Method for detecting brightness outside tunnel based on generating capacity of solar panel

Abstract

The invention discloses a method for detecting brightness outside a tunnel based on generating capacity of a solar panel. The method comprises the following steps: (1) detecting open-circuit voltage and short-circuit current of a main loop of the solar panel outside the tunnel; (2) establishing a mathematical model according to the measured open-circuit voltage and short-circuit current in combination with the environmental temperature and the characteristic parameters of the solar panel, and calculating the brightness value outside the tunnel hole; and (3) comparing the calculated brightness value outside the tunnel portal with a preset brightness threshold value of the tunnel portal, and adjusting the illumination intensity of the tunnel portal so as to reduce visual discomfort of a driver. The brightness outside the tunnel is judged through the open-circuit voltage and the short-circuit current of the solar panel, so that the cost is reduced, and the stability and the reliability of the system are improved. In addition, the method has the advantages of being easy and convenient to maintain, high in adaptability and the like.

Description

Technical Field

[0001] The present invention relates to the field of highway tunnel entrance brightness detection, and particularly to a method for detecting the brightness outside the tunnel based on the power generation of a solar panel. Background Art

[0002] At the entrance of a highway tunnel, due to the large difference in brightness inside and outside the tunnel, drivers are prone to visual discomfort when entering and leaving the tunnel, which affects driving safety. Therefore, accurately detecting the brightness outside the tunnel and adjusting the lighting inside the tunnel accordingly is crucial for ensuring driving safety. Existing technologies mostly use light brightness sensors to directly measure the brightness outside the tunnel, but the cost is relatively high and maintenance is inconvenient.

[0003] Therefore, there is an urgent need to develop a method for detecting the brightness outside the tunnel based on the power generation of a solar panel. Summary of the Invention

[0004] To solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A method for detecting the brightness outside the tunnel based on the power generation of a solar panel, comprising the following steps:

[0006] (1) Using an MPPT solar controller (maximum power point tracking controller) to detect the open-circuit voltage and short-circuit current of the main circuit of the solar panel outside the tunnel;

[0007] (2) According to the measured open-circuit voltage and short-circuit current, combined with the ambient temperature and the characteristic parameters of the solar panel, establishing a mathematical model to calculate the brightness value outside the tunnel;

[0008] (3) Comparing the calculated brightness value outside the tunnel with a preset tunnel entrance brightness threshold, and accordingly adjusting the lighting intensity at the tunnel entrance to reduce the visual discomfort of the driver.

[0009] Further, in step (1), under a light intensity of 1000 W / m 2 , measure the open-circuit voltage (Uoc) and short-circuit current (Isc) of the solar panel outside the tunnel;

[0010] In step (2), calculate the photocurrent (IL): Use the short-circuit current (Isc) as the photocurrent (IL);

[0011] In step (2), deduce the light intensity (S): Through the photocurrent (IL) and the above formula, combined with the effective area, material coefficient and temperature of the battery, the light intensity (S) can be deduced.

[0012] Short - circuit current (Isc): The short - circuit current refers to the output current of a solar cell in the short - circuit state under standard test conditions. It is proportional to the incident light intensity. The formula is: Isc = IL, where IL is the photo - generated current, which is proportional to the light intensity.

[0013] Further, in step (2), the open - circuit voltage (Uoc): The open - circuit voltage refers to the output voltage of a solar cell in the open - circuit state under standard test conditions. The formula is:

[0014]

[0015] where IL is the photo - generated current and I0 is the reverse saturation current of the P - N junction of the cell without light illumination.

[0016] Light intensity (S): The calculation formula for light intensity is:

[0017] IL = A c (C0 + C1T)S

[0018] That is, S = IL / A c (C0 + C1T)

[0019] where A c is the effective area of the solar photovoltaic cell, C0 and C1 are coefficients dependent on the cell material, and T is the temperature of the solar photovoltaic cell.

[0020] Due to the adoption of the above - mentioned technical solution, the technical progress achieved by the present invention compared with the prior art is:

[0021] The present invention determines the brightness outside the tunnel through the open - circuit voltage and short - circuit current of the solar panel, which not only reduces the cost, but also improves the stability and reliability of the system. In addition, this method also has the advantages of simple maintenance and strong adaptability. Specific embodiments

[0022] The following embodiments can help those skilled in the art to understand the present invention more comprehensively, but cannot limit the present invention in any way.

[0023] Embodiment

[0024] A method for detecting the brightness outside the tunnel based on the power generation of a solar panel, comprising the following steps:

[0025] (1) Detect the open - circuit voltage and short - circuit current of the main circuit of the solar panel outside the tunnel;

[0026] (2) According to the measured open - circuit voltage and short - circuit current, combined with the ambient temperature and the characteristic parameters of the solar panel, establish a mathematical model to calculate the brightness value outside the tunnel;

[0027] (3) Compare the calculated outdoor brightness value of the tunnel with the preset brightness threshold of the tunnel entrance, and accordingly adjust the lighting intensity of the tunnel entrance to reduce the visual discomfort of the driver.

[0028] Further, in step (1), an MPPT solar controller is used.

[0029] Further, in step (1), under the illumination intensity of 1000W / m 2 measure the open-circuit voltage (Uoc) and short-circuit current (Isc) of the solar panel outside the tunnel;

[0030] Further, in step (1), calculate the photocurrent (IL): Use the short-circuit current (Isc) as the photocurrent (IL).

[0031] Short-circuit current (Isc): The short-circuit current refers to the output current of the solar cell in the short-circuit state under standard test conditions. It is proportional to the incident light intensity. The formula is: Isc = IL, where IL is the photocurrent and is proportional to the light intensity.

[0032] Further, in step (2), open-circuit voltage (Uoc): The open-circuit voltage refers to the output voltage of the solar cell in the open-circuit state under standard test conditions. The formula is:

[0033]

[0034] where IL is the photocurrent and I0 is the reverse saturation current of the battery P-N junction in the absence of light.

[0035] Light intensity (S): The light intensity can be deduced from the photocurrent IL. The formula is:

[0036] IL = A c (C0 + C1T)S

[0037] That is, S = IL / A c (C0 + C1T)

[0038] where A c is the effective area of the solar photovoltaic cell, C0 and C1 are coefficients depending on the cell material, and T is the temperature of the solar photovoltaic cell.

[0039] In an embodiment of the present invention, step 1 detects the open-circuit voltage and short-circuit current of the main circuit of the solar panel outside the tunnel under standard test conditions. The standard test conditions are as follows:

[0040] Solar panel parameters:

[0041] Crystal specification: Monocrystalline silicon

[0042] Test temperature: 25 ± 0.5 °C

[0043] Standard test conditions: 0 - 1000 W / m2

[0044] Peak power: 100 W

[0045] Peak voltage: 19.5 V

[0046] Peak current: 5.29 A

[0047] Open circuit voltage: 22.6 V

[0048] Short circuit current: 5.56 A

[0049] The present invention has been generally and exhaustively described above. However, based on the present invention, some modifications or improvements can be made, which are obvious to those of ordinary skill in the art. Therefore, modifications or improvements made without departing from the spirit and idea of the present invention are within the protection scope of the present invention.

Claims

1. A method for detecting the brightness outside a tunnel based on the power generation of a solar panel, characterized in that: It includes the following steps: (1) Detect the open-circuit voltage and short-circuit current of the main circuit of the solar panel outside the tunnel entrance; (2) Based on the measured open-circuit voltage and short-circuit current, combined with the ambient temperature and the characteristic parameters of the solar panel, establish a mathematical model to calculate the brightness value outside the tunnel entrance; (3) Compare the calculated brightness value outside the tunnel entrance with the preset brightness threshold at the tunnel entrance, and accordingly adjust the lighting intensity at the tunnel entrance to reduce the visual discomfort of the driver.

2. The method for detecting the brightness outside the tunnel based on the power generation of the solar panel according to claim 1, characterized in that: In step (1), under the light intensity of 1000 W / m 2 , measure the open-circuit voltage and short-circuit current of the solar panels outside the tunnel.

3. The method for detecting the brightness outside the tunnel based on the power generation of the solar panel according to claim 2, characterized in that: In step (1), the short-circuit current Isc is used as the photocurrent IL.

4. The method for detecting the brightness outside the tunnel based on the power generation of the solar panel according to claim 1, wherein: In step (2), the open-circuit voltage Uoc: The open-circuit voltage refers to the output voltage of the solar cell in the open-circuit state under standard test conditions, and the formula is:

5. The method for detecting the brightness outside the tunnel based on the power generation of the solar panel according to claim 1, wherein: In step (2), the calculation formula for the light intensity is: IL = A c (C0 + C1T) S That is, S = IL / A c (C0 + C1T) Where A c is the effective area of the solar photovoltaic cell, C0 and C1 are coefficients dependent on the cell material, and T is the temperature of the solar photovoltaic cell.

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