Photocell irradiation sensor

Abstract

The present invention discloses a photocell irradiation sensor, comprising: a photocell selection circuit, a main control chip electrically connected to the photocell selection circuit, and an irradiation sampling circuit electrically connected to the main control chip, a maximum power tracking circuit, an energy storage circuit, and a wireless communication module; the maximum power tracking circuit is also electrically connected to the energy storage circuit. The main control chip controls the photocell selection circuit to connect or disconnect the photocell from the subsequent circuit according to the "irradiation detection" or "power supply" function to be realized. When the main control chip selects the "power supply" function, the main control chip controls the maximum power tracking circuit to make the photocell work at the maximum power position to output electrical energy, and stores it through the energy storage circuit, so that the energy storage circuit can power other components; when the main control chip selects the "irradiation detection" function, the irradiation sampling circuit transmits the irradiation signal to the main control chip for measurement; the wireless communication module sends the measured irradiation value through wireless communication.

Description

Technical Field

[0001] The invention relates to the field of photovoltaics, and in particular to a photocell irradiation sensor. Background Art

[0002] The power generation of solar photovoltaic power generation system is affected by factors such as local solar radiation, temperature, and solar panel performance. The intensity of solar radiation directly affects the amount of power generated. The greater the radiation intensity, the greater the power generation and the greater the power.

[0003] Radiation intensity is generally detected using irradiation sensors. Current irradiation sensors need to transmit irradiation values ​​through a wired interface, which makes it difficult to install and wire irradiation sensors in photovoltaic power generation systems. In addition, existing irradiation sensors are difficult to maintain and cannot meet the needs of continuous and comprehensive monitoring. Therefore, the current irradiation sensors have problems such as inconvenient installation, wiring requirements, and difficult maintenance. Summary of the invention

[0004] In order to solve at least one of the above technical problems, the present invention provides a flexibly deployed and maintenance-free photovoltaic cell irradiation sensor, which can meet the needs of continuous and comprehensive monitoring of irradiation in the current smart photovoltaic power generation system. Specifically, the technical solution of the present invention is as follows:

[0005] The present invention provides a photocell irradiation sensor, comprising:

[0006] A photocell selection circuit, a main control chip electrically connected to the photocell selection circuit, an irradiation sampling circuit electrically connected to the main control chip, a maximum power tracking circuit, an energy storage circuit, and a wireless communication module; the maximum power tracking circuit is also electrically connected to the energy storage circuit; wherein:

[0007] When the main control chip controls the photocell selection circuit to connect to the irradiation sampling circuit, the irradiation sampling circuit obtains the short-circuit current of the photocell and transmits it to the main control chip; the main control chip calculates the irradiation value of the photocell according to the short-circuit current, and sends the irradiation value of the photocell through the wireless communication module;

[0008] When the main control chip controls the photocell selection circuit to connect to the maximum power tracking circuit, the maximum power tracking circuit enables the photocell to operate at the maximum power point to output electrical energy under the control of the driving control signal of the main control chip, and stores the electrical energy through the energy storage circuit to facilitate power supply for each chip; the maximum power tracking circuit also collects the charging current, and feeds back the processing of the charging current to the main control chip to facilitate the main control chip to adjust the driving control signal and control the maximum power tracking circuit.

[0009] Preferably, the photocell selection circuit includes: a silicon photocell, and a switching switch electrically connected to the silicon photocell; the switching switch inputs the output current of the silicon photocell into the irradiation sampling circuit or the maximum power tracking circuit according to the channel selection of the main control chip.

[0010] Preferably, the radiation sampling circuit includes: an operational amplifier and a short-circuit current sampling resistor; the positive current of the silicon photocell is input into the non-inverting input terminal of the operational amplifier, and the non-inverting input terminal of the operational amplifier is grounded; the negative current of the silicon photocell is input into the inverting input terminal of the operational amplifier; a short-circuit current sampling resistor is connected in parallel between the inverting input terminal and the output terminal of the operational amplifier; the output terminal of the operational amplifier inputs the output short-circuit current to the main control chip.

[0011] Preferably, the maximum power tracking circuit includes: a driving subcircuit, a maximum power main circuit and a sampling subcircuit; wherein: the driving subcircuit drives the maximum power main circuit to output electrical energy when the silicon photocell operates at the maximum power point according to the PWM driving signal issued by the main control chip, and stores energy through the energy storage circuit; the sampling subcircuit samples the charging current, and amplifies the sampled charging current and then feeds it back to the main control chip.

[0012] Preferably, the driving subcircuit includes a driving transistor, the PWM driving control signal of the main control chip is input into the base of the driving transistor through a resistor, and the emitter of the driving transistor is grounded; the collector of the driving transistor is electrically connected to the maximum power main circuit to drive the maximum power main circuit;

[0013] The maximum power main circuit includes a circuit switch tube, a filter capacitor, a filter inductor, and a freewheeling diode; wherein the base of the circuit switch tube is electrically connected to the collector of the driving triode, the emitter of the circuit switch tube is electrically connected to the positive terminal of the silicon battery through the switching switch, and the emitter and base of the circuit switch tube are electrically connected through a resistor; the collector of the circuit switch tube is electrically connected to the filter inductor, and the other end of the filter inductor is electrically connected to the energy storage circuit; one end of the filter capacitor is electrically connected to the emitter of the circuit switch tube, and the other end of the filter capacitor is electrically connected to the input end of the freewheeling diode, the input end of the freewheeling diode is electrically connected to the negative terminal of the silicon photocell through the switching switch, and the output end of the freewheeling diode is electrically connected to the collector of the circuit switch tube;

[0014] The sampling subcircuit includes a charging current sampling resistor and an operational amplifier; one end of the charging current sampling resistor is electrically connected to the negative terminal of the silicon photocell and the input end of the freewheeling diode; the other end of the charging current sampling resistor is grounded; the in-phase input end of the operational amplifier is electrically connected to the input end of the freewheeling diode through a bias resistor, and the other end of the bias resistor is grounded through a capacitor; the inverting input end of the operational amplifier is grounded through an amplifying resistor, the inverting input end and the output end of the operational amplifier are electrically connected through another amplifying resistor, and the output end of the operational amplifier is electrically connected to the main control chip as a charging current measurement point.

[0015] Preferably, the energy storage circuit includes a farad capacitor and a voltage-stabilizing power supply chip; the positive terminal of the farad capacitor is electrically connected to the filter inductor, and the negative terminal of the farad capacitor is grounded; the input terminal of the voltage-stabilizing power supply chip is electrically connected to the filter inductor, and the output terminal of the voltage-stabilizing power supply chip serves as a power supply output terminal to supply power to each chip.

[0016] Preferably, the wireless communication module uses LORA communication mode for wireless communication.

[0017] Preferably, the wireless communication module includes a LORA chip SX1276.

[0018] Preferably, the main control chip is a single chip microcomputer of the STM32L series.

[0019] Preferably, the main control chip is a single-chip microcomputer STM32L151.

[0020] The present invention includes at least one of the following technical effects:

[0021] (1) The photovoltaic cell irradiation sensor of the present invention is easy to install and does not require operation and maintenance. The photovoltaic cell (such as a silicon photovoltaic cell) can be used as both a detection component and a power supply component. The two-in-one design fully taps the device potential of the silicon photovoltaic cell and works in conjunction with the corresponding circuit, so that the irradiation sensor of this scheme has the ability to be self-powered. It can operate for a long time as an independent individual (can work in the field for a long time), and can be connected to other sensors to form a sensor network to comprehensively monitor the irradiation conditions of photovoltaic power stations and power generation modules.

[0022] (2) The photocell irradiation sensor of the present invention uses a wireless communication module to transmit the detected irradiation value. Therefore, the photocell irradiation sensor can be flexibly deployed to solve the problem of inconvenient installation and wiring. Furthermore, the wireless transmission module can use a LoRa chip for wireless transmission. Due to the ultra-low power consumption of LoRa, silicon photocells are particularly advantageous for solar irradiation detection. At the same time, LoRa wireless transmission allows the irradiation sensor of this solution to be arbitrarily and flexibly deployed, which is particularly advantageous for application scenarios of double-sided photovoltaic modules that require multi-point irradiation monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 A circuit connection block diagram of an embodiment of the photocell irradiation sensor of the present invention;

[0025] Figure 2 A circuit connection block diagram of another embodiment of the photocell irradiation sensor of the present invention;

[0026] Figure 3 A circuit connection block diagram of another embodiment of the photocell irradiation sensor of the present invention;

[0027] Figure 4 A circuit connection diagram of another embodiment of the photocell irradiation sensor of the present invention;

[0028] Figure 5 This is a schematic diagram of the connection of the pins of the main control chip in another embodiment of the photocell irradiation sensor of the present invention. DETAILED DESCRIPTION

[0029] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0030] It should be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or collections.

[0031] In order to simplify the drawings, only the parts related to the present invention are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically drawn or marked. In this article, "one" not only means "only one", but also means "more than one".

[0032] It should be further understood that the term “and / or” used in the specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0034] The present invention provides a photocell irradiation sensor, which can be implemented as follows: Figure 1 As shown, including:

[0035] A photocell selection circuit 10, a main control chip 20 electrically connected to the photocell selection circuit 10, an irradiation sampling circuit 30 electrically connected to the main control chip 20, a maximum power tracking circuit 40, an energy storage circuit 50, and a wireless communication module 60; the maximum power tracking circuit 40 is also electrically connected to the energy storage circuit 50; wherein:

[0036] When the main control chip 20 controls the photocell selection circuit 10 to connect with the irradiation sampling circuit 30, the irradiation sampling circuit 30 obtains the short-circuit current of the photocell and transmits it to the main control chip 20; the main control chip 20 calculates the irradiation value of the photocell according to the short-circuit current, and sends the irradiation value of the photocell through the wireless communication module 60;

[0037] When the main control chip 20 controls the photocell selection circuit 10 to select and connect to the maximum power tracking circuit 40, the maximum power tracking circuit 40 enables the photocell to operate at the maximum power point to output electrical energy under the control of the driving control signal of the main control chip 20, and stores the electrical energy through the energy storage circuit 50 to facilitate power supply to each chip; the maximum power tracking circuit 40 also collects the charging current, and feeds back the processing of the charging current to the main control chip 20, so that the main control chip 20 can adjust the driving control signal and control the maximum power tracking circuit 40.

[0038] Photovoltaic cells, also called solar cells, directly convert sunlight into electricity. Therefore, the characteristic of photovoltaic cells is that they can convert a large amount of light energy absorbed by the earth from solar radiation into electrical energy. They are semiconductor components that generate electromotive force under the irradiation of light. There are many types of photovoltaic cells, and the commonly used ones are selenium photovoltaic cells, silicon photovoltaic cells, and thallium sulfide and silver sulfide photovoltaic cells.

[0039] In this embodiment, the photocell selection circuit 10 is used to provide the current of the photocell; and whether the photocell current is provided to the maximum power tracking circuit 40 or the irradiation sampling circuit 30 is controlled according to the selection of the main control chip 20. Specifically, if the photocell irradiation sensor is used to realize the irradiation detection function, the main control chip 20 controls the photocell selection circuit 10 to be connected with the irradiation sampling circuit 30, and then the photocell selection circuit 10 transmits the current of the photocell to the irradiation sampling circuit 30, and then the irradiation sampling circuit 30 obtains the short-circuit current of the photocell, and calculates the corresponding irradiation value through the main control chip 20 (the short-circuit current is proportional to the irradiation, and the irradiation value can be obtained according to the corresponding relationship). Finally, the calculated irradiation value can be transmitted through the wireless communication module 60. Transmitting the irradiation value through the wireless communication module 60 can make this solution The photovoltaic cell irradiation sensor can be arbitrarily and flexibly deployed, which is particularly beneficial for application scenarios of double-sided photovoltaic modules that require multi-point irradiation monitoring. If you are working in the field, you can choose to self-power the photovoltaic cell during the intervals between irradiation detection. Specifically, the main control chip 20 controls the photovoltaic cell selection circuit 10 to disconnect from the irradiation sampling circuit 30, and chooses to connect to the maximum power tracking circuit 40. In this way, the maximum power tracking circuit 40, under the control of the driving control signal of the main control chip 20, makes the photovoltaic cell work at the maximum power point to output electrical energy, and stores the electrical energy through the energy storage circuit 50, so as to power each chip.

[0040] In this embodiment, on the one hand, the wireless communication module transmits the irradiation value through wireless communication, which allows the irradiation sensor of this solution to be flexibly deployed, which is particularly beneficial for the application scenarios of double-sided photovoltaic modules that require multi-point irradiation monitoring. On the other hand, the photovoltaic cell is used as both a detection component and a power supply component. The two-in-one design fully taps the device potential of the photovoltaic cell and works in conjunction with the corresponding circuit, so that the irradiation sensor of this solution has the ability to be self-powered and can work in the field for a long time.

[0041] Another embodiment of the present invention, based on the above embodiment, the photovoltaic cell selection circuit 10 is as follows: Figure 2 As shown, it includes: a silicon photocell 11, and a switching switch K1 electrically connected to the silicon photocell 11; the switching switch K1 inputs the output current of the silicon photocell 11 to the irradiation sampling circuit 30 or the maximum power tracking circuit 40 according to the channel selection of the main control chip 20.

[0042] The silicon photocell 11 is generally installed on the upper surface of the irradiation sensor, with the front side facing the sun to receive sunlight. The silicon photocell 11 is connected to the switching switch K1, and the main control chip 20 controls the switching switch K1 to connect or disconnect the silicon photocell 11 and the subsequent circuit according to the "detection" or "power supply" function to be realized. That is to say, the main control chip 20 guides the silicon photocell 11 to the corresponding circuit through the switching switch K1 according to the current need to realize the irradiation detection or power supply function, connects to the irradiation sampling circuit 30 when measuring irradiation, and connects to the maximum power tracking circuit 40 when supplying power. Preferably, the switching switch K1 can select the DPDT analog switch MAX20327.

[0043] The maximum power tracking circuit 40, such as Figure 3 As shown, it includes: a driving subcircuit 41, a maximum power main circuit 42 and a sampling subcircuit 43; wherein: the driving subcircuit 41 drives the maximum power main circuit 42 according to the PWM driving signal issued by the main control chip 20 to output electric energy when the silicon photovoltaic cell 11 works at the maximum power point, and stores energy through the energy storage circuit 50; that is to say, the driving subcircuit 41 drives the maximum power main circuit 42 to work according to the PWM driving signal issued by the single-chip microcomputer 20; the maximum power main circuit makes the silicon photovoltaic cell 11 work at the maximum power point according to the driving signal of the driving subcircuit, and converts the solar power obtained by the silicon photovoltaic cell 11 into direct current to charge the energy storage circuit 50; the sampling subcircuit 43 samples the charging current, and amplifies the sampled charging current and then feeds it back to the main control chip 20.

[0044] The maximum power tracking circuit 40 works in conjunction with the main control chip 20, which is equivalent to a maximum power point tracking (MPPT) controller, which can detect the power generation voltage of the solar panel in real time and track the highest voltage and current value (VI), so that the system can charge the energy storage device with maximum power output. The output power of the photovoltaic cell is related to the operating voltage of the MPPT controller. Only when it works at the most suitable voltage will its output power have a unique maximum value. The MPPT controller will track the maximum power point in the solar panel in real time to maximize the effectiveness of the solar panel. Through maximum power tracking, more electricity can be output, thereby improving charging efficiency. In theory, a solar power generation system using an MPPT controller will be 50% more efficient than a traditional one.

[0045] The maximum power tracking circuit 40 detects the DC voltage and output current of the main circuit, and then calculates the output power of the silicon photovoltaic cell 11 through the main control chip 20, and realizes the tracking of the maximum power point. The main control chip 20 changes the current by changing the duty cycle of the driving signal, thereby generating a current disturbance. At the same time, the output current and voltage of the photovoltaic cell will also change accordingly. By measuring the changes in the output power and voltage of the photovoltaic cell before and after the disturbance, the disturbance direction of the next cycle is determined. When the disturbance direction is correct, the output power of the silicon photovoltaic cell 11 increases, and the next cycle continues to disturb in the same direction. Otherwise, it disturbs in the opposite direction. In this way, the disturbance and observation are repeated to make the output of the silicon photovoltaic cell 11 reach the maximum power point.

[0046] The radiation sampling circuit 30, such as Figure 4 As shown, it includes: an operational amplifier M1 and a short-circuit current sampling resistor Ra; the positive current of the silicon photocell 11 is input to the in-phase input terminal of the operational amplifier M1, and the in-phase input terminal of the operational amplifier M1 is grounded; the negative current of the silicon photocell 11 is input to the inverting input terminal of the operational amplifier M1; a short-circuit current sampling resistor Ra is connected in parallel between the inverting input terminal and the output terminal of the operational amplifier M1; the output terminal of the operational amplifier M1 inputs the output short-circuit current to the main control chip 20.

[0047] This circuit connection mode of the operational amplifier M1 and the silicon photocell 11 can bring out the short-circuit current of the silicon photocell 11. The short-circuit current flows through the short-circuit current sampling resistor Ra, and an output voltage proportional to the short-circuit current is obtained at the short-circuit current output point D. The main control chip 20 obtains the voltage value through AD sampling and calculates the short-circuit current. The short-circuit current is proportional to the irradiation, and then the irradiation value is obtained according to the corresponding relationship. Then the main control chip 20 transmits the calculated irradiation value through the wireless communication module 60.

[0048] Preferably, the maximum power tracking circuit 40 is specifically as follows Figure 4 As shown, the driving sub-circuit includes a driving transistor S1, the PWM driving control signal (point P input) of the main control chip 20 is input to the base of the driving transistor S1 through a resistor R1, and the emitter of the driving transistor S1 is grounded; the collector of the driving transistor S1 is electrically connected to the maximum power main circuit to drive the maximum power main circuit;

[0049] The maximum power main circuit includes a circuit switch tube S2, a filter capacitor C1, a filter inductor L1, and a freewheeling diode Q1; wherein the base of the circuit switch tube S2 is electrically connected to the collector of the driving triode S1, the emitter of the circuit switch tube S2 is electrically connected to the positive terminal of the silicon battery 11 through the switching switch K1, and the emitter and base of the circuit switch tube S2 are electrically connected through a resistor R2; the collector of the circuit switch tube S2 is electrically connected to the filter inductor L1, and the other end of the filter inductor L1 is electrically connected to the energy storage circuit 50; one end of the filter capacitor C1 is electrically connected to the emitter of the circuit switch tube S2, and the other end of the filter capacitor C1 is electrically connected to the input end of the freewheeling diode Q1, the input end of the freewheeling diode Q1 is electrically connected to the negative terminal of the silicon photocell 11 through the switching switch K1, and the output end of the freewheeling diode Q1 is electrically connected to the collector of the circuit switch tube S2;

[0050] The sampling subcircuit includes a charging current sampling resistor Rb and an operational amplifier M2; one end of the charging current sampling resistor Rb is electrically connected to the negative terminal of the silicon photocell 11 and the input end of the freewheeling diode Q1; the other end of the charging current sampling resistor Rb is grounded; the in-phase input end of the operational amplifier M2 is electrically connected to the input end of the freewheeling diode Q1 through a bias resistor R3, and the other end of the bias resistor R3 is grounded through a capacitor C3; the inverting input end of the operational amplifier M2 is grounded through an amplifying resistor R4, the inverting input end and the output end of the operational amplifier M2 are electrically connected through another amplifying resistor R5, and the output end of the operational amplifier M2 is electrically connected to the main control chip 20 as a charging current measurement point F.

[0051] The energy storage circuit 50 includes a farad capacitor C f , and a voltage stabilizing power supply chip LDO; the farad capacitor C f The positive terminal is electrically connected to the filter inductor L1, and the farad capacitor C f The negative terminal is grounded; the input end of the voltage-stabilized power supply chip LDO is electrically connected to the filter inductor L1, and the output end of the voltage-stabilized power supply chip LDO serves as a power supply output end to supply power to each chip.

[0052] In this embodiment, in order to make the silicon photovoltaic cell 11 work at the maximum power point to maximize the output of electrical energy. The maximum power tracking circuit is a DC to DC conversion circuit. The main control chip 20 measures the charging current at point F (point F is used as the charging current measurement point) while adjusting the PWM duty cycle input at point P, and determines the adjustment direction of the PWM duty cycle of the drive signal input at point P (PWM drive control signal input point) according to the size of the charging current. If the current increases, continue to adjust, if it decreases, adjust in the opposite direction, forming a closed-loop control to maximize the charging current and power. The charging current is sampled by the charging current sampling resistor Rb and amplified by the operational amplifier M2. The output of the operational amplifier is connected to the AD interface of the main control chip 20 to obtain the charging current value through AD sampling. The LDO power chip outputs a stable voltage to power the main control chip 20, the operational amplifier, etc.

[0053] Preferably, the wireless communication module 60 uses LORA communication mode for wireless communication. Through wireless communication based on LoRa spread spectrum, the MCU (main control chip) transmits the irradiation data. Furthermore, the wireless communication module 60 includes a LORA chip 20SX1276, and the RF frequency can be set according to the frequency allowed for use in different countries around the world. Due to the ultra-low power consumption of LoRa, the silicon photocell 11 is very advantageous for solar irradiation detection. LoRa wireless transmission allows the irradiation sensor of this solution to be arbitrarily and flexibly deployed, which is particularly advantageous for application scenarios of double-sided photovoltaic modules that require multi-point irradiation monitoring.

[0054] The irradiation sampling circuit 30 described in the above embodiment is electrically connected to the main control chip 20, and transmits the irradiation signal to the main control chip 20 for measurement; the LoRa chip is electrically connected to the main control chip 20, and the main control chip 20 sends the measured irradiation value through LoRa. The maximum power tracking circuit 40 is electrically connected to the energy storage circuit 50, and the energy storage circuit 50 supplies power to other components. The maximum power tracking circuit 40 is electrically connected to the energy storage circuit 50, and the energy storage circuit 50 stores electrical energy, and the energy storage circuit 50 then supplies power to other components.

[0055] The main control chip 20 in any of the above embodiments can adopt a single-chip microcomputer of the STM32L series. Preferably, the main control chip 20 realizes the entire detection, control, and communication functions, and adopts an STM32L151 ultra-low power single-chip microcomputer of the STM32L series based on the ARM Cortex-M3 core, which is suitable for battery-powered applications. The schematic diagram of its connection with each circuit is shown in FIG. Figure 5 As shown:

[0056] (1) Regarding the electrical connection between the main control chip and the wireless communication module: The main control chip STM32L151 and the LoRa chip SX1276 are electrically connected through corresponding pins. For specific connection pins, see Figure 5 , which will not be elaborated here.

[0057] (2) Regarding the electrical connection between the main control chip and the irradiation sampling circuit: Pin AD0 of the main control chip STM32L151 is electrically connected to the short-circuit current measurement point D at the output end of the irradiation sampling circuit, and is used to receive the short-circuit current of the photocell collected by the irradiation sampling circuit, thereby performing corresponding calculations to obtain the irradiation value, and sending the irradiation value through the LoRa chip SX1276.

[0058] (3) Regarding the electrical connection between the main control chip and the maximum power tracking circuit: the pin AD1 of the main control chip STM32L151 is electrically connected to the charging current measurement point F of the maximum power tracking circuit, and is used to receive the charging current fed back by the maximum power tracking circuit, so that the main control chip STM32L151 adjusts the PWM drive control signal of the maximum power tracking circuit according to the fed back charging current, so that the maximum power tracking circuit outputs electric energy at the maximum power position, and stores the electric energy through the energy storage circuit, which can power each chip component. The pin TIM2_CH1 of the main control chip STM32L151 is electrically connected to the PWM drive input point P of the maximum power tracking circuit, and is used to input the PWM drive control signal to the maximum power tracking circuit, and by adjusting the duty cycle of the PWM drive, the photovoltaic cell can work at the maximum power point to maximize the output of electric energy.

[0059] (4) Regarding the electrical connection between the main control chip and the photocell selection circuit: the GPIO pin of the main control chip STM32L151 is electrically connected to the channel selection input point T of the switching switch in the photocell selection circuit. After receiving the channel selection signal from the main control chip STM32L151, the switching switch switches the photocell to the corresponding circuit, thereby completing the corresponding "irradiation detection" or "power supply" function.

[0060] (5) Regarding the electrical connection between the main control chip and the energy storage circuit, Figure 5 Not shown, the photocell irradiation sensor of the present invention can realize long-term field operation because it has a self-powered function. The electric energy stored in the energy storage circuit can power each chip component, and the power input pin of the main control chip STM32L151 can be electrically connected to the energy storage circuit to obtain corresponding electric energy.

[0061] The photocell irradiation sensor in the present embodiment, if its photocell adopts silicon photocell, then the silicon photocell irradiation sensor has LoRa wireless transmission function, irradiation detection function and self-power supply function. The wireless communication method based on LoRa transmits data, which solves the problem of inconvenient installation and wiring. In order to avoid maintenance, realize self-power supply and store electrical energy, a silicon photocell is designed as a working mechanism that combines a "detection" element and a "power supply" element, and the two functions are switched by a switching switch. Since the short-circuit current of the silicon photocell is positively correlated with the irradiation, an "irradiation sampling circuit" is designed. This circuit obtains the short-circuit current of the silicon photocell, amplifies the short-circuit current, and then transmits it to the main control chip for sampling and calculation to obtain the irradiation value. In the sampling interval, the silicon photocell works as a power supply element, and a "maximum power tracking circuit" is designed. This circuit can maximize the power generation capacity of the silicon photocell to provide as much electrical energy as possible. "Farad capacitor C f "The electricity generated by the silicon photovoltaic cell is stored and then stabilized by the voltage regulator chip LDO to power other chips. Since LoRa has the characteristics of low power consumption, the main control chip also runs at low power consumption, and the power consumption of the entire system will also be relatively low. The main control chip serves as the core control to realize the above functions.

[0062] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0063] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0064] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0065] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0066] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A photocell irradiation sensor, characterized in that: include: A photocell selection circuit, a main control chip electrically connected to the photocell selection circuit, an irradiation sampling circuit electrically connected to the main control chip, a maximum power tracking circuit, an energy storage circuit, and a wireless communication module; the maximum power tracking circuit is also electrically connected to the energy storage circuit; wherein: The photocell selection circuit includes: a silicon photocell and a switch electrically connected to the silicon photocell; the switch inputs the output current of the silicon photocell to the irradiation sampling circuit or the maximum power tracking circuit according to the channel selection of the main control chip; When the main control chip controls the photocell selection circuit to connect with the irradiation sampling circuit, the silicon photocell is a detection component; the irradiation sampling circuit obtains the short-circuit current of the silicon photocell and transmits it to the main control chip; the main control chip calculates the irradiation value of the silicon photocell according to the short-circuit current, and sends the irradiation value of the silicon photocell through the wireless communication module; When the main control chip controls the photocell selection circuit to connect to the maximum power tracking circuit, the silicon photocell is the power supply component; the maximum power tracking circuit enables the silicon photocell to operate at the maximum power point to output electrical energy under the control of the driving control signal of the main control chip, and stores the electrical energy through the energy storage circuit to facilitate powering each chip; the maximum power tracking circuit also collects the charging current, and feeds back the processing of the charging current to the main control chip, so that the main control chip can adjust the driving control signal and control the maximum power tracking circuit.

2. A photocell irradiation sensor according to claim 1, characterized in that: The radiation sampling circuit includes: an operational amplifier and a short-circuit current sampling resistor; the positive current of the silicon photocell is input into the non-inverting input terminal of the operational amplifier, and the non-inverting input terminal of the operational amplifier is grounded; the negative current of the silicon photocell is input into the inverting input terminal of the operational amplifier; a short-circuit current sampling resistor is connected in parallel between the inverting input terminal and the output terminal of the operational amplifier; the output terminal of the operational amplifier inputs the output short-circuit current to the main control chip.

3. A photocell irradiation sensor according to claim 1, characterized in that: The maximum power tracking circuit includes: a driving subcircuit, a maximum power main circuit and a sampling subcircuit; wherein: The driving subcircuit drives the maximum power main circuit according to the PWM driving signal issued by the main control chip to output electric energy when the silicon photocell operates at the maximum power point, and stores energy through the energy storage circuit; the sampling subcircuit samples the charging current, amplifies the sampled charging current and feeds it back to the main control chip.

4. A photocell irradiation sensor according to claim 3, characterized in that: The driving subcircuit includes a driving transistor, the PWM driving control signal of the main control chip is input into the base of the driving transistor through a resistor, and the emitter of the driving transistor is grounded; the collector of the driving transistor is electrically connected to the maximum power main circuit to drive the maximum power main circuit; The maximum power main circuit includes a circuit switch tube, a filter capacitor, a filter inductor, and a freewheeling diode; wherein the base of the circuit switch tube is electrically connected to the collector of the driving transistor, the emitter of the circuit switch tube is electrically connected to the positive terminal of the silicon photocell through the switching switch, and the emitter and base of the circuit switch tube are electrically connected through a resistor; the collector of the circuit switch tube is electrically connected to the filter inductor, and the other end of the filter inductor is electrically connected to the energy storage circuit; one end of the filter capacitor is electrically connected to the emitter of the circuit switch tube, and the other end of the filter capacitor is electrically connected to the input end of the freewheeling diode, the input end of the freewheeling diode is electrically connected to the negative terminal of the silicon photocell through the switching switch, and the output end of the freewheeling diode is electrically connected to the collector of the circuit switch tube; The sampling subcircuit includes a charging current sampling resistor and an operational amplifier; one end of the charging current sampling resistor is electrically connected to the negative terminal of the silicon photocell and the input end of the freewheeling diode; the other end of the charging current sampling resistor is grounded; the in-phase input end of the operational amplifier is electrically connected to the input end of the freewheeling diode through a bias resistor, and the other end of the bias resistor is grounded through a capacitor; the inverting input end of the operational amplifier is grounded through an amplifying resistor, the inverting input end and the output end of the operational amplifier are electrically connected through another amplifying resistor, and the output end of the operational amplifier is electrically connected to the main control chip as a charging current measurement point.

5. A photocell irradiation sensor according to claim 4, characterized in that: The energy storage circuit includes a farad capacitor and a voltage-stabilizing power supply chip; the positive terminal of the farad capacitor is electrically connected to the filter inductor, and the negative terminal of the farad capacitor is grounded; the input terminal of the voltage-stabilizing power supply chip is electrically connected to the filter inductor, and the output terminal of the voltage-stabilizing power supply chip serves as a power supply output terminal to supply power to each chip.

6. A photocell irradiation sensor according to claim 1, characterized in that: The wireless communication module uses LORA communication mode for wireless communication.

7. A photocell irradiation sensor according to claim 6, characterized in that: The wireless communication module includes a LORA chip SX1276.

8. A photocell irradiation sensor according to claim 1, characterized in that: The main control chip is a single chip microcomputer of the STM32L series.

9. A photocell irradiation sensor according to any one of claims 1 to 8, characterized in that: The main control chip is a single-chip microcomputer STM32L151.

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