CN113162252B

CN113162252B - Laser power supply receiving end device and system for watt-level output power

Info

Publication number: CN113162252B
Application number: CN202110482167.6A
Authority: CN
Inventors: 魏建国; 刘伟麟; 黄辉; 黄凤; 邓辉
Original assignee: State Grid Corp of China SGCC; State Grid Shanxi Electric Power Co Ltd; Global Energy Interconnection Research Institute; Economic and Technological Research Institute of State Grid Shanxi Electric Power Co Ltd; Global Energy Interconnection Research Institute Europe GmbH
Current assignee: State Grid Corp of China SGCC; State Grid Shanxi Electric Power Co Ltd; Global Energy Interconnection Research Institute; Economic and Technological Research Institute of State Grid Shanxi Electric Power Co Ltd; Global Energy Interconnection Research Institute Europe GmbH
Priority date: 2021-04-30
Filing date: 2021-04-30
Publication date: 2023-11-07
Anticipated expiration: 2041-04-30
Also published as: CN113162252A

Abstract

A laser power supply receiving end device and system of watt-level output power, the laser power supply receiving end device includes: the first voltage converter is suitable for supplying power to the sensing node; the photovoltaic module is suitable for being electrically connected with the input end of the first voltage converter; the super capacitor energy storage module is further suitable for charging the super capacitor energy storage module, and the super capacitor energy storage module is suitable for being electrically connected with the input end of the first voltage converter; the first microcontroller performs loop feedback control on the incident laser power of the photovoltaic module based on the output power of the photovoltaic module and the first voltage converter and the working voltage of the super capacitor energy storage module, and controls the charge and discharge of the super capacitor energy storage module. The long-term reliability of the laser power supply receiving end device under the condition of continuously outputting watt-level power is improved.

Description

Laser power supply receiving end device and system for watt-level output power

Technical Field

The invention relates to the technical field of laser fiber power supply, in particular to a laser power supply receiving end device and system with watt-level output power.

Background

Laser fiber optic power is the preferred solution for sensor node power in High Voltage (HV) environments. The reason for selecting the laser fiber power supply system instead of the conventional power supply is the requirements on the aspects of electric isolation, lightning protection, electric spark resistance, electromagnetic interference resistance, weight reduction, corrosion resistance and the like, so that the laser fiber power supply system is particularly suitable for being applied to safe and reliable power supply of the monitoring sensing node of the high-voltage power transmission and transformation equipment. The load power requirements of laser fiber optic power systems for monitoring sensing applications in high voltage environments are typically in the range of a few watts or tens of watts, while the optical power transmitted through the fiber needs to be more than twice the load power, much higher than the optical power used in optical communications.

On-line monitoring of critical high voltage equipment conditions is an important means of early detection of anomalies and taking remedial action to ensure reliable operation of the grid and to avoid economic and personnel losses. The laser power supply receiving end device and the sensor node in the laser fiber power supply system are usually installed together in a high-potential area, so that great difficulty is brought to maintenance and troubleshooting of the laser fiber power supply system. Therefore, this places high demands on the long-term reliability of the core devices of the laser fiber optic power supply system.

Disclosure of Invention

The invention aims to solve the technical problem that the long-term reliability of the laser power supply receiving end device in the prior art is poor under the condition of continuously outputting watt-level power.

In order to solve the above technical problems, the present invention provides a laser power supply receiving end device with watt-level output power, including: the first voltage converter is suitable for supplying power to the sensing node; the photovoltaic module is suitable for being electrically connected with the input end of the first voltage converter; the photovoltaic module is further suitable for charging the super-capacitor energy storage module, and the super-capacitor energy storage module is suitable for being electrically connected with the input end of the first voltage converter; the first microcontroller performs loop feedback control on the incident laser power of the photovoltaic module based on the output power of the photovoltaic module and the first voltage converter and the working voltage of the super capacitor energy storage module, and controls the charge and discharge of the super capacitor energy storage module.

Optionally, the photovoltaic module includes a plurality of sub-photovoltaic cells connected in series, and the photovoltaic module integrates the plurality of sub-photovoltaic cells connected in series on a single sheet by adopting a vertically stacked multi-junction structure or a transversely segmented multi-section single junction structure.

Optionally, the photovoltaic module includes: from the first sub-photovoltaic cell to the Mth sub-photovoltaic cell vertically stacked from top to bottom, M is an integer greater than 2; the first tunneling junction is located between the jth sub-photovoltaic cell and the (j+1) th sub-photovoltaic cell, and j is an integer greater than or equal to 1 and less than or equal to M-1.

Optionally, each sub-photovoltaic cell includes a semiconductor PN junction, the thickness of the semiconductor PN junction of each sub-photovoltaic cell being in accordance withSetting; α (λ) is the light absorption coefficient at a given incident laser wavelength λ; t is t _i Is the ith sub-photovoltaicThe thickness of the semiconductor PN junction of the battery, i is an integer which is more than or equal to 1 and less than or equal to M-1; i _i Is the laser intensity entering the ith sub-photovoltaic cell, I _i+1 Is the laser intensity entering the (i+1) th sub-photovoltaic cell.

Optionally, M is an integer greater than or equal to 4.

Optionally, the thickness of the semiconductor PN junction in the Mth sub-photovoltaic cell is 2800-3200 nanometers.

Optionally, each of the first to the M-th sub-photovoltaic cells includes a back surface field layer, a base layer, an emission layer and a window layer stacked from bottom to top, the base layer and the emission layer form a semiconductor PN junction, the energy gap of the window layer is respectively greater than the energy gaps of the base layer and the emission layer, and the energy gap of the back surface field layer is respectively greater than the energy gaps of the base layer and the emission layer.

Alternatively, the material of the semiconductor PN junction comprises gallium arsenide, indium phosphide or gallium antimonide doped with conductive ions.

Optionally, the photovoltaic module further comprises: a substrate layer at the bottom of the Mth sub-photovoltaic cell; the conductivity type of the back surface field layer for the Mth sub-photovoltaic cell is the same as the conductivity type of the substrate layer; the conductivity type of the back surface field layer in the first to M-1 th sub-photovoltaic cells is the same as the conductivity type of the base layer and opposite to the conductivity type of the M-th sub-photovoltaic cell, and the conductivity type of the window layer in the first to M-th sub-photovoltaic cells is the same as the conductivity type of the emission layer.

Optionally, the thickness of the window layer of the first sub-photovoltaic cell is greater than the thicknesses of the window layers of the second sub-photovoltaic cell to the mth sub-photovoltaic cell, respectively.

Optionally, the photovoltaic module has a photoelectric conversion efficiency of 50% or more.

Optionally, the photovoltaic module further comprises: the grid line layer is positioned at the top of the first sub-photovoltaic cell; a contact layer between the gate line layer and the first sub-photovoltaic cell; an anti-reflection film located at the side of the contact layer and exposed by the gate line layer.

Optionally, the antireflection film includes a first sub antireflection film and a second sub antireflection film, the first sub antireflection film is located between the second sub antireflection film and the first sub photovoltaic cell, and the refractive index of the first sub antireflection film is between the refractive index of the second sub antireflection film and the refractive index of the window layer of the first sub photovoltaic cell.

Optionally, the grid line layer includes opposite main grid lines and a plurality of spaced thin grid lines located between the opposite main grid lines and connected with the main grid lines; the distance between the adjacent fine grid lines is 20-70 mu m; the height of the grid line layer is 1-3 mu m; the width of the main grid line is 90-130 mu m; the width of the thin grid line is 3-5 μm.

Optionally, the photovoltaic module is mounted on an insulating and heat conducting substrate, and the insulating and heat conducting substrate is provided with a heat dissipation package body for packaging the photovoltaic module, and the heat dissipation package body is provided with an interface for coupling and connecting the photovoltaic module and the energy optical fiber.

Optionally, the material of the insulating and heat conducting substrate comprises aluminum oxide, boron nitride, silicon carbide, or aluminum nitride.

Optionally, the material of the heat dissipation package is a metal heat dissipation material.

Optionally, the capacity of the super capacitor energy storage module is according toSetting;

or, the capacity C of the super capacitor energy storage module is as follows:

where P is the peak power required by the sensing node, T is the peak power duration, V _Capacitor1 Is the maximum value of the working voltage of the super capacitor energy storage module, V _Dropout Is the minimum discharge voltage of the super capacitor energy storage module, E _DC/DC The conversion efficiency of the first voltage converter is that C is the capacity of the super capacitor energy storage module; a is a safety margin.

Alternatively, whenWhen the super capacitor energy storage module is in use, the setting requirement of the threshold value of the lower limit working voltage of the super capacitor energy storage module is satisfied: />Q ₂ Is the lower operating voltage threshold.

Optionally, the number of photovoltaic modules in the tile-level output power laser power supply receiving end device is one or more, and the number of super capacitor energy storage modules in the tile-level output power laser power supply receiving end device is one or more; when the number of the photovoltaic modules in the laser power supply receiving end device of the watt-level output power is multiple, the photovoltaic modules are combined in series and then connected with at least one common super capacitor energy storage module in parallel to be connected with the first voltage converter, or the photovoltaic modules are connected with at least one common super capacitor energy storage module in parallel to be connected with the first voltage converter.

Optionally, the method further comprises: a first optical communication transceiver; and the internal power management module is suitable for taking energy from the output end of the photovoltaic module and supplying power to the first microcontroller and the first optical communication transceiver.

Optionally, the internal power management module includes a buck regulator, an internal energy storage, and a second boost voltage converter connected in series in sequence, the buck regulator being adapted to be electrically connected with the photovoltaic module, the second boost voltage converter being adapted to be electrically connected with the first microcontroller.

Optionally, the capacity of the internal energy accumulator is 2F-4F.

Optionally, the method further comprises: the switching unit comprises a first switch, a second switch and a third switch, wherein the first switch is positioned on a path between the output end of the photovoltaic module and the charging end of the super capacitor energy storage module; the second switch is positioned on a path between the output end of the photovoltaic module and the input end of the first voltage converter; the third switch is positioned on a path between the discharge end of the super capacitor energy storage module and the input end of the first voltage converter; the operating states of the first switch, the second switch and the third switch are controlled by the first microcontroller. Optionally, the first opening, the second switch and the third switch are all MOS transistors.

Optionally, the method further comprises: the first low-pass filter circuit is connected with the output end of the first voltage converter and the first microcontroller, and is suitable for smoothing the output voltage signal of the first voltage converter and inputting the output voltage signal to the first microcontroller; the first current sense amplifier is suitable for testing the current of the output end of the first voltage converter and outputting the current to the first microcontroller; the second low-pass filter circuit is connected with the output end of the photovoltaic module and the first microcontroller, and is suitable for smoothing the output voltage signal of the photovoltaic module and inputting the output voltage signal to the first microcontroller; the second current sense amplifier is suitable for testing the current of the output end of the photovoltaic module and outputting the current to the first microcontroller.

The invention also provides a laser fiber power supply system which comprises the laser power supply receiving end device of the watt-level output power.

The technical scheme of the invention has the following advantages:

the laser power supply receiving end device of the watt-level output power provided by the technical scheme of the invention comprises a super-capacitor energy storage module connected with a photovoltaic module in parallel, wherein the photovoltaic module is suitable for charging the super-capacitor energy storage module, and the super-capacitor energy storage module is electrically connected with a first voltage converter. The first microcontroller performs loop feedback control on the incident laser power of the photovoltaic module based on measuring the output power of the photovoltaic module and the first voltage converter and the working voltage of the super capacitor energy storage module, and controls the charge and discharge of the super capacitor energy storage module. The super capacitor energy storage module can quickly supplement the output power of the photovoltaic module through quick discharge when the sensing node has load peak power so as to fill a required power gap, so that the photovoltaic module can be prevented from generating excessive heat when continuously running in a high-power mode in order to meet the load peak power requirement, and the thermal stress of the photovoltaic module is reduced. The long-term reliability of the laser power supply receiving end device of the watt-level output power is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a laser fiber optic power supply system;

FIG. 2 is a schematic diagram of a power receiving end device for laser power supply with watt-level output power according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a five junction photovoltaic module according to an embodiment of the present invention;

FIG. 4 is a schematic top view of a grid line layer in a photovoltaic module according to an embodiment of the present invention;

FIG. 5 is a schematic view of a portion of a grid line layer in a photovoltaic module according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of an electrical connection between a photovoltaic module and a supercapacitor energy storage module according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of another electrical connection between a photovoltaic module and a supercapacitor energy storage module according to an embodiment of the present invention;

FIG. 8 is a block diagram of an internal power management module according to an embodiment of the invention.

Detailed Description

A laser fiber optic power supply system, referring to fig. 1, comprising: the system comprises a laser power supply base station 10, an optical fiber and a laser power supply receiving end device 20. The laser power supply base station 10 includes: a laser 11, a laser driver 12, a first microcontroller 13 and a first optical communication transceiver 14. The optical fibers include an energy fiber 31 and a data fiber 32. The laser powered sink device 20 comprises a photovoltaic module 21, an energy management unit 22, a second microcontroller 23 and a second optical communication transceiver 24.

The laser 11 is a high-power laser diode, and the laser 11 converts electrical energy into optical energy and transmits the optical energy to the laser power supply receiving end device 20 through an energy optical fiber. The output power of the laser 11 is regulated by the current of the laser driver 12. The laser power supply receiving end device 20 receives laser energy output from the laser power supply base station 10 through the energy optical fiber 31 and converts the light energy into electric energy through the photovoltaic module 21. The energy management unit 22 is used to provide a matched voltage and power to the sensing node. The energy management unit 22 contains an energy storage device and a DC/DC converter.

The laser fiber power supply system has poor long-term reliability under the condition of continuously outputting watt-level power.

The inventor researches find that:

the laser 11 and the photovoltaic module 21 are semiconductor devices whose performance and lifetime are susceptible to thermal stress. During the conversion of the laser 11 from electricity to light and the conversion of the photovoltaic module 21 from light to electricity, a large amount of energy will be lost in the form of heat, resulting in an increase in the operating temperature of the device and the circuit. The heat generated by the photovoltaic module 21 during the photovoltaic conversion process depends to a large extent on the required output power and the corresponding power conversion efficiency. On the one hand, if the output power of the photovoltaic module is longer than the power actually required by the load, energy waste and unnecessary heat are caused; on the other hand, a single photovoltaic module may not meet the load power requirements of some monitoring applications, especially in scenarios where the duration is not long but the peak power is high, and thus the laser 11 is required to continue to output sufficient optical power so that the photovoltaic module 21 can provide sufficient electrical power to meet the peak power requirements of the sensor at the time of the incident. This mode ensures a safe power supply, but has the biggest disadvantage that the photovoltaic module 21 needs to run continuously in high power mode and generates heat due to a lot of energy losses, more specifically, depending on the specific sensing application of the high voltage network, the peak power requirement of the sensing node may be very high, which results in a lot of heat energy generated by the photovoltaic module 21 when performing photovoltaic conversion, thus increasing the operating temperature of the devices and circuits.

The laser power receiving device 20 needs to be powered through laser voltage conversion, and the electric energy is very expensive, so a passive cooling method is necessary, and therefore, effective heat dissipation and temperature control on the working photovoltaic module 21 are very challenging. If the laser power supply receiving end device 20 cannot dissipate heat in time, the working temperature exceeds a certain threshold value, so that the photoelectric conversion efficiency of the photovoltaic module 21 is further reduced, more heat energy is further generated, vicious circle is formed, performance of the photovoltaic module 21 is finally reduced under the condition of long-term operation, and the service life is reduced.

On the basis, the embodiment provides a laser power supply receiving end device with watt-level output power, which comprises: the first voltage converter is suitable for supplying power to the sensing node; the photovoltaic module is suitable for being electrically connected with the input end of the first voltage converter; the photovoltaic module is further suitable for charging the super-capacitor energy storage module, and the super-capacitor energy storage module is suitable for being electrically connected with the input end of the first voltage converter; the first microcontroller performs loop feedback control on the incident laser power of the photovoltaic module based on the output power of the photovoltaic module and the first voltage converter and the working voltage of the super capacitor energy storage module, and controls the charge and discharge of the super capacitor energy storage module. The long-term reliability of the laser power supply receiving end device under the condition of continuously outputting watt-level power is improved.

The following description of the embodiments of the present invention will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the invention are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

An embodiment of the present invention provides a laser power supply receiving end device 100 with watt-level output power, referring to fig. 2, including:

the first voltage converter 103 is adapted to power the sensing node;

a photovoltaic module 101, said photovoltaic module 101 being adapted to be electrically connected to an input of a first voltage converter 103;

the super capacitor energy storage module 102, the photovoltaic module 101 is further adapted to charge the super capacitor energy storage module 102, and the super capacitor energy storage module 102 is electrically connected with the input end of the first voltage converter 103;

the first microcontroller 104 performs loop feedback control on the incident laser power of the photovoltaic module 101 based on the output power of the photovoltaic module 101 and the first voltage converter 103 and the working voltage of the super capacitor energy storage module 102, and controls the charge and discharge of the super capacitor energy storage module 102.

The laser power supply receiving end device 100 of the watt-level output power further includes: a first optical communication transceiver 105, an internal power management module 106. The first optical communication transceiver 105 is connected to the first microcontroller 104, and the first microcontroller 104 can control the first optical communication transceiver 105 to send data packets to the laser power supply base station.

The photovoltaic module 101 is adapted to perform photoelectric conversion. Specifically, the photovoltaic module 101 receives laser energy output from a laser powered base station and converts the laser energy into electrical energy. The photovoltaic module 101 is adapted to output electrical energy to a first voltage converter 103. The photovoltaic module 101 has a watt level of output power, and in one particular embodiment, the output power of the photovoltaic module 101 is 1W to 10W, such as 2W to 8W.

In a preferred embodiment, the photovoltaic module 101 has a photoelectric conversion efficiency of 50% or more, such as 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, in the output power range of 1W to 10W. In one embodiment, the photovoltaic module 101 has a high photoelectric conversion efficiency, and preferably, the photoelectric conversion efficiency of the photovoltaic module 101 is 50% or more.

An important aspect of the present invention is the improvement in the design of the photovoltaic module 101 to achieve a higher photovoltaic conversion efficiency of the photovoltaic module 101 while providing a higher output power.

The photovoltaic module 101 includes a semiconductor PN junction that absorbs photons and forms free carriers.

In one embodiment, the material of the semiconductor PN junction is made of a direct band gap semiconductor material with high absorption coefficient and high electron mobility, such as gallium arsenide (GaAs), indium phosphide (InP) or gallium antimonide (GaSb), that is, the material of the semiconductor PN junction is gallium arsenide doped with conductive ions, indium phosphide doped with conductive ions or gallium antimonide doped with conductive ions.

The optimal incident laser wavelength region range of the photovoltaic module 101 is determined by referring to the energy gap of the semiconductor material selected for the semiconductor PN junction at room temperature. In a specific embodiment, the semiconductor PN junction of the photovoltaic module 101 is made of gallium arsenide, and accordingly, the incident laser with 808 nm wavelength is selected, so that the photoelectric conversion efficiency index of about 50% or more can be achieved at a lower cost.

In one embodiment, to achieve higher photoelectric conversion efficiency at watt output power, the photovoltaic module 101 includes several sub-photovoltaic cells in series, each sub-photovoltaic cell including a semiconductor PN junction. A plurality of sub-photovoltaic cells are connected in series in a monolithic integration mode to increase the output voltage, and the output voltage of the photovoltaic module 101 is equal to the sum of the output voltages of the plurality of sub-photovoltaic cells. Further, for integrating multiple sub-photovoltaic cells in series on a single sheet, the photovoltaic module 101 integrates multiple sub-photovoltaic cells in series on a single sheet using a vertically stacked multi-junction structure or a laterally segmented multi-segment single junction structure. Preferably, the photovoltaic module 101 adopts a vertically stacked multi-junction structure to integrate a plurality of sub-photovoltaic cells in series, so as to form a multi-junction photovoltaic module, so that the complexity of an assembly and encapsulation process is reduced, the size of the photovoltaic module 101 is reduced, and the cost of mass production is reduced.

In one embodiment, when the photovoltaic module 101 integrates a plurality of sub-photovoltaic cells in series using a vertically stacked multi-junction structure, the thickness of the semiconductor PN junction in each sub-photovoltaic cell in the photovoltaic module 101 is precisely calculated to ensure that each sub-photovoltaic cell can absorb the same proportion of photons and generate equal current, to achieve current matching and maximize the photoelectric conversion efficiency, and specifically, in the photovoltaic module 101, the thickness of the semiconductor PN junction of each sub-photovoltaic cell is designed according to the Beer-Lambert (Beer-Lambert) index absorption law:

in formula 1, α (λ) is the light absorption coefficient at a given incident laser wavelength λ; from top to bottom in photovoltaic module 101 includes a first sub-photovoltaic cell to an Mth sub-photovoltaic cell, t _i The thickness of the semiconductor PN junction of the ith sub-photovoltaic cell is that i is an integer which is more than or equal to 1 and less than or equal to M-1; i _i Is the laser intensity entering the ith sub-photovoltaic cell in the photovoltaic module 101, I _i+1 Is the laser intensity entering the (i+1) th sub-photovoltaic cell. According to the above law, in the photovoltaic module 101, the thickness of the semiconductor PN junction in the first sub-photovoltaic cell to the thickness of the semiconductor PN junction in the mth sub-photovoltaic cell is increased layer by layer, and as the number of junctions increases, the thickness of the first sub-photovoltaic cell becomes thinner.

In a specific embodiment, the thickness of the semiconductor PN junction in the Mth sub-photovoltaic cell is 2800 nm to 3200 nm, such as 2800 nm, 2900 nm, 3000 nm, 3100 nm, or 3200 nm. The thickness of the first sub-photovoltaic cell to the thickness of the M-1 th sub-photovoltaic cell was designed according to the above-described Beer-Lambert (Beer-Lambert) exponential absorption law. If the thickness of the Mth sub-photovoltaic cell is too small, the first sub-photovoltaic cell to the Mth sub-photovoltaic cell cannot fully absorb the energy of the incident laser, so that the photoelectric conversion efficiency is not improved better; if the thickness of the Mth sub-photovoltaic cell is greater than 3200 nanometers, the thicknesses of the first sub-photovoltaic cell to the Mth-1 sub-photovoltaic cell are too thick, and different sub-photovoltaic cells cannot absorb photons according to the same proportion, so that current mismatch in each sub-photovoltaic cell is caused, and the photoelectric conversion efficiency is reduced. The thickness of the mth sub-photovoltaic cell provided with the underlayer is therefore very important for improvement of photoelectric conversion efficiency.

Further, M is 4 or more. When M is greater than or equal to 4, the number of the sub-photovoltaic cells is large, and the open-circuit voltage of the photovoltaic module is better improved.

When the photovoltaic module 101 adopts a vertically stacked multi-junction structure to integrate a plurality of sub-photovoltaic cells in series, and the material of the semiconductor PN junction of the sub-photovoltaic cells is gallium arsenide doped with conductive ions, the light absorption coefficient alpha (lambda) is 1.24 multiplied by 10 when the incident laser wavelength is 808nm ⁴ cm ^-1 。

When the photovoltaic module 101 integrates a plurality of sub-photovoltaic cells in series using a vertically stacked multi-junction structure, each sub-photovoltaic cell in the photovoltaic module 101 is interconnected in series by a tunneling junction. The tunneling junction is a highly doped thin layer PN junction, and the tunneling junction is made of gallium arsenide (GaAs), gallium aluminum arsenide (AlGaAs) or gallium indium phosphide (GaInP) doped with conductive ions. The tunnel junction absorbs the energy of the incident laser light but allows carriers to pass through with minimal voltage loss. Specifically, the plurality of tunneling junctions include a first tunneling junction to an M-1 tunneling junction, a j tunneling junction is located between the j sub-photovoltaic cell and the j+1th sub-photovoltaic cell, and j is an integer greater than or equal to 1 and less than or equal to M-1.

Theoretically, for a photovoltaic module 101 formed by a semiconductor PN structure using gallium arsenide material, a laser wavelength close to 850nm can be used to generate smaller heat loss, and better photoelectric conversion efficiency can be obtained under ideal conditions. However, in practical development, based on the quality of the crystal grown from gallium arsenide, and the structure and key parameter design of the photovoltaic module, the absorption efficiency of the incident laser, the resistance and the current mismatch loss are affected, and the achievable photoelectric conversion efficiency is finally affected. Given that 808nm is the standard wavelength of the diode pumped lasers currently on the market, there are many products with coupled fibers that are of high quality, high efficiency. In a preferred embodiment of the present invention, from practical application, the incident laser wavelength of the photovoltaic module 101 formed by the semiconductor PN structure of the gallium arsenide material is determined to be 808nm, and then the photovoltaic module is optimally designed according to the determined incident laser wavelength. It should be further noted that, if the open circuit voltage of the photovoltaic module of single junction gallium arsenide is up to about 1.2V, the required photocurrent and the resistance loss generated by the required photocurrent increase with the increase of the output power, so that the photoelectric conversion efficiency decreases, and the improvement of the photocurrent on the photovoltaic module with small area needs to improve the carrier density, which may put more technical requirements and challenges on the semiconductor materials, manufacturing process, optical coupling, and the like of the photovoltaic module and the laser. Thus, in a preferred embodiment of the present invention, photovoltaic modules of multi-junction gallium arsenide are employed to achieve a photovoltaic conversion efficiency of greater than 50% over a range of 1W to 10W output power.

In a specific embodiment, the photovoltaic module 101 employs a vertically stacked multi-junction structure to integrate a plurality of sub-photovoltaic cells in series, the plurality of sub-photovoltaic cells including a first sub-photovoltaic cell, a second sub-photovoltaic cell, a third sub-photovoltaic cell, a fourth sub-photovoltaic cell, and a fifth sub-photovoltaic cell vertically stacked from top to bottom, and for convenience of description, the photovoltaic module having the first sub-photovoltaic cell, the second sub-photovoltaic cell, the third sub-photovoltaic cell, the fourth sub-photovoltaic cell, and the fifth sub-photovoltaic cell is referred to as a five-junction photovoltaic module. Correspondingly, the five-junction photovoltaic module further comprises: a first tunnel junction between the first sub-photovoltaic cell and the second sub-photovoltaic cell; a second tunnel junction between the second sub-photovoltaic cell and the third sub-photovoltaic cell; a third tunnel junction between the third sub-photovoltaic cell and the fourth sub-photovoltaic cell; and a fourth tunnel junction between the fourth sub-photovoltaic cell and the fifth sub-photovoltaic cell.

In this embodiment, when the photovoltaic module 101 integrates a plurality of tandem sub-photovoltaic cells using a vertically stacked multi-junction structure, the photovoltaic module further includes: a substrate layer at the bottom of the Mth sub-photovoltaic cell; and the bottom contact metal layer is positioned on the substrate layer and is opposite to the Mth sub-photovoltaic cell. The substrate layer is a semiconductor wafer that grows the entire first to mth sub-photovoltaic cell and each tunnel junction, determining the type of lattice structure and the material composition that can be grown on it. In this embodiment, the substrate layer is N-type gallium arsenide (GaAs). The bottom contact metal layer covers the whole back surface of the substrate layer and forms ohmic contact with the substrate layer, and has good adhesion and lower contact resistance. The photovoltaic module further includes: the grid line layer is positioned at the top of the first sub-photovoltaic cell; a contact layer between the gate line layer and the first sub-photovoltaic cell; an anti-reflection film located at the side of the contact layer and exposed by the gate line layer.

Each of the first to M-th sub-photovoltaic cells comprises a back surface field layer, a base layer, an emission layer and a window layer which are laminated from bottom to top, wherein the base layer and the emission layer form a semiconductor PN junction. The window layer and the back surface field layer are transparent to incident laser, the energy gap of the window layer is respectively larger than the energy gaps of the base layer and the emitting layer, and the energy gap of the back surface field layer is respectively larger than the energy gaps of the base layer and the emitting layer, so that a plurality of carriers (multiple carriers) freely flow in the window layer and the back surface field layer, and the window layer and the back surface field layer form an energy barrier for minority carriers (the minority carriers), so that the minority carriers are prevented from diffusing to a metal-semiconductor interface to be subjected to surface recombination, and then the photovoltage and the conversion efficiency are reduced. In a specific embodiment, the material of the window layer is N-type aluminum gallium arsenide (AlGaAs), and the material of the back surface field layer is P-type or N-type aluminum gallium arsenide (AlGaAs).

In this embodiment, the conductivity types of the back surface field layers in the M-1 th sub-photovoltaic cell to the first sub-photovoltaic cell are P-type, such as P-type AlGaAs, the conductivity types of the middle back surface field layers in the M-th sub-photovoltaic cell are N-type, such as N-type AlGaAs (AlGaAs), and the conductivity types of the window layers in the first sub-photovoltaic cell to the M-th sub-photovoltaic cell are N-type, such as N-type AlGaAs (AlGaAs).

The conductivity type of the back surface field layer for the mth sub-photovoltaic cell is the same as the conductivity type of the substrate layer, which results in a higher quality of the growth of the mth sub-photovoltaic cell on the substrate layer.

And for the first to M-1 th sub-photovoltaic cells, the conductivity type of the back surface field layer in the first to M-1 th sub-photovoltaic cells is the same as that of the base layer and opposite to that of the M-1 th sub-photovoltaic cells, so that the quality of the base layer is better. And the conductivity type of the window layer in the first sub-photovoltaic cell to the Mth sub-photovoltaic cell is the same as that of the emission layer, so that the quality of the window layer is better. Such an arrangement for photoelectric conversion contributes to improvement of photoelectric conversion efficiency.

In this embodiment, the window layer of the first sub-photovoltaic cell also serves as a lateral conductive layer, and the thickness of the window layer of the first sub-photovoltaic cell is appropriately increased to improve the electrical conductivity of the top of the photovoltaic module 101, so as to reduce the dependence on the grid line layer, which is beneficial to finally obtain higher photoelectric conversion efficiency. The thickness of the window layer of the first sub-photovoltaic cell is respectively larger than that of the window layers of the second sub-photovoltaic cell to the Mth sub-photovoltaic cell.

In one embodiment, the conductivity type of the base layer is P-type and the conductivity type of the emissive layer is N-type. More specifically, the base layer is P-type GaAs, and the emitter layer is N-type GaAs. When the conductivity type of the base layer is P-type, the light emitting layer has a conductivity type of N-type, the photoelectric conversion efficiency is greater than when the conductivity type of the light emitting layer is P-type and the conductivity type of the base layer is N-type.

In one embodiment, for the first through M-th sub-photovoltaic cells, each sub-photovoltaic cell absorbs and converts about 1/M of the energy of the incident light to achieve current matching and higher photoelectric conversion efficiency.

When M is equal to 5, each sub-photovoltaic cell absorbs and converts about 1/5 of the incident light. More specifically, the thickness of the semiconductor PN junction in the fifth sub-photovoltaic cell is 3000nm, the thickness of the semiconductor PN junction in the fourth sub-photovoltaic cell is 474nm, the thickness of the semiconductor PN junction in the third sub-photovoltaic cell is 282nm, the thickness of the semiconductor PN junction in the second sub-photovoltaic cell is 199nm, and the thickness of the semiconductor PN junction in the first sub-photovoltaic cell is 154nm.

The semiconductor PN junction in each sub-photovoltaic cell is made of gallium arsenide doped with conductive ions, the incident laser wavelength of the photovoltaic module 101 is 800-850 nm, and the cross-sectional area of the photovoltaic module 101 receiving illumination is 20mm ² ～30mm ² Further, under irradiation with a selected 808nm incident laser wavelength, the cross-sectional area of the photovoltaic module 101 receiving the irradiation is 25mm ² The achievable open circuit voltage was 5.7V and the short circuit current was 1.3A. For a semiconductor PN structure adopting gallium arsenide material, the energy gap of gallium arsenide at room temperature is 1.42eVThe resulting photovoltaic module 101 is suitable for an incident laser wavelength region in the range of 800nm to 850nm.

The contact layer has high doping and high conductivity, allowing majority carriers to flow freely to the gate line layer without an energy barrier. The material of the contact layer comprises GaAs doped with conductive ions. The anti-reflection film is used for reducing reflection loss of incident laser on the top of the photovoltaic module. The antireflection film is of a laminated structure or a single-layer structure.

When the antireflection film is of a laminated structure, the antireflection film comprises a first sub antireflection film and a second sub antireflection film, the first sub antireflection film is positioned between the second sub antireflection film and the first sub photovoltaic cell, and the material of the first sub antireflection film comprises TiO ₂ The first sub-antireflection film has a thickness of 40nm to 50nm, for example 45nm, and the second sub-antireflection film comprises SiO ₂ The thickness of the second sub antireflection film is 100nm to 120nm, for example, 110nm. Such a combination can achieve an antireflection film having a reflectance of 1% or less at an incident laser wavelength of 740nm to 860 nm. The refractive index of the first sub-antireflection film is between the refractive index of the second sub-antireflection film and the refractive index of the window layer of the first sub-photovoltaic cell, so that more light energy enters the first sub-photovoltaic cell in an incident mode.

Referring to fig. 4, the gate line layer includes opposite main gate lines 201 and a plurality of spaced thin gate lines 202 between the opposite main gate lines 201 and connected to the main gate lines 201, and in the structure optimization design of the gate line layer, a gate line height c (refer to fig. 5), a gate line width a (refer to fig. 4) and a gate line interval b (refer to fig. 4) are key parameters, which directly affect the contact resistance loss and the shielding loss of the gate line layer. In the best case, when the resistive loss is approximately equal to the shielding loss, the maximization of the photoelectric conversion efficiency can be achieved. In one specific embodiment, the spacing between adjacent thin gate lines is 20 μm to 70 μm, such as 50 μm, the height of the gate line layer is 1 μm to 3 μm, such as 2 μm, the width of the thin gate lines is 3 μm to 5 μm, such as 4 μm, and the width of the main gate lines is 90 μm to 130 μm, such as 110 μm. The width of the thin gate line is smaller than the width of the main gate line. In one embodiment, the extension direction of the thin gate line is perpendicular to the extension direction of the main gate line.

The photovoltaic module 101 radiates heat by adopting a passive cooling heat radiation mode.

The photovoltaic module 101 is mounted on an insulating and thermally conductive substrate having a heat dissipating package thereon that encapsulates the photovoltaic module 101. The insulating and heat conducting substrate uses an insulating and heat conducting material such as alumina (Al ₂ O ₃ ) Boron Nitride (BN), silicon carbide (SiC), or aluminum nitride (AIN). The heat dissipation package uses a metal heat dissipation material, such as copper aluminum alloy. The heat dissipation package body is reserved with an interface, and the interface is used for coupling and connecting the photovoltaic module 101 and the energy optical fiber.

In a specific embodiment, the maximum continuous output power of the five-junction photovoltaic module is set to be 6W, the maximum peak output power is set to be 8W, the five-junction photovoltaic module is mounted on an insulating heat-conducting substrate of aluminum nitride with the size of 13.7x12.4mm2, bus bars of the five-junction photovoltaic module are connected to the insulating heat-conducting substrate of aluminum nitride through wire bonding, the five-junction photovoltaic module mounted on the insulating heat-conducting substrate of aluminum nitride is packaged in a heat-dissipating package of copper-aluminum alloy with the size of 40x58x28.50mm3, the surface temperature of the five-junction photovoltaic module can be controlled to be in the range of-40 ℃ to +85 ℃, and the top of the heat-dissipating package is provided with an interface.

The photovoltaic module 101 is adapted to be electrically connected to the input of the first voltage converter 103, and the photovoltaic module 101 is capable of outputting electrical energy to the first voltage converter 103. The photovoltaic module 101 is further adapted to be electrically connected with the super capacitor energy storage module 102, the photovoltaic module 101 is adapted to be connected in parallel with the super capacitor energy storage module 102, and the photovoltaic module 101 is further adapted to charge the super capacitor energy storage module 102. When the output power of the photovoltaic module 101 cannot meet the short-time peak power of the sensing node burst, the super capacitor energy storage module 102 supplies power to the sensing node together with the photovoltaic module 101.

In one embodiment, the laser power supply receiving end device of the watt-level output power further includes: and the switch unit (not shown) comprises a first switch, a second switch and a third switch, wherein the first switch is positioned on a path between the output end of the photovoltaic module and the charging end of the super capacitor energy storage module, and the first switch is required to be closed when the photovoltaic module charges the super capacitor energy storage module. The second switch is located on a path between the output of the photovoltaic module and the input of the first voltage converter, and the photovoltaic module and the first voltage converter are electrically connected when the second switch is closed. The third switch is located on a path between the discharge end of the super capacitor energy storage module and the input end of the first voltage converter, and when the super capacitor energy storage module supplies electric energy to the sensing node, the third switch is required to be closed. The operating states (closed or open) of the first switch, the second switch and the third switch are controlled by a first microcontroller.

Preferably, the first opening, the second switch and the third switch are all MOS transistors. The first switch supports unidirectional current flow from the photovoltaic module to the supercapacitor energy storage module. The second switch supports unidirectional flow of current from the output of the photovoltaic module to the first voltage converter. The third switch supports unidirectional flow of current from the supercapacitor energy storage module to the first voltage converter.

The first voltage converter 103 supplies the sensing node with a standard voltage. The standard voltages are, for example, 3.3V, 5V, 10V, 12V.

The first voltage converter 103 is a DC/DC converter, such as a step-up DC/DC converter, a step-down DC/DC converter, or a step-up DC/DC converter.

When the output voltage of the photovoltaic module 101 is lower than the operation voltage required by the sensing node, the first voltage converter 103 is a boost DC/DC converter; when the output voltage of the photovoltaic module 101 is higher than the operating voltage required by the sensing node, the first voltage converter 103 is a buck DC/DC converter; the first voltage converter 103 is a buck-boost DC/DC converter when the output voltage of the photovoltaic module 101 may be lower or higher than the plurality of operating voltages required by the sensing node.

In a specific embodiment, the first voltage converter 103 employs a buck-type DC/DC converter to support a more flexible power circuit design. The input voltage range of the step-up/step-down DC/DC converter is 0.8-18V, and the output voltage can be 3.3V, 5V or 10V through a jumper wire. Considering that the open-circuit voltage of the five-junction photovoltaic module is 5.7V, the buck-boost DC/DC converter can support the serial combination input of at most 3 five-junction photovoltaic modules.

The conversion efficiency of the first voltage converter 103 is about 88% to 92%, such as 90%.

In this embodiment, the laser power supply receiving end device of the watt-level output power further includes: the first low-pass filter circuit is connected with the output end of the first voltage converter and the first microcontroller, and is suitable for smoothing the output voltage signal of the first voltage converter and inputting the output voltage signal to the first microcontroller; a first current sense amplifier 107, the first current sense amplifier 107 being adapted to test the current at the output of the first voltage converter and output it to the first microcontroller 104; the second low-pass filter circuit is connected with the output end of the photovoltaic module and the first microcontroller 104, and is suitable for smoothing the output voltage signal of the photovoltaic module 101 and inputting the output voltage signal to the first microcontroller; the second current sense amplifier 108, the second current sense amplifier 108 is adapted to test the current at the output of the photovoltaic module 101 and output to the first microcontroller.

In this embodiment, the voltage and current at the output end of the first voltage converter 103 are measured and then input to the first microcontroller 104, and the first microcontroller calculates the average load power of the sensing node.

In a specific embodiment, the output voltage signal of the first voltage converter 103 is smoothed by a first low-pass filter circuit and then converted into a first voltage digital signal by an analog-to-digital converter built in the first microcontroller 104; the first low-pass filter circuit is externally arranged on the first microcontroller. The first voltage converter 103 is configured to drive a load current signal of the sensing node to be converted into a first current digital signal through an analog-to-digital converter built in the first microcontroller 104 after being subjected to low-pass filtering smoothing processing and measurement by the first current sense amplifier 107; the first microcontroller 104 obtains the average load power of the sensing node according to the first voltage digital signal and the first current digital signal.

In another specific embodiment, the output power of the first voltage converter 103 depends on the type of sensing node and the specific operation mode. The output power of the first voltage converter 103 is measured by a first power meter and then is input into the first microcontroller 104, and the first microcontroller 104 obtains the average load power of the sensing node according to the output power of the first voltage converter 103 measured by the first power meter.

In this embodiment, the voltage and current of the output end of the photovoltaic module 101 are measured and then input to the first microcontroller 104, and the first microcontroller 104 calculates the output power of the photovoltaic module 101.

In a specific embodiment, the output voltage signal of the photovoltaic module 101 is converted into a second voltage digital signal by an analog-to-digital converter built in the first microcontroller 104; the current at the output end of the photovoltaic module 101 is smoothed and measured by the low-pass filtering of the second current sense amplifier 108, and then is converted into a second current digital signal by an analog-to-digital converter built in the first microcontroller 104; the first microcontroller 104 obtains the average load power of the photovoltaic module 101 according to the second voltage digital signal and the second current digital signal.

In another specific embodiment, the output power of the photovoltaic module 101 is measured by a second power meter and then input to the first microcontroller 104; the first microcontroller 104 performs loop feedback control on the output optical power of the laser power supply base station through the first optical communication transceiver 105 based on the output power of the photovoltaic module 101 and the average load power of the sensing node, so as to realize tracking matching of the output power of the photovoltaic module 101 to the average load power.

The load curve of the sensing node is not constant. The sensing node has an idle mode, an operational mode, and an emergency mode. When the sensing node is in the idle mode, the sensing node does not detect tasks and only needs to execute the least necessary functions, and the power required by the sensing node in the idle mode is smaller than that required by the sensing node in the working mode. When the sensing node is in the working mode, the sensing node performs detection tasks, such as reading condition data (current, temperature and pressure), and the sensing node processes the condition data and sends the relevant condition data to the control center, so that a certain power is required when the sensing node is in the working mode. When the sensing node is in an emergency mode, if the laser fiber power supply system is abnormal, for example, when the condition parameter exceeds the condition threshold value, more sensing data are needed to be analyzed, and more data exchange is carried out between the sensing node and the control center, so that the peak power requirement occurs to the sensing node within a certain time, and the peak power of the sensing node in the emergency mode is larger than the working power of the sensing node in the working mode. The idle mode and the working mode of the sensing node occur regularly, but the emergency mode of the sensing node is unpredictable. The emergency mode of the sensing node is much less than the time when the working mode occurs, and the duration of the sensing node in the emergency mode is less than the duration of the sensing node in the working mode. The laser fiber power supply system should be able to meet peak power requirements in emergency mode.

In a specific embodiment, when the sensing node is in the idle mode, the power of the sensing node is 180mW to 220mW, such as 200mW; when the sensing node is in a working mode, the power of the sensing node is 3W-5W, such as 4W; when the sensing node is in the emergency mode, the peak power at the sensing node is above 15W and the duration is within 5 seconds.

In this embodiment, the super capacitor energy storage module 102 is advantageous in applications requiring high power, charge and discharge cycles, and longer service life in a short time. The super capacitor storage module 102 is adapted to meet peak power requirements of the sensing node in an emergency mode.

The super capacitor energy storage module 102 can supplement the output power of the photovoltaic module 101 through rapid discharge when the sensing node has a load transient power requirement, so as to fill the required power gap.

The load transient power demand is typically caused by increased signal acquisition, processing, and transmission operations when the sensing node suddenly detects an abnormal condition, with unpredictability. Due to the limited response time of feedback control through the loop, the instantaneous power demand of the sensing node cannot be met in real time by dynamically adjusting the output power of the photovoltaic module 101. The power supply buffer provided by the super capacitor energy storage module 102 can decouple the output power of the photovoltaic module 101 from the load instantaneous power requirement of the sensing node to a certain extent, so that the photovoltaic module 101 can be prevented from generating excessive heat when continuously operating in a high-power mode in order to meet the load instantaneous power requirement.

In one embodiment, the capacity of the supercapacitor energy storage module 102 is set according to the following formula:

where P is the peak power required by the sensing node, T is the peak power duration, V _Capacitor1 Is the maximum value of the operating voltage of the super capacitor energy storage module 102, V _Dropout The minimum voltage when the super capacitor energy storage module 102 stops discharging, namely the minimum discharging voltage; e (E) _DC/DC Is the efficiency of the first voltage converter 103 and C is the capacity of the supercapacitor storage capacitor module 102. In the T time, the voltage of the super capacitor energy storage module 102 is changed from V _Capcitor1 Reduced to V _Dropout 。

In another embodiment, the capacity C of the supercapacitor storage die 102 satisfies:

(equation 3), a is a safety margin.

In a specific embodiment, a is greater than 0 and less than or equal to 10F.

In (equation 3), the capacity of the super capacitor energy storage module 102 is set taking into account a safety margin. So that the reliability of the super capacitor energy storage module 102 to supply power to the sensing node in an emergency situation is improved.

The super capacitor energy storage module 102 is used for estimating the limit condition of the photovoltaic module 101 when the sensing node for supplying power in the instantaneous power requirement of the load is replaced by the photovoltaic module, so that the reliability and fault tolerance of the power supply are ensured.

V _Capacitor The operating voltage of the module for super capacitor 102. V (V) _Capacitor The energy stored in the super capacitor energy storage module 102 is determined, the working voltage of the super capacitor energy storage module 102 changes correspondingly with the charge and discharge of the super capacitor energy storage module 102, V _Capacitor Is set taking into account the operating environment temperature of the supercapacitor energy storage module 102 and the expected service life of the supercapacitor energy storage module 102. Suppose that a higher V is used at a higher ambient temperature _Capacitor1 The service life of the super capacitor energy storage module can be reduced. Thus for long service life or operation at relatively high ambient temperatures, V, which requires the supercapacitor energy storage module 102 _Capacitor1 The setting is lower.

In a specific embodiment, the capacity of the super capacitor energy storage module is 45F-60F, such as 50F, V _Capacitor1 Is set to 2.3V-2.7V.

V _Dropout The amount of electrical energy that cannot be extracted from the supercapacitor energy storage module 102 is determined, generally depending on the minimum input operating voltage of the first voltage converter 103. In a specific embodiment, V _dropout Minimum input operating voltage +v of=first voltage converter _difference 。V _difference 0V to 0.1V.

The efficiency of the first voltage converter 103 depends on the duty cycle (line and load) conditions, varying with load current and duty cycle.

Operating voltage V of the super capacitor energy storage module 102 _Capacitor Is continuously measured and input into a first microcontroller 104, the first microcontroller 104 being responsive to the operating voltage V _Capacitor Is provided for continuously monitoring and controlling the charging process of the photovoltaic module 101 to the super capacitor energy storage module 102. When the first microcontroller 104 monitors the operating voltage V of the super capacitor energy storage module 102 _Capacitor Less than the lower operating voltage threshold Q ₂ At this time, the photovoltaic module 101 is turned on to store the super capacitorA charging process of the module 102 is enabled.

When (when)At the time, the lower operating voltage threshold Q ₂ The setting requirements of (1) are as follows: the electric quantity releasable by the super capacitor energy storage module 102 meets the peak power requirement of the sensing node in an emergency mode, < ->

Lower limit operating voltage threshold Q ₂ Greater than V _Dropout And is smaller than V _Capacitor1 。

The first microcontroller 104 increases the output power of the photovoltaic module 101 through loop feedback control according to the continuously monitored output power of the photovoltaic module 101 and the output power of the first voltage converter 103, in combination with the target working voltage of the super capacitor energy storage module 102 and the target time for completing charging; when the working voltage V is monitored _Capacitor When the target operating voltage is reached, the photovoltaic module 101 stops charging the super capacitor energy storage module 102, and accordingly, the first microcontroller 104 decreases the output power of the photovoltaic module 101.

In a specific embodiment, the supercapacitor energy storage module 102 includes a plurality of supercapacitors connected in series. The total working voltage of the super capacitor energy storage module 102 can be increased by connecting a plurality of super capacitors in series, so that the electric energy stored by the whole capacitor energy storage module 102 can be increased.

In one embodiment, the super capacitor energy storage module 102 comprises an Electric Double Layer Capacitor (EDLC), the super capacitor energy storage module 102 has a capacity of 45F to 60F, such as 50F, and the operating voltage V of the super capacitor energy storage module 102 _Capacitor The maximum set to 2.5V and the maximum storable energy to 156 joules (J). Referring to the minimum input voltage of the first voltage converter 103, the minimum voltage V that the super capacitor energy storage module 102 can discharge _Dropout At 0.8V, the energy that the supercapacitor energy storage module 102 cannot release is 16J. Therefore, super capacitor energy storage module102 is 140J. Considering that the efficiency of the first voltage converter 103 is 90%, the energy available to power the load is about 126J. For a scenario where the sensing power savings has a peak load power of 15 watts (W) and a duration of 5 seconds, consider that separate power supply by the supercapacitor energy storage module 102 requires a capacity of at least 30F. The 50F super capacitor energy storage module 102 in this embodiment can continuously supply power for 8.4 seconds under the condition that the peak load power of sensing power saving is 15 watts, and can meet the application requirements and leave a certain safety margin.

Operating voltage V of the super capacitor energy storage module 102 _Capacitor After the signal is smoothed by the second low-pass filter circuit, the signal is converted into a third voltage digital signal through an analog-to-digital converter built in the first microcontroller 104; the first microcontroller 104 performs charge and discharge management of the super capacitor energy storage module 102 based on continuous monitoring of the operating voltage of the super capacitor energy storage module 102 and the output power of the photovoltaic module 101 and the first voltage converter 103. Specifically, in order to meet the situation that the peak load power is 15W and the duration is 5 seconds, the super capacitor energy storage module 102 of 50F stores at least about 99J of energy, and the corresponding operating voltage is about 2V. When the first microcontroller 104 monitors the operating voltage V of the super capacitor energy storage module 102 _Capacttor Below a lower operating voltage threshold (e.g., 2V), the charging process of the super capacitor energy storage module 102 by the photovoltaic module 101 is started. When the charging of the super capacitor energy storage module 102 by the photovoltaic module 101 is finished, the output power of the photovoltaic module 101 is higher than the average power actually required by the load, and the output power of the photovoltaic module 101 is reduced through loop feedback control so as to realize the matching of the load power of the sensing node, thus unnecessary energy loss and heat generated by the energy loss can be reduced.

In a specific embodiment, the initial average power of the load of the sensing node is 3W, the initial operating voltage of the supercapacitor energy storage module 102 is 2.5V, the energy transmission efficiency between the output of the photovoltaic module 101 and the input of the first voltage converter 103 is assumed to be 95%, the efficiency of the first voltage converter 103 is 90%, the corresponding energy transmission efficiency between the output of the photovoltaic module 101 and the sensing node is 85%, and the output power of the photovoltaic module 101 is calculated to be 3.5W. When the first microcontroller 104 monitors that the average load power of the sensing node suddenly increases to 4W, the first microcontroller 104 can immediately increase the laser output power of the laser power supply base station step by step through loop feedback control until the output power of the photovoltaic module 101 is stabilized at about 4.7W, and when the output power of the photovoltaic module 101 is linearly increased in the above process, the total time is 2 seconds, the average output power of the photovoltaic module 101 is 4.1W during 2 seconds, and the missing 0.6W average power is replenished through the rapid discharge of the super capacitor energy storage module 102. When the conversion efficiency of the first voltage converter 103 is 90%, the super capacitor energy storage module 102 releases about 1.3J of energy in total in the above process, and the remaining stored energy is about 154.7J, and the first microcontroller 104 monitors that the operating voltage of the super capacitor energy storage module 102 is only slightly reduced, so that the super capacitor energy storage module 102 can be not charged.

It should be noted that, in other embodiments, the first microcontroller 104 does not immediately perform the loop feedback control when the rise of the load average power of the sensing node is monitored for the first time, but continuously observes for a period of time and then makes a decision, and the power supply gap during the period is fully supplemented by the super capacitor energy storage module 102. When the first microcontroller 104 monitors that the load average power of the sensing node increases for a second time, for example, the load average power of the sensing node increases from 4W to 15W with a peak power for 5 seconds, if the first microcontroller 104 does not perform loop feedback control, the photovoltaic module 101 still maintains an output power of 4.7W (the power to the load is only 4W after the transmission loss), and the deficient 11W power needs to be discharged and supplemented by the super capacitor energy storage module 102. Considering that the conversion efficiency of the first voltage converter 103 is 90%, the supercapacitor energy storage module 102 needs to continuously output at 12.2W for 5 seconds, and in total, releases about 61.1J of energy, the remaining stored energy drops to about 93.6J, and the first microcontroller 104 monitors that the operating voltage of the supercapacitor energy storage module 102 correspondingly drops to about 1.9v, and 1.9v is lower than the lower operating voltage threshold of the supercapacitor energy storage module 102. At this time, the photovoltaic module 101 is required to charge the super capacitor energy storage module 102. If the first microcontroller 104 monitors that the average load power of the sensing node is restored to 4W, the output power of the photovoltaic module is increased through the feedback control loop because the output power of the photovoltaic module of 4.7W can just meet the power supply to the load. Assuming that the continuous output power of the photovoltaic module is increased from 4.7W to 6W and then charging of the super capacitor energy storage module 102 is started, considering that the photovoltaic module has an energy transmission efficiency of 95% to the super capacitor energy storage module 102, charging can be performed at a power of about 1.2W at maximum, and it takes at least about 52 seconds to fully charge to 156J.

The number of photovoltaic modules 101 in the laser power supply receiving end device 100 with the watt-level output power is one or more, and the number of super capacitor energy storage modules 102 in the laser power supply receiving end device 100 with the watt-level output power is one or more. When the number of the photovoltaic modules 101 in the tile-level output power laser power supply receiving end device 100 is multiple, the number of the super capacitor energy storage modules 102 in the tile-level output power laser power supply receiving end device 100 is multiple, so that the total output power of the tile-level output power laser power supply receiving end device 100 can be improved. When the number of photovoltaic modules 101 in the laser power supply receiving end device 100 of the watt level output power is plural, each photovoltaic module 101 inputs a separate laser beam, and the input of the laser beam to the plurality of photovoltaic modules 101 is achieved by using a light splitter or using a plurality of energy optical fibers. In one embodiment, a plurality of photovoltaic modules 101 are combined in series, and connected in parallel with at least one common super capacitor energy storage module 102 to be connected to the first voltage converter 103. The total output voltage of the photovoltaic modules 101 may be increased by a series combination of a plurality of photovoltaic modules 101. In another embodiment, the plurality of photovoltaic modules are connected in parallel with at least one common super capacitor energy storage module and then connected to the first voltage converter, and the plurality of photovoltaic modules 101 are connected in parallel to increase the total output current, so that if one photovoltaic module fails, the other photovoltaic module can still continue to supply power, and the fault tolerance capability is better.

In the above application embodiments, if the average power of the load of the sensing node is kept above 6W for a long period of time, it is required that the photovoltaic module can output at least more than 7W continuously. Considering that the super capacitor energy storage module 102 needs to be recharged after encountering peak load power discharge, the actual requirements for sustained output power of the photovoltaic module will be higher. Therefore, as an application embodiment of the present invention, in fig. 6, two photovoltaic modules are first combined in series and then connected in parallel with one super capacitor, and then connected to a DC/DC converter. The open-circuit voltage of about 11.4V can be realized by using the five-junction photovoltaic modules in series, the maximum continuous output power of 12W and the current of about 1.1A can be realized, the average load power of more than 6W and the 15W peak load power which lasts for 5 seconds can be simultaneously satisfied by using the two five-junction photovoltaic modules in parallel with the 50F super capacitor energy storage module, and the super capacitor energy storage module can be charged more quickly. In fig. 7, two photovoltaic modules are connected in parallel with one super capacitor energy storage module at the same time to the first voltage converter. The two five-junction photovoltaic modules are used in parallel, the output open-circuit voltage is still about 5.7V, the highest continuous output power of 12W and the current of about 2.2A are achieved, and the load power requirement can be met by the five-junction photovoltaic modules which are used in parallel with the 50F super capacitor.

It should be noted that, in this embodiment, one of the five-junction photovoltaic modules (with an open circuit voltage of about 5.7V) or two of the five-junction photovoltaic modules (with an open circuit voltage of about 11.4V when connected in series) may be used for power supply.

As a preferred embodiment of the present invention, the working voltage of the first microcontroller and the first optical communication transceiver is set to be 3.3V, the peak value of the total power consumption when the first microcontroller and the first optical communication transceiver jointly execute the tasks described above is not more than 350mW, the average power consumption is not more than 100mW, and the power consumption in the sleep is lower than 0.5mW.

As shown in fig. 8, the internal power management module in the laser power supply receiving end device of the watt-level output power includes: the photovoltaic module comprises a step-down voltage stabilizer, an internal energy accumulator and a second step-up voltage converter which are sequentially connected in series, wherein the step-down voltage stabilizer is suitable for being electrically connected with the photovoltaic module, the second step-up voltage converter is suitable for being electrically connected with the first microcontroller, and the second step-up voltage converter is a step-up DC/DC converter. The capacity of the internal energy accumulator is smaller, and the capacity of the internal energy accumulator is 2F-4F. The capacity of the internal energy accumulator is smaller than that of the super capacitor energy storage module. The internal power management module 106 takes power from the output of the photovoltaic module 101 and powers the components and modules that maintain the basic functions of the laser powered receiver apparatus 100 at a watt level of output power, including powering the first microcontroller 104 and the first optical communication transceiver 105. In a specific embodiment, the output voltage of the internal power management module 106 takes a typical value of 3.3V. The internal energy storage ensures that the first microcontroller 104 of the optically powered receiver device 100 can still communicate with the laser powered base station and the application center via the first optical communication transceiver 105 when the photovoltaic module 101 has no or insufficient power output, which is necessary for monitoring the power link integrity detection upon initial start-up or failure of the laser fiber power system.

The internal energy storage device uses a super capacitor, and is deployed in a high-voltage environment and has advantages in reliability and service life compared with other energy storage devices, such as advantages in reliability and service life compared with a lithium battery. In addition, the capacity of the internal energy accumulator is smaller, and the super capacitor with smaller capacity can be rapidly charged by the photovoltaic module 101 when the electric quantity is exhausted or insufficient, so that the time required by system starting and power supply link integrity detection is shortened, and the efficiency of power supply link integrity detection is improved.

In one embodiment, when the internal energy storage device adopts a super capacitor, the capacity of the internal energy storage device is 2F-4F. Specifically, if the initial output power of the five-junction photovoltaic module is set to be 2W and only the internal power management module is powered, the internal energy storage of 2F can be charged with the power of 1.9W in consideration of the conversion efficiency of 95% of the buck regulator, and the internal energy storage can be fully charged in about 3.8 seconds, so that the charging time is saved.

Considering that the working voltage range of the small-capacity internal energy accumulator is limited and is easily influenced by voltage fluctuation, the output of the photovoltaic module is firstly subjected to voltage reduction and stabilization, then the internal energy accumulator is charged, and finally the second boost voltage converter is adopted to carry out DC/DC boost on the internal energy accumulator to be converted into standard output voltage, and the standard output voltage is output to the first microcontroller.

Furthermore, the input voltage range of the step-down voltage stabilizer is 2.7V-17V, and the series connection of the two five-junction photovoltaic modules can be met at most. The efficiency of the step-down voltage stabilizer can reach 95% at most, and is more than 95%, such as 95%, 96% and 97%.

Further, the input voltage of the second boost voltage converter ranges from 1.8V to 5.5V, which determines the minimum discharge voltage of the internal energy storage to 1.8V. The efficiency of the second boost voltage converter may be up to 95%, specifically greater than 95%, such as 95%, 96%, 97%.

In a specific embodiment, the internal accumulator has a capacity of 2F, the maximum operating voltage of the internal accumulator is set to 2.7V, and the maximum storable energy of the internal accumulator is about 7.29 joules; with reference to the minimum input voltage of the second boost voltage converter, the minimum discharge voltage of the internal energy storage is 1.8V, and the energy that the internal energy storage cannot release is about 3.24J. Thus, the maximum releasable energy of the internal accumulator is about 4.05J. Considering that the conversion efficiency of the second boost-type voltage converter is about 95%, the second boost-type voltage converter may supply the load with energy of about 3.85J, which may support the first microcontroller and the first optical communication transceiver to operate for at least about 38.5 seconds at average power consumption of no more than 100mW, and also to operate for at least about 11 seconds at peak power of no more than 350 mW.

The first microcontroller 104 is a local computing control center. The functions of the first microcontroller 104 include: (1) Output power of photovoltaic module 101, output power of first voltage converter 103, and operating voltage V of supercapacitor energy storage module 102 _Capacitor Sampling and processing are carried out to obtain the numerical value of the variable; (2) Based on the measured value of the output power of the photovoltaic module 101, the measured value of the output power of the first voltage converter 103, the operating voltage V of the super capacitor energy storage module 102 _Capacitor Performs loop feedback control to realize tracking matching of output power of the photovoltaic module 101 to average load power of a sensing node, and charges and discharges the super capacitor energy storage module 102Performing row management and control; (3) In cooperation with the first optical communication transceiver 105, data exchange between the application control center and the sensing node is supported, while remote configuration and management of the laser powered sink device 100 and the sensing node for watt level output power is supported.

The first optical communication transceiver 105 is responsible for transmitting and receiving communication data packets required to support applications and remote management.

Another embodiment of the present invention further provides a laser fiber power supply system, including: the laser power supply receiving end device with the watt-level output power.

The laser fiber power supply system further includes: the laser power supply base station, the laser power supply base station includes: a laser, a second optical communication transceiver, a laser driver, and a second microcontroller.

The laser transmits laser light to the photovoltaic module through the energy optical fiber. The second optical communication transceiver is connected with the first optical communication transceiver through a data optical fiber. The laser driver supplies a drive current for the operation of the laser. The second microprocessor controls the operation of the laser, the laser driver, and the reception and transmission of data by the first optical communication transceiver.

And bidirectional data transmission can be realized between the second optical communication transceiver and the first optical communication transceiver.

It should be noted that, the above-mentioned loop feedback control means that the first microprocessor sends a data packet to the second optical communication transceiver through the first optical communication transceiver based on the acquired data, the second optical communication transceiver receives the data packet and then transmits the data packet to the second microcontroller, and the second microcontroller further controls the working states of the laser driver and the laser, and adjusts the output power of the laser to meet the requirements.

It is apparent that the above examples are given by way of illustration only and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While still being apparent from variations or modifications that may be made by those skilled in the art are within the scope of the invention.

Claims

1. A laser powered receiver device for a watt level of output power, comprising:

the first voltage converter is suitable for supplying power to the sensing node;

the photovoltaic module is suitable for being electrically connected with the input end of the first voltage converter;

the photovoltaic module is further suitable for charging the super-capacitor energy storage module, and the super-capacitor energy storage module is suitable for being electrically connected with the input end of the first voltage converter;

the first microcontroller performs loop feedback control on the incident laser power of the photovoltaic module based on the output power of the photovoltaic module and the first voltage converter and the working voltage of the super capacitor energy storage module, and controls the charge and discharge of the super capacitor energy storage module;

the capacity of the super capacitor energy storage module is according toSetting; or, the capacity C of the super capacitor energy storage module is as follows:

2. The tile-level output power laser power supply receiving end device according to claim 1, wherein the photovoltaic module comprises a plurality of sub-photovoltaic cells connected in series, and the photovoltaic module integrates the plurality of sub-photovoltaic cells connected in series on a single sheet by adopting a vertically stacked multi-junction structure or a transversely segmented multi-segment single junction structure.

3. The tile level output power laser powered sink device of claim 1, wherein the photovoltaic module comprises a plurality of sub-photovoltaic cells connected in series, the photovoltaic module comprising: from the first sub-photovoltaic cell to the Mth sub-photovoltaic cell vertically stacked from top to bottom, M is an integer greater than 2; the first tunneling junction is located between the jth sub-photovoltaic cell and the (j+1) th sub-photovoltaic cell, and j is an integer greater than or equal to 1 and less than or equal to M-1.

4. A tile-level output laser power receiver device according to claim 3, wherein each sub-photovoltaic cell comprises a semiconductor PN junction, the thickness of the semiconductor PN junction of each sub-photovoltaic cell being determined by Setting; α (λ) is the light absorption coefficient at a given incident laser wavelength λ; t is t _i The thickness of the semiconductor PN junction of the ith sub-photovoltaic cell is that i is an integer which is more than or equal to 1 and less than or equal to M-1; i _i Is the laser intensity entering the ith sub-photovoltaic cell, I _i+1 Is the laser intensity entering the (i+1) th sub-photovoltaic cell.

5. A laser powered receiver apparatus of the watt-level output power as defined in claim 3, wherein,

m is an integer greater than or equal to 4.

6. A laser powered receiver apparatus of the watt-level output power as defined in claim 3, wherein,

the thickness of the semiconductor PN junction in the Mth sub-photovoltaic cell is 2800-3200 nanometers.

7. A laser powered receiver apparatus of the watt-level output power as defined in claim 3, wherein,

in the first to M-th sub-photovoltaic cells, each sub-photovoltaic cell comprises a back surface field layer, a base layer, an emission layer and a window layer which are laminated from bottom to top, the base layer and the emission layer form a semiconductor PN junction, the energy gap of the window layer is respectively larger than the energy gaps of the base layer and the emission layer, and the energy gap of the back surface field layer is respectively larger than the energy gaps of the base layer and the emission layer.

8. The device of claim 4, wherein,

The material of the semiconductor PN junction comprises gallium arsenide, indium phosphide or gallium antimonide doped with conductive ions.

9. The apparatus of claim 7, wherein the power supply unit is configured to supply the laser beam with the output power,

the photovoltaic module further includes: a substrate layer at the bottom of the Mth sub-photovoltaic cell; the conductivity type of the back surface field layer for the Mth sub-photovoltaic cell is the same as the conductivity type of the substrate layer; the conductivity type of the back surface field layer in the first to M-1 th sub-photovoltaic cells is the same as the conductivity type of the base layer and opposite to the conductivity type of the M-th sub-photovoltaic cell, and the conductivity type of the window layer in the first to M-th sub-photovoltaic cells is the same as the conductivity type of the emission layer.

10. The apparatus of claim 7, wherein the power supply unit is configured to supply the laser beam with the output power,

the thickness of the window layer of the first sub-photovoltaic cell is respectively larger than that of the window layers of the second sub-photovoltaic cell to the Mth sub-photovoltaic cell.

11. The device of claim 1, wherein,

the photovoltaic module has a photoelectric conversion efficiency of 50% or more.

12. A tile level output power laser powered sink device as defined in claim 3, wherein said photovoltaic module further comprises: the grid line layer is positioned at the top of the first sub-photovoltaic cell; a contact layer between the gate line layer and the first sub-photovoltaic cell; an anti-reflection film located at the side of the contact layer and exposed by the gate line layer.

13. The tile-level output power laser powered receiving device according to claim 12, wherein the antireflection film comprises a first sub-antireflection film and a second sub-antireflection film, the first sub-antireflection film being located between the second sub-antireflection film and the first sub-photovoltaic cell, the first sub-antireflection film having a refractive index between the refractive index of the second sub-antireflection film and the refractive index of the window layer of the first sub-photovoltaic cell.

14. The apparatus of claim 12, wherein the laser power receiving end of the watt-level output power,

the grid line layer comprises opposite main grid lines and a plurality of thin grid lines which are positioned between the opposite main grid lines and are connected with the main grid lines at intervals; the distance between the adjacent fine grid lines is 20-70 mu m; the height of the grid line layer is 1-3 mu m; the width of the main grid line is 90-130 mu m; the width of the thin grid line is 3-5 μm.

15. The tile-level output power laser powered receiving end device of claim 1, wherein the photovoltaic module is mounted on an insulating and thermally conductive substrate having a heat dissipating package thereon for packaging the photovoltaic module, the heat dissipating package having an interface for coupling the photovoltaic module to an energy fiber.

16. The tile-scale output power laser powered sink device of claim 15, wherein the material of the insulating thermally conductive substrate comprises aluminum oxide, boron nitride, silicon carbide, or aluminum nitride.

17. The device of claim 15, wherein the heat sink package is made of a metal heat sink material.

18. The device of claim 1, wherein,

when (when)When the super capacitor energy storage module is in use, the setting requirement of the threshold value of the lower limit working voltage of the super capacitor energy storage module is satisfied: />Q ₂ Is the lower operating voltage threshold.

19. The tile-level output power laser power supply receiving end device according to claim 1, wherein the number of photovoltaic modules in the tile-level output power laser power supply receiving end device is one or more, and the number of super capacitor energy storage modules in the tile-level output power laser power supply receiving end device is one or more;

when the number of the photovoltaic modules in the laser power supply receiving end device of the watt-level output power is multiple, the photovoltaic modules are combined in series and then connected with at least one common super capacitor energy storage module in parallel to be connected with the first voltage converter, or the photovoltaic modules are connected with at least one common super capacitor energy storage module in parallel to be connected with the first voltage converter.

20. The tile level output power laser powered sink device of claim 1, further comprising: a first optical communication transceiver; and the internal power management module is suitable for taking energy from the output end of the photovoltaic module and supplying power to the first microcontroller and the first optical communication transceiver.

21. The apparatus of claim 20, wherein the laser power receiver for tile output power,

the internal power management module comprises a buck voltage stabilizer, an internal energy accumulator and a second boost voltage converter which are sequentially connected in series, wherein the buck voltage stabilizer is suitable for being electrically connected with the photovoltaic module, and the second boost voltage converter is suitable for being electrically connected with the first microcontroller.

22. The apparatus of claim 21, wherein the laser power receiver for tile output power,

the capacity of the internal energy accumulator is 2F-4F.

23. The tile level output power laser powered sink device of claim 1, further comprising: the switching unit comprises a first switch, a second switch and a third switch, wherein the first switch is positioned on a path between the output end of the photovoltaic module and the charging end of the super capacitor energy storage module; the second switch is positioned on a path between the output end of the photovoltaic module and the input end of the first voltage converter; the third switch is positioned on a path between the discharge end of the super capacitor energy storage module and the input end of the first voltage converter; the operating states of the first switch, the second switch and the third switch are controlled by the first microcontroller.

24. The apparatus of claim 23, wherein the laser power receiver for tile output power,

the first switch, the second switch and the third switch are all MOS transistors.

25. The tile level output power laser powered sink device of claim 1, further comprising: the first low-pass filter circuit is connected with the output end of the first voltage converter and the first microcontroller, and is suitable for smoothing the output voltage signal of the first voltage converter and inputting the output voltage signal to the first microcontroller; the first current sense amplifier is suitable for testing the current of the output end of the first voltage converter and outputting the current to the first microcontroller;

the second low-pass filter circuit is connected with the output end of the photovoltaic module and the first microcontroller, and is suitable for smoothing the output voltage signal of the photovoltaic module and inputting the output voltage signal to the first microcontroller; the second current sense amplifier is suitable for testing the current of the output end of the photovoltaic module and outputting the current to the first microcontroller.

26. A laser fiber optic power supply system, comprising: a laser powered sink device of watt level output power as claimed in any one of claims 1 to 25.