TWI502844B - Photovoltaic module and control method thereof - Google Patents

Description

Solar module and control method thereof

The invention relates to a solar module and a control method thereof, and in particular to a solar module with an identification unit and a control method thereof.

Please refer to FIG. 1 , which illustrates a schematic diagram of a conventional solar power generation system 100 . The solar power generation system 100 includes a solar array 110 and a DC/AC inverter 120. The solar array 110 converts the received light energy into electrical energy and provides the electrical energy to the DC/AC inverter 120. The DC/AC inverter 120 converts the received electrical energy into an alternating current, and then supplies the alternating current to the alternating current load 130 or to the mains 140.

The solar array 110 includes a plurality of solar panels 111. Since the voltage that each solar panel 111 can provide is not large, it is conventional to connect a plurality of solar panels 111 in series to form a solar panel string 110a for increasing the voltage value of the output. Then, the solar array 110 is formed by connecting a plurality of solar panel strings 110a in parallel to increase the amount of power generated by the solar power generation system 100.

When the solar panel 111 in the solar panel string 110a is lost When the output power is abnormal (such as when shading or damage occurs), the power generation efficiency of the solar power generation system is lowered. Since each of the solar panels 111 in the solar panel series 110a is connected in series such that the current output by each of the solar panels 111 is the same, the conventional detecting method must measure the output end and the input end of each of the solar panels 111 one by one. In order to trace whether the solar panel 111 is abnormal.

In large solar power plants, the output power may be on the order of megawatts or more. Therefore, a large number of solar panels are arranged in these power plants. However, if a conventional detection method is used, it is not possible to quickly and efficiently detect an abnormal solar panel. In other words, the traditional detection method is not only time-consuming and labor-intensive, but also affects the performance of the solar power system.

In order to solve the above problems, the present invention discloses a solar module and a control method thereof, thereby reducing the time for detecting the solar panel, and making the operation of the solar power generation system more efficient.

One aspect of the present disclosure is directed to a solar module. The solar module corresponds to a reading device. The solar module includes a solar panel, an identification unit, and a control unit. The solar panel is used to convert the received light energy into output electrical energy. The output power has a corresponding output voltage and output power. The identification unit includes an antenna and an identifier of the corresponding solar module, wherein the antenna is electrically coupled to the identifier. The control unit is electrically coupled between the solar panel and the identification unit, and is configured to receive the output voltage and according to whether the output power is in a preset range It is decided to enable or disable the antenna.

According to an embodiment of the invention, the control unit enables the antenna when the output power is within the preset range. The reading device receives the corresponding signal of the identifier through the antenna. The control unit disables the antenna when the output power is outside the preset range.

According to an embodiment of the invention, the control unit is further configured to compare the output voltage with the first voltage and compare the output voltage with the second voltage, and determine, according to a result of the comparison, whether the output power is located in the Preset range. When the output voltage is greater than or equal to the first voltage and less than or equal to the second voltage, the control unit determines that the output power is within the preset range. When the output voltage is less than the first voltage or greater than the second voltage, the control unit determines that the output power is outside the preset range.

According to an embodiment of the invention, the control unit includes a first comparator, a second comparator, and a AND gate. The first comparator has a first inverting terminal, a first non-inverting terminal, and a first output terminal. The first non-inverting terminal is electrically coupled to the solar panel and configured to receive the output voltage. The first inverting terminal is configured to receive the first voltage. The second comparator has a second inverting terminal, a second non-inverting terminal, and a second output terminal. The second inverting terminal is electrically coupled to the solar panel and configured to receive the output voltage. The second non-inverting terminal is configured to receive the second voltage. The gate has a first input, a second input, and an output. The first input end is electrically coupled to the first output end. The second input is electrically coupled to the second output.

According to an embodiment of the invention, the control unit further comprises a relay Device. The relay is electrically coupled between the output end of the NAND gate and the antenna of the identification unit, and is configured to be turned on or off according to the output signal of the NAND gate.

According to an embodiment of the invention, the preset range is between a maximum output power that the solar panel can provide, multiplied by a predetermined percentage and a maximum output power.

According to an embodiment of the invention, the identification unit comprises a Radio Frequency Identification (RFID) module, a Near Field Communication (NFC) module, or a combination thereof.

Another aspect of the present disclosure is directed to a method of controlling a solar module. The control method includes: detecting an output voltage of the electric energy provided by the solar panel in the solar module; determining whether to enable or disable the antenna in the solar module according to whether the output power of the electric energy provided by the solar panel is in a preset range When the output power is within the preset range, the antenna is enabled, and the reading device corresponding to the solar module receives the corresponding signal of the identifier in the solar module through the antenna, and disables the antenna when the output power is outside the preset range.

According to an embodiment of the invention, whether the output power of the electrical energy provided by the solar panel is located in the predetermined range determines whether the antenna in the solar module is enabled or disabled, when the output power is located When the preset range is within, the antenna is enabled, and the reading device corresponding to the solar module receives the corresponding signal of the identifier in the solar module through the antenna, when the output power is located in the When the preset range is out, the step of disabling the antenna further comprises: comparing the corresponding output power Whether the output voltage is greater than or equal to the first voltage; comparing whether the output voltage corresponding to the output power is less than or equal to the second voltage; when the output voltage is greater than or equal to the first voltage and less than or equal to the second voltage Determining that the output power is within the preset range; and when the output voltage is less than the first voltage or greater than the second voltage, determining that the output power is outside the preset range.

According to an embodiment of the invention, the preset range is between a maximum output power that the solar panel can provide, multiplied by a predetermined percentage and a maximum output power.

In summary, the detection method of the solar module provided by the present invention does not need to perform actual measurement on the input end and the output end of each solar module one by one, thereby greatly reducing the detection time. That is, the detection method of the solar module provided by the present invention can quickly and efficiently detect the abnormality of the solar module.

100‧‧‧Solar power system

110‧‧‧Solar array

110a‧‧‧Solar panel series

111‧‧‧ solar panels

120‧‧‧DC/AC inverter

130‧‧‧AC load

140‧‧‧Power

300‧‧‧ Radio Frequency Identification Module

310‧‧‧Antenna

320‧‧‧ logo

200‧‧‧ solar modules

210‧‧‧ solar panels

220‧‧‧ Identification unit

221‧‧‧Antenna

222‧‧‧ logo

230‧‧‧Control unit

240‧‧‧Reading device

400‧‧‧ solar modules

410‧‧‧ solar panels

420‧‧‧ Identification unit

321‧‧‧ Controller

322‧‧‧ memory

P11‧‧‧first inverting end

P12‧‧‧ first non-inverting end

P13‧‧‧ first output

P21‧‧‧Second inverting end

P22‧‧‧Second non-inverting end

P23‧‧‧second output

P31‧‧‧ first input

P32‧‧‧ second input

P33‧‧‧ output

421‧‧‧Antenna

422‧‧‧ logo

430‧‧‧Control unit

431‧‧‧First comparator

432‧‧‧Second comparator

433‧‧‧ and gate

434‧‧‧ Relay

435‧‧‧Lighting elements

LP‧‧‧ coil

D1‧‧‧ diode

SW‧‧ switch

The above and other objects, features, advantages and embodiments of the present invention will become more <RTIgt; <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; A block diagram of a solar module according to an embodiment of the invention; FIG. 2b is a graph showing an output power of a solar panel corresponding to an output voltage according to an embodiment of the invention; and FIG. 2c is a diagram according to the present invention. An embodiment of a solar panel FIG. 3 is a schematic diagram of a radio frequency identification module according to an embodiment of the invention; FIG. 4 is a schematic diagram of a solar module according to an embodiment of the invention; FIG. 5 is a flow chart of a method for controlling a solar module according to an embodiment of the invention.

Referring to FIG. 2a, FIG. 2a is a block diagram of a solar module 200 according to an embodiment of the invention. The solar module 200 includes a solar panel 210, an identification unit 220, and a control unit 230. The solar panel 210 is configured to convert received light energy into output electrical energy having a corresponding output voltage and output power. The identification unit 220 includes an antenna 221 and an identification 222. The identifier 222 has the data of the corresponding solar module 200 and is electrically coupled to the antenna 221, and the identifier 222 can be, for example, a wafer. The control unit 230 is electrically coupled between the solar panel 210 and the identification unit 220 and is configured to receive an output voltage provided by the solar panel 210. In addition, the control unit 230 determines whether to enable or disable the antenna 221 according to whether the output power is in a preset range. In an embodiment, the control unit 230 can be disposed in a junction box, but the invention is not limited thereto.

In an embodiment, the preset range is between a maximum power (MPP) that the solar panel 210 can provide, multiplied by a preset percentage and a maximum output power, wherein the preset percentage is Set according to the environment or design requirements.

Referring to FIG. 2a and FIG. 2b together, FIG. 2b is a graph of output power corresponding to output voltage of a solar panel according to an embodiment of the invention, wherein the horizontal axis represents the output voltage and the vertical axis represents the output. Power, and each curve represents a curve of the output power of the solar panel corresponding to the output voltage at different insolation illuminations. In this embodiment, the preset range is between 90% of the maximum output power and the maximum output power (for example, the blank area shown in FIG. 2b), but the embodiment is not limited thereto.

In an embodiment, as shown in FIG. 2b, when the solar illuminance is different, the maximum output power that the solar panel 210 can provide will also be different (for example, the maximum solar panel 210 can provide at an illumination of 1000 watts/m 2 ). The output power is greater than the maximum output power that the solar panel 210 can provide at an illumination of 800 watts per square meter. Therefore, when the control unit 230 detects the output power provided by the solar panel 210, it simultaneously detects the current solar illuminance, and determines the solar energy under the solar illuminance according to a built-in check value table (not shown). The maximum output supply rate that the board 210 can provide, and then establishes a preset range based on the maximum output power.

Specifically, when the solar module 200 is abnormal (such as shading or damage), the converted energy of the solar panel 210 cannot reach the preset normal output power (for example, the actual output power is less than the maximum output power). 90%). Therefore, the control unit 230 can detect whether the output power provided by the solar panel 210 under one-day illuminance (eg, 1000 watts/m 2 ) is within a preset range (eg, whether the actual output power is located at 180 watts and 200 watts). Between the two) to determine whether the solar module 200 is different often.

When the solar module 200 is operating normally, the control unit 230 detects that the output power provided by the solar panel 210 is within a preset range (eg, a blank area as shown in FIG. 2b). At this time, the control unit 230 can enable the antenna 221 in the unit 220 to be identified. Thereby, the reading device 240 corresponding to the solar module 200 can receive the corresponding signal of the identifier 222 through the antenna 221. In an embodiment, the identification 222 may have data of the corresponding solar module 200, such as: serial number, output power, solar illuminance, ambient temperature, and the like. Therefore, when the solar module 200 is in normal operation, the user can read the data of the corresponding solar module 200 through the reading device 240 for analysis.

Conversely, when an abnormality occurs in the solar module 200, the control unit 230 detects that the output power provided by the solar panel 210 is outside the preset range (eg, the shaded area shown in FIG. 2b). At this time, the control unit 230 disables the antenna 221; that is, the reading device 240 cannot receive the data of the marker 222 via the antenna 221. Thereby, whether the solar module 200 is abnormal is determined by whether the reading device 240 can receive the signal of the identification unit 220, and the solar module 200 can be detected quickly and efficiently.

On the other hand, the output power provided by the solar panel 210 is related to the ambient temperature in addition to the solar illuminance. Referring to FIG. 2c, FIG. 2c is a graph showing an output power of a solar panel corresponding to an output voltage according to another embodiment of the present invention, wherein a horizontal axis represents an output voltage, and a vertical axis represents an output power, and each of the strips The curve represents the curve of the output power of the solar panel corresponding to the output voltage at different ambient temperatures.

In an embodiment, as shown in Figure 2c, when the ambient temperature is different The maximum output power that the solar panel 210 can provide will also be different (eg, the maximum output power that the solar panel 210 can provide at a temperature of 25 degrees is greater than the maximum output power that the solar panel 210 can provide at a temperature of 50 degrees). In other words, the preset range will also change with the ambient temperature (for example, the preset range at a temperature of 25 degrees is between voltages V1 and V2, and the preset range at a temperature of 50 degrees is between voltages V1' and V2'. The preset range at a temperature of 75 degrees is between the voltages V1"~V2"). Therefore, when the control unit 230 detects the output power provided by the solar panel 210, it also detects the current ambient temperature, and determines the maximum output power that the solar panel 210 can provide at the ambient temperature according to the look-up table. Preset range.

Similarly, the control unit 230 can detect whether the output power provided by the solar panel 210 at an ambient temperature (eg, 25 degrees) is within a preset range (eg, whether the actual output power is between 180 watts and 200 watts). It is determined whether the solar module 200 is abnormal. When the solar module 200 is in normal operation, the control unit 230 detects that the output power provided by the solar panel 210 is within a preset range. When an abnormality occurs in the solar module 200, the control unit 230 detects that the output power provided by the solar panel 210 is outside the preset range. Then, the operation of the above embodiment is performed according to the result of the judgment, and details are not described herein again.

In an embodiment, the identification unit 220 may include a Radio Frequency Identification (RFID) module, a Near Field Communication (NFC) module, or a combination thereof. The reading device 240 can be a reading device with a radio frequency identification function (such as a radio frequency identification reader) or a device having a near field communication function (eg: Mobile phone with incoming communication). In other words, the type of the reading device 240 is determined according to the type of the identification unit 220 in the solar module 200.

Please refer to FIG. 3 , which is a schematic diagram of a radio frequency identification module 300 according to an embodiment of the invention. The radio frequency identification module 300 shown in FIG. 3 can be applied to the second embodiment. The solar module 200 shown and other solar modules in the following embodiments are not limited thereto.

As shown in FIG. 3, the radio frequency identification module 300 includes an antenna 310 and an identifier 320. The identifier 320 includes a controller 321 and a memory 322. When the reading device (not shown) transmits a radio signal, the radio frequency identification module 300 receives the radio signal through the antenna 310, and after the controller 321 performs the correlation operation processing (eg, decryption) on the radio signal, The memory 322 is read and written according to the processed signal. Then, the read data is subjected to correlation processing (eg, encryption) by the controller 321 and then transmitted back to the reader through the antenna 310. Therefore, when the antenna 310 is disabled, the reading device cannot perform any operation on the radio frequency identification module 300, that is, the corresponding signal of the identifier 320 cannot be read.

Referring to FIG. 4, FIG. 4 is a schematic diagram of a solar module 400 according to an embodiment of the invention. Similarly, the solar module 400 includes a solar panel 410, an identification unit 420, and a control unit 430. The identification unit 420 includes an antenna 421 and an identifier 422. The operation and connection relationship are similar to the connection and operation of the foregoing embodiment, and are not described herein. In this embodiment, the identification unit 420 includes a radio frequency identification module, but does not use this Limited.

As shown in FIG. 4, the control unit 430 includes a first comparator 431, a second comparator 432, and an AND gate 433. The first comparator 431 has a first inverting terminal P11, a first non-inverting terminal P12, and a first output terminal P13. The first non-inverting terminal P12 is electrically coupled to the solar panel 410 and configured to receive the output voltage Vo. The first inverting terminal P11 is configured to receive the first voltage V1. The second comparator 432 has a second inverting terminal P21, a second non-inverting terminal P22, and a second output terminal P23. The second inverting terminal P21 is electrically coupled to the solar panel 410 and configured to receive the output voltage Vo. The second non-inverting terminal P22 is configured to receive the second voltage V2. The gate 433 has a first input terminal P31, a second input terminal P32, and an output terminal P33. The first input terminal P31 and the second input terminal P32 are electrically coupled to the first output terminal P13 of the first comparator 431 and the second output terminal P23 of the second comparator 432, respectively.

Please refer to both Figure 2b and Figure 4. When the output power of the solar panel is within the preset range (such as the blank area shown in Figure 2), the output voltage is approximately between the first voltage V1 and the second voltage V2. between. Therefore, in the embodiment, the control unit 430 can determine whether the output power of the solar panel 410 is at a preset by detecting whether the output voltage Vo provided by the solar panel 410 is between the first voltage V1 and the second voltage V2. Within the scope.

In operation, when the control unit 430 detects that the output voltage Vo is greater than or equal to the first voltage V1, the first output terminal P13 of the first comparator 431 outputs a high logic level signal. When the output voltage Vo is smaller than the first voltage V1, the first output terminal P13 of the first comparator 431 is output low logic Bit signal. In addition, when the control unit 430 detects that the output voltage Vo is less than or equal to the second voltage V2, the second output terminal P23 of the second comparator 432 outputs a high logic level signal. When the output voltage Vo is greater than the second voltage V2, the second output terminal P23 of the second comparator 432 outputs a low logic level signal. When the gate 433 receives the high logic level signal at both the first input terminal P31 and the second input terminal P32, the gate 433 outputs a high logic level signal at the output terminal P33. When the first input terminal P31 or the second input terminal P32 receives the low logic level signal, the AND gate 433 outputs a low logic level signal at the output terminal P33.

In other words, when the output voltage Vo is between the first voltage V1 and the second voltage V2, the control unit 430 determines that the output power provided by the solar panel 410 is within a preset range, and outputs a high logic signal through the AND gate 433. Conversely, when the output voltage Vo is smaller than the first voltage V1 or greater than the second voltage V2, the control unit 430 determines that the output power provided by the solar panel 410 is outside the preset range, and outputs a low logic signal through the AND gate 433.

On the other hand, the control unit 430 may further include a relay 434. The relay 434 includes a coil LP, a diode D1, and a switch SW. The coil LP is electrically coupled to the output terminal P33 of the AND gate 433. The switch SW is electrically coupled to the antenna 421 of the identification unit 420. When the AND gate 433 outputs a high logic signal to the coil LP (i.e., there is current flowing through the coil LP), induced electromagnetic is generated on the coil LP, causing the switch SW to conduct and enable the antenna 421. Conversely, when the AND gate 433 outputs a low logic signal to the coil LP (that is, when there is no current flowing through the coil LP), the switch SW is maintained in the off state. The antenna 421 is disabled.

In an embodiment, the output terminal P33 of the gate 433 is also electrically coupled to the light-emitting element 435 (eg, a light-emitting diode), but the invention is not limited thereto. When the AND gate 433 outputs a high logic signal via the output terminal P33 (that is, the output power provided by the solar panel 410 is within a preset range), the light emitting element 435 can be enabled to emit light. Thereby, the user can directly determine whether the solar module 400 is abnormal according to whether the light-emitting element 435 emits light.

It can be seen from the above disclosure that determining whether the solar module 400 is abnormal by detecting the output voltage Vo of the solar panel 410 can simplify the design of the control unit 430 and increase the efficiency of detecting the solar module 400. In addition, the present embodiment only exemplifies an embodiment in which the output power of the solar panel 410 is judged whether the output power is within a preset range; in other words, any person having ordinary skill in the art, without departing from the spirit and scope of the present invention, When different embodiments can be designed, the above effect of determining whether the output power is within a preset range is achieved.

Referring to FIG. 5, FIG. 5 is a flow chart of a method for controlling a solar module according to an embodiment of the invention. For convenience and clarity of explanation, the following description of the control method is exemplified by the solar module 400 shown in FIG. 4, but is not limited thereto.

First, in step S510, the solar panel 410 in the solar module 400 is detected to provide electrical energy at a single illuminance and/or an ambient temperature. The electrical energy has a corresponding output power and an output voltage. Next, in step S530, it is determined whether the output power of the electric energy provided by the solar panel 410 is within a preset range at the solar illuminance or the ambient temperature, thereby It is decided to enable or disable the antenna 421 in the solar module 400. Further, by comparing whether the output voltage Vo provided by the solar panel 410 at the solar illuminance or the ambient temperature is greater than or equal to the first voltage V1, and comparing whether the output voltage Vo is less than or equal to the second voltage V2 (also That is, determining whether the output voltage Vo is between the first voltage V1 and the second voltage V2 determines whether the output power provided by the solar panel 410 is within a preset range, thereby determining whether the solar module 400 is abnormal.

When the output power provided by the solar panel 410 is within the preset range, then step S550 is performed to enable the antenna 421. At this time, the reading device corresponding to the solar module (eg, the RFID reader corresponding to the identification unit 420) receives the corresponding signal of the identifier 422 in the solar module 400 through the antenna 421. Further, when the output voltage Vo provided by the solar panel 410 is greater than or equal to the first voltage V1 and less than or equal to the second voltage V2 (that is, the output voltage Vo is between the first voltage V1 and the second voltage V2) The output power provided by the solar panel 410 is determined to be within a preset range. Accordingly, the solar module 400 is determined to be in a normal operating state, and the antenna 421 is enabled to enable the reading device to read the identifier 422. Corresponding signal.

When the output power provided by the solar panel 410 is outside the preset range (that is, the output voltage Vo is smaller than the first voltage V1 or greater than the second voltage V2), step S570 is performed to disable the antenna 421, so that the reading device cannot The corresponding signal of the solar module 400 is read through the antenna 421; that is, the solar module 400 is determined to be abnormal.

It can be seen from the above embodiments of the present invention that the solar module is configured by The identification unit, and by enabling or disabling the antenna in the identification unit, can detect whether the solar module is abnormal through the reading device of the corresponding solar module. Compared with the conventional detection method, the detection method of the solar module provided by the invention does not need to perform actual measurement on the input end and the output end of each solar module one by one, thereby greatly reducing the detection time. That is, the detection method provided by the present invention can quickly and efficiently detect an abnormality of the solar module.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and the present invention can be modified and modified without departing from the spirit and scope of the present invention. The scope is subject to the definition of the scope of the patent application attached.

200‧‧‧ solar modules

210‧‧‧ solar panels

220‧‧‧ Identification unit

221‧‧‧Antenna

222‧‧‧ logo

230‧‧‧Control unit

240‧‧‧Reading device

Claims (10)

A solar module corresponding to a reading device, the solar module comprising: a solar panel for converting received light energy into an output electrical energy, wherein the output electrical energy has an output voltage and an output power; An antenna and an identifier of the corresponding solar module, the antenna is electrically coupled to the identifier; and a control unit includes a relay electrically coupled between the solar panel and the identification unit, The antenna is configured to receive the output voltage and determine whether to turn on or off the relay to enable or disable the antenna according to whether the output power is within a predetermined range. The solar module of claim 1, wherein the control unit enables the antenna when the output power is within the preset range, and the reading device receives the corresponding signal of the identifier through the antenna, when the output power The control unit disables the antenna when it is outside the preset range. The solar module of claim 1 or 2, wherein the control unit is further configured to compare the output voltage with a first voltage and compare the output voltage with a second voltage to determine whether the output power is within the preset range When the output voltage is greater than or equal to the first voltage and less than or equal to the second voltage, the control unit determines that the output power is within the preset range, when the output voltage is less than the first voltage or greater than the second At the time of voltage, the control unit determines that the output power is outside the preset range. The solar module of claim 1 or 2, wherein the control unit comprises: a first comparator having a first inverting terminal, a first non-inverting terminal, and a first output terminal, wherein the first The non-inverting terminal is electrically coupled to the solar panel for receiving the output voltage, the first inverting terminal is configured to receive a first voltage, and the second comparator has a second inverting terminal, a first a second non-inverting terminal electrically coupled to the solar panel for receiving the output voltage, and a second non-inverting terminal for receiving a second voltage; And a first input end, a second input end, and an output end, wherein the first input end is electrically coupled to the first output end, and the second input end is electrically coupled to the second output end end. The solar module of claim 4, wherein the relay is electrically coupled between the output of the gate and the antenna of the identification unit for turning on or off according to an output signal of the gate. The solar module of claim 1 or 2, wherein the predetermined range is between a maximum output power that the solar panel can provide, multiplied by a predetermined percentage, and the maximum output power. The solar module of claim 1 or claim, wherein the identification unit The invention comprises a radio frequency identification (RFID) module, a near field communication (NFC) module or a combination thereof. A solar module control method includes: detecting an output voltage of a power provided by a solar panel in the solar module; determining whether the output power of the power provided by the solar panel is within a predetermined range An antenna of the solar module is configured to enable the antenna when the output power is within the preset range, and a reading device corresponding to the solar module receives an identifier of the solar module through the antenna Corresponding signal, when the output power is outside the preset range, the antenna is disabled. The method of claim 8, wherein determining whether to enable or disable an antenna in the solar module according to whether an output power of the power provided by the solar panel is located in a predetermined range, when the output power is at the preset In the range, the antenna is enabled, and a reading device corresponding to the solar module receives a corresponding signal of an identifier in the solar module through the antenna, and when the output power is outside the preset range, the antenna is disabled. The step of enabling the antenna further comprises: comparing whether the output voltage corresponding to the output power is greater than or equal to a first voltage; comparing whether the output voltage corresponding to the output power is less than or equal to a second voltage; when the output voltage is greater than or equal to the first voltage and less than or equal to the second voltage, determining that the output power is within the preset range; and when the output voltage is less than the first voltage or greater than When the second voltage is applied, it is determined that the output power is outside the preset range. The method of claim 8 or 9, wherein the predetermined range is between a maximum output power that the solar panel can provide, multiplied by a predetermined percentage, and the maximum output power.