top view schematic diagram of the snow depth detection sensor and the photovoltaic module. Specific implementation manners

[0041] As shown in the figure, the present invention includes a horizontal strip - shaped rectangular plate, and a plurality of vertical strip - shaped rectangular plates are evenly distributed along the length direction of the horizontal strip - shaped rectangular plate. The front vertical edge of the front - end vertical strip - shaped rectangular plate is the front edge of the heat sink, and the rear vertical edge of the rear - end vertical strip - shaped rectangular plate is the rear edge of the heat sink; the center line along the length direction of the horizontal strip - shaped rectangular plate passes through the center of the vertical strip - shaped rectangular plate; a horizontal strip - shaped electric heating tape is arranged on the heat sink, and the center line in the length direction of the horizontal strip - shaped electric heating tape coincides with the center line in the length direction of the horizontal strip - shaped rectangular plate. The front end of the horizontal strip - shaped electric heating tape is flush with the front end of the heat sink, and the rear end of the horizontal strip - shaped electric heating tape is flush with the rear end of the heat sink.

[0042] In the present invention, the designed horizontal "king" - shaped heat sink enables the heat energy emitted by the electric tracing heating tape to be effectively conducted to the photovoltaic module, making the snow - melting speed of each part on the surface of the photovoltaic module more uniform. Additionally, compared with fully covering the backplane of the photovoltaic module with heat sinks, the designed horizontal "king" - shaped heat sink can significantly reduce the consumption of heat sink materials and remarkably lower the cost.

[0043] There are four vertical strip - shaped rectangular plates.

[0044] The width of the horizontal strip - shaped electric tracing heating tape is less than the width of the horizontal strip - shaped rectangular plate.

[0045] There are multiple heat sinks, evenly distributed along the length direction of the photovoltaic module; the length direction of the heat sink is perpendicular to the length direction of the photovoltaic module; the front ends of each heat sink are in the same vertical direction; in the horizontal direction, the heat sink is centered at the back of the photovoltaic module.

[0046] There are six heat sinks.

[0047] The area between adjacent heat sinks is a detection point.

[0048] The center of the rectangular area enclosed by every four adjacent vertical strip - shaped rectangular plates is a detection point.

[0049] Select x×y detection points on the backplane of the photovoltaic module at uniform intervals, where x is the number of horizontal detection points and y is the number of vertical detection points. Design a horizontal "king" - shaped heat sink to enclose each detection point, as Figure 10 shown. Install 1 electric tracing heating tape at the center line position of each heat sink, and the horizontal center line of the heat sink coincides with the horizontal center line of the electric tracing heating tape.

[0050] m is the length of the photovoltaic module (unit: mm), n is the width of the photovoltaic module (unit: mm), k is the horizontal spacing of the detection points (unit: mm), p is the vertical spacing of the detection points (unit: mm), q is the longitudinal spacing of the heating tape (unit: mm), a is the width of the heat sink (unit: mm), e is the length of the heat sink (unit: mm), b is the width of the vertical strip - shaped rectangular plate (unit: mm), c is the width of the horizontal strip - shaped rectangular plate (unit: mm);

[0051] 0.8n≦e < n, 60mm≦b≦100mm, 60mm≦c≦100mm, 250mm≦a < p, k = n / (x + 1), p = m / (y + 1), q = p, the length of the electric tracing heating tape is equal to the length e of the heat sink; in the horizontal direction, the heat sink is centered at the back of the photovoltaic module, and the distance between the left edge of the photovoltaic module and the left edge of the heat sink is (n - e) / 2, and the distance between the right edge of the photovoltaic module and the right edge of the heat sink is also (n - e) / 2; the thickness of the heat sink is between 0.8mm and 1.5mm.

[0052] The power supply control circuits of each heating tape installed on each photovoltaic module are independent of each other. When there is snow on the surface of the photovoltaic module, instead of starting all the electric heating tapes to melt the snow, only the upper and lower two adjacent electric heating tapes at the position where the detection points with snow are identified are powered for heating, so as to achieve heating only at the snow-covered parts and not at the non-snow-covered parts. This can greatly save electric energy and reduce the snow melting cost.

[0053] The length of the photovoltaic module is 2094 mm and the width is 1038 mm.

[0054] The heat sink is an aluminum heat sink.

[0055] Taking the photovoltaic module with the model number YL450D-40d1 / 2 produced by Yingli Energy (China) Co., Ltd. as an example, the length of this module is 2094 mm and the width is 1038 mm. Select 15 detection points (5 rows × 3 columns) at uniform intervals on the back panel of the photovoltaic module, as Figure 11 shown. Design a horizontal "king" shaped aluminum heat sink, and the size of the heat sink is as Figure 12 shown, surrounding these 15 points. Each photovoltaic module uses a total of 6 heat sinks. Install 1 electric heating tape at the center line position of each heat sink, and the installation position is as Figure 13 shown. This solar panel uses a total of 6 electric heating tapes. Taking this model of photovoltaic module as an example, if the back panel is fully covered with aluminum heat sinks with a thickness of 1 mm, according to the aluminum density of 2700 kg / m [[ID=?]]<00?0001> calculated, the aluminum material required is 5.8686444 kg. If the designed horizontal "king" shaped aluminum heat sinks are used, the aluminum material required is 2.356776 kg, which is 40.16% of the aluminum material consumption when the back panel is fully covered with heat sinks.

[0056] The heat sink designed by the present invention can detect the snow depth at the detection points. The method for detecting the snow depth at the detection points of the photovoltaic module is as follows:

[0057] It should be noted that there seems to be an incorrect tag in your original text, <00?0001> which should probably be 3 . I've made the translation based on the assumption that it's 3 . If this is not correct, please clarify.A snow depth sensor is mounted on a CNC motorized pan-tilt head. The pan-tilt head controls the sensor's horizontal and vertical rotation. The pan-tilt head is fixed to a column perpendicular to the horizontal plane. The column is installed along the extension line of the centerline of photovoltaic module No. 1. f is the distance between the column and photovoltaic module 1 along the centerline direction (in mm), h is the height on the column from the horizontal plane where the leading edge of photovoltaic module 1 is located to the horizontal plane where the snow depth sensor is located (in mm), m is the length of photovoltaic module (in mm), n is the width of photovoltaic module (in mm), j is the spacing between photovoltaic modules (in mm), β is the horizontal rotation angle of the snow depth sensor probe (in °), d1 is the snow depth detected in the direction pointed by the snow depth sensor (in mm), d2 is the snow depth projected by d1 onto the top-view centerline direction of photovoltaic module (in mm), d is the snow depth projected by d2 onto the normal direction of photovoltaic module (in mm), θ is the angle between photovoltaic module and horizontal plane (in °), and δ is the pitch rotation angle of the snow depth sensor probe (in °).

[0058] To obtain the snow depth value *d* at a certain detection point of the photovoltaic module, it is first necessary to calculate the horizontal rotation angle β and the pitch rotation angle δ of the snow depth sensor pointing at that detection point. The sensor is then rotated to these angles by controlling a CNC motorized pan-tilt head, and the sensor detects the snow depth. Finally, the snow depth *d1* detected by the sensor in this direction is converted into the snow depth *d* in the normal direction of the photovoltaic module using an algorithm (see below). Figure 14 Taking five typical locations as examples (the algorithm for snow depth at other locations can be derived by referring to the algorithm for snow depth at these five typical locations), the snow depth calculation method is as follows.

[0059] (1) Algorithm for snow depth at detection point 1

[0060] First, calculate the required pitch angle δ and horizontal rotation angle β of the CNC electric pan-tilt head, as follows.

[0061] Depend on have to

[0062] Depend on have to

[0063] Then, the snow depth d1 detected by the snow depth sensor in the direction pointed by the CNC electric gimbal is converted into the snow depth d in the direction normal to the photovoltaic module, and the calculation is as follows.

[0064] Depend on We get d2 = d1 × cosβ

[0065] Depend on Obtain d=d2×sin(θ+δ)=d1×cosβ×sin(θ+δ)

[0066] (2) Algorithm for snow depth at detection point 2

[0067] Detection point 2 is located on the center line of photovoltaic module 1, so the horizontal rotation angle β is 0°, and d1 = d2. The required pitch rotation angle δ of the CNC electric pan-tilt head is calculated as follows.

[0068] Depend on have to

[0069] The snow depth d1 detected by the snow depth sensor in the direction pointed by the CNC electric gimbal is converted into the snow depth d in the direction normal to the photovoltaic module, and the calculation is as follows.

[0070] Depend on From d1 = d2, we get d = d1 × sin(θ + δ).

[0071] (3) Algorithm for snow depth at detection point 3

[0072] First, calculate the required pitch angle δ and horizontal rotation angle β of the CNC electric pan-tilt head, as follows.

[0073] Depend on have to

[0074] Depend on have to

[0075] Then, the snow depth d1 detected by the snow depth sensor in the direction pointed by the CNC electric gimbal is converted into the snow depth d in the direction normal to the photovoltaic module, and the calculation is as follows.

[0076] Depend on We get d2 = d1 × cosβ

[0077] Depend on Obtain d=d2×sin(θ+δ)=d1×cosβ×sin(θ+δ)

[0078] (4) Algorithm for snow depth at detection point 4

[0079] Detection point 4 is located on photovoltaic module 2, so the calculation needs to include the physical quantity j of the photovoltaic module spacing. First, calculate the required pitch rotation angle δ and horizontal rotation angle β of the CNC electric pan-tilt head, as follows.

[0080] Depend on have to

[0081] Depend on have to

[0082] Then, the snow depth d1 detected by the snow depth sensor in the direction pointed by the CNC electric gimbal is converted into the snow depth d in the direction normal to the photovoltaic module, and the calculation is as follows.

[0083] Depend on We get d2 = d1 × cosβ

[0084] Depend on Obtain d=d2×sin(θ+δ)=d1×cosβ×sin(θ+δ)

[0085] (5) Algorithm for snow depth at detection point 5

[0086] First, calculate the required pitch angle δ and horizontal rotation angle β of the CNC electric pan-tilt head, as follows.

[0087] Depend on have to

[0088] Depend on have to

[0089] Then, the snow depth d1 detected by the snow depth sensor in the direction pointed by the CNC electric gimbal is converted into the snow depth d in the direction normal to the photovoltaic module, and the calculation is as follows.

[0090] Depend on We get d2 = d1 × cosβ

[0091] Depend on Obtain d=d2×sin(θ+δ)=d1×cosβ×sin(θ+δ).

[0092] The method for calculating the theoretical output power of the photovoltaic module and the method for determining the start of snow melting in this invention are as follows:

[0093] 1) Calculation method for theoretical output power of photovoltaic modules

[0094] This invention proposes a method for calculating the theoretical output power of a photovoltaic module, which calculates the theoretical output power of the photovoltaic module from parameters such as actual irradiance, photovoltaic module backsheet temperature, and the number of years the photovoltaic module has been in operation.

[0095] The calculation process is as follows, where P th P represents the theoretical output power (in W) of a photovoltaic module. stc R represents the rated power of a photovoltaic module under standard testing conditions. ac Real-time irradiance of photovoltaic module surface (unit: W / m²) 2 ), R stcIrradiance under standard test conditions (unit: W / m²) 2 ), T b T represents the backsheet temperature of a photovoltaic module (in °C). stc Here, γ represents the module cell temperature under standard testing conditions (in °C), γ is the photovoltaic module power temperature coefficient (in % / °C, γ is negative), Y is the number of years the photovoltaic module has been in operation (the number of years is calculated by dividing the number of days the photovoltaic module has been in operation by 365, and the result is accurate to 3 decimal places), A1 is the power degradation rate of the photovoltaic module in the first year of operation (in %), and A... V K represents the annual linear power degradation rate (in %) of photovoltaic modules after the first year. d The influence coefficient of dust on the component surface.

[0096] When Y≦1,

[0097] When Y>1,

[0098] In the formula, K d The specific values ​​need to be calculated at 12 noon every day and the radiation intensity R ac >500W / m 2 Calculate K according to the following formula under the given conditions. d The real-time value of K obtained from this calculation d The real-time value is used as the value from that moment until the next time the above calculation conditions are met (12 noon and irradiance R). ac >500W / m 2 Between the times mentioned above, P is calculated. th K used in the formula d Value. The next time the above calculation conditions are met (12 noon and irradiance R) ac >500W / m 2 After that, recalculate K according to the following formula. d The real-time value, using the newly calculated K d The value replaces the previously calculated K. d Value calculation P th .

[0099] When Y≦1,

[0100] When Y>1,

[0101] In the formula, P ac R represents the real-time output power of the photovoltaic module (in W). stc =1000W / m 2 T stc =25℃, P stc γ, A1, A VThe photovoltaic module manufacturers provide specific parameter values ​​for different models of photovoltaic modules.

[0102] Compared with existing methods for calculating the theoretical output power of photovoltaic modules, this calculation method differs in the following ways:

[0103] (1) Previous algorithms multiplied the power degradation characteristics of photovoltaic modules over time by a fixed coefficient. This algorithm, however, considers the completely different power degradation characteristics of photovoltaic modules in the first and subsequent years. The power degradation is larger in the first year and smaller and linear in the second and subsequent years. Therefore, this algorithm calculates the theoretical output power for the first and subsequent years separately. In the first year of module use, the power degradation ratio due to time is (1-Y×A1); in the second year and subsequent years, the power degradation ratio due to time is [1-A1-(Y-1)×A1]. v The theoretical output power value of the photovoltaic module calculated in this way is more accurate than that obtained by previous algorithms.

[0104] (2) Because photovoltaic power plants are affected by factors such as the installation tilt angle of photovoltaic modules, fine dust particles brought by wind, whether there are factories emitting smoke and dust nearby, whether there is rain rinsing, and whether there are measures to regularly remove dust from photovoltaic modules, the thickness of dust on the surface of photovoltaic modules and its impact on the power generation efficiency of photovoltaic modules are variable, so the dust influence coefficient on the surface of the modules is variable.

[0105] Previous algorithms used a fixed surface dust influence coefficient (typically between 97% and 85%) when calculating the theoretical output power of photovoltaic modules, failing to consider the dynamic changes in the surface dust influence coefficient and thus reducing the accuracy of the calculated theoretical output power value. This patent proposes a calculation method that, under certain conditions (noon and irradiance R...),... ac >500W / m 2 Under the following conditions, based on the real-time output power P of the photovoltaic module ac , Number of years the photovoltaic module has been in operation Y, Real-time irradiance on the surface of the photovoltaic module R ac The real-time surface dust influence coefficient K is obtained by calculating parameters such as surface dust. d and at regular intervals, K d The value is dynamically updated using the newly calculated K. d The value replaces the previously calculated K. d This method allows for a more accurate calculation of the theoretical output power of photovoltaic modules.

[0106] 2) Methods for determining when to begin snow melting

[0107] Before activating the snow melting function, two prerequisites must be met: First, is there snow covering the surface of the photovoltaic modules? Second, has the snowfall ended? The snow melting function can only be activated when both conditions are met.

[0108] If the snow melting function is activated when there is no snow cover, the system will run idle, consuming electricity and reducing the lifespan of equipment such as CNC motorized pan-tilt units. Activating the snow melting function before the snowfall has ended will significantly increase the electricity consumption of the heating cable, because during snowfall, snow accumulation on the module surface may slide off (if the photovoltaic module's tilt angle is not 0 degrees) or be blown away by natural wind. Therefore, snow melting consumes the least amount of electricity when the snowfall has completely ended and the snow accumulation on the photovoltaic module surface is constant.

[0109] This invention provides a safe, reliable, energy-saving, and highly intelligent automatic snow melting system for photovoltaic power plants.

[0110] The present invention uses the following method to confirm the achievement of the above two prerequisites, and on this basis, determines whether to start snow melting of the components.

[0111] (1) Method for determining whether there is snow covering the surface of photovoltaic modules

[0112] If there is snow covering the surface of a photovoltaic module, its real-time output power will be significantly lower than its theoretical output power. The difference between these two power values ​​can be used to determine whether there is snow covering the surface of the photovoltaic module. The specific method is as follows.

[0113] Calculate the difference P between the theoretical output power and the actual output power of the photovoltaic module. dif (Unit: W)

[0114] P dif =P th -P ac

[0115] The theoretical output power P of the photovoltaic module th The calculation method is as described above, and the real-time output power P of the photovoltaic module is... ac The formula for calculating (unit W) is as follows.

[0116] P ac =U×I

[0117] Where U is the output voltage of the photovoltaic module (in V) and I is the output current of the photovoltaic module (in A).

[0118] Set power threshold P d (unit W), where P d =0.3×P th If Pdif >P d If this is the case, it can be determined that the surface of the photovoltaic module is covered with snow.

[0119] (2) Methods for determining whether snowfall has ended

[0120] Whether the snowfall has ended needs to be determined by whether the snow depth on the surface of the photovoltaic modules increases within a unit of time. The specific method is as follows.

[0121] Select a photovoltaic module at the center of the photovoltaic array, and measure the snow depth at all detection points on the surface of the photovoltaic module every 10 minutes, and calculate the average snow depth value d at these detection points. p (Unit: mm)

[0122]

[0123] In the formula d i Let be the snow depth value (in mm) at the i-th detection point on the surface of the photovoltaic module, where i = 1 to g, and g is the number of snow depth detection points on the surface of the photovoltaic module.

[0124] If the average snow depth value d p If the snowfall stops increasing for 30 consecutive minutes, it can be determined that the snowfall has ended.

[0125] The method for controlling the snow melting speed on the surface of photovoltaic modules in this invention is as follows:

[0126] Typically, the amount of snow accumulated on different parts of a photovoltaic (PV) module surface varies, meaning the snow depth differs across areas. If the same amount of electrical heating is applied to all snow-covered areas per unit time, areas with shallower snow depths will melt completely in a shorter time, while areas with deeper snow depths will take longer to melt. However, the nature of PV module power generation is such that if even a small portion of the module's surface is shaded, the module will stop generating power or experience a significant reduction in power output. In severe cases, this can lead to a "hot spot effect," causing permanent damage to the PV module. By applying more electrical heating to areas with deeper snow depths per unit time and less to areas with shallower snow depths per unit time, the difference in melting time across different parts of the PV module surface can be reduced, allowing for control over the snow melting rate.

[0127] This invention proposes a snow melting speed control method to supply different amounts of electrical heating to different snow depths on the surface of photovoltaic modules per unit time. The specific method is as follows.

[0128] Collect snow depth values ​​at various detection points on the surface of a single photovoltaic module and calculate d. a1 d a2 , ...d ay, where d a1 ~d ay y is the average snow depth (in mm) of all detection points at the same horizontal height from bottom to top for this photovoltaic module, and y is the number of longitudinal detection points.

[0129] The average snow depth d a Divided into 3 depth ranges: (1) 0mm <d a ≦15mm;(2)15mm <d a ≦30mm;(3)d a >30mm. The power supply modes of the electric heating tapes above and below the detection points with snow accumulation are divided into three types: ① heating time duty cycle of 50% and heating cycle of 2s; ② heating time duty cycle of 75% and heating cycle of 4s; ③ continuous uninterrupted heating.

[0130] The power supply modes for the electric heating cables are as follows, depending on the different snow depths of the photovoltaic modules.

[0131] 1. When d a1 ~d ay The snow depth information includes all three depth ranges. For depth range (1), the power supply mode ① is used for the upper and lower adjacent electric heating cables of the detection point; for depth range (2), the power supply mode ② is used for the upper and lower adjacent electric heating cables of the detection point; and for depth range (3), the power supply mode ③ is used for the upper and lower adjacent electric heating cables of the detection point.

[0132] 2. When d a1 ~d ay The snow depth includes depth range (2) and depth range (3). The electric heating cables above and below the detection point in depth range (2) are powered in mode ②, and the electric heating cables above and below the detection point in depth range (3) are powered in mode ③.

[0133] 3. When d a1 ~d ay The snow depth includes depth range (1) and depth range (2). The electric heating cables above and below the detection point in depth range (1) are powered in mode ②, and the electric heating cables above and below the detection point in depth range (2) are powered in mode ③.

[0134] 4. When d a1 ~d ay The snow depth includes depth range (1) and depth range (3). The power supply mode ① is adopted for the upper and lower adjacent electric heating cables of the detection point in depth range (1), and the power supply mode ③ is adopted for the upper and lower adjacent electric heating cables of the detection point in depth range (3).

[0135] 5. When d a1 ~d ayIt only includes the snow depth of depth interval (1), and the electric heating cables above and below the detection point of depth interval (1) adopt the power supply mode ③.

[0136] 6. When d a1 ~d ay Only the snow depth in depth interval (2) is included. The electric heating cables above and below the detection point in depth interval (2) are powered in mode ③.

[0137] 7. When d a1 ~d ay It only includes the snow depth of depth interval (3), and the electric heating cables above and below the detection point of depth interval (3) adopt the power supply mode ③.

[0138] 8. When the snow depth of adjacent detection points above and below a certain heat tracing cable is in different depth ranges, the power supply mode of the heat tracing cable shall be operated according to the power supply mode of the detection point with the larger snow depth value.

[0139] The optimization method of the snow melting system of the present invention is as follows:

[0140] 1) Optimize based on heating time

[0141] Due to differences in the specific locations and environments of each photovoltaic module—for example, some modules may be shaded, some may have poor air circulation, and some may have heat sources nearby—the heating time required for snow melting varies for each module and its components. This patent proposes a method to reduce the differences in heating time between different heating cables, as detailed below.

[0142] (1) Calculate the working time T of each heating cable of the photovoltaic module snow melting system from the start of heating to the stop of heating after the completion of snow melting in three snowfalls. i1 T i2 T i3 、(T i1 T i2 T i3 These represent the working time of the i-th tracing cable in the snow melting system during the 1st, 2nd, and 3rd snowfalls, respectively (i = 1 to v, where v is the total number of tracing cables used in the snow melting system). (This method is not limited to data from three snow melting processes; in practical applications, more data from a larger number of processes will yield more accurate results.)

[0143] (2) Calculate the total working time T for each tracing cable. i =T i1 +T i2 +T i3 .

[0144] (3) Calculate the average total working time of all tracing cables in the system.

[0145] (4) Calculate the difference D between the total working time of each tracing cable and the average time. i =T i -T av .

[0146] (5) Calculate the ratio of the time difference to the average time value for each tracing cable.

[0147] (6) Screening S i For heat tracing cables with a power rating >0.1, replace them with heat tracing cables that meet this condition with those having a higher power rating. Let the power rating of the heat tracing cable before replacement be P. i The power value of the replaced heat tracing cable is (1+S) i )×P i .

[0148] (7) Screening S i For heat tracing cables with a power value <-0.1, replace them with heat tracing cables that meet this condition with those having a lower power value. Let the power value of the heat tracing cable before replacement be P. i The power value of the replaced heat tracing cable is (1+S) i )×P i .

[0149] 2) Optimize based on heating power consumption

[0150] During the installation of photovoltaic snow melting systems, gaps or detachment may occur between the heating cable and the heat sink, or between the heat sink and the module backsheet, due to construction quality issues or aging after a period of use. This results in a significant reduction in the heat transferred from the heating cable to the photovoltaic module, leading to not only energy loss but also affecting the snow melting effect. This patent proposes a method to locate the module experiencing this problem, as detailed below.

[0151] (1) Calculate the electricity E consumed by each component during the snow melting process. i (i = 1 to w, w is the total number of photovoltaic modules, E i (This represents the electricity consumed by the i-th photovoltaic module during snow melting).

[0152] E i =E i1 +E i2 +...+E iz

[0153] Where z represents the total number of heat tracing cables installed on the backsheet of the photovoltaic module, and E i1 E represents the electricity consumed by the first heating cable on the backplane of the i-th photovoltaic module during snow melting. i2 This represents the amount of electricity consumed by the second heating cable on the backplate of the i-th photovoltaic module during the snow melting project, and so on.

[0154] (2) Calculate the average power consumption of all components during the snow melting process.

[0155] (3) Calculate the difference F between the power consumption of each component and the average power consumption. i =E i -E av

[0156] (4) Calculate the ratio of the power difference of each component to the average power consumption.

[0157] (5) Screening Q i For photovoltaic modules with a diameter >0.2 mm, conduct on-site inspections of the heating cable area and repair any problems found.

[0158] This invention's photovoltaic module snow melting controller includes a CPU circuit, a heating cable control circuit, a photovoltaic module voltage detection circuit, a current detection circuit, an irradiation detection circuit, a keyboard and LCD screen circuit, a GPRS communication circuit, a CNC pan-tilt control circuit, a snow depth detection circuit, an angle detection circuit, and a temperature detection circuit. The signal transmission ports of the CPU circuit are respectively connected to the signal transmission ports of the heating cable control circuit, the voltage detection circuit, the current detection circuit, the irradiation detection circuit, the keyboard and LCD screen circuit, the GPRS communication circuit, the CNC pan-tilt control circuit, the snow depth detection circuit, the angle detection circuit, and the temperature detection circuit. The control signal output port of the heating cable control circuit is connected to the electric heating cable. The detection signal of the current detection circuit... The input port is connected to the current transformer (the junction box on the back of the photovoltaic module outputs two wires, which are the positive and negative outputs of the photovoltaic module, respectively. The current transformer has a circular hole in the center, which can pass through a wire with a maximum diameter of 13.6mm. By passing the positive or negative wire of the photovoltaic module through this hole, the output current value of the photovoltaic module can be detected). The detection signal input port of the irradiation detection circuit is connected to the detection signal output port of the irradiation sensor. The CNC pan-tilt control circuit is connected to the CNC pan-tilt. The CNC pan-tilt is mounted on the column. A snow depth sensor and a pan-tilt angle sensor are installed on the upper part of the CNC pan-tilt. A photovoltaic module angle sensor is installed on the photovoltaic module. The detection signal output ports of the pan-tilt angle sensor and the photovoltaic module angle sensor are respectively connected to the detection signal input port of the angle detection circuit. The detection signal output port of the snow depth sensor is connected to the detection signal input port of the snow depth detection circuit.

[0159] The CPU circuit is the core of the controller. Its functions include collecting various physical signals, controlling the rotation of the CNC electric gimbal, calculating the snow depth at the measured points on the surface of the photovoltaic module, and determining which electric heating cables need to be powered and which power supply mode to use for these electric heating cables.

[0160] The snow depth detection circuit detects the snow depth in real time through a snow depth sensor, converts the 485 signal output by the snow depth sensor into a serial TTL signal through a level signal conversion circuit to communicate with the CPU, and achieves electrical isolation between the controller circuit and the snow depth sensor through a power isolation circuit.

[0161] The CNC gimbal control circuit realizes the horizontal and vertical rotation of the gimbal through real-time control of the gimbal by the CPU. The 485 signal output by the gimbal is converted into a serial TTL signal through a level signal conversion circuit to communicate with the CPU, and the controller circuit and the CNC electric gimbal are electrically isolated through a power isolation circuit.

[0162] The angle detection circuit uses an angle sensor to detect the angles of the photovoltaic module and the snow depth sensor in real time. The 485 signal output by the angle sensor is converted into a serial TTL signal through a level signal conversion circuit to communicate with the CPU. The power isolation circuit realizes the electrical isolation between the controller circuit and the angle sensor.

[0163] The irradiation detection circuit detects the irradiation intensity in real time through an irradiation sensor. The irradiation sensor outputs the irradiation intensity as a current signal. The current signal is converted into a voltage signal by a signal conditioning circuit. The voltage signal is converted into a digital signal by an AD conversion module inside the CPU.

[0164] The current detection circuit samples the current output by the photovoltaic module proportionally through a current sensor and outputs a corresponding voltage signal. The voltage signal is then converted into a digital signal by the AD conversion module inside the CPU after passing through the signal conditioning circuit.

[0165] The voltage detection circuit samples the voltage output by the photovoltaic module proportionally through a voltage transformer and outputs a corresponding current signal. The current signal is converted into a voltage signal by a signal conditioning circuit, and the voltage signal is converted into a digital signal by an AD conversion module inside the CPU.

[0166] In the temperature detection circuit, the temperature sensor converts the temperature of the photovoltaic module backsheet into a digital signal and communicates with the CPU via a single data bus to send the module backsheet temperature information to the CPU.

[0167] In the keyboard and LCD screen circuit, the CPU identifies trigger keys using external interrupts and scanning. The CPU communicates with the LCD screen module via serial synchronous communication and controls the LCD screen display content. The function of the keyboard and LCD screen circuit is to set system control parameters and view the system's operating status.

[0168] The heat tracing cable control circuit outputs a control signal from the CPU's I / O port, which, after optocoupler isolation, controls whether the relay control terminal coil is powered, thereby controlling whether each heat tracing cable is heated. The 24V power supply to the relay control terminal is electrically isolated from the 24V power supply in the controller circuit through a power isolation circuit.

[0169] In the GPRS communication circuit, the CPU communicates with the GPRS wireless transparent transmission module through a serial asynchronous communication interface, and realizes remote wireless communication through the GPRS network.

[0170] The snow depth detection circuit, CNC gimbal control circuit, angle detection circuit, irradiation detection circuit, current detection circuit, voltage detection circuit, temperature detection circuit, keyboard and LCD screen circuit, heat tracing control circuit, and GPRS communication circuit are all connected to the CPU circuit.

[0171] In use, the snow depth sensor is mounted on a CNC motorized pan-tilt head. The pan-tilt head controls the sensor's horizontal and vertical rotation. The pan-tilt head is fixed to a column perpendicular to the horizontal plane, which is installed along the extension of the center line of photovoltaic module No. 1. An angle sensor is mounted on the snow depth sensor to detect the angle it points to. Another angle sensor is mounted on the photovoltaic module to detect the angle between the photovoltaic module and the horizontal plane. The output wire of the photovoltaic module is passed through the central hole of the current sensor. Figure 15 The three photovoltaic modules are electrically connected in series. Connect the positive and negative terminals of the three photovoltaic modules to the PV+ and PV- pins of the voltage signal input connector in the voltage detection circuit, respectively. Fix the temperature sensor on the back panel of the photovoltaic modules, away from the area covered by the heating cable and heat sink. Fix the irradiance sensor on a plane with the same tilt angle as the photovoltaic modules, ensuring it is not shaded. Fix each heat sink to the back panel of the photovoltaic modules according to the positioning requirements described above, and fix each heating cable at the horizontal centerline of each heat sink.

[0172] like Figure 2 As shown, when this invention starts working, the first step is to input various known physical parameters using the keyboard, including the rated power of the module, the power temperature coefficient of the module, the power degradation rate of the photovoltaic module in the first year of operation, and the linear power degradation rate of the photovoltaic module in each year thereafter. Initial parameters are then set, including the inspection cycle and the power threshold P. dThe process involves several steps, including snow melting duration, followed by a cyclical procedure. The second step involves collecting data on the irradiance of the photovoltaic module surface and the backsheet temperature, and calculating the theoretical output power of the photovoltaic module based on parameters such as the number of years the module has been in operation and the algorithm proposed in this invention. The third step involves collecting the voltage and current values ​​at the output terminals of the photovoltaic module, calculating the actual output power, and then calculating the difference P between the actual and theoretical output power. dif Compare P dif With P d The magnitude of the value, if P dif Not greater than P d If P dif Greater than P d Then proceed to step four. Step four involves detecting the snow depth at all detection points on a typical photovoltaic module and calculating the average snow depth d on the module's surface. p It is checked and calculated every 10 minutes. If d p If there is no increase within 30 minutes, proceed to step five; if d p If the snow depth increases within 30 minutes, repeat step four. Step five: Control the gimbal to rotate, causing the snow depth sensor to sequentially detect all set detection points. Calculate the snow depth at each detection point using the algorithm proposed in this invention. Step six: Based on the snow depth at each detection point of the photovoltaic module, and according to the snow melting speed control method proposed in this invention, start heating and melting the snow using the corresponding power supply mode for each heating cable, then enter a snow melting duration waiting period. Step seven: Re-detect the snow depth at all detection points. Determine if the snow depth at all detection points is zero. If not, return to step five to continue the snow melting process; if zero, stop heating. After the inspection cycle waiting time, return to step two and repeat the above cyclical procedure.

[0173] The CPU circuit uses the MM32F3273D7P chip U1. Pins 1-4 of U1 are connected to +3.3V, LCD-A0, LCD-RST, and LCD-CS respectively. Pin 5 of U1 is connected to one end of resistor R1, one end of crystal oscillator X1, and one end of capacitor C1. The other end of C1 is connected to ground and one end of capacitor C2. The other end of C2 is connected to the other end of X1, the other end of R1, and pin 6 of U1. Pins 7-12 of U1 are connected to RST, RD2, RD3, SCL, SDA, and GND respectively. Pin 12 of U1 is connected to the positive terminal of capacitor C3 and one end of capacitor C4. The negative terminal of C3 is connected to the other end of C4 and pin 13 of U1. Pins 14-32 of U1 are connected to UART4-TX, UART4-RX, UART2-TX, UART2-RX, GND, +3.3V, UART5-TX, and UART5-RX respectively. Connect ADC1, ADC2, ADC4, GPRS-PWR, ADC3, ADC5, GND, UART3-TX, UART3-RX, GND, and +3.3V accordingly. Connect pins 18 and 19 of U1 to both ends of C5, and connect pins 31 and 32 of U1 to both ends of C6.

[0174] Pins 33 to 64 of U1 are connected to L6 to L1, LE3 to LE1, UART1-RX, UART1-TX, RD1, INT3, JTMS, GND, +3.3V, JTCK, ROW5 to ROW1, COL5 to COL1, GND, RD4, T-DQ, GND, and +3.3V respectively.

[0175] Pin 3 of P1 in the BM117-3.3 chip is connected to +15V, and pin 2 of P1 is connected to +3.3V. One end of switch SW1 is connected to ground and one end of capacitor C13. The other end of SW1 is connected to one end of resistor R2, RST, and the other end of capacitor C13. The other end of R2 is connected to +3.3V.

[0176] The CPU is a 32-bit microcontroller, model MM32F3273D7P, manufactured by Shanghai Lingdong Microelectronics Co., Ltd. The communication module is an embedded GPRS wireless transparent transmission module, model USR-GPRS232-7S3, manufactured by Jinan Youren IoT Technology Co., Ltd. The LCD screen module is a product manufactured by Shenzhen Jinglianxun Electronics Co., Ltd., model JLX12864G-183-BN. The relay is a low-power miniature relay, model HK4100F-DC24V-SDAG, manufactured by Ningbo Huike New Era Electric Co., Ltd., with a coil voltage of 24V and coil power consumption of 0.15W. The 24V power isolation module is a product manufactured by Shenzhen Hailingke Electronics Co., Ltd., model HLK-10D2424B. The 3.3V power module is a product manufactured by Shanghai Baili Microelectronics Co., Ltd., model BM1117-3.3. The voltage transformer is a product manufactured by Nanjing Qihuo Technology Co., Ltd., model VSM025A / 10. The current sensor is a product manufactured by Jiangsu Zhonghuo Sensing Technology Co., Ltd., model HDIB-CE-10P2O2.

[0177] The snow depth detection circuit includes a common-mode inductor LDM1. The first terminal of LDM1 is connected to +24V. The second terminal of LDM1 is connected to one end of inductor L1. The other end of L1 is connected to pin 1 of P2 of the HLK-10D2424B chip. Pin 2 of P2 is connected to the third terminal of LDM1. The fourth terminal of LDM1 is grounded. Pin 4 of P2 is connected to +24V-HM31 through inductor L2, and pin 3 of P2 is connected to GND-HM31 through inductor L3.

[0178] Pin 1 of ST3485 chip U2 is connected to UART1-RX, pins 2 and 3 of U2 are connected to RD1, pin 4 of U2 is connected to UART1-TX, pin 5 of U2 is connected to ground and one end of capacitor C21, the other end of C21 is connected to +3.3V and pin 8 of U2, pin 6 of U2 is connected to one end of resistor R5, one end of resistor R6 and one end of resistor R7, the other end of R6 is connected to +3.3V, the other end of R7 is connected to RS485-A1, the other end of R5 is connected to pin 7 of U2, one end of resistor R3 and one end of resistor R4, the other end of R3 is grounded, and the other end of R4 is connected to RS485-B1.

[0179] The snow depth sensor used is a laser snow depth sensor, model HM31, manufactured by SOMMER GmbH of Austria, with a snow depth measurement range of 0-15m. The CNC electric pan-tilt head is a worm gear lightweight pan-tilt head, model HY-LW18-01B, manufactured by Sichuan Huiyuan Optical Communication Co., Ltd., with a horizontal rotation angle range of 0~360°, a pitch angle range of -60~60°, and a positioning accuracy of 0.1°. An angle sensor is installed on the snow depth sensor to detect the angle pointed to by the snow depth sensor. An angle sensor is installed on the back panel of the photovoltaic module to detect the angle between the photovoltaic module and the horizontal plane. The angle sensor used is a dual-axis tilt sensor, model SINDT02-485, manufactured by Shenzhen Weite Intelligent Technology Co., Ltd., with an angle detection accuracy of 0.1°. The temperature sensor uses a wide-range single-bus temperature measurement chip, model QT18B20, manufactured by Beijing Qixin Zhongchuang Technology Co., Ltd., with a measurement range of -55℃ to +125℃. The maximum error is ±0.5℃ within the range of -10℃ to +85℃, and ±1.5℃ across the entire temperature range. The irradiation sensor uses a product manufactured by Wuhan Chenyun Technology Co., Ltd., model YGC-TBQ-KV-A2, with an irradiation detection range of 0~2000W / m². 2 The electric heating cable used is a glass fiber constant power electric heating cable manufactured by Anhui Huanrui Electric Heating Equipment Co., Ltd., model RDP2-J4-60, powered by 220V, with a heating power of 60W / m and a cable width of 9.5mm.

[0180] The CNC gimbal control circuit includes a common-mode inductor LDM2. The first terminal of LDM2 is connected to +24V. The second terminal of LDM2 is connected to one end of inductor L4. The other end of L4 is connected to pin 1 of P3 of the HLK-10D2424B chip. Pin 2 of P3 is connected to the third terminal of LDM2. The fourth terminal of LDM2 is grounded. Pin 4 of P3 is connected to +24V-HY through inductor L5, and pin 3 of P3 is connected to GND-HY through inductor L6.

[0181] Pin 1 of ST3485 chip U3 is connected to UART2-RX, pins 2 and 3 of U3 are connected to RD2, pin 4 of U3 is connected to UART2-TX, pin 5 of U3 is connected to ground and one end of capacitor C29, the other end of C29 is connected to +3.3V and pin 8 of U3, pin 6 of U3 is connected to one end of resistor R10, one end of resistor R11, and one end of resistor R12, the other end of R11 is connected to +3.3V, the other end of R12 is connected to RS485-A2, the other end of R10 is connected to pin 7 of U3, one end of resistor R8, and one end of resistor R9, the other end of R8 is grounded, and the other end of R9 is connected to RS485-B2.

[0182] The temperature detection circuit uses a QT18B20 chip PE3, with pins 1, 2, and 3 of PE3 connected to T-GND, T-DQ, and T-3.3V, respectively.

[0183] The angle detection circuit includes a common-mode inductor LDM3. The first terminal of LDM3 is connected to +24V. The second terminal of LDM3 is connected to one end of inductor L7. The other end of L7 is connected to pin 1 of P4 of the HLK-10D2424B chip. Pin 2 of P4 is connected to the third terminal of LDM3. The fourth terminal of LDM3 is grounded. Pin 4 of P4 is connected to +24V-SINDT through inductor L8. Pin 3 of P4 is connected to GND-SINDT through inductor L9.

[0184] Pin 1 of ST3485 chip U4 is connected to UART3-RX; pins 2 and 3 of U4 are connected to RD3; pin 4 of U4 is connected to UART3-TX; pin 5 of U4 is connected to ground and one end of capacitor C38; the other end of C38 is connected to +3.3V and pin 8 of U4; pin 6 of U4 is connected to one end of resistor R16, one end of resistor R17, and one end of resistor R18; the other end of R17 is connected to +3.3V; the other end of R18 is connected to RS485-A3; the other end of R16 is connected to pin 7 of U4, one end of resistor R14, and one end of resistor R15; the other end of R14 is grounded; the other end of R15 is connected to RS485-B3.

[0185] Pin 1 of ST3485 chip U5 is connected to UART4-RX, pins 2 and 3 of U5 are connected to RD4, pin 4 of U5 is connected to UART4-TX, pin 5 of U5 is connected to ground and one end of capacitor C39, the other end of C39 is connected to +3.3V and pin 8 of U5, pin 6 of U5 is connected to one end of resistor R21, one end of resistor R22, and one end of resistor R23, the other end of R22 is connected to +3.3V, the other end of R23 is connected to RS485-A4, the other end of R21 is connected to pin 7 of U5, one end of resistor R19, and one end of resistor R20, the other end of R19 is grounded, and the other end of R20 is connected to RS485-B4.

[0186] The irradiation detection circuit includes an LM324 chip CA1A. Pin 3 of CA1A is connected to CURRENT. Pin 2 of CA1A is connected to pin 1 of CA1A and one end of resistor R25. The other end of R25 is connected to ADC5 through resistor R26.

[0187] Pins 1, 2, and 3 of the YGC-TBQ-KV-A2 chip PE6 are connected to +24V, GND, and CURRENT respectively.

[0188] The current detection circuit includes an LM324 chip CA1B. Pin 5 of CA1B is connected to one end of resistor R29 and one end of resistor R30. The other end of R29 is connected to the other end of R30 and ground. Pin 6 of CA1B is connected to one end of resistor R27 and one end of resistor R28. The other end of R27 is connected to S-CUR. The other end of R28 is connected to pin 7 of CA1B and one end of resistor R31. The other end of R31 is connected to pin 9 of the LM324 chip CA1C and one end of resistor R32. Pin 10 of CA1C is grounded through resistor R33. The other end of R32 is connected to pin 8 of CA1C and one end of resistor R34. The other end of R34 is connected to ADC4 through resistor R35.

[0189] Pins 5 to 8 of the HDIB-CE-10P2O2 chip PE7 are connected to +24V, GND, S-CUR, and GND respectively.

[0190] The voltage detection circuit includes a VSM025A / 10 chip U6. Pin 1 of U6 is connected to PV+ through parallel resistors R36 and R37. Pin 2 of U6 is connected to PV-. Pin 5 of U6 is connected to pin 3 of the LM324 chip CA2A through resistor R39. Pin 2 of CA2A is connected to pin 1 of CA2A and one end of resistor R40. The other end of R40 is connected to ADC1.

[0191] VSM025A / 10 chip U7, pin 1 of U7 is connected to PV+ through parallel resistors R41 and R42, pin 2 of U7 is connected to PV-, pin 5 of U7 is connected to pin 5 of LM324 chip CA2B through resistor R44, pin 6 of CA2B is connected to pin 7 of CA2B and one end of resistor R45, and the other end of R45 is connected to ADC2;

[0192] The VSM025A / 10 chip U8 has pin 1 connected to PV+ via parallel resistors R46 and R47, pin 2 connected to PV-, and pin 5 connected to pin 10 of the LM324 chip CA2C via resistor R49. Pin 9 of CA2C is connected to pin 8 of CA2C and one end of resistor R50, with the other end of R50 connected to ADC3.

[0193] The keyboard and LCD screen circuit includes a 74LV08A chip U9 and a JLX12864G-183-BN chip U10. Pins 1, 2, 5, 8, 9, and 12 of U9 are respectively connected to COL1, COL2, COL3, INT3, COL5, and COL4.

[0194] Pins 8 to 12 of U10 are connected to SDA, SCL, LCD-A0, LCD-RST, and LCD-CS respectively.

[0195] The heat tracing control circuit includes a common-mode inductor LDM4. The first terminal of LDM4 is connected to +24V. The second terminal of LDM4 is connected to one end of inductor L10. The other end of L10 is connected to pin 1 of P5 of the HLK-10D2424B chip. Pin 2 of P5 is connected to the third terminal of LDM4. The fourth terminal of LDM4 is grounded. Pin 4 of P5 is connected to +24V-RELAY through inductor L11, and pin 3 of P5 is connected to GND-RELAY through inductor L12.

[0196] Pins 3, 4, 7, 8, 13, and 14 of the 74LVC373ADB chip U11 are connected to L1 to L6 respectively. Pin 11 of U11 is connected to LE1. Pins 2, 5, 6, 9, 12, and 15 of U11 are connected to L1-1 to L1-6 respectively.

[0197] Pins 2, 4, 6, and 8 of TLP521-4 chip U12 are connected to pins L1-1 to L1-4 respectively; pins 2 and 4 of TLP521-2 chip U13 are connected to pins L1-5 and L1-6 respectively; pins 15, 13, 11, and 9 of U12 are connected to KM1-1, KM1-2, KM1-3, and KM1-4 respectively; and pins 7 and 5 of U13 are connected to pins KM1-5 and KM1-6 respectively.

[0198] Pins 2, 4, 6, and 8 of the TLP521-4 chip U15 are connected to pins L2-1 to L2-4 respectively; pins 2 and 4 of the TLP521-2 chip U16 are connected to pins L2-5 and L2-6 respectively; pins 15, 13, 11, and 9 of U15 are connected to KM2-1, KM2-2, KM2-3, and KM2-4 respectively; and pins 7 and 5 of U16 are connected to pins KM2-5 and KM2-6 respectively.

[0199] Pins 3, 4, 7, 8, 13, and 14 of the 74LVC373ADB chip U14 are connected to L1 to L6 respectively. Pin 11 of U14 is connected to LE2. Pins 2, 5, 6, 9, 12, and 15 of U14 are connected to L2-1 to L2-6 respectively.

[0200] Pins 2, 4, 6, and 8 of the TLP521-4 chip U18 are connected to pins L3-1 to L3-4 respectively; pins 2 and 4 of the TLP521-2 chip U19 are connected to pins L3-5 and L3-6 respectively; pins 15, 13, 11, and 9 of U18 are connected to KM3-1, KM3-2, KM3-3, and KM3-4 respectively; and pins 7 and 5 of U19 are connected to pins KM3-5 and KM3-6 respectively.

[0201] Pins 3, 4, 7, 8, 13, and 14 of the 74LVC373ADB chip U17 are connected to L1 to L6 respectively. Pin 11 of U17 is connected to LE3. Pins 2, 5, 6, 9, 12, and 15 of U17 are connected to L3-1 to L3-6 respectively.

[0202] The GPRS communication circuit includes a USR-GPRS232-7S3 chip U20. Pins 6 and 7 of U20 are connected to USR-TX and USR-RX respectively. Pin 10 of U20 is connected to PWR, and pin 15 of U20 is connected to G-LINK.

[0203] Pin 1 of P6 in the TPS79328DBVR chip is connected to +3.3V, one end of capacitor C64, and one end of resistor R74. The other end of R74 is connected to pin 3 of P6. The other end of C64 is connected to ground and pin 2 of P6. Pin 4 of P6 is connected to ground and one end of capacitor C65 through capacitor C66. The other end of C65 is connected to pin 5 of P6.

[0204] The base of NPN transistor Q1 is connected to one end of resistor R75 and one end of resistor R76. The other end of R75 is connected to USR-TX. The other end of R76 is connected to +2.8V and one end of resistor R77. The other end of R77 is connected to the collector of Q1 and the base of NPN transistor Q2. The emitters of Q1 and Q2 are grounded. The collector of Q2 is connected to one end of resistor R78 and UART5-RX. The other end of R78 is connected to +3.3V.

[0205] Pin 1 of the TLP521-1 chip U21 is connected to GPRS-PWR through resistor R83. Pin 2 of U21 is grounded. Pin 4 of U21 is connected to +3.3V. Pin 3 of U21 is connected to one end of resistor R84, one end of capacitor C67, and one end of resistor R85. The other end of R84 is connected to the other end of C67 and ground. The other end of R85 is connected to the base of NPN transistor Q5. The emitter of Q5 is grounded, and the collector of Q5 is connected to PWR.

[0206] The base of NPN transistor Q3 is connected to one end of resistor R79 and one end of resistor R80. The other end of R79 is connected to UART5-TX. The other end of R80 is connected to +3.3V and one end of resistor R81. The other end of R81 is connected to the collector of Q3 and the base of NPN transistor Q4. The emitters of Q3 and Q4 are grounded. The collector of Q4 is connected to one end of resistor R82 and USR-RX. The other end of R82 is connected to +2.8V.

[0207] The base of NPN transistor Q6 is connected to G-LINK through resistor R86. The collector of Q6 is connected to +4V through LED1 and resistor R87 respectively. One end of resistor R88 is connected to the emitter of Q6 and ground through LED2.

[0208] Pin 1 of P7 in the MP2303 chip is connected to MP-BS. Pin 2 of P7 is connected to the cathode of diode D11 and one end of resistor R89. The anode of D11 is connected to +15V. The other end of R89 is connected to pin 7 of P7. Pin 3 of P7 is connected to +4V, one end of capacitor C72, one end of inductor L13, one end of capacitor C73, one end of capacitor C74, and one end of resistor R90. The other end of C72 is connected to MP-BS and the cathode of diode D12. The anode of D12 is connected to the other end of L13. The other end of R90 is connected to pin 5 of P7 and one end of resistor R91. The other end of R91 is connected to ground and one end of resistor R92. The other end of R92 is connected to pin 6 of P7 through capacitor C75.

[0209] P1 is a 3.3V power supply module with a maximum output current of 1A, powering the electronic components in the controller that require 3.3V power. P2-P5 are 24V DC power isolation modules with a maximum output power of 10W, used to achieve electrical isolation between the controller and various external devices, preventing electromagnetic interference and surges caused by external devices from affecting the controller. P6 is a 2.8V power supply module with a maximum output current of 200mA, powering the communication level conversion circuit in the GPRS communication circuit. P7 is a 4V power supply module with a maximum output current of 3A, powering the GPRS wireless transparent transmission module in the GPRS communication circuit.

[0210] PE1 to PE7 are external devices that connect to the controller circuit board via connectors for power supply and data transmission. Specifically, PE1 is a snow depth sensor (model HM31), connected to the circuit board via connector J3; PE2 is a CNC electric pan-tilt head (model HY-LW18-01B), connected to the circuit board via connector J4; PE3 is a temperature sensor (model QT18B20), connected to the circuit board via connector J5; PE4 is an angle detection sensor (model SINDT02-485) mounted on the snow depth sensor, connected to the circuit board via connector J6; PE5 is an angle detection sensor (model SINDT02-485) mounted on the photovoltaic module backplane, connected to the circuit board via connector J7; PE6 is an irradiance sensor (model YGC-TBQ-KV-A2), connected to the circuit board via connector J8; and PE7 is a current sensor (model HDIB-CE-10P2O2), connected to the circuit board via connector J9.

[0211] Connectors J10, J11, and J12 are the voltage signal input ports for the photovoltaic modules. Pin 1 of connector J10 is connected to the positive output terminal of photovoltaic module 1, and pin 2 of connector J10 is connected to the negative output terminal of photovoltaic module 1. Pin 1 of connector J11 is connected to the positive output terminal of photovoltaic module 2, and pin 2 of connector J11 is connected to the negative output terminal of photovoltaic module 2. Pin 1 of connector J12 is connected to the positive output terminal of photovoltaic module 3, and pin 2 of connector J12 is connected to the negative output terminal of photovoltaic module 3.

[0212] Connect pin 1 of connector J14 to the live wire of the 220V AC power supply, and pin 2 of J14 to the neutral wire of the 220V AC power supply. Connect pins 1, 3, 5, 7, 9, and 11 of connector J15 to one end of the six heating cables of photovoltaic module 1, and pins 2, 4, 6, 8, 10, and 12 of connector J15 to the other end of the six heating cables on the backsheet of photovoltaic module 1. Connect pins 1, 3, 5, 7, 9, and 11 of connector J16 to one end of the six heating cables on the backsheet of photovoltaic module 2, and pins 2, 4, 6, 8, 10, and 12 of connector J16 to the other end of the six heating cables on photovoltaic module 2. Connect pins 1, 3, 5, 7, 9, and 11 of connector J17 to one end of the six heating cables on the backsheet of photovoltaic module 3, and pins 2, 4, 6, 8, 10, and 12 of connector J17 to the other end of the six heating cables on photovoltaic module 3.

[0213] In addition, connector J1 is the DC power supply interface for the controller, J2 is the program download interface for the CPU, and connector J13 is connected to the 5×5 keyboard.

[0214] R24 is a precision resistor with 1% accuracy and a resistance of 150Ω. R38, R43, and R48 are precision resistors with 1% accuracy and a resistance of 130Ω. R90 is a precision resistor with 1% accuracy and a resistance of 40.2KΩ. R91 is a precision resistor with 1% accuracy and a resistance of 10KΩ.

[0215] LED1 (green) is the GPRS communication network status indicator. When it is lit, it indicates that the GPRS network connection has been established; when it is off, it indicates that the GPRS network connection has been disconnected. LED2 (red) is the GPRS wireless pass-through module power indicator. When it is lit, it indicates that the GPRS wireless pass-through module is powered on; when it is off, it indicates that the GPRS wireless pass-through module is not powered.

[0216] LDM1 to LDM4 are common-mode inductors used to suppress common-mode electromagnetic interference signals in the power supply, with an inductance value of 10mH.

[0217] This invention uses the MM32F3273D7P chip as the CPU of the controller. The chip has 52 general-purpose input / output ports. If it is necessary to control more electric heating tapes, it can be achieved by selecting a chip with more general-purpose input / output ports as the CPU or by adding input / output port expansion circuits.

[0218] It is understood that the above specific description of the present invention is only for illustrating the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention to achieve the same technical effect; as long as the use needs are met, they are all within the protection scope of the present invention.

Claims

1. A photovoltaic module testing device, comprising a photovoltaic module voltage detection circuit, a current detection circuit, an irradiation detection circuit, a snow depth detection circuit, an angle detection circuit, and a temperature detection circuit, characterized in that... The signal transmission ports of the CPU circuit are connected to the signal transmission ports of the voltage detection circuit, current detection circuit, irradiation detection circuit, snow depth detection circuit, angle detection circuit, and temperature detection circuit, respectively. The detection signal input port of the current detection circuit is connected to the current transformer, and the detection signal input port of the irradiation detection circuit is connected to the detection signal output port of the irradiation sensor. A snow depth sensor and a gimbal angle sensor are installed on the upper part of the CNC pan-tilt unit, and a photovoltaic module angle sensor is installed on the photovoltaic module. The detection signal output ports of the pan-tilt unit angle sensor and the photovoltaic module angle sensor are connected to the detection signal input port of the angle detection circuit, respectively; the detection signal output port of the snow depth sensor is connected to the detection signal input port of the snow depth detection circuit. The angle detection circuit includes a common-mode inductor LDM3. The first terminal of LDM3 is connected to +24V. The second terminal of LDM3 is connected to one end of inductor L7. The other end of L7 is connected to pin 1 of P4 of the HLK-10D2424B chip. Pin 2 of P4 is connected to the third terminal of LDM3. The fourth terminal of LDM3 is grounded. Pin 4 of P4 is connected to +24V-SINDT through inductor L8. Pin 3 of P4 is connected to GND-SINDT through inductor L9. Pin 1 of ST3485 chip U4 is connected to UART3-RX, pins 2 and 3 of U4 are connected to RD3, pin 4 of U4 is connected to UART3-TX, pin 5 of U4 is connected to ground and one end of capacitor C38, the other end of C38 is connected to +3.3V and pin 8 of U4, pin 6 of U4 is connected to one end of resistor R16, one end of resistor R17 and one end of resistor R18, the other end of R17 is connected to +3.3V, the other end of R18 is connected to RS485-A3, the other end of R16 is connected to pin 7 of U4, one end of resistor R14 and one end of resistor R15, the other end of R14 is grounded, and the other end of R15 is connected to RS485-B3; Pin 1 of ST3485 chip U5 is connected to UART4-RX, pins 2 and 3 of U5 are connected to RD4, pin 4 of U5 is connected to UART4-TX, pin 5 of U5 is connected to ground and one end of capacitor C39, the other end of C39 is connected to +3.3V and pin 8 of U5, pin 6 of U5 is connected to one end of resistor R21, one end of resistor R22, and one end of resistor R23, the other end of R22 is connected to +3.3V, the other end of R23 is connected to RS485-A4, the other end of R21 is connected to pin 7 of U5, one end of resistor R19, and one end of resistor R20, the other end of R19 is grounded, and the other end of R20 is connected to RS485-B4.

2. The photovoltaic module testing device according to claim 1, characterized in that... The snow depth detection circuit includes a common-mode inductor LDM1. The first terminal of LDM1 is connected to +24V. The second terminal of LDM1 is connected to one end of inductor L1. The other end of L1 is connected to pin 1 of HLK-10D2424B chip P2. Pin 2 of P2 is connected to the third terminal of LDM1. The fourth terminal of LDM1 is grounded. Pin 4 of P2 is connected to +24V-HM31 through inductor L2. Pin 3 of P2 is connected to GND-HM31 through inductor L3. Pin 1 of ST3485 chip U2 is connected to UART1-RX, pins 2 and 3 of U2 are connected to RD1, pin 4 of U2 is connected to UART1-TX, pin 5 of U2 is connected to ground and one end of capacitor C21, the other end of C21 is connected to +3.3V and pin 8 of U2, pin 6 of U2 is connected to one end of resistor R5, one end of resistor R6 and one end of resistor R7, the other end of R6 is connected to +3.3V, the other end of R7 is connected to RS485-A1, the other end of R5 is connected to pin 7 of U2, one end of resistor R3 and one end of resistor R4, the other end of R3 is grounded, and the other end of R4 is connected to RS485-B1.

3. The photovoltaic module testing device according to claim 1, characterized in that... The temperature detection circuit uses the QT18B20 chip PE3, with pins 1, 2, and 3 of PE3 connected to T-GND, T-DQ, and T-3.3V, respectively.

4. The photovoltaic module testing device according to claim 1, characterized in that... The irradiation detection circuit includes an LM324 chip CA1A. Pin 3 of CA1A is connected to CURRENT. Pin 2 of CA1A is connected to pin 1 of CA1A and one end of resistor R25. The other end of R25 is connected to ADC5 through resistor R26.

5. The photovoltaic module testing device according to claim 1, characterized in that... The current detection circuit includes an LM324 chip CA1B. Pin 5 of CA1B is connected to one end of resistor R29 and one end of resistor R30. The other end of R29 is connected to the other end of R30 and ground. Pin 6 of CA1B is connected to one end of resistor R27 and one end of resistor R28. The other end of R27 is connected to S-CUR. The other end of R28 is connected to pin 7 of CA1B and one end of resistor R31. The other end of R31 is connected to pin 9 of the LM324 chip CA1C and one end of resistor R32. Pin 10 of CA1C is grounded through resistor R33. The other end of R32 is connected to pin 8 of CA1C and one end of resistor R34. The other end of R34 is connected to ADC4 through resistor R35. Pins 5 to 8 of the HDIB-CE-10P2O2 chip PE7 are connected to +24V, GND, S-CUR, and GND respectively. The voltage detection circuit includes a VSM025A / 10 chip U6. Pin 1 of U6 is connected to PV+ through parallel resistors R36 and R37. Pin 2 of U6 is connected to PV-. Pin 5 of U6 is connected to pin 3 of the LM324 chip CA2A through resistor R39. Pin 2 of CA2A is connected to pin 1 of CA2A and one end of resistor R40. The other end of R40 is connected to ADC1. VSM025A / 10 chip U7, pin 1 of U7 is connected to PV+ through parallel resistors R41 and R42, pin 2 of U7 is connected to PV-, pin 5 of U7 is connected to pin 5 of LM324 chip CA2B through resistor R44, pin 6 of CA2B is connected to pin 7 of CA2B and one end of resistor R45, and the other end of R45 is connected to ADC2. The VSM025A / 10 chip U8 has pin 1 connected to PV+ via parallel resistors R46 and R47, pin 2 connected to PV-, and pin 5 connected to pin 10 of the LM324 chip CA2C via resistor R49. Pin 9 of CA2C is connected to pin 8 of CA2C and one end of resistor R50, with the other end of R50 connected to ADC3.

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