A corona discharge based power extraction system for high voltage DC power transmission lines

Abstract

The present application relates to a kind of corona discharge-based high voltage direct current transmission line energy extraction system, including energy extraction device and electric energy storage device, energy extraction device is used to be arranged in the periphery of transmission cable to collect the ion flow generated by transmission cable corona discharge and ion flow is converted into electric energy;Energy extraction device includes shell, support structure and several energy extraction electrodes, shell is used to be arranged in the periphery of transmission cable, support structure connects shell and transmission cable to fix shell at a certain distance around transmission cable, several energy extraction electrodes are distributed on the surface of shell close to transmission cable;Electric energy storage device is electrically connected with energy extraction device, for detecting, transforming and distributing electric energy.The energy extraction system collects the ion flow generated by transmission cable and converts it into electric energy, energy extraction device does not have direct electrical contact with transmission cable, and will not affect the performance of transmission cable itself, while using the energy that should be dissipated in the external environment, improve the energy utilization rate.

Description

Technical Field

[0001] This invention belongs to the field of power technology, specifically relating to a high-voltage direct current transmission line energy harvesting system based on corona discharge. Background Technology

[0002] To meet my country's continuously growing electricity demand, the construction of ultra-high-voltage (UHV) power grids is an important way to achieve optimal resource allocation. As voltage increases, the electric field strength on the surface of the conductor increases. When this field exceeds a certain value, the air near the transmission line surface will ionize, causing a discharge phenomenon. The process of generating and absorbing charges in the conductor during corona discharge causes corona loss, which is detrimental to the economical transmission of electrical energy. At the same time, various industries have increasingly higher requirements for power quality, and power systems are gradually developing towards larger capacity, higher voltage, and greater intelligence. This makes the reliability of line operation and intelligent control requirements more stringent, thus making the monitoring of high-voltage transmission line conditions increasingly important.

[0003] The first challenge in achieving smart grid construction is obtaining power from monitoring devices. Current power extraction technologies rely on AC transmission lines and cannot draw energy from DC transmission lines. Therefore, with the comprehensive implementation of ultra-high-voltage direct current (UHVDC) transmission projects, efficiently and economically constructing a smart UHVDC grid has become a crucial issue that must be addressed. Summary of the Invention

[0004] To address the aforementioned problems in the existing technology, this invention provides a high-voltage direct current transmission line energy harvesting system based on corona discharge. The technical problem to be solved by this invention is achieved through the following technical solution:

[0005] This invention provides a high-voltage direct current transmission line energy harvesting system based on corona discharge, comprising an energy harvesting device and an energy storage device, wherein...

[0006] The energy harvesting device is used to be placed around the power transmission cable to collect the ion flow generated by the corona discharge of the power transmission cable and convert the ion flow into electrical energy; the energy harvesting device includes a housing, a support structure and a plurality of energy harvesting electrodes, the housing is used to be placed around the power transmission cable, the support structure connects the housing and the power transmission cable and is used to fix the housing at a certain distance around the power transmission cable, and the plurality of energy harvesting electrodes are distributed on the surface of the housing near the power transmission cable;

[0007] The energy storage device is electrically connected to the energy harvesting device and is used to detect, transform, and distribute the energy.

[0008] In one embodiment of the present invention, the length of the housing decreases as the voltage level of the power transmission cable increases and increases as the power supply demand increases.

[0009] In one embodiment of the present invention, the distance between the housing and the power transmission cable increases as the voltage level of the power transmission cable increases.

[0010] In one embodiment of the invention, the shape of the housing includes a cylindrical shape.

[0011] In one embodiment of the present invention, the plurality of energy harvesting electrodes are parallel to each other.

[0012] In one embodiment of the present invention, the plurality of energy harvesting electrodes are arranged parallel to the power transmission cable.

[0013] In one embodiment of the present invention, the number of the plurality of energy harvesting electrodes increases with the increase of power supply demand, and the spacing between adjacent energy harvesting electrodes decreases with the increase of power supply demand.

[0014] In one embodiment of the present invention, the energy harvesting device further includes an insulating medium.

[0015] The insulating medium is disposed on the surface of the housing near the power transmission cable and is in contact with the power transmission cable;

[0016] The plurality of energy harvesting electrodes are disposed on the surface of the insulating medium and are in contact with the housing.

[0017] In one embodiment of the present invention, the energy storage device includes a power management chip, a power supply unit, and an energy storage unit, wherein,

[0018] The input terminal of the power management chip is electrically connected to the plurality of energy harvesting electrodes, and the output terminal is electrically connected to the input terminal of the power supply unit and the input terminal of the energy storage unit.

[0019] In one embodiment of the present invention, the power management chip is a flyback power management chip based on third-generation semiconductor power devices.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] The high-voltage direct current transmission line energy harvesting system of the present invention is based on the principle of corona discharge. It collects the ion flow generated by the transmission cable and converts it into electrical energy. The energy harvesting device has no direct electrical contact with the transmission cable and will not affect the performance of the transmission cable itself. At the same time, it utilizes the energy that should be dissipated in the external environment, and can provide a reliable power source for equipment around the high-voltage direct current transmission circuit. It solves the problems of unstable wind power and short lifespan of solar power, and improves the energy utilization rate. Attached Figure Description

[0022] Figure 1This is a schematic diagram of a high-voltage direct current transmission line energy harvesting system based on corona discharge, provided in an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of the structure of an energy harvesting device provided in an embodiment of the present invention;

[0024] Figure 3 A schematic cross-sectional view of an energy harvesting device perpendicular to the direction of the power transmission cable 3, provided in an embodiment of the present invention;

[0025] Figure 4 A schematic cross-sectional view of an energy harvesting device parallel to the direction of the power transmission cable 3, provided in an embodiment of the present invention;

[0026] Explanation of reference numerals in the attached figures:

[0027] 1-Energy harvesting device; 2-Energy storage device; 3-Power transmission cable; 11-Housing shell; 12-Supporting structure; 13-Energy harvesting electrode; 21-Power management chip; 22-Power supply unit; 23-Energy storage unit. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0029] Example 1

[0030] Please see Figure 1 , Figure 1 This is a schematic diagram of a high-voltage direct current transmission line energy harvesting system based on corona discharge, provided as an embodiment of the present invention.

[0031] The energy harvesting system includes an energy harvesting device 1 and an energy storage device 2. The energy harvesting device 1 is used to collect the ion flow generated by the corona discharge of the power transmission cable 3 and convert the ion flow into electrical energy. The energy storage device 2 is electrically connected to the energy harvesting device 1 and is used to detect, convert and distribute the electrical energy.

[0032] In this embodiment, the power transmission cable 3 includes, but is not limited to, DC power transmission cables and AC power transmission cables, as long as the power transmission cable has the phenomenon of corona discharge generating ion flow.

[0033] Please see Figure 2 , Figure 2 This is a schematic diagram of an energy harvesting device provided in an embodiment of the present invention.

[0034] In one specific embodiment, the energy harvesting device 1 includes a housing 11, a support structure 12, and a plurality of energy harvesting electrodes 13. The housing 11 is disposed around the power transmission cable 3; the support structure 12 connects the housing 11 and the power transmission cable 3, and is used to fix the housing 11 at a certain distance around the power transmission cable 3; the plurality of energy harvesting electrodes 12 are distributed on the surface of the housing 11 near the power transmission cable 3, and are used to collect the ion flow generated by the corona discharge of the power transmission cable 3.

[0035] In one specific embodiment, the length of the housing 11 is mainly determined by the voltage level of the power transmission cable 3 and the power supply requirements. Its length decreases as the voltage level of the power transmission cable 3 increases and increases as the power supply requirements increase. In cases where the voltage level of the power transmission cable 3 is high, the length of the housing 11 can be appropriately reduced; in cases with high power supply requirements, the length of the housing 11 can be appropriately extended. Furthermore, the voltage level and power supply requirements can be represented by a target current, meaning the length of the housing 11 is determined by the magnitude of the target energy extraction current. The target current is the product of the ion current and the housing length. The magnitude of the ion current changes with the housing length at a rate of 10–20 mA / m. Therefore, the larger the target current, the larger the required length of the housing 11; the smaller the target current, the smaller the required length of the housing 11.

[0036] In one specific embodiment, the distance between the housing 11 and the power transmission cable 3 is determined by the voltage level of the power transmission cable 3, and the distance between them increases as the voltage level of the power transmission cable 3 increases. Specifically, the distance between the housing 11 and the power transmission cable 3 can be about 5 to 10 centimeters.

[0037] In this embodiment, there is a certain distance between the housing 11 and the power transmission cable 3, which can avoid direct breakdown.

[0038] Please see Figure 3 , Figure 3 This is a schematic cross-sectional view of an energy harvesting device perpendicular to the direction of the power transmission cable 3, provided in an embodiment of the present invention.

[0039] Specifically, the cross-sectional shape of the housing 11 includes, but is not limited to, a circle, a square, or a triangle. The housing 11 can wrap around the entire power transmission cable 3, that is, the housing 11 completely wraps around the power transmission cable 3. In this case, its cross-sectional shape is a complete circle, a square, or a triangle, etc.; the housing 11 can also wrap around a part of the power transmission cable 3, that is, the housing 11 does not completely wrap around the power transmission cable 3. In this case, its cross-sectional shape is an incomplete circle, a square, or a triangle, etc.

[0040] Specifically, the support structure 12 can be a bracket, and its shape includes, but is not limited to, rectangle, trapezoid, etc. The number of support structures 12 can also be adjusted according to the number of energy harvesting electrodes 13 and the spacing between the energy harvesting electrodes 13, so as to fix the shell without obstructing the energy harvesting electrodes from harvesting power.

[0041] Please see Figure 4 , Figure 4 This is a schematic cross-sectional view of an energy harvesting device parallel to the direction of the power transmission cable 3, provided in an embodiment of the present invention.

[0042] In one specific embodiment, the plurality of energy harvesting electrodes 13 can be arranged either non-parallel or parallel. Preferably, the plurality of energy harvesting electrodes 13 are parallel to each other, which is beneficial for a more uniform ion current density. Furthermore, the plurality of energy harvesting electrodes 13 can be parallel to or non-parallel to the transmission cable 3. Preferably, the plurality of energy harvesting electrodes 13 are parallel to the transmission cable 3, which is beneficial for ensuring a uniform electric field between the transmission cable 3 and the energy harvesting electrodes 13, and ensuring stable voltage.

[0043] Specifically, the number of energy harvesting electrodes 13 increases with the increase of power supply demand, and the spacing between adjacent energy harvesting electrodes 13 decreases with the increase of power supply demand. In other words, the number and spacing of energy harvesting electrodes 13 can be adjusted according to specific power supply demand. In cases where power supply demand is high, the number of energy harvesting electrodes can be appropriately increased or the spacing between energy harvesting electrodes can be reduced.

[0044] Specifically, the material of the energy harvesting electrode 13 is a conductor material, such as a metal plate.

[0045] The working principle of the energy harvesting device in this embodiment is as follows: a plurality of energy harvesting electrodes 13 collect the ion flow generated by the corona discharge of the power transmission cable 3. The collected ion flow forms a current through the resistance between the energy harvesting electrodes 13 and the shell 11. The current formed is transmitted to the energy storage device 2 by the energy harvesting electrodes 13.

[0046] In one specific embodiment, the energy harvesting device 1 further includes an insulating medium disposed on the surface of the housing near the power transmission cable 3 and in contact with the power transmission cable 3. Several energy harvesting electrodes are disposed on the surface of the insulating medium and in contact with the housing 11. In this case, the distance between the housing 11 and the power transmission cable 3 needs to take into account the insulating capacity of the insulating medium to ensure that the insulating medium is not broken down. The better the insulating capacity of the insulating medium, the smaller the distance between the housing 11 and the power transmission cable 3; the worse the insulating capacity of the insulating medium, the larger the distance between the housing 11 and the power transmission cable 3. For example, in the atmosphere, air can be used as the medium, and the medium thickness can be between 5 and 10 centimeters.

[0047] Specifically, the materials for insulating media include, but are not limited to, epoxy resin fiberglass and insulating rubber, plastic and ceramic.

[0048] In this embodiment, an insulating medium is provided between the power transmission cable 3 and the housing 11. The insulating medium can support the housing and prevent the housing from directly contacting the power transmission cable 3, which would lead to breakdown.

[0049] The size of the energy harvesting device in this embodiment can be adjusted according to the properties of the power transmission cable 3 and the energy harvesting requirements. The energy harvesting technology is highly flexible and is not limited to DC transmission lines. It can be applied on a large scale to high voltage DC transmission networks and has a wide range of applications.

[0050] In one specific embodiment, the energy storage device 2 includes a power management chip 21, a power supply unit 22, and an energy storage unit 23. The input terminal of the power management chip 21 is electrically connected to a plurality of energy harvesting electrodes 13, and the output terminal is connected to the input terminal of the energy storage unit 23 and the input terminal of the power supply unit 22.

[0051] Specifically, the power management chip 21 is a flyback power management chip based on third-generation semiconductor power devices, such as GaN power devices, and its structure is similar to that of NCP1342 and NCP1651. This embodiment uses a flyback power management chip based on third-generation semiconductor power devices, which can improve the reliability and safety of the system and ensure normal power supply to downstream equipment under high-voltage and harsh outdoor conditions. The specific structures of the power supply unit 22 and the energy storage unit 23 can be found in existing technologies and will not be described in detail in this embodiment.

[0052] Specifically, the power management chip 21 is used to detect and analyze the electrical energy transmitted by the energy harvesting device, and then perform operations such as inversion, rectification, and step-up / step-down according to the power supply demand. A portion of the electrical energy is directly allocated to the power supply unit 22, and another portion is allocated to the energy storage unit 23. At the same time, the power management chip is also used to control the energy harvesting time of the energy harvesting device. The power supply unit 22 is used to provide the received electrical energy to the downstream electrical equipment, such as the power transmission cable 3 detection device or other equipment located around the power transmission line. The energy storage unit 23 is used to store the received electrical energy to ensure that the electrical equipment can operate normally when the power transmission line fails, and to ensure that the electrical equipment can work stably and reliably for a long time.

[0053] The high-voltage direct current (HVDC) transmission line energy harvesting system of this embodiment utilizes the corona discharge principle of HVDC transmission lines. It collects the ion flow generated by the corona discharge of the transmission cable 3 and converts it into directly usable electrical energy to power downstream equipment. The energy harvesting device has no direct electrical contact with the transmission cable 3, thus avoiding any impact on the performance of the transmission line itself. At the same time, the ion flow generated by the corona discharge of the HVDC transmission line is dissipated in the surrounding environment, which is a waste of energy. However, the energy harvesting system of this embodiment utilizes the energy that should be dissipated in the external environment, providing a reliable power source for equipment around the HVDC transmission circuit, greatly improving energy utilization efficiency, and solving the problems of unstable and short lifespan of wind power and solar power.

[0054] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A high-voltage direct current transmission line energy harvesting system based on corona discharge, characterized in that, It includes an energy harvesting device (1) and an energy storage device (2), wherein, The energy harvesting device (1) is used to be set around the power transmission cable (3) to collect the ion flow generated by the corona discharge of the power transmission cable (3) and convert the ion flow into electrical energy; the energy harvesting device (1) includes a housing (11), a support structure (12) and a plurality of energy harvesting electrodes (13). The housing (11) is used to be set around the power transmission cable (3) and at a certain distance from the power transmission cable (3). The support structure (12) connects the housing (11) and the power transmission cable (3) and is used to fix the housing (11) at a certain distance around the power transmission cable (3). The plurality of energy harvesting electrodes (13) are distributed on the surface of the housing (11) close to the power transmission cable (3) and at a certain distance from the power transmission cable (3). An insulating medium is disposed on the surface of the housing (11) near the power transmission cable (3) and in contact with the power transmission cable (3); a plurality of energy harvesting electrodes (13) are disposed on the surface of the insulating medium and in contact with the housing (11); The energy storage device (2) is electrically connected to the energy harvesting device (1) and is used to detect, transform and distribute the energy.

2. The high-voltage direct current transmission line energy harvesting system based on corona discharge according to claim 1, characterized in that, The length of the housing (11) decreases as the voltage level of the power transmission cable (3) increases and increases as the power supply demand increases.

3. The high-voltage direct current transmission line energy harvesting system based on corona discharge according to claim 1, characterized in that, The distance between the housing (11) and the power transmission cable (3) increases as the voltage level of the power transmission cable (3) increases.

4. The high-voltage direct current transmission line energy harvesting system based on corona discharge according to claim 1, characterized in that, The shell (11) has a cylindrical shape.

5. The high-voltage direct current transmission line energy harvesting system based on corona discharge according to claim 1, characterized in that, The plurality of energy harvesting electrodes (13) are parallel to each other.

6. The high-voltage direct current transmission line energy harvesting system based on corona discharge according to claim 1, characterized in that, The plurality of energy harvesting electrodes (13) are arranged in parallel with the power transmission cable (3).

7. The high-voltage direct current transmission line energy harvesting system based on corona discharge according to claim 1, characterized in that, The number of the plurality of energy harvesting electrodes (13) increases with the increase of power supply demand, and the spacing between adjacent energy harvesting electrodes (13) decreases with the increase of power supply demand.

8. The high-voltage direct current transmission line energy harvesting system based on corona discharge according to claim 1, characterized in that, The energy storage device (2) includes a power management chip (21), a power supply unit (22), and an energy storage unit (23), wherein, The input terminal of the power management chip (21) is electrically connected to the plurality of energy harvesting electrodes (13), and the output terminal is electrically connected to the input terminal of the power supply unit (22) and the input terminal of the energy storage unit (23).

9. The high-voltage direct current transmission line energy harvesting system based on corona discharge according to claim 8, characterized in that, The power management chip (21) is a flyback power management chip (21) based on third-generation semiconductor power devices.

Images