A design method for lighting device and lighting device

Abstract

The present invention discloses a design method for a lighting device and a lighting device, and relates to the field of lighting technology. The lighting device includes: a load, an energy storage module, and a power generation module. In the design method for the lighting device of the present invention, the output voltage of the power generation module at the maximum power point is greater than or equal to the maximum charging voltage of the energy storage module, so as to avoid a sharp drop in the charging efficiency of the power generation module to the energy storage module, so that the power generation module can charge the energy storage module with a higher efficiency, so as to improve the charging efficiency of the power generation module to the energy storage module, thereby reducing the time required for the energy storage module to be fully charged, and using a smaller power power generation module can meet the demand, thereby reducing the cost of the lighting device.

Description

Technical Field

[0001] The present invention relates to the field of lighting technology, and in particular to a design method for a lighting device and a lighting device. Background Art

[0002] The light source module in the lighting device needs to be powered by electricity to drive the light-emitting unit of the light source module to emit light. The light source module on the lighting device can be connected to external power, or the power generation module on the lighting device can convert other energy collected by the lighting device into electrical energy, thereby making the light source module emit light.

[0003] Specifically, the power generation module in the lighting device can convert the collected energy into electrical energy and store it in the energy storage module, and then the energy storage module releases the electrical energy to the light source module.

[0004] Taking solar photovoltaic panels as power generation modules as an example, the inventors found that the open circuit voltage and short circuit current of solar photovoltaic panels under a certain constant illumination do not change much. Figure 1 As shown, the output of the solar photovoltaic panel can be approximated as a constant current source, so that the output power is greatly affected by the load (energy storage module). When the charging voltage input to the energy storage module is small, the output voltage of the power generation module is also small, and vice versa. And when the charging voltage input to the energy storage module (when charging, it is equal to the output voltage of the power generation module) is less than the maximum power point output voltage of the power generation module, the output power of the power generation module increases with the increase of the output voltage, and the charging efficiency at this time gradually increases. When the charging voltage input to the energy storage module is greater than the output voltage of the maximum power point of the power generation module, the output power of the power generation module decreases with the increase of the output voltage, and the charging efficiency drops sharply.

[0005] However, in actual applications, both the power generation module and the energy storage module are made of standard components, and are equipped with a standard controller to control the charging of the energy storage module by the power generation module. Since both the power generation module and the energy storage module are made of standard components, there is no specific requirement for the value between the output power of the power generation module and the charging voltage of the energy storage module. Once the charging voltage input to the energy storage module is greater than the output voltage of the maximum power point of the power generation module, the charging efficiency of the power generation module to the energy storage module drops sharply. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a design method of a lighting device and a lighting device.

[0007] In a first aspect, the present invention provides a design method for a lighting device, wherein the lighting device includes a load, an energy storage module, and a power generation module, and the design method includes:

[0008] Selecting an energy storage module according to the load, and calculating the maximum charging voltage of the energy storage module;

[0009] The power generation module is selected so that the output voltage of the power generation module at the maximum power point at the highest operating temperature is greater than or equal to the maximum charging voltage of the energy storage module.

[0010] In the above-mentioned design method, the energy storage module includes at least one energy storage element, and when the number of the energy storage elements is more than two, they are connected in series; the power generation module includes at least one power generation unit, and when the number of the power generation units is more than two, they are connected in series.

[0011] The above-mentioned design method, wherein the energy storage module is selected according to the load, comprises:

[0012] Determining the number of the energy storage elements in the energy storage module, wherein the maximum charging voltages of the energy storage elements are equal;

[0013] The maximum charging voltage of the energy storage module is obtained by multiplying the maximum charging voltage of the energy storage element by the number of the energy storage elements.

[0014] The above-mentioned design method, wherein the power generation module is selected, and the output voltage of the maximum power point of the power generation module at the highest operating temperature is greater than or equal to the maximum charging voltage of the energy storage module, comprises:

[0015] Obtaining the output voltage of the maximum power point of the power generation unit at the highest operating temperature, wherein the output voltage of the maximum power point of the power generation module at the highest operating temperature is equal to the sum of the output voltages of the maximum power points of all the power generation units at the highest operating temperature, wherein the first power generation unit has the smallest output voltage of the maximum power point at the highest operating temperature among all the power generation units;

[0016] The difference between the output voltage of the maximum power point of the power generation module at the highest temperature and the maximum charging voltage of the energy storage module is smaller than the output voltage of the maximum power point of the first power generation unit at the highest operating temperature.

[0017] In the above design method, the output voltages of the maximum power points of all the power generation units in the power generation module at the highest operating temperature are equal;

[0018] or

[0019] The output voltages of the maximum power points of all the power generation units in the power generation module at the highest operating temperature are not completely equal, and in the step of obtaining the output voltages of the maximum power points of the power generation units at the highest operating temperature, it includes: obtaining the output voltages of the maximum power points of all the power generation units at the highest operating temperature whose output voltages of the maximum power points at the highest operating temperature are not completely equal.

[0020] The above-mentioned design method, wherein obtaining the output voltage of the maximum power point of the power generation unit at the highest operating temperature comprises:

[0021] Obtaining the output voltage of the power generation unit at the maximum power point at ambient temperature;

[0022] The power generation unit receives a preset input energy, and after a preset time, measures an operating temperature of the power generation unit as a maximum operating temperature of the power generation unit;

[0023] The output voltage of the power generation unit at the maximum power point at the highest operating temperature is calculated.

[0024] In a second aspect, the present invention provides a design method for a lighting device, wherein the lighting device includes an energy storage module and a power generation module, and the design method includes:

[0025] Obtaining the output voltage of the power generation module at the maximum power point at the highest operating temperature;

[0026] The energy storage module is selected so that the maximum charging voltage of the energy storage module is less than or equal to the output voltage of the maximum power point of the power generation module at the highest operating temperature.

[0027] In the above-mentioned design method, obtaining the output voltage of the maximum power point of the power generation module at the highest total temperature includes:

[0028] Obtain the output voltage of the power generation module at the maximum power point at ambient temperature;

[0029] The power generation module receives a preset input energy, and after a preset time, measures the operating temperature of the power generation module as the maximum operating temperature of the power generation module;

[0030] The output voltage of the power generation module at the maximum power point at the highest operating temperature is calculated.

[0031] In a third aspect, the present invention provides a lighting device, comprising:

[0032] load;

[0033] An energy storage module stores electrical energy and provides power to the load;

[0034] A power generation module, used to convert input energy from the environment into electrical energy and charge the energy storage module;

[0035] The output voltage of the maximum power point of the power generation module is greater than or equal to the maximum charging voltage of the energy storage module.

[0036] In the above-mentioned lighting device, the output voltage of the maximum power point of the power generation module includes: the output voltage of the maximum power point of the power generation module at the highest operating temperature.

[0037] The above-mentioned lighting device further includes a controller, which is connected to the energy storage module and the power generation module to control the power generation module to charge the energy storage module.

[0038] In the above-mentioned lighting device, the energy storage module includes at least one energy storage element, and when the number of the energy storage elements is more than two, the energy storage elements are connected in series; the power generation module includes at least one power generation unit, and when the number of the power generation units is more than two, the power generation units are connected in series.

[0039] In the above-mentioned lighting device, the power generation module includes a first power generation unit with the smallest output voltage at the maximum power point at the highest operating temperature, and the difference between the output voltage of the maximum power point of the power generation module at the highest operating temperature and the maximum charging voltage of the energy storage module is less than the output voltage of the first power generation unit at the maximum power point at the highest operating temperature.

[0040] In the above-mentioned lighting device, the output voltages of the maximum power points of all the power generation units in the power generation module at the highest operating temperature are equal, and / or the maximum charging voltages of all the energy storage elements in the energy storage module are equal.

[0041] In the above-mentioned lighting device, the output voltage of the maximum power point of the power generation unit at the highest operating temperature is less than or equal to the maximum charging voltage of the energy storage element.

[0042] In the above-mentioned lighting device, the maximum charging voltage of the energy storage element is 6 to 10 times the output voltage of the maximum power point of the power generation unit at the highest operating temperature.

[0043] In the above-mentioned lighting device, the energy storage element includes a battery core, and / or the power generation unit includes a solar cell.

[0044] In the design method of the lighting device of the present invention, the output voltage of the power generation module at the maximum power point is greater than or equal to the maximum charging voltage of the energy storage module, thereby avoiding a sharp drop in the charging efficiency of the power generation module to the energy storage module, so that the power generation module can charge the energy storage module with a higher efficiency, so as to improve the charging efficiency of the power generation module to the energy storage module, thereby reducing the time required for the energy storage module to be fully charged, and using a smaller power power generation module can meet the demand, thereby reducing the cost of the lighting device. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0046] Figure 1 is a graph showing the relationship between the output power, light intensity and output voltage of the photovoltaic panel of the lighting device in an embodiment of the present invention;

[0047] Figure 2 is a graph showing the relationship between the output power, the operating temperature and the output voltage of the photovoltaic panel of the lighting device in an embodiment of the present invention;

[0048] Figure 3 is a flow chart of a design method for an illumination device in a first embodiment of the present invention;

[0049] Figure 4 is a flow chart of a design method for an illumination device in a second embodiment of the present invention;

[0050] Figure 5 is a module diagram of a lighting device in a third embodiment of the present invention;

[0051] Figure 6 The photovoltaic panel voltage and the battery voltage that change with time in Experimental Example 1 of the lighting device in the third embodiment of the present invention;

[0052] Figure 7 1 and 2 show the photovoltaic panel voltage and battery voltage that vary with time in Experimental Example 2 of the lighting device in the third embodiment of the present invention.

[0053] Reference numerals:

[0054] 100-lighting device; 10-load; 20-energy storage module; 30-power generation module; 40-controller. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0056] Combination Figure 1It can be seen that when the charging voltage input to the energy storage module (equal to the output voltage of the power generation module during charging) is less than the maximum power point output voltage of the power generation module, the output power of the power generation module increases with the increase of the output voltage, and the charging efficiency at this time gradually increases. When the charging voltage input to the energy storage module is greater than the output voltage of the maximum power point of the power generation module, the output power of the power generation module decreases with the increase of the output voltage, and the charging efficiency drops sharply. Figure 2 It can be seen that as the temperature of the power generation module increases, the output voltage of the maximum power point thereof gradually decreases. In order to improve the charging efficiency of the power generation module to the energy storage module, the present application provides a design method of a lighting device and a lighting device.

[0057] Example 1

[0058] Embodiment 1 of the present invention discloses a design method for a lighting device, wherein the lighting device includes a load, an energy storage module and a power generation module. Figure 3 , the design method includes the following steps:

[0059] S1: Selecting an energy storage module according to the load, and calculating the maximum charging voltage of the energy storage module.

[0060] S2: Select the power generation module, the output voltage of the maximum power point of the power generation module at the highest operating temperature is greater than or equal to the maximum charging voltage of the energy storage module.

[0061] In the design method of the lighting device of the present invention, the output voltage of the maximum power point of the power generation module at the highest operating temperature is greater than or equal to the maximum charging voltage of the energy storage module. The design method of Example 1 of the present invention avoids a sharp drop in the charging efficiency of the power generation module to the energy storage module, so that the power generation module can charge the energy storage module with a higher efficiency, so as to improve the charging efficiency of the power generation module to the energy storage module, thereby reducing the time required for the energy storage module to be fully charged, and a smaller power generation module can be used to meet the demand, thereby reducing the cost of the lighting device.

[0062] Specifically, the load of the lighting device may be a light source module for emitting light, or other modules that do not emit light, such as a timing module for timing, a driving module for driving components to move, etc. The power generation module may be a photovoltaic panel that converts light energy into electrical energy, or other power generation devices that convert wind energy or vibration energy into electrical energy. The energy storage module may be a battery, or other devices that can store circuits, such as a capacitor.

[0063] The energy storage module may include at least two energy storage elements connected in series, or may include only one energy storage element; the power generation module may include at least two power generation units connected in series, or may include only one power generation unit. Furthermore, the energy storage element may include a battery cell, and the energy storage module is a battery composed of battery cells connected in series; the power generation unit may include a solar cell power generation module, which is a photovoltaic panel composed of solar cells connected in series. Of course, the energy storage element may be other components that can store electrical energy, and will not be elaborated here. The power generation unit may be other devices that can generate electricity, such as those that can convert wind energy into electrical energy to achieve power generation.

[0064] In S1, the maximum charging voltage of the energy storage module can be selected according to the power of the load. In addition, a transformer electrically connected between the energy storage module and the load is selected according to the power of the load and the maximum charging voltage of the energy storage module.

[0065] Furthermore, S1 includes S11 and S12.

[0066] S11: Determine the number of the energy storage elements in the energy storage module, and the maximum charging voltages of the energy storage elements are equal.

[0067] S12: The maximum charging voltage of the energy storage module is obtained by multiplying the maximum charging voltage of the energy storage element by the number of the energy storage elements, that is, the maximum charging voltage of all energy storage elements is summed to obtain the maximum charging voltage of the energy storage module.

[0068] As a variation, in S11, the maximum charging voltages of the energy storage elements may not be completely equal, and in S12, the maximum charging voltages of all the energy storage elements in the energy storage module may also be summed to obtain the maximum charging voltage of the energy storage module.

[0069] S2 includes S21 and S22.

[0070] S21: Obtain the output voltage of the maximum power point of the power generation unit at the highest operating temperature, the output voltage of the maximum power point of the power generation module at the highest operating temperature is equal to the sum of the output voltages of the maximum power points of all the power generation units at the highest operating temperature, wherein the first power generation unit has the smallest output voltage of the maximum power point at the highest operating temperature among all the power generation units. That is, among all the power generation units in the power generation module, the first power generation unit has the smallest output voltage of the maximum power point at the highest operating temperature.

[0071] S22: The difference between the output voltage of the maximum power point of the power generation module at the highest temperature and the maximum charging voltage of the energy storage module is smaller than the output voltage of the maximum power point of the first power generation unit at the highest operating temperature. Specifically, the absolute value of the difference is smaller than the output voltage of the maximum power point of the first power generation unit at the highest operating temperature.

[0072] Since the power generation module can charge the energy storage module at a higher efficiency when the output voltage of the maximum power point at the highest temperature is greater than or equal to the maximum charging voltage of the energy storage module, and when the output voltage of the maximum power point at the highest temperature is equal to the maximum charging voltage of the energy storage module, the charging efficiency of the energy storage module by the power generation module is the highest. Therefore, the smaller the absolute value of the difference between the output voltage of the maximum power point of the power generation module at the highest temperature and the maximum charging voltage of the energy storage module, the higher the charging efficiency. In this design method, the absolute value of the difference between the output voltage of the maximum power point of the power generation module at the highest temperature and the maximum charging voltage of the energy storage module can be minimized as much as possible to maximize the charging efficiency.

[0073] In S21, the output voltages of the maximum power points of all power generation units of the power generation module at the highest operating temperature may be equal, that is, all power generation units in the power generation module are first power generation units. Of course, the output voltages of the maximum power points of all power generation units of the power generation module at the highest operating temperature may be completely unequal, so it is necessary to obtain the output voltages of the maximum power points of all power generation units whose output voltages of the maximum power points at the highest operating temperature are not completely equal, or to obtain the output voltages of the maximum power points of all power generation units in the power generation module at the highest operating temperature.

[0074] It should be noted that when the output voltages of the maximum power points of the power generation units in the power generation module at the highest operating temperature are equal, and the maximum charging voltages of all energy storage elements in the energy storage module are also equal, the maximum charging voltage value of each energy storage element is greater than or equal to the output voltage value of the maximum power point of each power generation unit at the highest operating temperature. Specifically, the maximum charging voltage of the energy storage element may be 6 to 10 times the output voltage of the maximum power point of the power generation unit at the highest operating temperature. In addition, when the output voltages of the maximum power points of the power generation units in the power generation module at the highest operating temperature are not completely equal, and the maximum charging voltages of all energy storage elements in the energy storage module are not completely equal, the maximum charging voltage value of the energy storage element may also be greater than or equal to the output voltage value of the maximum power point of the power generation unit at the highest operating temperature.

[0075] S21 also includes S211, S212 and S213.

[0076] S211: Obtaining the output voltage of the maximum power point of the power generation unit at the ambient temperature, that is, measuring the output voltage of the maximum power point of the power generation unit at the ambient temperature.

[0077] S212: The power generation unit receives a preset input energy, and after a preset time, measures the operating temperature of the power generation unit as the maximum operating temperature of the power generation unit. After the power generation unit receives input energy for a certain period of time, the operating temperature stabilizes, and the temperature measured at this time is the maximum operating temperature of the power generation unit.

[0078] S213: Calculate the output voltage of the maximum power point of the power generation unit at the highest operating temperature. Specifically, in the design method, the power generation module takes a photovoltaic panel as an example, and the relationship between the output voltage of the maximum power point and the temperature is as follows:

[0079] V mpp =v to (1+(T1-T0)·β) (1)

[0080] Among them, V mpp v is the output voltage of the solar cell (or photovoltaic panel) at the maximum power point at temperature T1; to is the output voltage of the maximum power point of the solar cell (or photovoltaic panel) at temperature T0; T1 is the ambient temperature; T0 is 25°C; β is the temperature coefficient of the solar cell (or photovoltaic panel), for example, single crystal silicon is usually -0.32% / °C.

[0081] In the embodiment of the present invention, the output voltage of the maximum power point of a single or several power generation units (i.e., solar cells) at the highest operating temperature is measured, and the output voltage of the maximum power point of the power generation module at the highest temperature is obtained in combination with the number of power generation units in the power generation module. In practical applications, the output voltage of the maximum power point of the power generation module (i.e., photovoltaic panel) at the highest operating temperature can also be directly measured.

[0082] Example 2

[0083] Embodiment 2 of the present invention discloses a design method for a lighting device, wherein the lighting device includes an energy storage module and a power generation module, and the lighting device may also include a load. Figure 4 , the design method includes the following steps:

[0084] S1,': obtaining the output voltage of the maximum power point of the power generation module at the highest operating temperature;

[0085] S2': Select the energy storage module so that the maximum charging voltage of the energy storage module is less than or equal to the output voltage of the maximum power point of the power generation module at the highest operating temperature.

[0086] In embodiment 2 of the present invention, after selecting a power generation module, an energy storage module matching the power generation module is selected so that the maximum charging voltage of the energy storage module is less than or equal to the output voltage of the maximum power point of the power generation module at the highest operating temperature. The power generation module can charge the energy storage module with higher efficiency.

[0087] After S2', S3' may be further included: selecting the power of the load according to the maximum charging voltage of the energy storage element. In addition, selecting a transformer electrically connected between the energy storage module and the load according to the power of the load and the maximum charging voltage of the energy storage module.

[0088] Specifically, similar to the first embodiment, the load of the lighting device may be a light source module for emitting light, or other modules that do not emit light, such as a timing module for timing, a driving module for driving components, and the like.

[0089] S1' includes S11', S12' and S13'.

[0090] S11': Obtain the output voltage of the maximum power point of the power generation module at ambient temperature.

[0091] S12': The power generation module receives a preset input energy, and after a preset time, measures the operating temperature of the power generation module as the maximum operating temperature of the power generation module.

[0092] S13': Calculate the output voltage of the maximum power point of the power generation module at the highest operating temperature.

[0093] Similarly, with the aid of formula (1) in Example 1, the output voltage of the maximum power point of the power generation module at the highest operating temperature can be calculated.

[0094] The main difference between Example 2 of the present invention and Example 1 lies in the order of selecting the power generation module and the energy storage module. Without affecting the order of selecting the power generation module and the energy storage module in Example 2, Example 2 can have the same scheme as Example 1.

[0095] Example 3

[0096] The embodiment of the present invention discloses a lighting device. Specifically, the lighting device can be a solar lamp, a wind energy lamp, a vibration energy lamp, etc., such as a solar garden lamp, or a lamp that emits light using wind energy or vibration energy. The lighting device can be powered by electric energy converted by a power generation module, or can be directly powered by an external power supply.

[0097] like Figure 5 As shown, the lighting device 100 includes a load 10 , an energy storage module 20 and a power generation module 30 .

[0098] The load 10 may be a light source module, which includes a light source substrate and a light emitting unit, and the light emitting unit is disposed on the light source substrate. Of course, the load 10 may also be other modules other than those that emit light, such as a timing module for timing, a driving module for driving components to move, and the like.

[0099] The energy storage module 20 can store electrical energy, and the stored electrical energy can provide power for the light source module, so that the lighting device 100 can achieve the lighting function without relying on an external power supply.

[0100] The power generation module 30 can convert input energy in the environment into electrical energy for charging the energy storage module 20. During charging, the output voltage of the power generation module 30 is equal to the charging voltage of the energy storage module 20.

[0101] In the embodiment of the present invention, the output voltage of the power generation module 30 at the maximum power point is greater than or equal to the maximum charging voltage of the energy storage module 20, so as to avoid a sharp drop in the charging efficiency of the power generation module 30 to the energy storage module 20, so that the power generation module 30 can charge the energy storage module with higher efficiency, so as to improve the charging efficiency of the power generation module 30 to the energy storage module, thereby reducing the time required for the energy storage module to be fully charged, and using a smaller power power generation module 30 can meet the demand, thereby reducing the cost of the lighting device 100.

[0102] The maximum power point refers to the operating point at which the power generation module 30 has the maximum power output.

[0103] The power generation module 30 may be a photovoltaic panel that converts light energy into electrical energy, or other power generation devices that convert wind energy or vibration energy into electrical energy. The energy storage module 20 may be a battery, or other devices that can store electricity, such as capacitors.

[0104] Generally, the output voltage of the power generation module 30 at the maximum power point is negatively correlated with the operating temperature. The initial operating temperature of the power generation module 30 is close to the ambient temperature. As the working time of the power generation module 30 increases, the operating temperature gradually rises to the temperature. Based on this factor, the output voltage of the power generation module 30 at the maximum operating temperature and the maximum power point is limited to be greater than or equal to the maximum charging voltage of the energy storage module 20. Figure 2 As the battery temperature increases, the output voltage at its maximum power point gradually decreases. Therefore, the output voltage of the battery at the maximum power point at the highest operating temperature is limited to be greater than or equal to the maximum charging voltage of the energy storage module 20. Generally, the maximum operating temperature of the battery can be 70 degrees Celsius, so the output voltage of the battery at 70 degrees Celsius and the maximum power point can be limited to be greater than or equal to the maximum charging voltage of the energy storage module 20; of course, depending on the type and model of the battery, its specific maximum operating temperature will vary.

[0105] The lighting device 100 may further include a controller 40, which is connected to the energy storage module 20 and the power generation module 30 to turn on or off the power generation module 30 charging the energy storage module 20. Of course, the lighting device 100 may also include a power monitoring module, which is connected to the controller 40 and the energy storage module 20 and detects the remaining power value in the energy storage module 20. The controller 40 receives the remaining power value sent by the power monitoring module, and when the remaining power value reaches a first threshold, drives the power generation module 30 to supply power to the energy storage module 20, and when the remaining power value reaches a second threshold, drives the power generation module 30 to stop supplying power, wherein the second threshold may be greater than the first threshold.

[0106] The power generation module 30 may include at least two power generation units, and at least two power generation units may be connected in series to form the power generation module 30, and then the output voltage of the power generation module 30 may be increased or decreased by controlling the number of power generation units in the power generation module 30. The energy storage module 20 may include at least two energy storage elements, and multiple energy storage elements may be connected in series to form the energy storage module 20. Of course, the power generation module 30 may have only one power generation unit, and the energy storage module 20 may have only one energy storage element.

[0107] The power generation module 30 includes a first power generation unit having a minimum output voltage at a maximum power point at a maximum operating temperature. Figure 1 It can be seen that the closer the output voltage of the power generation module 30 at the maximum power point is to the maximum charging voltage value of the energy storage module 20, the higher the charging efficiency. Therefore, in order to improve the charging efficiency as much as possible, the absolute value of the difference between the output voltage of the power generation module 30 at the maximum power point at the highest temperature and the maximum charging voltage of the energy storage module 20 should be smaller than the output voltage of the maximum power point of a first power generation unit at the highest temperature.

[0108] Specifically, the output voltages of the maximum power points of at least two power generation units in the power generation module 30 at the highest operating temperature may be equal or incompletely equal. Of course, the maximum charging voltages of at least two energy storage elements in the energy storage module 20 may be equal or incompletely equal.

[0109] When the output voltages of the maximum power points of at least two power generation units in the power generation module 30 at the highest operating temperature can be equal, it can be considered that all power generation units in the power generation module 30 are first power generation units. At this time, if the maximum charging voltages of at least two energy storage elements of the energy storage module 20 are also equal, the product of the output voltage of the maximum power point of the first power generation unit in the power generation module 30 and the number of all first power generation units is greater than or equal to the product of the maximum charging voltage of the energy storage element in the energy storage module 20 and the number of all energy storage units.

[0110] The output voltage of the maximum power point of the power generation unit at the highest temperature is less than or equal to the maximum charging voltage of the energy storage element. If the output voltage of the maximum power point of the power generation unit is equal to the maximum charging voltage of the energy storage element, the total number of power generation units is equal to the total number of energy storage elements, which means that the output voltage of the maximum power point of the power generation module 30 is equal to the maximum charging voltage of the energy storage module 20. At this time, the charging efficiency of the power generation module 30 is the highest.

[0111] Of course, under normal circumstances, the output voltage of the maximum power point of the power generation unit is not equal to the maximum charging voltage of the energy storage element. For example, if the output voltage of the maximum power point of the power generation unit is less than the maximum charging voltage of the energy storage element, then the total number of power generation units is greater than the total number of energy storage elements. Specifically, in practice, the output voltage of the power generation unit at the maximum power point can be much less than the maximum charging voltage of the energy storage element, so that the output voltage of the maximum power point of the power generation module 30 can be adjusted by increasing or decreasing the number of power generation units. Of course, the output voltage of the power generation unit at the maximum power point can also be greater than the maximum charging voltage of the energy storage element, which will not be repeated.

[0112] Specifically, the maximum charging voltage of the energy storage element can be 6 to 10 times the output voltage of the maximum power point of the power generation unit at the highest operating temperature. Taking solar lamps as an example, the energy storage module 20 can be a lithium iron phosphate battery, which includes several battery cells, each of which has a typical voltage of Vbo (typical value 3.2V), a maximum charging voltage of Vbm (typical value 3.8V), and a maximum voltage of multiple cells connected in series is an integer multiple of 3.8V; the power generation unit of the power generation module 30 can be a constant current solar cell, each of which has an open circuit voltage of Vo (cell value 0.5V), and a maximum power point voltage of Vm (typical value 0.4V) at 25°C.

[0113] Taking solar garden lights as an example, the following will specifically introduce how to use photovoltaic panels in solar garden lights to efficiently power batteries.

[0114] The solar garden light includes a light source module, a photovoltaic panel, a controller and a battery. The battery can provide power to the light source module, the photovoltaic panel receives light energy and converts it into power, and the controller controls the photovoltaic panel to charge the battery. The output voltage of the photovoltaic panel at the maximum power point is greater than or equal to the maximum charging voltage of the battery.

[0115] like Figure 2 As shown, the output voltage at the maximum power point of the photovoltaic panel decreases as the temperature rises. In order to ensure that the charging voltage of the battery is less than the output voltage at the maximum power point so that the photovoltaic panel can charge the battery at a maximum temperature less than 100 °C, it is necessary to make the output voltage at the maximum power point of the photovoltaic panel at the highest operating temperature greater than or equal to the maximum charging voltage of the battery.

[0116] Specifically, the relationship between the output voltage and temperature at the maximum power point is as follows:

[0117] V mpp =v to (1+(T1-T0)·β)

[0118] Among them, V mpp v is the output voltage of the photovoltaic panel at the maximum power point at temperature T1; to is the output voltage of the maximum power point of the photovoltaic panel at temperature T0; T1 is the ambient temperature; T0 is 25°C; β is the temperature coefficient of the photovoltaic panel, for example, single crystal silicon is usually -0.32% / °C.

[0119] For example, in order to obtain the output voltage of the maximum power point of the photovoltaic panel when the maximum operating temperature is 70°C, the output power calculated by taking T1 as 70°C in the above formula is the output voltage of the maximum power point at 70°C.

[0120] The battery in the solar garden light can be a lithium iron phosphate battery. The lithium iron phosphate battery is composed of multiple cells connected in series. The typical voltage of each cell is Vbo (typical value 3.2V), the maximum charging voltage is Vbm (typical value 3.8V), and the maximum voltage of multiple cells in series is an integer multiple of 3.8V. The photovoltaic panel is composed of multiple cells in series. The open circuit voltage of each cell is Vo (cell value 0.5V), and the maximum power point voltage at 25℃ is Vm (typical value 0.4V). In order to avoid a sharp drop in the charging efficiency of the solar photovoltaic panel to the battery during voltage fluctuations, the following conditions need to be ensured:

[0121] Vm*M≥Vbm*N

[0122] Among them, M is the number of solar cells connected in series in the photovoltaic panel, and N is the number of battery cells connected in series in the battery.

[0123] Furthermore, in order to maximize the charging efficiency of solar photovoltaic panels to batteries, the following conditions need to be met:

[0124] Vbm*(N+1)≥Vm*M≥Vbm*N

[0125] In order to verify the feasibility of the method, two different experimental examples were built for comparative testing, and the configuration parameters of the two experimental examples are shown in Table 1. Among them, the battery voltage in Table 1 is the maximum charging voltage. Taking lithium iron phosphate battery as an example, the battery in Experimental Example 1 has 4 cells, so that the maximum charging voltage of the battery in Experimental Example 1 is 15.2V, and the battery in Experimental Example 2 has 5 cells, so that the maximum charging voltage of the battery in Experimental Example 2 is 19V.

[0126]

[0127] Figure 6 This is the test image corresponding to Experimental Example 1. Figure 6 It can be seen that after a night of discharge, the system with a maximum battery charge voltage of 15.2V was fully charged at 10:03:24 am; Figure 7 This is the test image corresponding to Experimental Example 2. Figure 7 It can be seen that after a night of discharge, the system with a maximum battery charging voltage of 19V was fully charged at 9:32:37 a.m. Experimental Example 2 can be fully charged earlier than Experimental Example 1, that is, the charging efficiency of Experimental Example 2 is higher.

[0128] It should be noted that Figure 6 and Figure 7 When the battery is fully charged, the photovoltaic panel and the battery can be disconnected, and the measured photovoltaic panel voltage is its open circuit voltage.

[0129] The specific examples described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for designing a lighting device, characterized in that: The lighting device includes a load, an energy storage module and a power generation module, and the design method includes: Selecting an energy storage module according to the load, and calculating the maximum charging voltage of the energy storage module; Selecting the power generation module, the output voltage of the maximum power point of the power generation module at the highest operating temperature is greater than or equal to the maximum charging voltage of the energy storage module; The energy storage module includes at least one energy storage element, and when the number of the energy storage elements is more than two, they are connected in series; the power generation module includes at least one power generation unit, and when the number of the power generation units is more than two, they are connected in series; The step of selecting the power generation module, wherein the output voltage of the power generation module at the maximum power point at the highest operating temperature is greater than or equal to the maximum charging voltage of the energy storage module, comprises: Obtaining the output voltage of the maximum power point of the power generation unit at the highest operating temperature, wherein the output voltage of the maximum power point of the power generation module at the highest operating temperature is equal to the sum of the output voltages of the maximum power points of all the power generation units at the highest operating temperature, wherein the first power generation unit has the smallest output voltage of the maximum power point at the highest operating temperature among all the power generation units; The difference between the output voltage of the maximum power point of the power generation module at the highest temperature and the maximum charging voltage of the energy storage module is smaller than the output voltage of the maximum power point of the first power generation unit at the highest operating temperature.

2. The design method according to claim 1, characterized in that: The step of selecting an energy storage module according to the load includes: Determining the number of the energy storage elements in the energy storage module, wherein the maximum charging voltages of the energy storage elements are equal; The maximum charging voltage of the energy storage module is obtained by multiplying the maximum charging voltage of the energy storage element by the number of the energy storage elements.

3. The design method according to claim 1, characterized in that: The output voltages of the maximum power points of all the power generation units in the power generation module at the highest operating temperature are equal; or The output voltages of the maximum power points of all the power generation units in the power generation module at the highest operating temperature are not completely equal, and in the step of obtaining the output voltages of the maximum power points of the power generation units at the highest operating temperature, it includes: obtaining the output voltages of the maximum power points of all the power generation units at the highest operating temperature whose output voltages of the maximum power points at the highest operating temperature are not completely equal.

4. The design method according to claim 1, characterized in that: The obtaining the output voltage of the power generation unit at the maximum power point at the highest operating temperature comprises: Obtaining the output voltage of the power generation unit at the maximum power point at ambient temperature; The power generation unit receives a preset input energy, and after a preset time, measures an operating temperature of the power generation unit as a maximum operating temperature of the power generation unit; The output voltage of the power generation unit at the maximum power point at the highest operating temperature is calculated.

5. A method for designing a lighting device, characterized in that: The lighting device includes an energy storage module and a power generation module, and the design method includes: Obtaining the output voltage of the power generation module at the maximum power point at the highest operating temperature; The energy storage module is selected so that the maximum charging voltage of the energy storage module is less than or equal to the output voltage of the maximum power point of the power generation module at the highest operating temperature; The energy storage module includes at least one energy storage element, and when the number of the energy storage elements is more than two, they are connected in series; the power generation module includes at least one power generation unit, and when the number of the power generation units is more than two, they are connected in series; The output voltage of the maximum power point of the power generation module at the highest operating temperature is equal to the sum of the output voltages of the maximum power points of all the power generation units at the highest operating temperature, the power generation module includes a first power generation unit with the smallest output voltage at the maximum power point at the highest operating temperature, and the difference between the output voltage of the maximum power point of the power generation module at the highest operating temperature and the maximum charging voltage of the energy storage module is less than the output voltage of the first power generation unit at the maximum power point at the highest operating temperature.

6. The design method according to claim 5, characterized in that: The step of obtaining the output voltage of the power generation module at the maximum power point under the highest total operating temperature includes: Obtain the output voltage of the power generation module at the maximum power point at ambient temperature; The power generation module receives a preset input energy, and after a preset time, measures the operating temperature of the power generation module as the maximum operating temperature of the power generation module; The output voltage of the power generation module at the maximum power point at the highest operating temperature is calculated.

7. A lighting device, characterized in that: include: load; An energy storage module stores electrical energy and provides power to the load; A power generation module, used to convert input energy from the environment into electrical energy and charge the energy storage module; The output voltage of the maximum power point of the power generation module is greater than or equal to the maximum charging voltage of the energy storage module; The energy storage module includes at least one energy storage element, and when the number of the energy storage elements is more than two, they are connected in series; the power generation module includes at least one power generation unit, and when the number of the power generation units is more than two, they are connected in series; The output voltage of the maximum power point of the power generation module at the highest operating temperature is equal to the sum of the output voltages of the maximum power points of all the power generation units at the highest operating temperature, the power generation module includes a first power generation unit with the smallest output voltage at the maximum power point at the highest operating temperature, and the difference between the output voltage of the maximum power point of the power generation module at the highest operating temperature and the maximum charging voltage of the energy storage module is less than the output voltage of the first power generation unit at the maximum power point at the highest operating temperature.

8. The lighting device according to claim 7, characterized in that: The output voltage of the maximum power point of the power generation module includes: the output voltage of the maximum power point of the power generation module at the highest operating temperature.

9. The lighting device according to claim 7, characterized in that: The lighting device further includes a controller, which is connected to the energy storage module and the power generation module and controls the power generation module to charge the energy storage module.

10. The lighting device according to claim 7, characterized in that: The output voltages of the maximum power points of all the power generation units in the power generation module at the highest operating temperature are equal, and / or the maximum charging voltages of all the energy storage elements in the energy storage module are equal.

11. The lighting device according to claim 10, characterized in that: The output voltage of the maximum power point of the power generation unit at the highest operating temperature is less than or equal to the maximum charging voltage of the energy storage element.

12. The lighting device according to claim 11, characterized in that: The maximum charging voltage of the energy storage element is 6 to 10 times the output voltage of the maximum power point of the power generation unit at the highest operating temperature.

13. The lighting device according to claim 7, characterized in that: The energy storage element includes a battery cell, and / or the power generation unit includes a solar cell.

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