JP2007237823A - Marine buoy - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a marine buoy capable of allowing a light emitter to continuously emit light without being influenced by weather condition. <P>SOLUTION: The marine buoy is equipped with a power monitoring controller mounted on a buoy body, a wave power generation device which is mounted to the buoy body so as to be connected to the power monitoring controller, a solar energy generation device mounted to the buoy body so as to be connected to the power monitoring controller, an electric discharge controller mounted to the buoy body so as to connected to the power monitoring controller, the light emitter mounted to the buoy body so as to be connected to the electric discharge controller, a capacitor which is mounted to the buoy so as to be connected to the power monitoring controller and discharges the power of large current, and a lithium ion secondary battery which is mounted to the buoy body so as to be connected to the capacitor, connected to the discharge controller through a switch, and has an anode containing lithium titanium oxide as a negative electrode active material, and an electrolysis solution containing γ-butyl lactone. The electric discharge controller detects the electric energy supplied from the power monitoring controller, and has a function for turning on the switch when the detected electric energy is less than the electric energy required for enabling the light emitter to emit the light. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light buoy installed on the ocean, a so-called maritime buoy.

  Conventionally, various maritime buoys have been installed for the purpose of safe navigation of ships, detection of marine accidents, reception of signals from space, transmission of emergency signals, collection of weather information, and the like. As a power generation system incorporated in this marine buoy, it is generally configured by combining a primary battery such as a solar power generation device, a wave power generation device, and an air battery.

  However, in the case of a primary battery, since it cannot be charged, cost and labor are required for the maintenance of the maritime buoy installed on the ocean.

  On the other hand, Patent Document 1 discloses a buoy including a solar cell device, a fuel cell device, and a storage battery that sequentially discharges electricity for signal transmission and display light emission. Patent Document 2 discloses a self-charging observation buoy equipped with a storage battery (secondary battery) and a generator for charging the storage battery.

However, a conventional secondary battery, for example, a storage battery such as a lithium ion secondary battery using a carbon material as a negative electrode active material, a nickel hydride secondary battery, or a nickel cadmium secondary battery, is usually charged for 1 to 2 hours. Therefore, the surplus electric power from a solar power generation device and a wave power generation device cannot be charged efficiently. In addition, since nickel-hydrogen secondary batteries, nickel cadmium secondary batteries, or primary batteries, which are air batteries, contain aqueous electrolytes, some of the electrolytes freeze in an offshore environment that reaches negative temperatures. This limits the original operation of the battery. As a result, the operation of the maritime buoy is hindered.
JP 2001-278183 A JP-A-7-223583

  The present invention provides a marine buoy that can continuously emit light from a light emitter without being affected by weather conditions.

According to the present invention, a buoy body installed on the ocean;
A power monitoring controller mounted on the buoy body;
A wave power generator attached to the buoy body so as to be connected to the power monitoring controller;
A solar power generator attached to the buoy body so as to be connected to the power monitoring controller;
A discharge controller mounted on the buoy body to be connected to the power monitoring controller;
A light emitter attached to the buoy body to be connected to the discharge controller;
A capacitor that is attached to the buoy body so as to be connected to the power monitoring controller, and that discharges a large amount of power,
Lithium having a negative electrode containing lithium titanium oxide as a negative electrode active material and an electrolyte containing γ-butyllactone, connected to the capacitor on the buoy body and connected to the discharge controller through a switch An ion secondary battery,
The discharge controller has a function of detecting the amount of power supplied from the power monitoring controller and turning on the switch when the detected amount of power is less than the amount of power required to cause the light emitter to emit light. A maritime buoy characterized by that is provided.

  According to the present invention, when it is not possible to obtain power from a wave power generator or a solar power generator for a long time due to weather conditions, or when exposed to an offshore environment that reaches a negative temperature (for example, minus 20 ° C.). Even in such a case, it is possible to provide a maritime buoy capable of causing the light emitting device to emit light stably.

  Hereinafter, a marine buoy according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2. FIG. 1 is a schematic cross-sectional view of a maritime buoy according to the embodiment, and FIG. 2 is an equivalent circuit diagram of the maritime buoy of FIG.

  The buoy body 1 includes a hollow circular body 2, a support shaft 3 extending vertically through the center of the hollow circular body 2, and a cylinder coaxially fixed to the support shaft 3 on the hollow circular body 2. A body 4 and a first support base 5 and a second support base 6 that are disposed in the hollow circular body 2 and are vertically mounted on the support shaft 3. A connecting ring 7 is attached to the bottom of the hollow circular body 2 of the buoy main body 1 and is connected to a weight 9 on the bottom of the water through a wire 8 to float at a certain position on the sea.

  The solar power generation device 10 includes a solar panel 11 attached to the upper part of the cylindrical body 4 of the buoy main body 1 and a power generation controller 12 built in the cylindrical body 4. The wave power generation device 13 is mounted on the hollow circular body 2 of the buoy main body 1. The wave power generation device 12 includes an air turbine 14 and a generator 15 as shown in the circuit diagram shown in FIG. The antenna 16 is attached to the top of the cylindrical body 4 of the buoy body 1. The antenna 16 is connected to a signal transmitting / receiving device (not shown).

  The lithium ion secondary battery 17 is loaded on the second support 6 in the hollow circular body 2 of the buoy body 1. The secondary battery 17 has a negative electrode containing lithium titanium oxide as a negative electrode active material and an electrolytic solution containing γ-butyllactone. The light emitter 18 is attached to the side surface of the cylindrical body 4 of the buoy main body 1. The power monitoring controller 19 is attached on the first support 5 in the hollow circular body 2 of the buoy body 1. The power monitoring controller 19 is connected to the solar power generation device 10, the wave power generation device 12, the secondary battery 17, and the light emitter 18.

  The above-described maritime buoy will be described with reference to the block diagram shown in FIG.

  The generator 15 that generates power by the air turbine 14 that operates with wave power is connected to the power monitoring controller 19, and supplies the generated AC power to the power monitoring controller 19. The solar panel 11 that generates direct-current power by sunlight is connected to the power monitoring controller 19 through the power generation controller 12 and supplies the generated DC power to the power monitoring controller 19. The power monitoring controller 19 has a function of selecting one or both of the wave power generation apparatus 13 and the solar power generation apparatus 10 according to the generated power, a function of stabilizing the power, the wave power generation apparatus 13. The AC / DC converter which converts the alternating current power from DC into direct current power is provided.

  The power monitoring controller 19 is connected to a discharge controller 20 and a first charge controller 21. The discharge controller 20 is connected to the light emitter 18 and supplies DC power for causing the light emitter 18 to emit light. The first charge controller 21 is connected to a capacitor 22 that discharges a large current. The capacitor 22 is connected to the lithium secondary battery 17 through the second charge controller 23.

  The discharge controller 20 is also connected to the secondary battery 17. For example, the switch 24 composed of an FET is interposed between the discharge controller 20 and the secondary battery 17 and is in an OFF state during normal operation (charging). The discharge controller 20 detects the amount of DC power supplied from the power monitoring controller 19, and when the detected power amount is less than the power amount (threshold value) necessary for causing the light emitter 18 to emit light. The switch 24 has a function of applying a predetermined voltage to turn it on. That is, when the amount of DC power supplied from the power monitoring controller 19 is less than the amount of power required to cause the light emitter 18 to emit light, or the power is supplied from the power monitoring controller 19 to the discharge controller 20. If not, the DC power generated by the discharge of the secondary battery 17 is supplied to the light emitter 18 via the discharge controller 20 to emit light.

  The first charge controller 21 supplies the power to the capacitor 22 when the amount of power supplied from the power monitoring controller 19 to the discharge controller 20 is excessive, and when charging the capacitor 22 Charge control. The second charge controller 23 controls the discharge timing of the capacitor 22 on the upstream side and the charge state of the secondary battery 17, and power to the secondary battery when the secondary battery 17 is fully charged. It has a function to limit supply.

  The power monitoring controller 19 is connected to a signal transmission / reception device (not shown) and supplied with power for driving the device.

  In a maritime buoy having such a configuration, in a weather situation where waves are generated on the sea and sunlight falls, the wave energy is converted into AC power by the wave power generator 13 and supplied to the power monitoring controller 19. Here, it is converted into DC power by an AC / DC converter. The solar energy is converted into DC power by the solar power generation device 10 and supplied to the power monitoring controller 19. The DC power supplied to the power monitoring controller 19 is stabilized here, and the power is supplied to the discharge controller 20 and the first charge controller 21, respectively.

  The discharge controller 20 detects the amount of DC power supplied from the power monitoring controller 19, and the detected power amount is greater than or less than a threshold necessary for causing the light emitter 18 to emit light. It is determined whether it is. When the supplied DC power amount is equal to or greater than the threshold value, the power supply (discharge power) from the secondary battery 17 is not performed without turning on the switch 24 between the secondary battery 17 and the discharge controller 20. Without being received, the DC power supplied from the power monitoring controller 19 is supplied to the light emitter 18 to emit light.

  The first charge controller 21 determines whether or not the supplied DC power amount is surplus, and if it is surplus, the power is supplied to the capacitor 22 and charged as a charge. Here, “surplus” means that the amount of power necessary to cause the light emitter 18 to emit light is exceeded. In this charge accumulation in the capacitor 22, when the second charge controller 23 detects that a sufficient amount of charge has been accumulated from the capacitor 22 to be discharged, the capacitor 22 is charged with the second current. The battery is discharged through the controller 23 to the rapidly chargeable lithium ion secondary battery 17 having a negative electrode containing lithium titanium oxide as a negative electrode active material, and is quickly charged. The operation of discharging a large current from the capacitor 22 to the secondary battery 17 through the second charge controller 23 and rapidly charging it is repeated a plurality of times, and when the secondary battery 17 is fully charged, the second charge controller 23 Thus, power supply to the secondary battery 17 is limited.

  On the other hand, when the sea is in a dredging state and changes to a weather condition such as cloudy, the power supply from the wave power generation device 13 and the solar power generation device 10 to the power monitoring controller 19 becomes small. In such a situation, the amount of power supplied to the first charge controller 21 is not determined to be excessive, and power supply to the capacitor 22 is not performed. Further, since the DC power amount detected by the discharge controller 20 becomes less than the threshold value, the switch 24 between the secondary battery 17 and the discharge controller 20 is turned on. When the switch 24 is turned on, the discharge power of the secondary battery 17 is supplied to the light emitter 18 through the discharge controller 20, and the light emitter 18 is caused to emit light continuously even if the weather condition changes.

  The lithium secondary battery includes a negative electrode containing lithium titanium oxide as an active material and an electrolytic solution containing γ-butyllactone (for example, an electrolytic solution containing γ-butyllactone and ethylene carbonate as an organic solvent).

  As disclosed in JP-A-2005-123183, the lithium titanium oxide as an active material is a material capable of inserting and extracting lithium, and insertion / extraction of lithium ions is around 1.4V to 1.7V / Li. Done in For this reason, even if the secondary battery is rapidly charged with a large current, it is possible to ensure safety without causing lithium deposition compared to the case where a carbon material is used as a conventional negative electrode active material. In addition, since expansion and contraction associated with insertion and extraction of lithium can be suppressed, structural destruction of the negative electrode active material can be suppressed even when rapid charging with 20 C current is repeatedly performed. As a result, a long life can be maintained even when charging and discharging are repeated.

  In addition, since γ-butyllactone, which is an organic solvent in the electrolytic solution, is excellent in low temperature characteristics, a lithium ion secondary battery having this electrolytic solution is under an offshore environment that reaches a negative temperature (eg, minus 20 ° C.). It becomes possible to perform normal charging / discharging.

  Specifically, a lithium ion secondary battery assembled by the following method can be charged to a battery capacity of about 80% by charging at 20 C for 3 minutes in an environment of −10 ° C. It was confirmed that it was a secondary battery. Here, “C” is a unit representing a charge / discharge rate, and a rate that can be calculated in one hour when a constant current charge from complete discharge to full charge (or from full charge to complete discharge) is calculated is expressed as 1C. In the case of 1/10 hour, it is expressed as 10C. Therefore, for example, 20C charging requires 20 times as much current as 1C charging.

<Production of negative electrode>
As an active material, lithium titanate (Li ₄ Ti ₅ O ₁₂ ) powder having an average particle diameter of 5 μm and an Li storage potential of 1.55 V (vs. Li / Li ⁺ ), and carbon having an average particle diameter of 0.4 μm as a conductive agent. The powder and polyvinylidene fluoride (PVdF) as a binder were blended in a weight ratio of 90: 7: 3, and these were dispersed in an n-methylpyrrolidone (NMP) solvent to prepare a slurry.

  In addition, the laser diffraction type particle size distribution measuring apparatus (Shimadzu Corporation model number SALD-300) was used for the measurement of the particle diameter of an active material. First, about 0.1 g of a sample was put in a beaker or the like, and then a surfactant and 1 to 2 mL of distilled water were added and stirred sufficiently, and poured into a stirred water tank. The light intensity distribution was measured 64 times at intervals of 2 seconds, the particle size distribution data was analyzed, and the particle size (D50) having a cumulative frequency distribution of 50% was defined as the average particle size.

Next, an aluminum foil (purity: 99.99%) having a thickness of 10 μm was applied to the negative electrode current collector, dried, and then pressed to prepare a negative electrode having an electrode density of 2.4 g / cm ³ .

<Preparation of positive electrode>
Lithium cobalt oxide (LiCoO ₂ ) as an active material, graphite powder as a conductive material, and polyvinylidene fluoride (PVdF) as a binder are blended in a weight ratio of 87: 8: 5. -A slurry was prepared by dispersing in a methylpyrrolidone (NMP) solvent. The slurry was applied to an aluminum foil (purity 99.99%) having a thickness of 15 μm, dried, and then pressed to prepare a positive electrode having an electrode density of 3.5 g / cm ³ .

<Assembly of secondary battery>
An aluminum-containing laminate film having a thickness of 0.1 mm was prepared as a forming material for the container (exterior member). The aluminum layer of this aluminum-containing laminate film had a thickness of about 0.03 mm. Polypropylene was used as the resin for reinforcing the aluminum layer. By laminating the laminate film by heat fusion, a container (exterior member) was obtained, and further housed in a metal aluminum container.

  Next, a strip-like positive electrode terminal was electrically connected to the positive electrode, and a strip-like negative electrode terminal was electrically connected to the negative electrode. A separator made of a polyethylene porous film having a thickness of 12 μm was coated in close contact with the positive electrode. The positive electrode covered with the separator was overlapped with the negative electrode so as to face each other, and these were wound in a spiral shape to produce an electrode group. This electrode group was pressed into a flat shape. An electrode group formed into a flat shape was inserted into a container (exterior member).

LiBF ₄ , which is a lithium salt, is dissolved in an organic solvent in which ethylene carbonate (EC) and γ-butyllactone (GBL) are mixed at a volume ratio (EC: GBL) of 1: 2 to obtain a liquid. A non-aqueous electrolyte was prepared. The obtained nonaqueous electrolyte was poured into the container to assemble a lithium secondary battery.

  The first charge controller, the capacitor of 100F, and the second charge controller were connected to the DC power source in this order, and the finally obtained secondary battery was connected to the second charge controller. DC power was supplied from the DC power source to the capacitor through the first charge controller for 3 minutes at 20 C in an environment of −10 ° C., and a large current was supplied from the capacitor to the secondary battery through the second charge controller. . As a result, it was possible to charge up to about 80% battery capacity. The secondary battery could be used at a full charge voltage of 2.8 V and a discharge end voltage of 1.5 V.

  According to the embodiment described above, the lithium ion secondary battery 17 having a negative electrode containing lithium titanium oxide as an active material, that is, the lithium ion secondary battery 17 capable of rapid charging with a large current is combined with the capacitor 22. By mounting the buoy body 1 on the buoy body 1, the light-emitting device 18 can continuously emit light without being affected by the weather conditions, which can contribute to safe navigation of the ship.

  That is, when the power generation amount in the wave power generation device 13 and the solar power generation device 10 is surplus, the surplus power is transferred from the power monitoring controller 19 to the first charge controller 21, the capacitor 22, and the second charge controller 23. The secondary battery 17 can be quickly charged through the light source 18, and the light emitting device 18 can emit light by the discharge power from the secondary battery 17 when the sea surface is in a drought state and changes to a weather condition such as cloudy weather.

  Further, for example, surplus power generated by the solar power generation device 10 such as a weather condition where the sea is in a drought condition and is sunny or cloudy is converted from the power monitoring controller 19 to the first charging controller 21, the capacitor 22, and the second charging. Even when the secondary battery 17 cannot be supplied to the secondary battery 17 through the controller 23 for a sufficiently long time, the secondary battery 17 can be rapidly charged (for example, charged to about 80% battery capacity by charging at 20 C for 3 minutes). Therefore, the secondary battery 17 can be charged to a state near full charge. In other words, with a conventional maritime buoy loaded with a secondary battery that takes 1 to 2 hours to charge, it is practically difficult to charge the secondary battery to a nearly full state under such weather conditions. It becomes impossible to function as a backup power source of the light emitter.

  Therefore, by loading the buoy body 1 with the lithium ion secondary battery 17 capable of rapid charging with a large current in combination with the capacitor 22, the light emitter 18 can continuously emit light without being affected by weather conditions. Can contribute to safe navigation of ships.

  Further, the lithium ion secondary battery 17 has an electroconductivity containing γ-butyllactone, which has high electrical conductivity at a minus temperature (eg, minus 20 ° C.) and excellent low-temperature characteristics as compared with conventionally used dimethyl carbonate and diethyl carbonate. Since it has a liquid, it is charged and discharged normally even in an offshore environment that reaches a negative temperature (for example, minus 20 ° C.), and can function as a backup power source for the light emitting device 18.

  Further, when the lithium ion secondary battery 17 capable of rapid charging with a large current is combined with the capacitor 22, when the amount of power supplied from the power monitoring controller to the discharge controller is excessive, the power is supplied to the capacitor. A first charging controller 21 for supplying is provided on the upstream side of the capacitor 22 and controls the charging state of the secondary battery 17, and to the secondary battery 17 when the secondary battery 17 is fully charged. By interposing a second charging controller 23 between the capacitor 22 and the secondary battery 17 to limit the power supply of the secondary power generated by the wave power generator 13 and the solar power generator 10 The battery 17 can be charged efficiently and the life of the secondary battery 17 can be improved.

1 is a schematic cross-sectional view showing a maritime buoy according to an embodiment of the present invention. The block diagram of the maritime buoy of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Buoy body, 10 ... Solar power generation device, 12 ... Wave power generation device, 17 ... Lithium ion secondary battery, 18 ... Light-emitting device, 19 ... Electric power monitoring controller, 20 ... Discharge controller, 21 ... 1st charge Controller, 22 ... capacitor, 23 ... second charge controller, 24 ... switch.

Claims (2)

A buoy body installed on the ocean,
A power monitoring controller mounted on the buoy body;
A wave power generator attached to the buoy body so as to be connected to the power monitoring controller;
A solar power generator attached to the buoy body so as to be connected to the power monitoring controller;
A discharge controller mounted on the buoy body to be connected to the power monitoring controller;
A light emitter attached to the buoy body to be connected to the discharge controller;
A capacitor that is attached to the buoy body so as to be connected to the power monitoring controller, and that discharges a large amount of power,
Lithium having a negative electrode containing lithium titanium oxide as a negative electrode active material and an electrolyte containing γ-butyllactone, connected to the capacitor on the buoy body and connected to the discharge controller through a switch An ion secondary battery,
The discharge controller has a function of detecting the amount of power supplied from the power monitoring controller and turning on the switch when the detected amount of power is less than the amount of power required to cause the light emitter to emit light. A maritime buoy characterized by that.   When the power monitoring controller is interposed between the capacitor and the branching part that branches from the power monitoring controller to the discharge controller and the capacitor, and when the power supplied from the power monitoring controller to the discharge controller is excessive A first charge controller for supplying the power to the capacitor, and interposed between the capacitor and the secondary battery to control a charging state of the secondary battery and to fully charge the secondary battery. The marine buoy according to claim 1, further comprising a second charge controller for restricting power supply to the secondary battery in a state.

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