Seawater multi-target electric energy transmission device based on electric field coupling conduction

Abstract

The invention relates to a seawater multi-target electric energy transmission device based on electric field coupling conduction. In electric energy transmission, r electric energy receiving parts are connected with r load targets; the electric energy transmitting part is used for providing electric energy; the transmitting end and the receiving ends of the r electric energy receiving parts form a coupling structure, and the coupling structure is arranged in seawater and forms a coupling capacitor with the seawater; the first common-mode circuit is connected with the r second common-mode circuits through a single wire, so as to establish a common potential of the electric energy transmitting part and the r electric energy receiving parts, and guide the electric energy gathered at the transmitting end in the coupling capacitor to be conducted to the r receiving ends in seawater; each electric energy receiving portion is used for obtaining electric energy from a corresponding receiving end to charge a corresponding load target. According to the invention, the feasibility of conducting current in a seawater environment to realize multi-target charging is expanded, and the realization difficulty of a wet plugging charging technology in the marine environment is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the field of charging technology, and in particular to a multi-target electric energy transmission device in seawater based on electric field coupling conduction. Background Art

[0002] The existing methods of power replenishment for working equipment in the ocean mostly use underwater wet plug-in, manual salvage and wireless charging technology. However, underwater wet plug-in and manual salvage have problems such as wear, labor consumption and low concealment. Wireless charging, with its non-contact power transmission characteristics, can effectively improve the endurance of underwater equipment and become an effective method of underwater charging.

[0003] At present, wireless charging technologies mainly include magnetic coupling wireless power transmission with magnetic field as energy transmission medium and electric coupling wireless power transmission with electric field as energy transmission medium. However, due to the high voltage in the deep sea, most working equipment uses metal casing, eddy current loss and magnetic shielding problems limit the application of magnetic coupling wireless power transmission technology. Electric field coupling has the advantage of penetrating metal to transmit energy, but studies have shown that seawater is an electrolyte with high conductivity (3-6S / m). When using electric field to excite the coupling plates to transfer energy, it will mainly generate conduction current rather than displacement current. In this way, most of the energy in the seawater flows on the transmitting side, and a small amount diffuses freely.

[0004] When seawater equipment such as underwater sensors require multiple targets for power replenishment, multiple power transmission devices and multiple transmitting parts are usually required. The charging process is complicated and uneconomical. Therefore, it is urgent to develop a transmission device that can conduct electric energy by electric field coupling with a single transmitter and multiple receivers. Summary of the invention

[0005] The embodiment of the present invention provides a multi-target electric energy transmission device in seawater based on electric field coupling conduction, which is used to at least realize the transmission of electric field coupling conduction electric energy of a single transmitter and multiple receivers in seawater.

[0006] The present invention provides a multi-target power transmission device in seawater based on electric field coupling conduction, the multi-target power transmission device in seawater comprises a power transmitting part and n power receiving parts; the first end and the second end of the power transmitting part are respectively provided with a first common mode circuit and a transmitting end; the first end and the second end of each power receiving part are respectively provided with a second common mode circuit and a receiving end; in power transmission:

[0007] r power receiving parts are connected to r load targets; 1≤r≤n; n is an integer not less than 2;

[0008] The electric energy transmitting part is used to provide electric energy;

[0009] The transmitting end and the receiving ends of the r electric energy receiving parts form a coupling structure, and the coupling structure is used to be placed in seawater and form a coupling capacitor with the seawater;

[0010] The first common mode circuit is connected to the r second common mode circuits through a single wire to establish a common potential between the power transmitting part and the r power receiving parts, and guide the power energy accumulated at the transmitting end in the coupling capacitor to be conducted in the seawater to the r receiving ends;

[0011] Each power receiving part is used to obtain power energy from a corresponding receiving end to charge a corresponding load target.

[0012] Optionally, the first common-mode circuit and each second common-mode circuit are mainly composed of Y-type capacitors; the midpoint of the Y-type capacitor is connected to the single wire.

[0013] Optionally, a compensation circuit is provided between the first common mode circuit of the power transmitting part and the transmitting end and between the second common mode circuit of each power receiving part and the receiving end.

[0014] The compensation circuit between the first common mode circuit and the transmitting end is used to make the transmitting end output a constant current or a constant voltage;

[0015] The compensation circuit between the second common mode circuit and the receiving end is used to regulate the power transmission of the power receiving part.

[0016] Optionally, each compensation circuit includes at least one compensation inductor.

[0017] Optionally, the compensation circuit is a double-sided L or double-sided LC resonant circuit; r power receiving parts constitute a parallel branch.

[0018] Optionally, the current value of the single wire is a preset multiple of the ratio of the excitation current of the transmitting end to the excitation current of the receiving end.

[0019] Optionally, when the compensation circuit is a double-sided LC resonant circuit, the input current of the power transmitting part is not affected by the change in the number of subsequent power receiving units;

[0020] When the compensation circuit is a double-sided L resonant circuit, the input voltage of the power transmitting part is not affected by changes in the number of subsequent power receiving units.

[0021] Optionally, the transmitting end includes a first transmitting plate and a second transmitting plate, and each receiving end includes a first receiving plate and a second receiving plate;

[0022] The area of ​​the first emitting plate is larger than the area of ​​the second receiving plate; and / or the area of ​​the first receiving plate is larger than the area of ​​the second receiving plate.

[0023] Optionally, the power transmission part further includes a DC power supply and an inverter circuit; the DC power supply, the inverter circuit, the compensation circuit of the power transmission part and the transmitting end are connected in series; the DC power supply is provided with the first common mode circuit;

[0024] Each power receiving part also includes a rectifying and filtering circuit; the receiving end, the compensation circuit of the power receiving part, the rectifying and filtering circuit and the target load are connected in series; and the target load is connected to the second common mode circuit.

[0025] Optionally, the coupling structure is located inside a metal casing of the target load, and the metal casing is in direct contact with the seawater to form a double electric layer structure, thereby generating a larger coupling capacitance for transmitting the electrical energy gathered at the transmitting end through the metal casing to the seawater.

[0026] The present invention realizes that a single DC power supply in seawater supplies power to multiple load targets at the same time. The difference from the traditional power supply for multiple loads lies in that a multi-target single-conductor connection method is extended on the basis of a single conductor. Compared with the traditional positive and negative two-wire connection method and the use of multiple electrical appliances, a single underwater cable reduces the number of cables and eliminates the risk of cable short circuit, which greatly reduces the requirements for plug-in technology, and the engineering implementation difficulty is small. At the same time, it also allows a small amount of seawater to be immersed (the original two-wire short circuit caused by a small amount of seawater immersion is ignored), avoiding the breakdown risk caused by the pressure difference between the two cables in the same insulation layer, and the reduced insulation material also reduces the cost; compared with the wireless charging technology, it effectively solves the problem that the existing electric field coupling wireless charging technology cannot transmit energy due to the primary side circulation in seawater applications, and can effectively avoid the risk of short circuit caused by cable rupture: when the underwater cable ruptures, the single wire is directly connected to the seawater. At this time, the DC power supply and the battery current must flow back to the circuit through the common-mode capacitor, which greatly increases the loop resistance. At this time, the common-mode circuit plays a role of safety protection, avoiding the danger of cable rupture and short circuit, and ensuring safe and reliable power transmission.

[0027] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0029] Figure 1 A schematic diagram of a multi-target electric energy transmission device in seawater based on electric field coupling conduction provided by an embodiment of the present invention;

[0030] Figure 2 A circuit schematic diagram of electric energy transmission to a single load target in a multi-target electric energy transmission device in seawater based on electric field coupling conduction provided by an embodiment of the present invention;

[0031] Figure 3 for Figure 2 Equivalent circuit diagram of

[0032] Figure 4 A circuit schematic diagram of electric energy transmission between two load targets in a multi-target electric energy transmission device in seawater based on electric field coupling conduction provided by an embodiment of the present invention;

[0033] Figure 5 for Figure 4 Equivalent circuit diagram of

[0034] Figure 6 A schematic diagram of transmitting electric energy to a single load target in a multi-target electric energy transmission device in seawater based on electric field coupling conduction provided by an embodiment of the present invention;

[0035] Figure 7 A schematic diagram of an electric energy transmitting part provided by an embodiment of the present invention;

[0036] Figure 8 A schematic diagram of a power receiving part provided by an embodiment of the present invention;

[0037] Fig. 9 A schematic diagram of a common mode part provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0038] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0039] In the subsequent description, the suffixes such as "module", "component" or "unit" used to represent elements are used only to facilitate the description of the present invention and have no specific meanings. Therefore, "module", "component" or "unit" can be used in a mixed manner. Expressions such as "first" and "second" are only used to distinguish technical terms.

[0040] The embodiment of the present invention provides a multi-target electric energy transmission device in seawater based on electric field coupling conduction, such as Figure 1-Figure 9As shown, the multi-target power transmission device in seawater includes a power transmitting part (such as a Y-type capacitor, a DC power supply, an inverter circuit, a first compensation circuit, and a transmitting end) and n power receiving parts (such as a receiving end, a second compensation circuit, a rectifier filter circuit, a battery, and a Y-type capacitor); the first end and the second end of the power transmitting part are respectively provided with a first common mode circuit and a transmitting end (such as an emitter plate P T1 , P T2 ); The first end and the second end of each power receiving part are respectively provided with a second common mode circuit and a receiving end (eg, a receiving plate P R1-1 , P R1-2 ); In power transmission:

[0041] r power receiving parts are connected to r load targets (batteries); the r power receiving parts form a parallel branch; 1≤r≤n; n is an integer not less than 2;

[0042] The electric energy transmitting part is used to provide electric energy;

[0043] The transmitting end and the receiving ends of the r electric energy receiving parts form a coupling structure, and the coupling structure is used to be placed in seawater and form a coupling capacitor with the seawater;

[0044] The first common mode circuit is connected to the r second common mode circuits through a single wire to establish a common potential between the power transmitting part and the r power receiving parts, and guide the power energy accumulated at the transmitting end in the coupling capacitor to be conducted in the seawater to the r receiving ends;

[0045] Each power receiving part is used to obtain power energy from a corresponding receiving end to charge a corresponding load target.

[0046] The embodiment of the present invention realizes that a single DC power supply in seawater can supply power to multiple load targets at the same time. The difference from the traditional power supply to multiple loads is that the embodiment of the present invention is based on a multi-target single-wire connection method extended on the basis of a single wire (here the single wire is a branch, and the second branch required to form an energy circuit is formed by a metal plate and seawater to form a coupling capacitor and a resistance characterized by the seawater conduction path). Compared with the traditional positive and negative two-wire connection method and the use of multiple electrical appliances, the number of wiring is reduced, which has a significant gain mainly for underwater dynamic wet plug-in technology and reduces its implementation difficulty. Specifically, for marine environment equipment, the connection difficulty of the original underwater dynamic wet plug-in technology is reduced, mainly characterized by the original need for at least two or more wire terminals to be dynamically inserted underwater, and it must be ensured that no seawater infiltration is required to avoid short circuits, which makes the technical implementation difficult, the implementation process is highly worn, and the life is short. If there is only one endpoint, seawater infiltration can be allowed, which reduces the difficulty of wet plug-in technology.

[0047] The embodiment of the present invention uses a single wire to adjust the length of the power transmission distance, achieving power transmission of up to 100 meters, and the access of the power receiving part only requires the access of the single wire.

[0048] In addition, under high-frequency excitation current, seawater is used as a common branch in the loop, and multiple connecting wires are added to form multiple receiving charging circuits similar to parallel structures. This multi-wire connection form can be preset and applied in the underwater sensor network structure to achieve the goal of stable power supply. This power level is low and the transmission efficiency requirements are small, but long-term operation requires continuous power supply. Therefore, this patent effectively reduces the number of underwater cables and the difficulty of implementation, thereby improving economy.

[0049] In addition, based on this single wire, the connection nodes of this wire are arranged at different underwater distance nodes, which can provide power to multiple underwater equipment at the same time. This is an extension of the single-line application, reduces the requirements for the number of energy base stations, and increases the number of underwater equipment endurance nodes. Moreover, each node only requires a single-wire terminal, which greatly increases the endurance and concealment of underwater equipment.

[0050] In some embodiments, the first common-mode circuit and each second common-mode circuit are mainly composed of Y-type capacitors; the midpoint of the Y-type capacitor is connected to the single wire. For example, the four capacitors used in the first common-mode circuit and the second common-mode circuit are designed to form a Y-type capacitor structure to ensure uniform current flow. The first common-mode circuit and the second common-mode circuit are located on the DC side to ensure that the circuit will not be short-circuited when the single wire breaks in seawater. The first common-mode circuit and the second common-mode circuit are designed to be symmetrical structures. When the LC resonant circuit is adopted at the same time, although they participate in the operation of the resonant circuit, they have no effect on the circuit resonance condition and the circuit output.

[0051] In this embodiment, in order to avoid the safety problems caused by the rupture of the underwater cable, a common mode circuit is introduced, and the connection position of the single wire is set at the midpoint of the common mode circuit of the DC power supply and the battery of the target load (DC circuit), so that when the cable is ruptured and short-circuited with the seawater, the common mode circuit plays a blocking role. In addition, through this setting, the compensation circuit can be reasonably designed, the power transmission can be adjusted, and the power supply demand can be met.

[0052] In some embodiments, the power transmitting part also includes a DC power supply and an inverter circuit; the DC power supply, the inverter circuit, the compensation circuit of the power transmitting part and the transmitting end are connected in series; the DC power supply is provided with a first common mode circuit; each power receiving part also includes a rectifier and filter circuit; the receiving end, the compensation circuit of the power receiving part, the rectifier and filter circuit and the target load are connected in series; the target load is connected to the second common mode circuit.

[0053] A compensation circuit is provided between the first common mode circuit and the transmitting end of the power transmitting part and between the second common mode circuit and the receiving end of each power receiving part. The compensation circuit between the first common mode circuit and the transmitting end is used to make the transmitting end output a constant current or a constant voltage; the compensation circuit between the second common mode circuit and the receiving end is used to regulate the power transmission of the power receiving part.

[0054] Each compensation circuit includes at least one compensation inductor, which is used to generate coupling capacitance resonance with the coupling structure to regulate the power transmission of the power receiving part and compensate for reactive power. During the operation of the compensation circuit, there is a short period of time when the rectifier diode of the receiving part is in a fully-on state in the same bridge arm.

[0055] The input current of the power transmitting part is not affected by the number of subsequent power receiving units and the change of reflected impedance; the compensation circuit of the power transmitting part is also used to control the power energy to be output in constant voltage or constant current. Among them, r power receiving parts constitute a parallel branch; the power receiving part on each parallel branch is used to change the reflected impedance of the power transmitting part to achieve the obtained power energy; the compensation circuit is a double-sided L or double-sided LC resonant circuit. For example, when the compensation circuit is a double-sided LC resonant circuit, the input current of the power transmitting part is not affected by the change of the number of subsequent power receiving units; when the compensation circuit is a double-sided L resonant circuit, the input voltage of the power transmitting part is not affected by the change of the number of subsequent power receiving units.

[0056] Among them, the passive compensation devices of the compensation circuit, such as compensation inductors and compensation capacitors, increase significantly with the increase in the number of loads, which increases the complexity of circuit analysis. In addition, as the load is dynamically connected or disconnected, the circuit state switches in real time, which puts certain requirements on stable power control and stable input and output.

[0057] The compensation circuit in the circuit structure uniformly uses two passive devices (an inductor and a capacitor) to form an LC network. The compensation network has two functions: 1. Compensating reactive power; 2. Regulating system output.

[0058] For example, the numerical relationship between the compensation inductor and the compensation capacitor can be linked according to the target, which is often referred to as the resonance condition. Therefore, only a certain value needs to be determined to obtain the value of another passive component (usually by designing and selecting the compensation capacitor C for calculation, after determination, the corresponding value of the compensation inductor L is obtained). The value of the compensation capacitor C is used as a variable. The compensation capacitor of the power transmitting part will affect the area between the transmitting end and the receiving end (the input current and input voltage from the power transmitting part to the power receiving part); and the compensation capacitor of the power receiving part will affect the voltage and current on the load target and the reflected impedance of the power receiving part to the power transmitting part, which is specifically manifested as a functional relationship with the load target resistance R, the compensation capacitor C and the frequency f (here, it is considered that due to the parallel relationship of multiple load targets in the circuit structure, the input voltage of each power receiving unit is the same, and its reflected impedance affects the current distribution from the power transmitting part to the power receiving part). By changing the value of C, the voltage and current required by each charging load target are finally met to achieve power distribution.

[0059] Of course, the compensation circuit is not limited to the LC network structure. There are also CLC or LCLC networks, etc. These topologies are essentially to control the input current by changing the reflected impedance of a certain power receiving part to the power transmitting part in this parallel branch, thereby achieving the goal of meeting the different charging needs of different charging units, that is, power regulation.

[0060] The inductor L1 and the capacitor C1 are set in the power transmission part to form a resonant network to ensure that the power transmission part has a constant current output. Therefore, for multiple (more than 2) load targets or increasing or decreasing the number of loads, the relationship between the loads is a parallel relationship, the input current is constant, and the current distributed between each load is the ratio of the load impedance, thereby achieving the purpose of power distribution.

[0061] Of course, the power transmission part can also be set up with not only an LC resonant network, but also an LCL resonant network to ensure that the power transmission part has a constant voltage output, so that the voltage at both ends of the load target connected or connected is the same. At this time, as the load increases or decreases, the total impedance changes, and the input current of the power transmission part also changes accordingly, but for each load target, the input voltage remains unchanged, so it is not affected by the increase or decrease of the load, but the total input power will change, realizing a power distribution method.

[0062] The above methods are all designed on the power supply side compensation circuit. If the compensation circuit is designed for each load side, the power output can be further flexibly controlled. For example, the CL resonant network on the right side can control the input current to a load voltage with a certain gain according to the ratio of the compensation inductance on the power supply side and the load side under a certain resonance parameter relationship. However, this greatly increases the complexity of the circuit, and it is necessary to design the power supply side and the load side for loads with different power requirements, and the two must work together to reduce the system reactive power and increase efficiency.

[0063] The energy is transferred to the seawater through the metal shell by using the coupled electric field, and then transmitted back to the charging body through the common branch seawater conduction path and the coupled electric field. Finally, a single wire is used to connect each power receiving part in parallel to a single wire, and then return to the power supply side to form a charging circuit. This process includes contactless energy transmission and single-wire charging. The reflected impedance of the receiving circuit can be adjusted according to the reactive power compensation of high-frequency coupling and the designed charging target power demand, and the total input and energy distribution of each charging unit can be controlled.

[0064] In detail, a single load target (r=1) is used as an example for introduction, and then expanded to two load targets and then n targets. In the multi-target electric energy transmission device in seawater based on electric field coupling conduction provided by the embodiment of the present invention, its circuit principle is as follows Figure 2 shown.

[0065] Select the double-sided LC compensation circuit topology, from Figure 1 The circuit is selected into two parts ① and ② to introduce the power transmission. The equivalent circuits are as follows: Figure 3 shown.

[0066] from Figure 3 (a) Start the analysis. The power transmitting part provides an AC voltage source, which is connected to the LC resonance (the values ​​of L1 and C1 are in series resonance, ω 2 L1C1=1) circuit, and all subsequent circuits are equivalent to Z R1 (called the reflected impedance of the latter stage) can be deduced to obtain the current I output by the power transmission part at this time T1 The current relationship satisfies (1)

[0067] I T1 =-U inv *jωC1 (1)

[0068] Formula (1) shows that the output current of the power transmission part has nothing to do with the magnitude of the subsequent stage reflection impedance, but is only related to the value of the compensation capacitor C1.

[0069] For the power receiving circuit of ② Figure 3(b) is analyzed because the current passing through the transmitting part coupling mechanism to the receiving part coupling mechanism is also a constant current, which is I R1 At this time, the CL circuit (L2 and C2 values ​​are also in series harmonic relationship, ω 2 The subsequent circuit of L2C2=1) is also equivalent to Z1, and the circuit calculation has the following relationship:

[0070]

[0071] The formula shows that first, the output voltage U of the power transmission part rec It is also independent of the equivalent impedance Z1 of the subsequent circuit, and has a constant voltage function as a whole. According to the design of the quadrupole equivalent circuit, when both sides form an LC circuit at the same time, I R1 =I T1 , at this time there is output U rec =-C1 / C2*U inv , for the overall circuit, the value of C2 affects the output.

[0072] Similarly, the equivalent impedance of the receiving part ② is shown in formula (3), indicating that by controlling the size of C2, the equivalent impedance Z1 of the subsequent stage can be amplified or reduced, which is reflected in the transmitting part circuit ① as Z R1 That is, the influence of the subsequent stage reflection impedance. So the next step is to expand to two target circuits, and there is an equivalent circuit Figure 4 shown.

[0073] At this time, Z R1 With Z R2 The value is controlled by the equivalent impedance of the load circuit Z1 and Z2 and the two receiving parts C2 and C3. The specific expression is

[0074]

[0075] In this way, the output current I T1 In this case, Z1 and Z2 are connected in parallel to split the current, so the calculation is as follows: R1 have

[0076]

[0077] Then the current is diverted to the first receiving part, and then substituted into (2) to obtain the load voltage of the first receiving part:

[0078]

[0079] From the above formula, it can be seen that when charging two load targets, the charging voltage of a single receiving part is affected by the load impedance Z of each part and the compensation capacitor C (the compensation inductor L can also be used for control here, and the two can be converted to each other when they meet the resonance condition), so it has the ability to regulate power distribution, and the input current of the transmitting part is not affected by the number of parallel connections and impedance changes of the subsequent stage. This compensation situation can be expanded to charge three targets or even n targets.

[0080] In some embodiments, the transmitting end includes a first transmitting plate and a second transmitting plate, and each receiving end includes a first receiving plate and a second receiving plate. The area of ​​the first transmitting plate and the first receiving plate is greater than the area of ​​the second transmitting plate and the second receiving plate, so as to enhance the electric field convergence and obtain better transmission performance.

[0081] In some embodiments, the current value of a single wire is a preset multiple of the ratio of the excitation current of the transmitting end and the receiving end. Wherein, the transmitting end and the receiving end each include two plates, and the current in a single wire can be designed to be the ratio of the excitation current of the two plates to reduce its value. The main function is to build an energy flow path to achieve less loss in long-distance transmission lines and improve the overall system efficiency. For example, the current in a single wire is one-fifth of the excitation current of the transmitting end and the receiving end, which can effectively improve the efficiency while avoiding the increase of losses in other parts. The input current of the power transmitting part is not affected by the number of subsequent power receiving units and changes in reflected impedance.

[0082] In some embodiments, the coupling structure is located inside a metal casing of the target load, and the metal casing is in direct contact with the seawater to form a double electric layer structure, thereby generating a larger coupling capacitance for transferring the electrical energy gathered at the transmitting end through the metal casing into the seawater.

[0083] In detail, the current starts from the electric energy transmitting part, forms a coupling capacitor through the plate, and transmits energy to the seawater through the metal shell through the displacement current, and reaches the surface of the metal shell of the receiving end of the coupling mechanism in the form of conduction current through the common mode circuit, and transmits the energy to the metal shell through the displacement current, and finally returns to the power supply in the common mode circuit to form a current loop. In addition, since it works in seawater and the coupling mechanism forms a coupling capacitor with the seawater, the coupling device needs to be waterproof and insulated to avoid direct connection between the seawater and the coupling device. When the metal shell of the equipment in the seawater is in direct contact with the seawater, a double electric layer structure will be spontaneously formed, resulting in a large coupling capacitor, which is not a direct electrical connection. The electric field transmits energy through the metal shell to the seawater. The metal shell of the equipment in the seawater will produce a very small relative potential with the seawater, and will not break down the double electric layer structure. In addition, the position of the transmitting end and the receiving end of the coupling mechanism can move in a large range of positions and directions without affecting the power transmission capability.

[0084] Various embodiments of the present invention provide a multi-target electric energy transmission device in seawater by electric field coupling conduction, which realizes underwater electric field coupling conduction electric energy transmission, including an electric energy transmitting part, an electric energy receiving part and a common mode part (including a first common mode circuit and a second common mode circuit). Due to the high conductivity of seawater, the excitation electric field will generate a conduction current rather than a displacement current in the seawater, which makes the traditional quadrupole plate electric field coupling wireless charging system produce a strong self-coupling phenomenon, and most of the electric energy flows only in the transmitting part, while a small amount diffuses freely in the seawater instead of flowing to the receiving part.

[0085] The embodiments of the present invention can guide electric energy to flow in seawater and mark the electric energy receiving part to realize underwater electric field coupled electric energy transmission, wherein the function of the common mode part is to establish a connection through the common potential point of the electric energy transmitting part and the electric energy receiving part, generate a potential difference between the coupling plates, and form a second energy flow path of the system, and then under the action of a reasonable compensation network, guide the conductive current in the seawater to flow through the electric energy receiving part to complete the underwater energy transmission.

[0086] Since the system works underwater, the equivalent capacitance of the underwater coupling mechanism is mainly formed by the coupling of seawater and the plate, so the plate needs to be waterproofed and insulated to avoid direct connection with seawater. In addition, since the plate is surrounded by seawater due to underwater operation, the system allows the plate to change direction and position over a wide range without affecting the transmission capacity. The metal shell and seawater electrolyte in the seawater will spontaneously form a double-layer structure, generating a large equivalent coupling capacitance, through which displacement current flows, and it is not directly connected to the seawater.

[0087] The area of ​​the first emitter plate and the first receiving plate should be larger than that of the second emitter plate and the second receiving plate to obtain better electric field convergence. The topology circuit can select a bilateral L or bilateral LC circuit to form a constant current and constant voltage output, thereby increasing the voltage level between the plates and effectively solving the problem that the traditional quadrupole plates of the electric field coupled wireless charging system cannot transmit energy in seawater.

[0088] According to the above embodiments, a specific embodiment is provided below.

[0089] This embodiment proposes a multi-target power transmission device in seawater based on electric field coupling conduction, realizing a single-transmitter multi-receiver charging device for electric field coupling wireless charging in a seawater environment, and uses a Y-type capacitor and a single line connecting the midpoints to form a multi-target electric field coupling conduction power transmission. The power transmission part (referred to as the transmission part) includes a common mode circuit, a DC power supply, an inverter circuit, a compensation circuit and two metal plates P T1 and P T2 The transmitting end is composed of an unlimited number of power receiving parts. Each power receiving part (referred to as the receiving part) includes a common mode circuit, a target load (battery), a rectifier and filter circuit, a compensation circuit and two metal plates P Rn-1 and P Rn-2The receiving end of the composition.

[0090] By designing the first compensation circuit of the electric energy transmitting part and outputting a constant voltage or a constant current at the transmitting coupling mechanism, a single electric energy receiving part can be regulated to be connected to the whole system in series or in parallel, so that the number of receiving parts can be added or reduced at will, while the power transmission of other original receiving parts can be controlled to remain unchanged or increase instantly.

[0091] By designing the compensation circuits of the transmitting and receiving parts, the power distribution of the entire system can be adjusted to meet the expected needs. The Y-type capacitor that constitutes the common mode part can effectively ensure the safety of the system when the underwater cable breaks, and prevent the DC power supply from short-circuiting with the single line through seawater. The existence of the single line not only establishes the common potential of the transmitting and receiving parts, guides the flow of conductive current in the seawater, but also is a sign of power transmission, ensuring the accuracy of energy flow.

[0092] At this time, compared with the traditional wet plug-in technology, a single underwater cable reduces the number of cables and eliminates the risk of cable short-circuit, which greatly reduces the requirements for plug-in technology and makes the project easier to implement. It also allows a small amount of seawater to enter (the short-circuit between the two wires caused by the original small amount of seawater entering is ignored), avoiding the risk of breakdown caused by the pressure difference between the two cables in the same insulation layer, and reducing the insulation material also reduces the cost.

[0093] Compared with wireless charging technology, this method solves the problem of existing quadrupole electric field coupling wireless charging technology that the original side circulates but cannot transmit energy in seawater applications. The addition of Y-type capacitors on both sides and a single wire connecting the midpoint can effectively avoid the risk of short circuit caused by cable rupture. For example, when an underwater cable ruptures, the single wire is directly connected to the seawater. At this time, the DC power supply and battery current must flow back to the circuit through the common mode circuit, which greatly increases the loop resistance. At this time, the common mode circuit plays a role in safety protection, avoiding the danger of short circuit when the cable ruptures, and ensuring safe and reliable power transmission.

[0094] The embodiment of the present invention can adjust the power transmission distance according to the length of the single line, realizing power transmission of up to 100 meters, and the access of the receiving part only requires the access of the single line, and through the compensation circuit design, it will not affect other receiving parts.

[0095] Detailed, such as Figures 1 to 9As shown, the multi-target power transmission device in seawater based on electric field coupling conduction includes a power transmitting part 1, a power receiving part 2 and a common mode part 4, wherein the power transmitting part 1 includes a DC power supply 11, an inverter circuit 12, a first compensation circuit 13, a first connection line 14, a second connection line 15 and a transmitting end 16, the power receiving part 2 includes a receiving end 21, a third connection line 22, a fourth connection line 23, a second compensation circuit 24, a rectifier filter circuit 25, and a battery 26, and the common mode part includes a first common mode circuit 41, a fifth connection line 42 and a second common mode circuit 43.

[0096] The DC power supply 11 provides power input for the whole system. The inverter circuit 12 should be a full-bridge inverter, which works to convert DC power into the required AC power of a certain frequency. The first compensation circuit 13 can raise the system voltage level, enhance the transmission capacity, and compensate for the reactive power of the transmitting circuit 1. The transmitting end 16 includes a first transmitting plate 161 and a second transmitting plate 162, and the receiving end 21 includes a first receiving plate 211 and a second receiving plate 212. The second compensation circuit is used to adjust the system output voltage or current to obtain the desired result and compensate for the reactive power of the receiving circuit 2. The rectifier and filter circuit 25 is used to convert the input AC power into DC power for charging the battery. The first common-mode circuit includes a first transmitting common-mode capacitor 411 and a second transmitting common-mode capacitor 412, and the second common-mode circuit includes a first receiving common-mode capacitor 431 and a second receiving common-mode capacitor 432. The two work together to establish a common potential point between the transmitting part and the receiving part, generate a common-mode current, establish a second energy flow path for the system, guide the flow of seawater current, and realize underwater electric field coupling conduction power transmission.

[0097] Among them, the first transmitting common-mode capacitor 411 and the second transmitting common-mode capacitor 412 of the first common-mode circuit 41 and the first receiving common-mode capacitor 431 and the second receiving common-mode capacitor 432 of the second common-mode circuit 43 are the same, forming a Y-type capacitor to ensure the safety of the device when the same common-mode current flows and the fifth connecting line is broken.

[0098] The first common-mode circuit and the second common-mode circuit are designed to be symmetrical structures. When the LC resonant circuit is adopted at the same time, although they participate in the operation of the resonant circuit, they have no effect on the circuit resonance condition and the circuit output.

[0099] The first compensation circuit and the second compensation circuit each include at least one compensation inductor to generate coupling capacitance resonance with the quadrupole plate to compensate for reactive power. The compensation circuits 13 and 24 can be double-sided L or double-sided LC topologies to improve the system transmission capacity.

[0100] During the operation of the resonant circuit, there is a short period of time when the rectifier diode of the receiving part is fully on in the same bridge arm. Preferably, the current flowing through the fifth connection line 42 can be designed to be very small compared with the excitation current of the coupling mechanism transmitting part 16 and the coupling mechanism receiving part 21, and the function is to build an energy flow path.

[0101] The current starts from the transmitting part, forms a coupling capacitor through the emitter plate, and transmits energy to the seawater through the metal shell through the displacement current. It is guided to the surface of the metal shell of the receiving part of the coupling mechanism through the common mode part in the form of conduction current, and transfers energy to the shell through the displacement current. Finally, it returns to the power supply in the common mode part in the form of conduction current, forming a current loop.

[0102] Since the device is working in seawater 3 and the coupling mechanism forms a coupling capacitor with seawater 3, the coupling device needs to be waterproofed and insulated to prevent the seawater from being directly connected to the coupling device. When the metal shell of the equipment in seawater is in direct contact with the seawater, a double electric layer structure will be spontaneously formed, resulting in a large coupling capacitor. It is not a direct electrical connection, and the electric field transmits energy through the metal shell to the seawater. The metal shell of the equipment in seawater will produce a very small relative potential with the seawater and will not break down the double electric layer structure.

[0103] The transmitting end 16 and the receiving end 21 can move in a wide range of positions and directions without affecting the ability to transmit electrical energy. The area of ​​the first transmitting plate 161 and the first receiving plate 211 should be larger than the area of ​​the second transmitting plate 162 and the second receiving plate 212 to enhance the electric field convergence and obtain better transmission performance.

[0104] This embodiment realizes the transmission device of electric field coupling conduction of electric energy in seawater by using electric field to penetrate metal shell and safely guide seawater current to flow to multi-target receiving parts. It uses two transmitting metal plates as energy transmitting ends, and there may be two or more receiving parts for electric energy replenishment. Each receiving part uses two receiving metal plates to penetrate the shell of the underwater device to collect energy, and uses corresponding compensation circuits and rectifier circuits to power the battery. At the same time, there is a group of Y-type capacitors and a single line connecting the midpoint connected to the transmitting part, so as to guide the energy to flow to the required part, and has the function of preventing the risk of short circuit when the underwater cable breaks. The design can establish a common potential of the power transmitting part and the power receiving part through a single line, forming a potential difference between the two transmitting plates and the two receiving plates, so as to guide the free divergent current in the seawater to flow to the desired power receiving part, and realize the power transmission of underwater equipment with metal shell. The device is designed according to the charging requirements of the receiving part, and the power distribution is adjusted to meet the power requirements of different receiving parts. When a new receiving part joins or leaves, it has no effect on other receiving parts, and only the input power of the transmitting part increases or decreases.

[0105] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0106] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0107] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A multi-target electric energy transmission device in seawater based on electric field coupling conduction, characterized in that: The multi-target power transmission device in seawater includes a power transmitting part and n power receiving parts; The first end and the second end of the power transmitting part are respectively provided with a first common mode circuit and a transmitting end; the first end and the second end of each power receiving part are respectively provided with a second common mode circuit and a receiving end; in power transmission: r power receiving parts are connected to r load targets; 1≤r≤n; n is an integer not less than 2; The electric energy transmitting part is used to provide electric energy; The transmitting end and the receiving ends of the r electric energy receiving parts form a coupling structure, and the coupling structure is used to be placed in seawater and form a coupling capacitor with the seawater; The first common mode circuit is connected to the r second common mode circuits through a single wire to establish a common potential between the power transmitting part and the r power receiving parts, and guide the power energy accumulated at the transmitting end in the coupling capacitor to be conducted in the seawater to the r receiving ends; Each power receiving part is used to obtain power energy from a corresponding receiving end to charge a corresponding load target.

2. The multi-target power transmission device in seawater according to claim 1, characterized in that: The first common mode circuit and each second common mode circuit are mainly composed of Y-type capacitors; the midpoint of the Y-type capacitor is connected to the single wire.

3. The multi-target power transmission device in seawater according to claim 1, characterized in that: A compensation circuit is provided between the first common mode circuit and the transmitting end of the power transmitting part and between the second common mode circuit and the receiving end of each power receiving part. The compensation circuit between the first common mode circuit and the transmitting end is used to make the transmitting end output a constant current or a constant voltage; The compensation circuit between the second common mode circuit and the receiving end is used to regulate the power transmission of the power receiving part.

4. The multi-target power transmission device in seawater according to claim 2, characterized in that: Each compensation circuit includes at least one compensation inductor.

5. The multi-target power transmission device in seawater according to claim 4, characterized in that: The compensation circuit is a double-sided L or double-sided LC resonant circuit; r electric energy receiving parts constitute a parallel branch.

6. The multi-target power transmission device in seawater according to claim 5, characterized in that: When the compensation circuit is a double-sided LC resonant circuit, the input current of the power transmitting part is not affected by the change in the number of subsequent power receiving units; When the compensation circuit is a double-sided L resonant circuit, the input voltage of the power transmitting part is not affected by changes in the number of subsequent power receiving units.

7. The multi-target power transmission device in seawater according to claim 1, characterized in that: The current value of the single wire is a preset multiple of the ratio of the excitation current of the transmitting end to the excitation current of the receiving end.

8. The multi-target power transmission device in seawater according to claim 1, characterized in that: The transmitting end includes a first transmitting plate and a second transmitting plate, and each receiving end includes a first receiving plate and a second receiving plate; The area of ​​the first emitting plate is larger than the area of ​​the second receiving plate; and / or the area of ​​the first receiving plate is larger than the area of ​​the second receiving plate.

9. The multi-target power transmission device in seawater according to claim 1, characterized in that: The electric energy transmitting part further includes a DC power supply and an inverter circuit; the DC power supply, the inverter circuit, the compensation circuit of the electric energy transmitting part and the transmitting end are connected in series; the DC power supply is provided with the first common mode circuit; Each power receiving part also includes a rectifying and filtering circuit; the receiving end, the compensation circuit of the power receiving part, the rectifying and filtering circuit and the target load are connected in series; and the target load is connected to the second common mode circuit.

10. The multi-target power transmission device in seawater according to any one of claims 1 to 9, characterized in that: The coupling structure is located in the metal shell of the target load, and the metal shell is in contact with the seawater to form a double electric layer structure, thereby generating a larger coupling capacitance for transmitting the electric energy gathered at the transmitting end through the metal shell to the seawater.

Images