Underwater power supply system, power receiving device, and power supply method

Abstract

To steadily control charging of a storage battery included in a power receiving system following an operation delay of a feedback system when a stack DC / DC power supply is adopted for the power receiving system.SOLUTION: A power transmission device includes a power transmission coil that transmits electric power via a magnetic field, and a transmission-side processor that controls electric power from a transmission power source. A power-receiving device includes a power-receiving coil that receives electric power from the power transmission coil, a receiving power source that has a plurality of multi-purpose power source components and a storage battery and that charges the storage battery on the basis of the received electric power and the plurality of multi-purpose power source components, a receiving-side processor that cyclically controls a charging current running to the storage battery, and a current sensor that detects the charging current. The receiving-side processor calculates a parameter for returning control to the transmission power source on the basis of a difference between a value of a charging current and a target current value when the value of the charging current is outside of a specified range. The transmission-side processor controls the electric power from the transmission power source on the basis of the return control parameter.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present disclosure relates to an underwater power supply system and a power receiving device that receive electric power underwater and charge a storage battery. [Background technology]

[0002] Patent document 1 discloses a wireless power transmission device having an information acquisition unit that executes at least one of a process for acquiring transmitted power information from a power transmitting unit and a process for acquiring received power information from a power receiving unit that receives power transmitted from the power transmitting unit, and a control unit that is capable of executing a plurality of processes among a process for adjusting the power transmitting unit in accordance with the transmitted power information, a process for adjusting the impedance of the power receiving unit in accordance with the transmitted power information, a process for adjusting the power transmitting unit in accordance with the received power information, and a process for adjusting the impedance of the power receiving unit in accordance with the received power information, and that switches between and selects one of the plurality of processes based on predetermined conditions, and executes the selected process. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2015 / 001672 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, it is not assumed that a load having a power receiving unit moves underwater (e.g., under the sea) or that power is transmitted from a power transmitting unit to a power receiving unit of a load underwater. In recent years, an underwater power supply method has been proposed in which a power receiving device capable of moving underwater, such as underwater, receives charging power from a power transmitting device such as a ship moored on the water surface, such as the sea, and charges a built-in storage battery (rechargeable battery). In the underwater power supply method, a custom power supply is required for underwater power supply because there is no general-purpose charging power supply. However, if a charging power supply can be configured by feedback control using a power supply (hereinafter referred to as a "stack DC / DC power supply") that combines multiple general-purpose DC / DC converters, not only can the cost of system construction be significantly reduced, but it can also be adapted to various charging configurations and specifications by combining power supplies, and is considered to be a useful method.

[0005] However, when feedback control is performed using a stack DC / DC power supply in the power receiving system, operational delays in the feedback system (i.e., each component involved in feedback control; same below) occur depending on performance variations in the stack DC / DC power supply, the state of the storage battery, the charging current, etc., so there was a problem that the operation of subsea power supply would not be stable unless feedback control was performed taking into account the factors that cause delays.

[0006] The present disclosure has been devised in view of the above-mentioned conventional situation, and provides an underwater power supply system that stably controls charging of a storage battery built into a power receiving system in accordance with the operational delay of a feedback system when a stack DC / DC power supply is adopted in the power receiving system. 、 Powered Device and power supply method to provide. [Means for solving the problem]

[0007] The present disclosure relates to an underwater power supply system having a power transmitting device and a power receiving device movable underwater, wherein the power transmitting device comprises a power transmitting coil that transmits power to the power receiving device via a magnetic field, and a power transmitting side processor that controls the power from a power transmitting power source and supplies it to the power transmitting coil, and the power receiving device comprises a power receiving coil that receives power from the power transmitting coil, a plurality of general-purpose power supply components, and a storage battery, and comprises a power receiving power source that charges the storage battery based on the power received by the power receiving coil and the plurality of general-purpose power supply components, a power receiving side processor that periodically controls a charging current to the storage battery, and a current sensor that detects the charging current, and when the power receiving side processor determines that the detected charging current value is a current value outside a predetermined range, it calculates a feedback control parameter to the power transmitting power source based on the difference between the value of the charging current and a target current value and transmits the feedback control parameter to the power transmitting side processor, and the power transmitting side processor controls the power from the power transmitting power source based on the feedback control parameter. When the power receiving processor determines that the detected charging current value has become a current value within the predetermined range, the power receiving processor starts estimating a delay time of an operation occurring in a feedback control system of the charging current, sets the feedback control parameter to a fixed value until the delay time estimation is completed, and when the power receiving processor determines that a difference between the previously detected charging current value and the latest detected charging current value has become less than a predetermined value, ends the delay time estimation, and calculates the feedback control parameter for each estimated delay time interval after the delay time estimation is completed. The present invention provides an underwater power supply system.

[0008] The present disclosure also relates to an underwater power supply system having a power transmitting device and a power receiving device movable underwater, wherein the power transmitting device comprises a power transmitting coil that transmits power to the power receiving device via a magnetic field, and a power transmitting side processor that controls the power from a power transmitting power source and supplies it to the power transmitting coil, and the power receiving device comprises a power receiving coil that receives power from the power transmitting coil, a plurality of general-purpose power source components, and a storage battery, and comprises a power receiving power source that charges the storage battery based on the power received by the power receiving coil and the plurality of general-purpose power source components, a power receiving side processor that periodically controls a charging current to the storage battery, and a current sensor that detects the charging current, and when the power receiving side processor determines that the detected charging current value is a current value outside a predetermined range, it calculates a feedback control parameter to the power receiving power source based on a difference between the value of the charging current and a target current value, and the power receiving power source controls the charging current to the storage battery based on the feedback control parameter to charge the storage battery. When the power receiving processor determines that the detected charging current value has become a current value within the predetermined range, the power receiving processor starts estimating a delay time of an operation occurring in a feedback control system of the charging current, sets the feedback control parameter to a fixed value until the delay time estimation is completed, and when the power receiving processor determines that a difference between the previously detected charging current value and the latest detected charging current value has become less than a predetermined value, ends the delay time estimation, and calculates the feedback control parameter for each estimated delay time interval after the delay time estimation is completed. The present invention provides an underwater power supply system.

[0009] The present disclosure also provides a power receiving device capable of moving underwater and receiving power transmitted from a power transmitting device having a power transmitting coil, the power receiving device including a power receiving coil that receives power from the power transmitting coil, a plurality of general-purpose power supply components and a storage battery, the power receiving device including a power receiving power source that charges the storage battery based on the power received by the power receiving coil and the plurality of general-purpose power supply components, a power receiving processor that periodically controls a charging current to the storage battery, and a current sensor that detects the charging current, wherein when the power receiving processor determines that the detected charging current value is a current value outside a predetermined range, the power receiving processor calculates a feedback control parameter to a power transmitting power source based on a difference between the value of the charging current and a target current value, and instructs the power transmitting device to control power from the power transmitting power source based on the feedback control parameter. When the power receiving processor determines that the detected charging current value has become a current value within the predetermined range, the power receiving processor starts estimating a delay time of an operation occurring in a feedback control system of the charging current, sets the feedback control parameter to a fixed value until the delay time estimation is completed, and when the power receiving processor determines that a difference between the previously detected charging current value and the latest detected charging current value has become less than a predetermined value, ends the delay time estimation, and calculates the feedback control parameter for each estimated delay time interval after the delay time estimation is completed. The present invention provides a power receiving device.

[0010] The present disclosure also provides a power receiving device capable of moving underwater and receiving power transmitted from a power transmitting device having a power transmitting coil, the power receiving device including a power receiving coil that receives power from the power transmitting coil, a plurality of general-purpose power supply components and a storage battery, the power receiving device including a power receiving power source that charges the storage battery based on the power received by the power receiving coil and the plurality of general-purpose power supply components, a power receiving processor that periodically controls a charging current to the storage battery, and a current sensor that detects the charging current, wherein when the power receiving processor determines that the detected charging current value is a current value outside a predetermined range, the power receiving processor calculates a feedback control parameter to the power receiving power source based on the difference between the value of the charging current and a target current value, and the power receiving power source controls the charging current to the storage battery based on the feedback control parameter to charge the storage battery. When the power receiving processor determines that the detected charging current value has become a current value within the predetermined range, the power receiving processor starts estimating a delay time of an operation occurring in a feedback control system of the charging current, sets the feedback control parameter to a fixed value until the delay time estimation is completed, and when the power receiving processor determines that a difference between the previously detected charging current value and the latest detected charging current value has become less than a predetermined value, ends the delay time estimation, and calculates the feedback control parameter for each estimated delay time interval after the delay time estimation is completed. The present invention provides a power receiving device. Effect of the Invention

[0011] According to the present disclosure, when a stack DC / DC power supply is adopted in a power receiving system, charging of a storage battery built into the power receiving system that follows the operational delay of the feedback system can be stably controlled. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram illustrating an example of a usage environment in which an underwater power supply system according to an embodiment of the present invention is installed; [Diagram 2] FIG. 1 is a diagram showing an example of a hardware configuration of an underwater power supply system according to an embodiment of the present invention; [Diagram 3] A block diagram showing a configuration example of a power receiving side processor corresponding to feedback control route 1. [Figure 4] Block diagram showing a configuration example of a power receiving side processor corresponding to feedback control route 2 [Diagram 5] 1 is a flowchart showing an example of an operation procedure of a power receiving side processor according to an embodiment of the present invention. [Figure 6] 1 is a flowchart showing an example of an operation procedure of a power receiving side processor according to an embodiment of the present invention. [Figure 7] A flowchart showing an example of an operation procedure of the delay re-measurement determination process of FIG. 5. [Figure 8] 1 is a graph showing an example of a change in the current value of a charging current detected at each periodic interrupt process. [Figure 9] A graph showing an example of the experimental results of the stability of the charging current when the estimated delay time interval is set to 40 ms. [Figure 10] A graph showing an example of the experimental results of the charging current stability when the estimated delay time interval is set to 50 ms. [Figure 11] A graph showing an example of the experimental results of the charging current stability when the estimated delay time interval is set to 60 ms. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] (Background to the present embodiment) As described above, in the conventional subsea power supply, when feedback control is performed using a stack DC / DC power supply in the power receiving system, delays in the operation of the feedback system (i.e., each component involved in the feedback control) occur depending on the performance variation of the stack DC / DC power supply, the state of the storage battery, the charging current, etc. For this reason, there is a problem that the operation of the subsea power supply is not stable unless feedback control that takes into account the factors that cause delays is performed. Here, feedback control route 1 (see Figure 3) and feedback control route 2 (see Figure 4) are considered as feedback control methods. If only the charge control to the storage battery built into the power receiving system is considered, either feedback control route 1 or 2 can be executed. However, when a stack DC / DC power supply is adopted in the power receiving system, the charging efficiency using the stack DC / DC power supply depends on the primary voltage (i.e., the transmission power) of the primary side (i.e., the power transmission system). Therefore, when the power supply efficiency of the entire subsea power supply system is considered, it can be considered that feedback control route 2 has better power supply efficiency than feedback control route 1.

[0014] However, feedback control route 2 is likely to have a larger operational delay in the feedback system (e.g., operational delay due to fluctuations in charging current and impedance) compared to feedback control route 1 because the feedback control goes through each coil on the power transmitting side and power receiving side. For this reason, when implementing feedback control route 2, a mechanism for detecting operational delays in the feedback system and updating delay information is considered to be more necessary than for feedback control route 1. Also, in both feedback control routes 1 and 2, it is known that the impedance of the storage battery during charging is very small, and therefore, unless the charging current can be accurately controlled in the power receiving system, it becomes difficult to stably control the charging current.

[0015] In view of the above, the following embodiment describes an example of an underwater power supply system and a charge control device that stably controls charging to a storage battery built into a power receiving system that follows the operational delay of the feedback system when a stack DC / DC power supply is adopted in the power receiving system.

[0016] (Present embodiment) Hereinafter, an embodiment (hereinafter referred to as "the present embodiment") specifically disclosing an underwater power supply system and a charge control device according to the present disclosure will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed description of already well-known matters and duplicated description of substantially identical configurations may be omitted. This is to avoid the following description becoming unnecessarily redundant and to facilitate understanding by those skilled in the art. Note that the attached drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0017] Fig. 1 is a diagram showing a schematic example of a usage environment in which an underwater power supply system 1000 according to the present embodiment is installed. The underwater power supply system 1000 has a power transmitting device 100, a power receiving device 200, and a plurality of coils CL (see Fig. 2). The power transmitting device 100 transmits power to the power receiving device 200 wirelessly (i.e., without contact) via the plurality of coils CL according to a magnetic resonance method. The number of coils CL to be arranged is n (n: an integer of 2 or more) and is arbitrary.

[0018] The coil CL is formed, for example, in a ring shape and insulated by being covered with a resin cover. The coil CL is formed, for example, by a cab-tire cable, a helical coil, or a spiral coil. A helical coil is a ring-shaped coil wound in a helical shape not in the same plane but along the direction of power transmission by the magnetic resonance method. A spiral coil is a ring-shaped coil formed in a spiral shape in the same plane. The use of a spiral coil makes it possible to make the coil CL thinner. The use of a helical coil makes it possible to secure a large space inside the wound coil CL. Note that FIG. 1 shows an example of a spiral coil.

[0019] The coil CL used for power transmission includes a power transmitting coil CLA and a power receiving coil CLB. The power transmitting coil CLA is a primary coil. The power receiving coil CLB is a secondary coil. The coil CL may include at least one relay coil CLC (Booster Coil) arranged between the power transmitting coil CLA and the power receiving coil CLB. The relay coil CLC is an example of a power transmitting coil. When there are multiple relay coils CLC, the relay coils CLC are arranged substantially parallel to each other, and more than half of the openings formed by the relay coils CLC overlap. The interval between the multiple relay coils CLC is, for example, equal to or greater than the radius of the relay coil CLC. The relay coil CLC assists the power transmission by the power transmitting coil CLA.

[0020] The power transmitting coil CLA is provided in the power transmitting device 100 (see FIG. 2). The power receiving coil CLB is provided in the power receiving device 200 (see FIG. 2). The relay coil CLC may be provided in the power transmitting device 100, in the power receiving device 200, or separately from the power transmitting device 100 and the power receiving device 200. A part of the relay coil CLC may be provided in the power transmitting device 100, and another part may be provided in the power receiving device 200.

[0021] The power transmitting device 100 may be partially installed on the ship 50, or may be disposed in another location (e.g., a power supply facility 1200 installed on land). The power receiving device 200 may be set in a mobile underwater vehicle 70 (e.g., a submarine, a bottom drilling machine), or may be installed in a fixedly installed underwater facility (e.g., a seismometer, a surveillance camera, a geothermal generator). In FIG. 1, a submarine is illustrated as an example of the underwater vehicle 70. Each coil CL is disposed underwater (e.g., in the sea).

[0022] The underwater vehicle 70 may be, for example, a Remotely Operated Vehicle (ROV), an Unmanned Underwater Vehicle (UUV), or an Autonomous Underwater Vehicle (AUV).

[0023] A part of the vessel 50 is above the water surface 90 (e.g., sea surface), i.e., above the water, and another part of the vessel 50 is below the water surface 90, i.e., underwater (e.g., under the sea). The vessel 50 is movable on the water (e.g., above sea), and can freely move to, for example, a data acquisition location on the water (e.g., above sea). A power cable 280 connects the power transmitting device 100 installed on the vessel 50 to the power transmitting coil CLA. The power cable 280 is connected to a driver 151 (see FIG. 2) in the power transmitting device 100 via a connector on the water.

[0024] The underwater vehicle 70 can travel underwater and freely move to a predetermined data acquisition point based on instructions from the ship 50. The instructions from the ship 50 may be transmitted by communication via each coil CL or by other communication methods.

[0025] The coils CL are arranged at equal intervals, for example. The distance between adjacent coils CL (coil interval) is, for example, 5 m. The coil interval is, for example, about half the diameter of the coil CL. Considering the attenuation of the magnetic field strength underwater (for example, under the sea), the transmission frequency is, for example, 40 kHz or less and preferably less than 10 kHz. In addition, when transmitting power at a transmission frequency of 10 kHz or more, it is necessary to perform a predetermined simulation based on the provisions of the Radio Law, and this work can be omitted when the frequency is less than 10 kHz. Note that the lower the transmission frequency, the longer the power transmission distance, the larger the coil CL, and the longer the coil interval. Note that the transmission frequency may be a frequency higher than 40 kHz, for example, when a communication signal is superimposed.

[0026] The transmission frequency is determined based on coil characteristics such as the inductance of the coil CL, the diameter of the coil CL, and the number of turns of the coil CL. The diameter of the coil CL is, for example, several meters to several tens of meters. The larger the diameter of the coil CL, that is, the larger the wire diameter of the coil CL, the smaller the electrical resistance in the coil CL and the smaller the power loss. The power transmitted through the coil CL is, for example, 50 W or more, and may be in the order of kW.

[0027] The power transmission device 100 may also include one or more bobbins bn around which the wire of the coil is wound. The material of the bobbins bn is a non-conductive or weakly magnetic material (e.g., resin such as polyvinyl chloride, acrylic, or polyester). The material of the bobbins bn may have dielectric properties. For example, if polyvinyl chloride is used as the material of the bobbins bn, it is inexpensive, easy to obtain, and easy to process. By making the bobbins bn non-conductive, the power transmission device 100 can suppress the magnetic field generated by the alternating current flowing through the coil CL from being absorbed by the bobbins bn. In FIG. 1, a power supply station including a bobbin bn10 floating in water and a power supply station including a bobbin bn11 arranged on the seabed are installed to perform underwater power supply (e.g., undersea power supply).

[0028] In the power supply station including the bobbin bn10, a power transmission coil CLA11 and a relay coil CLC11 are wound and arranged around the outer circumference of the cylindrical bobbin bn10. A power cable 280 is connected to the power transmission coil CLA11, and power is supplied from a ship 50 moored on the sea via the power cable 280. The power cable 280 supports this power supply station in a floating state in the sea. In the floating state, openings on both sides of the cylindrical bobbin bn10 may face horizontally. The underwater vehicle 70 may enter the entrance of the floating power supply station in the horizontal direction and receive power while remaining inside the bobbin bn10.

[0029] The power supply station including the bobbin bn11 is fixed to the top of two pillars 1101 embedded in the seabed 910. The entrance of this power supply station may face horizontally. In the power supply station, the power transmitting coil CLA12 is wound around the cylindrical bobbin bn11, but the relay coil CLC is not arranged. For example, a power cable 280A laid on the seabed 910 may be connected to the power transmitting coil CLA12, and power may be supplied from the power supply facility 1200 via the power cable 280A. The underwater vehicle 70 may enter the entrance of the power supply station installed on the seabed 910 in the horizontal direction and receive power while remaining inside the bobbin bn11.

[0030] 2 is a diagram showing an example of a hardware configuration of the underwater power supply system 1000 according to the present embodiment. As described above, the underwater power supply system 1000 includes the power transmitting device 100, the power receiving device 200, and a plurality of coils CL.

[0031] The power transmitting device 100 includes an AC power source 110, an ADC (AC / DC converter) 120, a power transmitting processor 130, an information communication unit 140, and a power transmitting circuit 150.

[0032] The ADC 120 converts AC power supplied from an AC power source 110, which is an example of a power source for power transmission, into DC power. The converted DC power is sent to the power transmission circuit 150.

[0033] The power transmitting processor 130 is configured using, for example, a CPU (Central Processing Unit), and controls the operations of each part of the power transmitting device 100 (for example, the AC power supply 110, the ADC 120, the information communication part 140, and the power transmitting circuit 150).

[0034] The information communication unit 140 has a modulation / demodulation circuit for modulating or demodulating communication data communicated with the power receiving device 200. The information communication unit 140 transmits, for example, control information from the power transmitting device 100 to the power receiving device 200 via the coil CL. The information communication unit 140 receives, for example, data from the power receiving device 200 to the power transmitting device 100 via the coil CL. This data includes, for example, data on the results of underwater exploration or bottom exploration by the underwater vehicle 70, or feedback control parameters (for example, feedback control value IB) calculated by the power receiving device 200. The information communication unit 140 can quickly communicate data with the underwater vehicle 70 (in other words, the power receiving device 200) while the underwater vehicle 70 is performing operations such as data collection.

[0035] The power transmitting circuit 150 includes a driver 151, a resonant circuit 152, and a matching circuit 153. The driver 151 converts the DC power from the ADC 120 into an AC voltage of a predetermined frequency (e.g., a pulse waveform). The resonant circuit 152 includes a capacitor CA and a power transmitting coil CLA, and generates an AC voltage of a sine wave waveform from the AC voltage of the pulse waveform from the driver 151. The power transmitting coil CLA resonates at a predetermined resonant frequency in response to the AC voltage applied from the driver 151. The power transmitting coil CLA is impedance-matched to the output impedance of the power transmitting device 100 by the matching circuit 153.

[0036] The frequency of the AC voltage obtained by the conversion by the driver 151 corresponds to the transmission frequency of the power transmission between the power transmitting device 100 and the power receiving device 200, and corresponds to the resonance frequency. The transmission frequency may be set based on the Q value of each coil CL, for example.

[0037] The power receiving device 200 includes a power receiving circuit 210 , a power supply unit 220 , a power receiving side processor 230 , an information communication unit 240 , and a current detection unit 250 .

[0038] The power receiving circuit 210 includes a rectifier circuit 211, a resonant circuit 212, and a matching circuit 213. The rectifier circuit 211 converts AC power induced in the power receiving coil CLB into DC power. The resonant circuit 212 includes a capacitor CB and a power receiving coil CLB, and receives AC power transmitted from the power transmitting coil CLA. The power receiving coil CLB is impedance-matched to the input impedance of the power receiving device 200 by the matching circuit 213.

[0039] The power supply unit 220 as an example of a power supply for power reception includes a stack DC / DC power supply 221, a charge control circuit 222, and a secondary battery 223 as an example of a storage battery. The stack DC / DC power supply 221 constitutes a power supply circuit in which a plurality of DC / DC converters, which are general-purpose circuit components (an example of general-purpose power supply components), are combined as a power supply for charging the secondary battery 223 in the underwater power supply system 1000, and supplies the DC power from the power receiving circuit 210 to the charge control circuit 222 by boosting or lowering the voltage based on a control signal (see FIG. 3) from the power receiving side processor 230. The charge control circuit 222 controls charging the secondary battery 223 according to the type of the secondary battery 223. For example, the charge control circuit 222 starts charging the secondary battery 223 at a constant voltage based on the DC power from the stack DC / DC power supply 221. The secondary battery 223 stores the power transmitted from the power transmitting device 100. The secondary battery 223 is, for example, a lithium ion battery.

[0040] The power receiving side processors 230, 230A are configured using, for example, a CPU, and control the operation of each part (for example, the power receiving circuit 210, the power supply unit 220, the current detection unit 250, and the information communication unit 240) of the power receiving device 200. The power receiving side processors 230, 230A execute periodic interrupt processing for periodically controlling the charging current to the secondary battery 223 (see Figs. 5 to 7). The periodic interrupt processing is executed, for example, every 10 ms, but when a delay time is measured as described later, the periodic interrupt processing is executed periodically at each delay time interval obtained as a result of the delay measurement. The details of the power receiving side processors 230, 230A will be described later with reference to Fig. 3 or Fig. 4.

[0041] The information communication unit 240 includes a modulation / demodulation circuit for modulating or demodulating communication data communicated with the power transmitting device 100. The information communication unit 240 receives, for example, control information from the power transmitting device 100 to the power receiving device 200 via the coil CL. The information communication unit 240 transmits, for example, data from the power receiving device 200 to the power transmitting device 100 via the coil CL. This data includes, for example, a feedback control parameter (e.g., a feedback control value IB) calculated by the power receiving device 200, or exploration results data obtained by underwater exploration or bottom exploration by the underwater vehicle 70. The information communication unit 240 can quickly communicate data with the ship 50 (in other words, the power transmitting device 100) while the underwater vehicle 70 is performing operations such as data collection.

[0042] The current detection unit 250, which is an example of a current sensor, detects the current (that is, the charging current) to the secondary battery 223 of the power supply unit 220 and sends it to the power receiving side processors 230, 230A.

[0043] The relay coil CLC, like the power transmitting coil CLA and the power receiving coil CLB, configures a resonant circuit together with the capacitor CC. That is, in this embodiment, the resonant circuits are arranged in multiple stages underwater, and power is transmitted by the magnetic resonance method.

[0044] Here, power transmission from the power transmitting device 100 to the power receiving device 200 will be briefly described with reference to FIG.

[0045] In the resonant circuit 152 of the power transmitting device 100, when a current flows through the power transmitting coil CLA of the power transmitting device 100, a magnetic field is generated around the power transmitting coil CLA. The oscillation of the generated magnetic field is transmitted to a resonant circuit including the relay coil CLC that resonates at the same frequency as the resonant frequency in the resonant circuit 152.

[0046] In the resonant circuit including the relay coil CLC, a current is excited in the relay coil CLC due to the oscillation of the magnetic field, and a magnetic field is generated around the relay coil CLC. The oscillation of the generated magnetic field is transmitted to the resonant circuit including the other relay coil CLC that resonates at the same frequency as the resonant frequency in the resonant circuit 152, and to the resonant circuit 212 including the power receiving coil CLB.

[0047] In the resonant circuit 212 of the power receiving device 200, an AC current is induced in the power receiving coil CLB due to the oscillation of the magnetic field of the relay coil CLC. The induced AC current is rectified by the rectifier circuit 211 and converted to a predetermined voltage in the power supply unit 220, and a charging current flows, thereby charging the secondary battery 223.

[0048] Next, a configuration example of the power receiving side processor 230 relating to the feedback control route 1 will be described with reference to Fig. 3. The feedback control route 1 performs feedback control (feedback control) so that the charging current to the secondary battery 223, which is the secondary side, is set to a target current value by the power receiving device 200 alone. Fig. 3 is a block diagram showing a configuration example of the power receiving side processor 230 corresponding to the feedback control route 1. The power receiving side processor 230 includes a memory 231, an AD conversion unit 232, a feedback system delay determination unit 233, a feedback control value determination unit 234, and a power supply control unit 235.

[0049] The memory 231 stores data or programs referenced during processing executed by the power receiving processor 230, and temporarily stores data generated during processing executed by the power receiving processor 230. The memory 231 stores, for example, a plurality of thresholds A, B, C, and D (see FIG. 8) used to control the delay time of the operation of the feedback system, and further stores a target current value (see FIG. 8) suitable for charging the secondary battery 223. Hereinafter, the plurality of thresholds A, B, C, and D and the target current value may be collectively referred to as a "reference current value."

[0050] The AD conversion section 232 converts the charging current to the secondary battery 223 detected by the current detection section 250 into a digital value.

[0051] The feedback system delay determination unit 233 compares the reference current value (see above) read from the memory 231 with the value of the charging current after conversion by the AD conversion unit 232. The feedback system delay determination unit 233 determines the operational delay of the feedback system based on the difference between the value of the charging current and the reference current value, and sends the determination result to the feedback control value determination unit 234. For example, while the operational delay is being measured (see time t5 to time t9 in FIG. 8), the feedback system delay determination unit 233 sends the determination result to the feedback control value determination unit 234 that the feedback control value IA is to be fixed. This determination of the operational delay will be described in detail with reference to FIGS. 5 to 7.

[0052] The feedback control value determination unit 234 calculates a feedback control value IA (for example, a current value indicating the difference between a target current value and the value of the charging current after conversion by the AD conversion unit 232) as an example of a feedback control parameter based on the determination result from the feedback system delay determination unit 233, and sends the calculated feedback control value IA to the power supply control unit 235. The feedback control value determination unit 234 determines to fix the feedback control value IA to the previously calculated value based on the determination result from the feedback system delay determination unit 233 during measurement of the operation delay. The feedback control value determination unit 234 may also send the feedback control value IA to the information communication unit 240.

[0053] The power supply control unit 235 generates a control signal for bringing the charging current closer to a target current value based on the feedback control value IA from the feedback control value determination unit 234 , and supplies the control signal to the stack DC / DC power supply 221 .

[0054] Next, a configuration example of the power receiving side processor 230A relating to the feedback control route 2 will be described with reference to Fig. 4. The feedback control route 2 performs feedback control (feedback control) so that the charging current to the secondary battery 223 becomes a target current value in cooperation with both the power receiving device 200 on the secondary side and the power transmitting device 100 on the primary side. Fig. 4 is a block diagram showing a configuration example of the power receiving side processor 230A corresponding to the feedback control route 2. In the description of Fig. 4, the same components as those shown in Fig. 3 are given the same reference numerals, and the description is simplified or omitted, and differences will be described. The power receiving side processor 230A includes a memory 231, an AD conversion unit 232, a feedback system delay determination unit 233, a feedback control value determination unit 234A, and a power supply control unit 235A.

[0055] The feedback control value determination unit 234A calculates a feedback control value IB (for example, a current value indicating the difference between a target current value and the value of the charging current after conversion by the AD conversion unit 232) as an example of a feedback control parameter based on the determination result from the feedback system delay determination unit 233, and sends the calculated feedback control value IB to the information communication unit 240. Similar to the feedback control value determination unit 234, the feedback control value determination unit 234A determines to fix the feedback control value IB to the previously calculated value based on the determination result from the feedback system delay determination unit 233 during measurement of the operation delay.

[0056] The power supply control unit 235A generates a control signal for bringing the current value closer to a predetermined value and supplies the stack DC / DC power supply 221 with the generated control signal.

[0057] The information communication unit 240 transmits the feedback control value IB from the feedback control value determination unit 234A to the information communication unit 140 of the power transmitting device 100. The information communication unit 140 receives the feedback control value IB transmitted from the information communication unit 240 of the power receiving device 200 and transmits it to the power transmitting side processor .

[0058] Based on the feedback control value IB from the information communication unit 140, the power transmitting side processor 130 generates a control signal for controlling the transmitted power from the power transmitting circuit 150, which is the primary side, in order to bring the charging current closer to the target current value, and supplies the control signal to the power transmitting circuit 150.

[0059] Based on a control signal from the power transmitting side processor 130, the power transmitting circuit 150 converts AC power from the AC power source 110 into power corresponding to the control signal, and transmits the power to the power receiving circuit 210.

[0060] Next, an example of an operation procedure of periodic control of the charging current in the power receiving device 200 according to the present embodiment will be described with reference to Figs. 5 to 8. Figs. 5 and 6 are flowcharts showing an example of an operation procedure of the power receiving processors 230, 230A according to the present embodiment. Fig. 7 is a flowchart showing an example of an operation procedure of the delay remeasurement determination process of Fig. 5. Fig. 8 is a graph showing an example of a transition of the current value of the charging current detected for each periodic interrupt process. For ease of explanation, the periodic interrupt process by the power receiving processor 230 will be described below by taking the feedback control route 1 (see Fig. 3) as an example.

[0061] In Fig. 5, the power receiving side processor 230 acquires the current value (i.e., the value of the charging current) detected by the current detection unit 250 from the output of the AD conversion unit 232 (St1). In the explanation of Figs. 5 to 8, the current value acquired in step St1 may be simply referred to as the "current value". After acquiring the current current value in step St1, the power receiving side processor 230 executes a delay remeasurement determination process (St2) for determining whether or not it is necessary to measure the delay again (in other words, for determining whether or not the charging current is appropriately controlled). The details of the delay remeasurement determination process in step St2 will be described later with reference to Fig. 7.

[0062] The power receiving processor 230 judges whether or not the current timing is the N-th periodic interrupt process (St3). If the measurement of the operational delay of the feedback system has not started, N is set to an initial value (=1). If the measurement of the operational delay of the feedback system has ended (i.e., the estimated delay time has been determined), N=(determined estimated delay time) / T. Note that T is the execution period of the periodic interrupt process, and is, for example, 10 ms. If the current timing is not the N-th periodic interrupt process (St3, NO), the periodic interrupt process of the power receiving processor 230 ends.

[0063] When it is not the timing of the N - fold periodic interrupt process this time, referring to FIG. 8, the timings are at times t11, t12, t14, and t15. As will be described later, when the estimated delay time is calculated as T×N [ms] as the delay measurement result, since the power - receiving - side processor 230 controls the charging current every T×N [ms], the periodic interrupt process is not executed at the timings of t11 and t12 when T×N [ms] has not elapsed since time t10, and further at the timings of t14 and t15 when T×N [ms] has not elapsed since time t13.

[0064] On the other hand, when the power - receiving - side processor 230 determines that this is the timing of the N - fold periodic interrupt process (St3, YES), it compares a plurality of threshold values A and D (see FIG. 8) read from the memory 231 with the current value obtained in step St1, and determines whether "threshold value A < current value" or "threshold value D > current value" holds (St4).

[0065] When the power - receiving - side processor 230 determines that "threshold value A < current value" or "threshold value D > current value" holds (St4, YES), it determines whether "threshold value A < current value" holds (St5). When the power - receiving - side processor 230 determines that "threshold value A < current value" holds (St5, YES), since the current value at present is considerably larger than the target current value (see FIG. 8), in order to approach the target current value, it calculates the current control value (that is, the feedback control value IA) as "the current control value at present (that is, the feedback control value IA) - X" (St6). X is a real - valued variable (0 < X) and corresponds to, for example, the difference between the current value at present and the target current value. After step St6, the periodic interrupt process of the power - receiving - side processor 230 ends.

[0066] If the power receiving processor 230 determines that "threshold A<current value" does not hold (St5, NO), then since "threshold D>current value" holds (see FIG. 8), it calculates the current control value (i.e., feedback control value IA) to be "current current control value (i.e., feedback control value IA)+X" to approach the target current value (St7). After step St7, the periodic interrupt process of the power receiving processor 230 ends.

[0067] When the power receiving processor 230 determines that neither "threshold A<current value" nor "threshold D>current value" is satisfied (St4, NO), since "threshold D<current value<threshold A" is satisfied (see FIG. 8), it determines that the current value approaches the target current value and starts measuring the operational delay of the feedback system, or continues to measure the operational delay of the feedback system if it has already started (St8). In FIG. 8, the operational delay of the feedback system starts at time t5, and the current value is far from the target current value from time 0 to time t4, and since it is not necessary to obtain the delay characteristic value in this time region, measurement of the operational delay of the feedback system is not started. Also, while measuring the operational delay of the feedback system, the power receiving processor 230 uses the current feedback control value IA as a fixed value (i.e., fixes the feedback control value IA so as not to change it) in order to further suppress the occurrence of the operational delay of the feedback system.

[0068] The power receiving side processor 230 determines whether the delay determination flag stored in the memory 231 is ON (i.e., whether the measurement of the operational delay of the feedback system in step St8 has been completed or not) (St9). Whether the delay determination flag is ON or OFF is temporarily stored in the memory 231 by the power receiving side processor 230. When the power receiving side processor 230 determines that the delay determination flag is OFF (i.e., the measurement of the operational delay of the feedback system in step St8 has not been completed) (St9, NO), it determines whether there is a difference between the current value acquired in step St1 of the current periodic interrupt process and the previous current value (previous sample value) acquired in step St1 of the previous periodic interrupt process (St10).

[0069] When the power receiving processor 230 determines that there is a difference (for example, a certain range value of about ±10 mA) between the current value acquired in step St1 of the current periodic interrupt process and the previous current value (previous sample value) acquired in step St1 of the previous periodic interrupt process (St10, YES), it increments the periodic count flag (St11). The periodic count flag is a parameter that is counted during measurement of the operational delay of the feedback system, and has the role of indicating how many times the estimated delay time obtained as the measurement result is the period of the periodic interrupt process. After step St11, the periodic interrupt process of the power receiving processor 230 ends.

[0070] On the other hand, when the power receiving processor 230 determines that there is no difference between the current value acquired in step St1 of the current periodic interrupt process and the previous current value (previous sample value) acquired in step St1 of the previous periodic interrupt process (St10, YES), it sets the value of the periodic count flag at that point to N (St12) and sets the delay determination flag to ON (St13). After step St13, the periodic interrupt process of the power receiving processor 230 ends.

[0071] 8, for example, measurement of the operational delay of the feedback system is started at time t5, and ends at time t9 when it is determined that there is no difference from the previous sample value. In this measurement, the estimated delay time that would have occurred in the feedback system is the product of the period (T [ms]) of the periodic interrupt process and the value (N) of the periodic count flag at the measurement end timing (T×N [ms]). Therefore, from time t10 following time t9 when measurement of the operational delay of the feedback system ends, the power receiving side processor 230 executes periodic interrupt process at every estimated delay time interval.

[0072] When the receiving side processor 230 determines that the delay determination flag is ON (i.e., the measurement of the operational delay of the feedback system in step St8 has been completed) (St9, YES), it determines whether or not "threshold B < current value < threshold A" is true using thresholds A and B read from memory 231 (St14).

[0073] In FIG. 6, when the power receiving side processor 230 determines that "threshold B < current value < threshold A" holds (St14, YES), since the current value is greater than the target current value (see FIG. 8), in order to approach the target current value, the current control value (i.e., feedback control value IA) is calculated as "current current control value (i.e., feedback control value IA) - Y" (St15). Y is a real variable value (0 < Y << X) and corresponds to, for example, the difference between the current current value and the target current value. After step St15, the periodic interrupt process of the power receiving side processor 230 ends.

[0074] On the other hand, when the power receiving side processor 230 determines that "threshold B < current value < threshold A" does not hold (St14, NO), threshold D < current value < threshold B is obtained (see FIG. 8), and it is determined whether "target value < current value" holds (St16). When the power receiving side processor 230 determines that "target value < current value" holds (St16, YES), since the current value is slightly greater than the target value (see FIG. 8), in order to approach the target current value, the current control value (i.e., feedback control value IA) is calculated as "current current control value (i.e., feedback control value IA) - Z" (St17). Z is a real variable value (0 < Z < Y << X) and corresponds to, for example, the difference between the current current value and the target current value. After step St17, the periodic interrupt process of the power receiving side processor 230 ends.

[0075] When the power receiving side processor 230 determines that "target value < current value" does not hold (St16, NO), threshold D < current value < target current value is obtained (see FIG. 8), and it is determined whether "threshold D < current value < threshold C" holds (St18). When the power receiving side processor 230 determines that "threshold D < current value < threshold C" holds (St18, YES), since the current value is less than the target value (see FIG. 8), in order to approach the target current value, the current control value (i.e., feedback control value IA) is calculated as "current current control value (i.e., feedback control value IA) + Y" (St19). After step St19, the periodic interrupt process of the power receiving side processor 230 ends.

[0076] On the other hand, if the power receiving processor 230 determines that "threshold D<current value<threshold C" is not true (St18, NO), the current current value is slightly smaller than the target value (see FIG. 8), so it calculates the current control value (i.e., feedback control value IA) as "current current control value (i.e., feedback control value IA)+Z" to bring it closer to the target current value (St20). After step St20, the periodic interrupt process of the power receiving processor 230 ends.

[0077] The delay remeasurement determination process shown in FIG. 7 is a process executed to check whether the charging current is appropriately controlled, for example, because the time characteristics of the operation delay of the feedback system may change after the measurement of the operation delay of the feedback system is completed, and because the delay characteristics may change due to a change in the coupling coefficient of the coil caused by the positional relationship between the power transmitting device 100 and the power receiving device 200 becoming position-free in the case of the feedback control route 2. The time characteristics of the operation delay of the feedback system may change, for example, because the impedance of the secondary battery 223 during charging is very small, and the battery impedance changes as the battery characteristics of the secondary battery 223 change with the increase in the battery voltage of the secondary battery 223 due to charging. Specifically, the power receiving side processor 230 determines whether remeasurement of the operation delay of the feedback system is necessary by monitoring the moving average value and standard deviation (i.e., the variation in the current value) of the current value detected by the current detection unit 250 in the delay remeasurement determination process.

[0078] In Fig. 7, the power receiving side processor 230 judges whether or not a variable i indicating the number of samples of the current value is equal to or greater than a predetermined number of moving average samples K (St21). The number of moving average samples K is the number required to calculate the moving average value of the current value by a formula described later. If it is judged that the variable i is less than the number of moving average samples K (St21, NO), the power receiving side processor 230 increments the variable i (St22). After step St22, the delay re-measurement judgment process of the power receiving side processor 230 ends, and the process of the power receiving side processor 230 proceeds to step St3.

[0079] When the power receiving processor 230 determines that the variable i is equal to or greater than the moving average sample number K (St21, YES), it reads out data on the current value (Current[i]) detected by the current detection unit 250 (St23). The power receiving processor 230 uses the data on the K current values ​​to calculate a moving average value M of the K current values ​​according to equation (1) (St24). Like the variable i, n indicates the ordinal number of the read current value and is a positive integer. The power receiving processor 230 uses the moving average value M calculated in step St24 to calculate a standard deviation α indicating the variation of the K current values ​​according to equation (2) (St25).

[0080]

number

[0081]

number

[0082] The power receiving side processor 230 judges whether the delay determination flag is OFF or not by referring to the memory 231 (St26). When the power receiving side processor 230 judges that the delay determination flag is OFF (i.e., the estimated delay time is not determined) (St26, YES), the power receiving side processor 230 increments the variable i (St29). After step St29, the delay remeasurement determination process of the power receiving side processor 230 ends, and the process of the power receiving side processor 230 proceeds to step St3.

[0083] On the other hand, when the power receiving processor 230 determines that the delay determination flag is ON (i.e., the estimated delay time is determined) (St26, NO), it determines whether the standard deviation α calculated in step St25 is greater than a predetermined stability threshold stored in the memory 231 (in other words, whether the current value that should be controlled based on the feedback control value IA varies) (St27).

[0084] When the power receiving processor 230 determines that the standard deviation α is greater than a predetermined stability threshold (St27, YES), the delay determination flag is ON and the estimated delay time is determined, but the current value varies widely, so it is necessary to remeasure the operational delay of the feedback system, and the delay determination flag is set to OFF (St28). After step St28, the process of the power receiving processor 230 proceeds to step St29.

[0085] On the other hand, when the power receiving processor 230 judges that the standard deviation α is smaller than the predetermined stability threshold (St27, NO), the delay determination flag is ON and the estimated delay time is determined, but the variation in the current value is small, so that the charging current can be controlled relatively stably, and therefore remeasurement of the operational delay of the feedback system is deemed unnecessary, and the variable i is incremented (St29). After step St29, the delay remeasurement determination process of the power receiving processor 230 ends, and the process of the power receiving processor 230 proceeds to step St3.

[0086] Next, the results of an experiment on how the stability of the charging current changes when the estimated delay time is changed will be described with reference to Figs. 9 to 11. Fig. 9 is a graph showing an example of the experimental results of the stability of the charging current when the estimated delay time interval is 40 ms. Fig. 10 is a graph showing an example of the experimental results of the stability of the charging current when the estimated delay time interval is 50 ms. Fig. 11 is a graph showing an example of the experimental results of the stability of the charging current when the estimated delay time interval is 60 ms.

[0087] In this experiment, the delay time of the feedback system (see FIG. 3 or FIG. 4) was not measured, and the estimated delay time interval (i.e., the execution interval of the periodic interrupt process shown in FIG. 5 to FIG. 7) was a fixed value, but it was found that the stability of the charging current changes depending on the value of the estimated delay time interval, which is a fixed value. For example, FIG. 9 shows the time transition of the charging current when the estimated delay time interval is set to 40 ms, FIG. 10 shows the estimated delay time interval to 50 ms, and FIG. 11 shows the time transition of the charging current when the estimated delay time interval is set to 60 ms. In the experiment, a battery simulator (21 cells) was used to evaluate the charging current, and a 3-stack power supply was used as the stack DC / DC power supply 221 of the power supply unit 220 of the power receiving device 200. Referring to FIG. 9 to FIG. 11, it was found that in this experiment, the charging current transitions most stably when the estimated delay time interval is 50 ms.

[0088] As described above, the underwater power supply system 1000 according to the present embodiment includes the power transmitting device 100 and the power receiving device 200 that can move underwater. The power transmitting device 100 includes a power transmitting coil CLA that transmits power to the power receiving device 200 via a magnetic field, and a power transmitting side processor 130 that controls power from a power transmitting power source (e.g., AC power source 110) and supplies the power to the power transmitting coil CLA. The power receiving device 200 includes a power receiving coil CLB that receives power from the power transmitting coil CLA, a stack DC / DC power source 221 that is a plurality of general-purpose power supply components (e.g., a power supply circuit in which a plurality of DC / DC converters are combined), and a storage battery (e.g., a secondary battery 223), and includes a power receiving power source (e.g., a power supply unit 220) that charges the storage battery based on the power received by the power receiving coil CLB and the plurality of general-purpose power supply components, a power receiving side processor 230A that periodically controls a charging current to the storage battery, and a current sensor (e.g., a current detection unit 250) that detects the charging current. When the power receiving processor 230A determines that the detected charging current value is outside a predetermined range (for example, a range from threshold D to threshold A), it calculates a feedback control parameter (for example, a feedback control value IB) to the power transmission power source based on the difference between the charging current value and the target current value, and transmits the feedback control parameter to the power transmission processor. The power transmission processor controls the power from the power transmission power source based on the feedback control parameter.

[0089] As a result, even if a stack DC / DC power supply 221 that combines multiple general-purpose power supply components is adopted for the power receiving device 200, the underwater power supply system 1000 can stably control charging of a storage battery (e.g., a secondary battery 223) that follows the operational delay of the feedback system in the feedback control route 2 between the power receiving device 200 that can move underwater and the power transmitting device 100.

[0090] In addition, the underwater power supply system 1000 in this embodiment includes a power transmitting device 100 and a power receiving device 200 that can move underwater. The power transmitting device 100 includes a power transmitting coil CLA that transmits power to the power receiving device 200 via a magnetic field, and a power transmitting side processor 130 that controls power from a power transmitting power source (e.g., AC power source 110) and supplies the power to the power transmitting coil CLA. The power receiving device 200 includes a power receiving coil CLB that receives power from the power transmitting coil CLA, a plurality of general-purpose power supply components (e.g., a power supply circuit in which a plurality of DC / DC converters are combined) and a storage battery (e.g., a secondary battery 223), a power receiving power source (e.g., a power supply unit 220) that charges the storage battery based on the power received by the power receiving coil CLB and the plurality of general-purpose power supply components, a power receiving side processor 230 that periodically controls a charging current to the storage battery, and a current sensor (e.g., a current detection unit 250) that detects the charging current. When the power receiving processor 230 determines that the detected charging current value is outside a predetermined range (for example, the range from threshold D to threshold A), it calculates a feedback control parameter (for example, feedback control value IA) to the power receiving power source based on the difference between the charging current value and the target current value. The power receiving power source controls the charging current to the storage battery based on the feedback control parameter to charge the storage battery.

[0091] As a result, even if a stack DC / DC power supply 221 that combines multiple general-purpose power supply components is adopted for the power receiving device 200, the underwater power supply system 1000 can stably control charging of a storage battery (e.g., a secondary battery 223) that follows the operational delay of the feedback system in the feedback control route 1 between the power receiving device 200 that can move underwater and the power transmitting device 100.

[0092] Furthermore, when the power receiving processor 230, 230A determines that the detected charging current value is within a predetermined range, it starts estimating the delay time of the operation generated in the feedback control system of the charging current, and sets the feedback control parameter to a fixed value until the estimation of the delay time is completed. This allows the power receiving processor 230, 230A to start measuring the operational delay of the feedback system when the charging current becomes close to a target current value at which the feedback system is likely to experience an operational delay depending on the charging current, and also fixes the feedback control parameter during measurement, thereby suppressing the variation in the charging current during measurement.

[0093] Furthermore, the power receiving processor 230, 230A terminates the estimation of the delay time when it is determined that the difference between the previously detected value of the charging current and the latest value of the detected charging current is less than a predetermined value. This allows the power receiving processor 230, 230A to detect that the transition of the charging current has stabilized based on the determination result that the difference between the previously detected value of the charging current and the latest value of the detected charging current is less than a predetermined value, and to appropriately terminate the estimation (measurement) of the delay time.

[0094] After estimating the delay time, the power receiving processor 230, 230A calculates a feedback control parameter for each estimated delay time interval. This allows the power receiving processor 230, 230A to suppress unnecessary periodic interrupt processing and adaptively determine whether the transition of the charging current is stable.

[0095] Moreover, the power transmitting device 100 further includes a power transmitting side communication unit (e.g., information communication unit 140). The power receiving device 200 further includes a power receiving side communication unit (e.g., information communication unit 240). The power receiving side communication unit transmits feedback control parameters to the power transmitting side communication unit. This can simplify data communication between the power transmitting device 100 and the power receiving device 200 in the feedback control route 2.

[0096] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications, corrections, substitutions, additions, deletions, and equivalents within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present disclosure. In addition, the components in the various embodiments described above may be arbitrarily combined within the scope of the invention.

[0097] In the above-described embodiment, the power receiving device 200 may be a generator or the like installed on the seabed. In this case, the power receiving device 200 is fixedly installed underwater. In this way, even if the structure is fixedly installed on the seabed and it is difficult to move the structure for charging, the power transmitting device 100 can approach the power receiving device 200 to improve the efficiency of power transmission underwater and charge the device.

[0098] In the above-described embodiment, the power transmitting coil CLA and the multiple relay coils CLC are arranged transversely (horizontally) in seawater, but they may be arranged vertically (vertically). In the vertical orientation, the planes of the power transmitting coil CLA and the relay coil CLC are substantially parallel to the water surface. In the vertical orientation, the power receiving coil CLB mounted on the AUV 800 may also be mounted vertically so as to be aligned with the magnetic field direction. In other words, the plane of the power receiving coil CLB may be substantially parallel to the water surface. In the case of a power transmitting coil structure in which the power transmitting coil CLA and the relay coil CLC are connected via a connector, even if the power transmitting coil structure is arranged vertically, the underwater vehicle 70 may be able to enter and exit the power transmitting coil horizontally. On the other hand, in the case of a transmission coil in which the transmission coil CLA and the relay coil CLC are wound around a bobbin bn, if the transmission coil is arranged vertically, the underwater vehicle 70 may enter the inside of the transmission coil through openings of the bobbin bn located at the upper and lower ends of the bobbin bn. [Industrial Applicability]

[0099] The present disclosure relates to an underwater power supply system that stably controls charging of a storage battery built into a power receiving system in accordance with the operational delay of a feedback system when a stack DC / DC power supply is adopted in the power receiving system. 、 Powered Device and power supply method It is useful as. [Explanation of symbols]

[0100] 50 ships 70 Underwater vehicle 100 Power transmission equipment 110 AC power supply 120 ADC 130 Power transmission processor 140, 240 Ministry of Information and Communications 150 Power transmission circuit 151 Drivers 152, 212 resonant circuit 153, 211 matching circuit 200 Powered Device 210 Receiving circuit 211 Rectifier circuit 220 Power supply section 221 Stack DC / DC Power Supply 222 Charging control circuit 223 Secondary battery 230 Receiving Processor 231 Memory 232 AD conversion section 233 Feedback system delay judgment unit 234, 234A Feedback control value determination section 235 Power supply control unit 250 Current detection section 1000 Underwater Power Supply System CLA Transmitting Coil CLB Receiving coil

Claims

1. An underwater power supply system having a power transmitting device and a power receiving device movable underwater, The power transmitting device is A power transmitting coil that transmits power to the power receiving device via a magnetic field; a power transmission side processor that controls the power from a power transmission power source and supplies the power to the power transmission coil; The power receiving device is a receiving coil that receives power from the transmitting coil; a power receiving power source including a plurality of general-purpose power supply components and a storage battery, the power receiving power source charging the storage battery based on the power received by the power receiving coil and the plurality of general-purpose power supply components; A power receiving processor that periodically controls a charging current to the storage battery; a current sensor for detecting the charging current; when it is determined that the detected charging current value is a current value outside a predetermined range, the power receiving processor calculates a feedback control parameter to the power transmission power source based on a difference between the charging current value and a target current value, and transmits the feedback control parameter to the power transmission processor; The power transmitting processor controls the power from the power transmission power source based on the feedback control parameter; The power receiving side processor, When it is determined that the detected charging current value has become a current value within the predetermined range, an estimation of a delay time of an operation occurring in a feedback control system of the charging current is started, and the feedback control parameter is set to a fixed value until the estimation of the delay time is completed; when it is determined that a difference between the previously detected value of the charging current and the latest detected value of the charging current is less than a predetermined value, the estimation of the delay time is terminated; After the estimation of the delay time is completed, the feedback control parameter is calculated for each estimated delay time interval. Underwater power supply system.

2. An underwater power supply system having a power transmitting device and a power receiving device movable underwater, The power transmitting device is A power transmitting coil that transmits power to the power receiving device via a magnetic field; a power transmission side processor that controls the power from a power transmission power source and supplies the power to the power transmission coil; The power receiving device is a receiving coil that receives power from the transmitting coil; a power receiving power source including a plurality of general-purpose power supply components and a storage battery, the power receiving power source charging the storage battery based on the power received by the power receiving coil and the plurality of general-purpose power supply components; A power receiving processor that periodically controls a charging current to the storage battery; a current sensor for detecting the charging current; when it is determined that the detected charging current value is a current value outside a predetermined range, the power receiving processor calculates a feedback control parameter to the power receiving power source based on a difference between the charging current value and a target current value; the power receiving power source controls a charging current to the storage battery based on the feedback control parameter to charge the storage battery; The power receiving side processor, When it is determined that the detected charging current value has become a current value within the predetermined range, an estimation of a delay time of an operation occurring in a feedback control system of the charging current is started, and the feedback control parameter is set to a fixed value until the estimation of the delay time is completed; when it is determined that a difference between the previously detected value of the charging current and the latest detected value of the charging current is less than a predetermined value, the estimation of the delay time is terminated; After the estimation of the delay time is completed, the feedback control parameter is calculated for each estimated delay time interval. Underwater power supply system.

3. The power transmitting device further includes a power transmitting side communication unit, The power receiving device further includes a power receiving side communication unit, The power receiving side communication unit transmits the feedback control parameter to the power transmitting side communication unit. The underwater power supply system according to claim 1 .

4. A power receiving device that is movable underwater and receives power transmitted from a power transmitting device having a power transmitting coil, a receiving coil that receives power from the transmitting coil; a power receiving power source including a plurality of general-purpose power supply components and a storage battery, the power receiving power source charging the storage battery based on the power received by the power receiving coil and the plurality of general-purpose power supply components; A power receiving processor that periodically controls a charging current to the storage battery; a current sensor for detecting the charging current; when it is determined that the detected charging current value is a current value outside a predetermined range, the power receiving processor calculates a feedback control parameter to a power transmission power source based on a difference between the charging current value and a target current value, and instructs the power transmitting device to control power from the power transmission power source based on the feedback control parameter; The power receiving side processor, When it is determined that the detected charging current value has become a current value within the predetermined range, an estimation of a delay time of an operation occurring in a feedback control system of the charging current is started, and the feedback control parameter is set to a fixed value until the estimation of the delay time is completed; when it is determined that a difference between the previously detected value of the charging current and the latest detected value of the charging current is less than a predetermined value, the estimation of the delay time is terminated; After the estimation of the delay time is completed, the feedback control parameter is calculated for each estimated delay time interval. Powered device.

5. A power receiving device that is movable underwater and receives power transmitted from a power transmitting device having a power transmitting coil, a receiving coil that receives power from the transmitting coil; a power receiving power source including a plurality of general-purpose power supply components and a storage battery, the power receiving power source charging the storage battery based on the power received by the power receiving coil and the plurality of general-purpose power supply components; A power receiving processor that periodically controls a charging current to the storage battery; a current sensor for detecting the charging current; when it is determined that the detected charging current value is a current value outside a predetermined range, the power receiving processor calculates a feedback control parameter to the power receiving power source based on a difference between the charging current value and a target current value; the power receiving power source controls a charging current to the storage battery based on the feedback control parameter to charge the storage battery; The power receiving side processor, When it is determined that the detected charging current value has become a current value within the predetermined range, an estimation of a delay time of an operation occurring in a feedback control system of the charging current is started, and the feedback control parameter is set to a fixed value until the estimation of the delay time is completed; when it is determined that a difference between the previously detected value of the charging current and the latest detected value of the charging current is less than a predetermined value, the estimation of the delay time is terminated; After the estimation of the delay time is completed, the feedback control parameter is calculated for each estimated delay time interval. Powered device.

6. A power supply method performed by an underwater power supply system having a power transmitting device and a power receiving device movable underwater, the power transmitting device includes a power transmitting coil that transmits power to the power receiving device via a magnetic field, and a power transmitting side processor that controls the power from a power transmission power source and supplies the power to the power transmitting coil; the power receiving device includes a power receiving coil that receives power from the power transmitting coil, a plurality of general-purpose power supply components, and a storage battery, a power receiving power source that charges the storage battery based on the power received by the power receiving coil and the plurality of general-purpose power supply components, a power receiving processor that periodically controls a charging current to the storage battery, and a current sensor that detects the charging current; when the power receiving processor determines that the detected charging current value is a current value outside a predetermined range, the power receiving processor calculates a feedback control parameter to the power transmission power source based on a difference between the charging current value and a target current value, and transmits the feedback control parameter to the power transmission processor; The power transmitting processor controls the power from the power transmission power source based on the feedback control parameter; When the power receiving processor determines that the detected charging current value has become a current value within the predetermined range, it starts estimating a delay time of an operation occurring in a feedback control system of the charging current, sets the feedback control parameter to a fixed value until the estimation of the delay time is completed, and when it determines that a difference between the previously detected charging current value and the latest detected charging current value has become less than a predetermined value, it terminates the estimation of the delay time, and calculates the feedback control parameter for each estimated delay time interval after the estimation of the delay time is completed. Power supply method.

7. A power supply method performed by an underwater power supply system having a power transmitting device and a power receiving device movable underwater, comprising: the power transmitting device includes a power transmitting coil that transmits power to the power receiving device via a magnetic field, and a power transmitting side processor that controls the power from a power transmission power source and supplies the power to the power transmitting coil; the power receiving device includes a power receiving coil that receives power from the power transmitting coil, a plurality of general-purpose power supply components, and a storage battery, a power receiving power source that charges the storage battery based on the power received by the power receiving coil and the plurality of general-purpose power supply components, a power receiving processor that periodically controls a charging current to the storage battery, and a current sensor that detects the charging current; when the power receiving processor determines that the detected charging current value is a current value outside a predetermined range, the power receiving processor calculates a feedback control parameter to the power receiving power source based on a difference between the charging current value and a target current value; charging the storage battery by controlling a charging current to the storage battery based on the feedback control parameter by the power receiving power source; When the power receiving processor determines that the detected charging current value has become a current value within the predetermined range, it starts estimating a delay time of an operation occurring in a feedback control system of the charging current, sets the feedback control parameter to a fixed value until the estimation of the delay time is completed, and when it determines that a difference between the previously detected charging current value and the latest detected charging current value has become less than a predetermined value, it terminates the estimation of the delay time, and calculates the feedback control parameter for each estimated delay time interval after the estimation of the delay time is completed. Power supply method.

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