Composite energy taking device based on photovoltaic and electric field energy taking

Abstract

The invention discloses a composite energy taking device based on photovoltaic and electric field energy taking, and relates to the field of electrical equipment, and the energy taking device comprises an acquisition module, a conversion module, an energy storage module and a control module. The acquisition module comprises a photovoltaic energy taking path and an electric field energy taking path; the conversion module processes the initial current obtained by the photovoltaic energy taking path and the electric field energy taking path to obtain a target current; the energy storage module stores the target current output by the conversion module and supplies power based on a preset energy management strategy; and the control module is used for controlling a transformation strategy in the transformation module and an acquisition path in the acquisition module. The composite energy taking device can capture electric field energy and solar energy at the same time, power is supplied through mutual cooperation of the two kinds of energy, and the utilization rate of space energy is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical equipment, and more specifically, to a composite energy harvesting device based on photovoltaic and electric field energy harvesting. Background Art

[0002] With the rapid development of smart grids, in order to ensure the safe operation of power systems, a large number of distributed state monitoring devices have been put into lines and substations to monitor various states including voltage, current, temperature, wind deflection, icing, and partial discharge. However, since most monitoring devices are deployed in remote outdoor areas, their operation and maintenance work face great difficulties, which has given rise to the development and application of various energy harvesting technologies. Currently, overhead transmission lines mainly adopt photovoltaic energy harvesting and electric field energy harvesting. Among them, photovoltaic energy harvesting technology is based on the photovoltaic effect, which converts the absorbed solar energy into electrical energy and usually combines with a storage battery to supply power to monitoring devices; electric field energy harvesting technology is based on the principle of capacitive voltage division, which captures the electric field energy in the environment to supply power to monitoring devices. The two energy harvesting technologies have achieved certain results in their respective fields and can independently support the operation of some low-power monitoring devices.

[0003] However, these two energy harvesting technologies also have obvious limitations in practical applications. For example, for photovoltaic energy harvesting, on the one hand, solar photovoltaic panels are large in volume, inconvenient to install, and have low energy conversion efficiency; on the other hand, the output of photovoltaic energy harvesting is unstable and is significantly affected by weather conditions, especially light intensity. For electric field energy harvesting, its output power is proportional to the voltage level of the line. The electric field energy around low-voltage lines is relatively low, and it is difficult to obtain sufficient output power to drive high-power loads. In order to increase the captured electric field energy, a larger energy harvesting electrode area is required, which results in a larger wind-exposed area of the electric field energy harvester and is easily damaged, limiting the improvement of electric field energy harvesting power. To overcome the above limitations, there is an urgent need for a fusion solution to leverage the complementary advantages of the two. Summary of the Invention

[0004] In view of this, the present invention provides a composite energy harvesting device based on photovoltaic and electric field energy harvesting, which can capture the electric field energy and solar energy in the environment simultaneously.

[0005] To achieve the above object, the following solution is proposed: A composite energy harvesting device based on photovoltaic and electric field energy harvesting, the composite energy harvesting device includes: a collection module, a conversion module, an energy storage module, and a control module; The collection module includes a photovoltaic energy harvesting path and an electric field energy harvesting path; The conversion module processes the initial currents obtained from the photovoltaic energy harvesting path and the electric field energy harvesting path respectively to obtain target currents; The energy storage module stores the target currents output by the conversion module and supplies power based on a preset energy management strategy; The control module controls the transformation strategy in the transformation module and the acquisition path in the acquisition module.

[0006] Preferably, the transformation module includes: a rectifier circuit, a first voltage stabilizing circuit, a maximum power point tracking circuit, and a second voltage stabilizing circuit.

[0007] Preferably, the process of the transformation module processing the initial current obtained from the electric field energy harvesting path includes: The rectifier circuit converts the initial current obtained from the electric field energy harvesting path from alternating current to direct current; The first voltage stabilizing circuit stabilizes the direct current to obtain a target current of low-voltage direct current.

[0008] Preferably, the process of the transformation module processing the initial current obtained from the photovoltaic energy harvesting path includes: The maximum power point tracking circuit obtains the maximum power output by the photovoltaic energy harvesting path, so that the photovoltaic energy harvesting path outputs the initial current at the maximum power; The second voltage stabilizing circuit stabilizes the initial current to obtain a target current of low-voltage direct current.

[0009] Preferably, the energy storage module includes: a super capacitor, a lithium battery, a path management circuit, and a load.

[0010] Preferably, the process of supplying power based on a preset energy management strategy includes: If the voltage on the super capacitor does not reach the preset upper limit value and the photovoltaic energy harvesting path reaches the minimum turn-on voltage, the electric field energy harvesting path charges the super capacitor, and the path management circuit controls the photovoltaic energy harvesting path to supply power to the load; If the voltage on the super capacitor does not reach the preset upper limit value and the photovoltaic energy harvesting path does not reach the minimum turn-on voltage, the electric field energy harvesting path charges the super capacitor, and the lithium battery supplies power to the load; If the voltage on the super capacitor reaches the preset upper limit value, the super capacitor supplies power to the load, and the path management circuit controls the photovoltaic energy harvesting path to charge the lithium battery.

[0011] Preferably, the photovoltaic energy harvesting path includes photovoltaic cells; The electric field energy harvesting path includes induction electrodes.

[0012] Preferably, the structure of the acquisition module from top to bottom is a tempered glass layer, a first encapsulation layer, photovoltaic cells, a second encapsulation layer, an induction electrode layer, and a backplane layer; The photovoltaic cells are used to capture solar energy and convert it into electrical energy; The induction electrode layer is used to convert the spatial electric field energy into electrical energy; The acquisition module further includes: a frame and a junction box; The frame provides support for each layer; The junction box is used to lead out the outgoing wires of the photovoltaic cells and the induction electrode layer, and output the initial current collected by the photovoltaic cells and the induction electrode layer to the conversion module.

[0013] According to the specific embodiments provided by the present invention, the following technical effects are disclosed by the present invention: The composite energy harvesting device based on photovoltaic and electric field energy harvesting provided by the present invention includes a harvesting module, a conversion module, an energy storage module and a control module. The harvesting module includes a photovoltaic energy harvesting path and an electric field energy harvesting path; the conversion module processes the initial current obtained from the photovoltaic energy harvesting path and the electric field energy harvesting path respectively to obtain the target current; the energy storage module stores the target current output by the conversion module and supplies power based on a preset energy management strategy; the control module controls the conversion strategy in the conversion module and the harvesting path in the harvesting module. The composite energy harvesting device of the present invention can capture electric field energy and solar energy simultaneously, and supply power through the cooperation of the two kinds of energy, improving the utilization rate of spatial energy.

[0014] The composite energy harvesting device based on photovoltaic and electric field energy harvesting provided by the present invention is of a flat structure, with small volume and light weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0016] Figure 1 It is a schematic structural diagram of a composite energy harvesting device based on photovoltaic and electric field energy harvesting provided by an embodiment of the present invention; Figure 2 It is a flowchart of the energy management strategy of the energy storage module provided by an embodiment of the present invention; Figure 3 It is an installation schematic diagram of a composite energy harvesting device based on photovoltaic and electric field energy harvesting provided by an embodiment of the present invention; Figure 4 It is a schematic structural diagram of a harvesting module provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0018] First, in combination with Figure 1 the composite energy harvesting device based on photovoltaic and electric field energy harvesting provided by the present invention will be introduced. As Figure 1 shown, the energy harvesting device includes: a collection module, a conversion module, an energy storage module, and a control module.

[0019] The collection module includes a photovoltaic energy harvesting path and an electric field energy harvesting path. The collection module captures electric field energy and solar energy from the environment around the power line through the photovoltaic energy harvesting path and the electric field energy harvesting path. Among them, the photovoltaic energy harvesting path includes photovoltaic cells, which capture solar energy in the ambient space through the photovoltaic cells and convert it into electrical energy; the electric field energy harvesting path includes induction electrodes, which convert the electric field energy in the space around the power line into electrical energy through the induction electrodes.

[0020] The output end of the collection module is connected to the conversion module. The conversion module processes the initial currents obtained from the photovoltaic energy harvesting path and the electric field energy harvesting path respectively to obtain the target current. The conversion module includes a rectifier circuit, a first voltage stabilization circuit, a maximum power point tracking circuit, and a second voltage stabilization circuit.

[0021] The initial current output from the electric field energy harvesting path to the conversion module is alternating current. The rectifier circuit in the conversion module rectifies the initial current to convert the initial alternating current into direct current. Then, in order to store the electrical energy into the super capacitor of the energy storage module, the conversion module stabilizes the direct current through the first voltage stabilization circuit to obtain the target current of low-voltage direct current.

[0022] To solve the problem of unstable output of the photovoltaic energy harvesting path, the conversion module obtains the maximum power output from the photovoltaic energy harvesting path through a maximum power point tracking (MPPT) circuit, so that the photovoltaic energy harvesting path always outputs the initial current close to or reaching the maximum power. Then, for better subsequent path management, the conversion module stabilizes the initial current through the second voltage stabilization circuit to obtain the target current of low-voltage direct current. The MPPT circuit can be implemented based on a BOOST circuit. By controlling the on and off moments of the MOS transistor, the equivalent resistance of the load is changed, and the magnitude of the output voltage is adjusted, so that the photovoltaic energy harvesting path can output at the maximum power. In addition, the MPPT circuit can also be implemented based on a BUCK circuit or other circuits.

[0023] The output end of the conversion module is connected to the energy storage module. The energy storage module stores the target current output by the conversion module and supplies power based on a preset energy management strategy. The energy storage module includes a super capacitor, a lithium battery, a path management circuit, and a load.

[0024] The energy storage module is connected to the control module, and the control module controls the conversion module and the energy storage module. The control module can control the conversion strategy in the conversion module by turning on and off the switching devices of the MPPT circuit, the first voltage stabilizing circuit, and the second voltage stabilizing circuit. The control module controls the acquisition path in the acquisition module to realize the selection and switching of the electric field energy acquisition path and the photovoltaic energy acquisition path. The power supply of the control circuit in the control module comes from the lithium battery, and after being processed by the voltage stabilizing circuit, a stable power supply available for the control circuit is obtained.

[0025] The composite energy acquisition device based on photovoltaic and electric field energy acquisition provided by the embodiment of the present invention includes an acquisition module, a conversion module, an energy storage module, and a control module. The acquisition module includes a photovoltaic energy acquisition path and an electric field energy acquisition path; the conversion module processes the initial current obtained by the photovoltaic energy acquisition path and the electric field energy acquisition path respectively to obtain a target current; the energy storage module stores the target current output by the conversion module and supplies power based on a preset energy management strategy; the control module controls the conversion strategy in the conversion module and the acquisition path in the acquisition module. The composite energy acquisition device of the present invention can capture electric field energy and solar energy simultaneously, and supply power through the cooperation of the two energies, improving the utilization rate of spatial energy.

[0026] The composite energy acquisition device based on photovoltaic and electric field energy acquisition provided by the embodiment of the present invention is of a flat structure, with a small volume and a light weight.

[0027] Next, the embodiment of the present invention introduces the energy management strategy of the energy storage module as follows: The energy storage module stores the electric energy collected by the electric field energy acquisition path through a super capacitor. When the voltage of the super capacitor reaches the preset upper limit value, the super capacitor supplies power to the load; when the voltage of the super capacitor is lower than the preset lower limit value, the power supply to the load is stopped, and charging is carried out through the electric field energy acquisition path.

[0028] The energy storage module controls the output path of the photovoltaic energy acquisition path through the path management module. When the energy of the photovoltaic energy acquisition path is higher than the minimum turn-on voltage for the operation of the conversion module, the photovoltaic energy acquisition path preferentially supplies power to the load. If there is excess energy, the excess energy is stored in the lithium battery; when the energy of the photovoltaic energy acquisition path is lower than the minimum turn-on voltage for the operation of the conversion module, the lithium battery supplies power to the load.

[0029] The power supply paths of the photovoltaic energy acquisition path and the electric field energy acquisition path to the load are mutually exclusive. When the super capacitor supplies power to the load, the power supply path of the photovoltaic energy acquisition is closed; when the super capacitor is in the charging state, the power supply path of the photovoltaic energy acquisition path is opened.

[0030] As Figure 2 shown, the process of supplying power based on the preset energy management strategy in the embodiment of the present invention includes: (1) If the voltage on the supercapacitor does not reach the preset upper limit value and the photovoltaic energy harvesting path reaches the minimum turn-on voltage, the electric field energy harvesting path charges the supercapacitor, and the supercapacitor does not supply power to the load. At the same time, the path management circuit controls the photovoltaic energy harvesting path to supply power to the load. If there is excess energy, the excess energy is stored in the lithium battery, and the lithium battery does not supply power to the load.

[0031] (2) If the voltage on the supercapacitor does not reach the preset upper limit value and the photovoltaic energy harvesting path does not reach the minimum turn-on voltage, the electric field energy harvesting path charges the supercapacitor, and the supercapacitor does not supply power to the load. The path management circuit controls the lithium battery in the photovoltaic energy harvesting path to supply power to the load.

[0032] (3) When the voltage on the supercapacitor reaches the preset upper limit value, the supercapacitor preferentially supplies power to the load. The path management circuit controls the photovoltaic energy harvesting path to charge the lithium battery, and the lithium battery does not supply power to the load. When the voltage on the supercapacitor is lower than the preset lower limit, the supercapacitor stops supplying power to the load and re-enters the charging state. The path management circuit controls the photovoltaic energy harvesting path or the lithium battery to supply power to the load.

[0033] The composite energy harvesting device provided by the embodiment of the present invention can capture solar energy and electric field energy simultaneously, realizing the efficient utilization of spatial energy, and proposes two energy management strategies for the two energies to cooperate with each other in power supply. The two energy harvesting paths cooperate and supply power alternately, improving the overall power supply efficiency.

[0034] The composite energy harvesting device provided by the present invention can be installed not only on the side of the transmission tower, but also in the power corridor under the line and in the substation and other environments. Next, taking the installation on the side of the transmission tower as an example, the installation structure of the composite device is introduced as follows Figure 3 As shown, the system includes: an overhead transmission line 1, a transmission tower 2, a composite energy harvester 3, a circuit box 4, and a status monitoring device 5. According to the voltage level of the overhead transmission line 1, a corresponding insulation safety distance is maintained between the overhead transmission line 1 and the composite energy harvester 3. The transmission tower 2 serves as the installation carrier for the composite energy harvester 3, the circuit box 4, and the status monitoring device 5, providing attachment for the above devices. That is, the composite energy harvester 3 and the circuit box 4 form a composite energy harvesting device. The composite energy harvester 3 corresponds to the acquisition module, and the circuit box 4 integrates the hardware circuits of the conversion module, the energy storage module, and the control module, as well as the lithium battery. The composite energy harvester 3 can capture solar energy and electric field energy simultaneously, and the captured energy is connected to the circuit box 4 through an insulated cable. The circuit box 4 is provided with a metal box to protect the internal devices, and the circuit box 4 supplies electrical energy to the status monitoring device 5 through an insulated cable. The status monitoring device 5 corresponds to the load, and the status monitoring device 5 can be any transmission line sensor or monitoring device that requires power supply.

[0035] The embodiment of the present invention proposes that the composite energy harvesting device can be installed in outdoor strong electric field environments such as on the side of transmission towers, in the power corridor under the line, and in substations, without a strict insulation structure, and has high equipment safety and stability. It also has high solar energy and high electric field energy, and can capture these two kinds of energy simultaneously and efficiently by using this device, and will not cause a burden on the transmission line.

[0036] Next, the embodiment of the present invention will be combined with Figure 4 to introduce the structure of the composite energy harvester 4 (acquisition module). As Figure 4 shown, the layers inside the composite energy harvester 4 from top to bottom are a tempered glass layer 31, a first encapsulation layer 32, a photovoltaic cell 33, a second encapsulation layer 34, an induction electrode layer 35, and a backplane layer 36. The acquisition module also includes a frame 37 and a junction box 38. The frame 37 fixes the internal layers and provides support, and the junction box 38 is used to lead out the outgoing wires of the photovoltaic cell 33 and the induction electrode layer 35, and output the initial current collected by the photovoltaic cell 33 and the induction electrode layer 35 to the conversion module. The material of the first encapsulation layer 32 can be ethylene-vinyl acetate copolymer (EVA), and the material of the second encapsulation layer 34 can be EVA or other insulating media such as polyethylene. The second encapsulation layer 34 is used to provide electrical insulation between the photovoltaic cell 33 and the electrode layer 35.

[0037] The photovoltaic cell 33 and the induction electrode layer 35 capture solar energy and electric field energy in the surrounding environment respectively. The outgoing wires of the photovoltaic cell 33 and the induction electrode layer 35 are respectively connected to the circuit box 4 through the junction box 37. When the frame 37 of the composite energy harvester 3 is a metal frame, the edge of the induction electrode layer 35 contacts the metal frame through an insulating material to avoid short-circuiting between the electrode layer and the metal frame; when the frame 37 of the composite energy harvester 3 is an insulating frame, the induction electrode layer 35 can directly contact the insulating frame. The composite energy harvester 3 can capture solar energy and electric field energy simultaneously, and can supply energy to the status monitoring device 5 after circuit processing.

[0038] The acquisition module provided by the embodiment of the present invention has a flat structure. Compared with the tubular structure, it has the advantages of small volume and light weight. In addition to being fixed in a certain place for use, the acquisition module of the embodiment of the present invention can also be used as a portable energy harvesting device.

[0039] The acquisition module provided by the embodiment of the present invention can capture solar energy and electric field energy simultaneously. By compounding an induction electrode layer between the encapsulation layer and the backplane layer, the simultaneous capture of the two kinds of energy is realized, saving extra space. This design can greatly improve the stability of the traditional electric field energy harvesting plate, extend its service life, and reduce the probability of damage by wind.

[0040] In addition, the induction electrode layer can be located not only inside the backplane layer, but also outside the backplane layer, or a structure with two or more electrode layers can be adopted.

[0041] Finally, it should also be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0042] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. For the same or similar parts among the various embodiments, reference may be made to each other.

[0043] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A composite energy harvesting device based on photovoltaic and electric field energy harvesting, characterized in that: The composite energy acquisition device includes: a collection module, a conversion module, an energy storage module and a control module; The collection module includes a photovoltaic energy acquisition path and an electric field energy acquisition path; The conversion module processes the initial currents obtained from the photovoltaic energy acquisition path and the electric field energy acquisition path respectively to obtain the target current; The energy storage module stores the target current output by the conversion module and supplies power based on a preset energy management strategy; The control module controls the transformation strategy in the transformation module and the acquisition path in the acquisition module.

2. The composite energy harvesting device based on photovoltaic and electric field energy harvesting according to claim 1, characterized in that: The conversion module includes: a rectifier circuit, a first voltage stabilizing circuit, a maximum power point tracking circuit and a second voltage stabilizing circuit.

3. The composite energy harvesting device based on photovoltaic and electric field energy harvesting according to claim 2 is characterized in that: The process of the conversion module processing the initial current obtained by the electric field energy extraction path includes: The rectifier circuit converts the initial current obtained by the electric field energy extraction path from alternating current to direct current; The first voltage stabilizing circuit stabilizes the direct current to obtain a target current of a low-voltage direct current.

4. The composite energy harvesting device based on photovoltaic and electric field energy harvesting according to claim 2, characterized in that: The process of the conversion module processing the initial current obtained by the photovoltaic energy acquisition path includes: The maximum power output by the photovoltaic energy acquisition path is obtained through a maximum power point tracking circuit, so that the photovoltaic energy acquisition path outputs an initial current at the maximum power; The second voltage stabilizing circuit stabilizes the initial current to obtain a target low-voltage direct current.

5. The composite energy harvesting device based on photovoltaic and electric field energy harvesting according to claim 1, characterized in that: The energy storage module includes: supercapacitor, lithium battery, path management circuit and load.

6. The composite energy harvesting device based on photovoltaic and electric field energy harvesting according to claim 5, characterized in that: The process of power supply based on the preset energy management strategy includes: If the voltage on the supercapacitor does not reach the preset upper limit value, and the photovoltaic energy acquisition path reaches the minimum start-up voltage, the electric field energy acquisition path charges the supercapacitor, and the path management circuit controls the photovoltaic energy acquisition path to supply power to the load; If the voltage on the supercapacitor does not reach the preset upper limit value, and the photovoltaic energy acquisition path does not reach the minimum start-up voltage, the electric field energy acquisition path charges the supercapacitor and the lithium battery supplies power to the load; If the voltage on the supercapacitor reaches a preset upper limit, the supercapacitor supplies power to the load, and the path management circuit controls the photovoltaic energy path to charge the lithium battery.

7. The composite energy extraction device based on photovoltaic and electric field energy extraction according to any one of claims 1 to 6, characterized in that: The photovoltaic energy acquisition path includes photovoltaic cells; The electric field energy extraction path includes a sensing electrode.

8. The composite energy harvesting device based on photovoltaic and electric field energy harvesting according to claim 7, characterized in that: The structure of the acquisition module from top to bottom is tempered glass layer, first packaging layer, photovoltaic cell sheet, second packaging layer, sensing electrode layer and backplane layer; Photovoltaic cells are used to capture solar energy and convert it into electricity; The sensing electrode layer is used to convert the space electric field energy into electrical energy; The acquisition module also includes: a frame and a junction box; The frame provides support for the layers; The junction box is used to lead out the outgoing wires of the photovoltaic cell and the sensing electrode layer, and output the initial current collected by the photovoltaic cell and the sensing electrode layer to the conversion module.

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