JP2021197861A - Power supply system using environmental energy - Google Patents

Abstract

To provide a power supply system that can stably obtain a high output voltage by enabling series connection of primary batteries that cannot be connected in series, such as microbial fuel cells, in an electric circuit.SOLUTION: A power supply system 60, which uses environmental energy, includes a plurality of primary batteries 2, which generates electricity by converting the environmental energy of the natural world into electrical energy, and a plurality of isolated converters 4, in which input and output portions are isolated from each other. Each input portion of the plurality of isolated converters 4 is connected to each of the plurality of primary batteries 2, and each output portion of the plurality of isolated converters 4 is connected in series.SELECTED DRAWING: Figure 1

Description

The present invention relates to a power supply system utilizing environmental energy in the natural world.

Primary batteries that utilize the environmental energy of the natural world are solar cells (photoelectric power generation batteries) that use sunlight, metal-air batteries that use air and water or seawater, temperature difference power generation batteries that use temperature differences, and organic substances and plants in the soil. There are microbial fuel cells, etc. that utilize organic substances in the soil by photosynthesis. Since these primary batteries use environmental energy, they do not emit carbon dioxide and are clean energy, but the output voltage that can be taken out is as low as 0.5 to 1.5V, and it is high due to series connection and booster circuit. It is necessary to make it a voltage. Solar cells that use sunlight can be connected in series, but their output is unstable because they can generate electricity only when the sun is shining and depend on the irradiation intensity.

A microbial fuel cell is a system that produces electric energy from organic substances by utilizing the catabolic metabolic ability of microorganisms, and utilizes sugars produced from photosynthesis of organic substances in soil and plants. Sugar is released from the roots and decomposed by bacteria (Schwanella bacteria) present in the soil to produce hydrogen ions (H +) and electrons. For this reason, the electrodes need to be installed in the soil, and technical ingenuity is required for continuous series continuation.

Patent Document 1 discloses a microbial fuel cell using hedro. It is composed of a tubular retainer made of an insulating material and an aqueous layer and a hedro layer that fill the inside. It has an anode electrode attached to the lower part of the inner wall surface of the holder 102 and a cathode electrode attached to the upper part of the inner wall surface, the anode electrode is arranged in the hedro layer, and the cathode electrode is arranged in the aqueous layer. Has been done. In this case, it is disclosed that if the water content of the hedro at the lower end is at least 80%, the individual microbial fuel cells can be made independent and connected in series.

Patent Document 2 discloses a two-layer type microbial fuel cell using a plant. The vessel comprises an anode compartment and a cathode compartment, separated from each other by an ion exchange membrane. Microbial fuel cells in individual containers can be connected in series.

Japanese Unexamined Patent Publication No. 2013-084541 U.S. Patent Application Publication No. 2010/0190039

Microbial fuel cells have a low output voltage that can be taken out, and it is necessary to increase the voltage by connecting in series or using a booster circuit. When the microbial fuel cell is composed of independent individual containers, it can be connected in series, but when the electrodes are installed in soil such as wilderness or hedro, it is difficult to connect in series, and it is necessary to enclose it in an insulated container. In addition, the output voltage of microbial fuel cells tends to be unstable depending on the growing condition of plants and the condition of soil. Solar cells that use sunlight also generate electricity only when the sun irradiates, and the output voltage becomes unstable due to variations in irradiation.

However, for example, there are characteristics such as high efficiency of solar cells and constant power generation regardless of the weather of microbial fuel cells, and a power supply system capable of stably extracting a high output voltage by taking advantage of these characteristics is desired. There is.

In order to solve the above problems, it is an object of the present invention to provide a power supply system capable of stably extracting a high output voltage by allowing a primary battery such as a microbial fuel cell, which cannot be connected in series, to be connected in series by an electric circuit. ..

[1] The power supply system of the present invention is a power supply system that uses environmental energy, and is a plurality of primary batteries that convert natural environmental energy into electrical energy to generate electricity, and a plurality of batteries in which an input unit and an output unit are insulated. The isolated converters are provided, each input unit of the plurality of isolated converters is connected to each of the plurality of primary batteries, and each output unit of the plurality of isolated converters is connected in series. It is a feature.

As described above, in the power supply system of the present invention, each input unit (primary side) of the isolated converter is connected to each of the primary batteries, and each insulated output unit (secondary side) is connected in series. Therefore, the power supply system of the present invention is a power supply system capable of stably extracting a high output voltage by allowing a primary battery such as a microbial fuel cell, which cannot be connected in series, to be connected in series by an electric circuit. In this case, by burying a plurality of cathode electrodes and anode electrodes of the microbial fuel cell in the soil, connecting each electrode to each input section of the isolated converter, and connecting each output section of the plurality of isolated converters in series. Higher voltage is possible.

[2] In the power supply system of the present invention, the primary battery includes any one or more of a vibration power generation battery, a photopower generation battery, a temperature difference power generation battery, a metal air battery, a fuel cell, and a microbial fuel cell. It is preferably a battery.

As described above, the power supply system of the present invention can be applied to primary batteries of various principles utilizing environmental energy in the natural world, for example, vibration power generation batteries, photovoltaic power generation batteries (solar batteries), temperature difference power generation batteries, and metals. By using an air battery, a microbial fuel cell, or a combination thereof, it becomes possible to construct an energy-efficient power generation system that makes the best use of each characteristic.

Further, in the power supply system of the present invention, particularly when a microbial fuel cell is used as a primary battery, a storage battery is used when a current is not passed through a load by taking advantage of the feature that the microbial fuel cell can always generate power regardless of the weather. By charging the battery, it becomes possible to build an energy-efficient power supply system.

Further, since the power supply system 60 of the present invention uses a microbial fuel cell, a stable output voltage can be obtained, and at the same time, it can be used as a power storage system utilizing the feature of constant power generation.

[3] In the power supply system of the present invention, the power supply system further controls the output voltage from both ends of the plurality of isolated converters 4 connected in series to a constant voltage and outputs the constant voltage. It is preferable to have a circuit.

As described above, according to the power supply system of the present invention, a stable output voltage can be obtained by providing a constant voltage circuit on the output side of the isolated converter connected in series.

[4] In the power supply system of the present invention, the power supply system further includes a plurality of the isolated converter, the constant voltage circuit, a plurality of isolated converters, and a control unit for controlling the operation of the constant voltage circuit. A boost control unit, a storage battery that stores electric energy, a switching control unit that switches the connection state between the storage battery, the boost control unit, and a load, a charging direction to the storage battery, and an electric energy supply direction from the storage battery. It is preferable to provide a bidirectional control unit for controlling the above.

With such a configuration, according to the power supply system of the present invention, even when the output of the primary battery is insufficient, it is possible to stably supply energy to the load by using the storage battery together.

[5] In the power supply system of the present invention, the bidirectional control unit has a voltage conversion function, and when the storage battery is charged, the voltage is converted to the rated voltage of the storage battery, and when the electric energy is supplied from the storage battery, the voltage is converted. It is preferable to convert the voltage to the load voltage required for the load.

Since the bidirectional control unit has a voltage conversion function, it is possible to supply electrical energy from both the primary battery and the storage battery at an appropriate voltage to the load, and it is also possible to charge the storage battery from the primary battery at the rated voltage of the storage battery. It becomes.

[6] In the power supply system of the present invention, the storage battery is connected to the load via the bidirectional control unit and the switching control unit, and is also connected to the bidirectional control unit, the switching control unit, and the booster. It is preferable that the battery is connected to the plurality of primary batteries via a control unit.

As described above, according to the power supply system of the present invention, the electric energy of the storage battery can be supplied to the load by the bidirectional control unit and the switching control unit, and the electric energy of the primary battery is charged to the storage battery. You can also.

[7] In the power supply system of the present invention, the power supply system further reverses the voltage from the storage battery to each primary battery in a state where the boost control unit 56 and the load are separated from the storage battery by the switching control unit. It is preferable to include a reverse bias control unit that applies a polarity.

As described above, according to the power supply system of the present invention, the electric energy of the storage battery can also be used for the regeneration of the microbial fuel cell. That is, it is possible to prevent deterioration of the anode electrode and to collect electrons on the anode electrode to prevent deterioration of power generation efficiency.

[8] In the power supply system of the present invention, it is preferable that the reverse bias control unit can adjust the reverse bias voltage applied to the primary battery with the reverse polarity.

As described above, according to the power supply system of the present invention, the reverse bias voltage can be arbitrarily adjusted, and the optimum reverse bias voltage can be applied.

[9] According to the power supply system of the present invention, the primary cell is preferably a microbial fuel cell.

By using a microbial fuel cell as the primary battery, electric energy can be effectively used and stored because it constantly generates electricity regardless of the weather.

[10] In the power supply system of the present invention, it is preferable that the isolated converter is provided with a drive unit on the input side for performing pulse width modulation, frequency modulation or phase modulation by a switching element.

As described above, according to the power supply system of the present invention, by pulse width modulation, frequency modulation or phase modulation of the isolated converter, the output voltage of the isolated converter can be adjusted according to the state of each primary battery.

[11] In the power supply system of the present invention, the boost control unit further includes a total voltage detection unit that detects the total voltage on the output side or the input side of the constant voltage circuit and a total current detection unit that detects the current. The power supply system further includes a storage battery voltage detection unit that detects the voltage of the storage battery, and a storage battery output voltage detection unit that detects the voltage and current after the voltage of the storage battery is voltage-converted by the bidirectional control unit. It is preferable to include a unit, a storage battery output current detection unit, a load voltage detection unit for detecting the voltage of the load, and a load current detection unit for detecting the current flowing through the load.

With such a configuration, according to the power supply system of the present invention, the voltage and current of the constant voltage circuit, the storage battery, and the bidirectional control unit can be monitored, and can be controlled by a computer. As a result, the normal operation of supplying the electric energy of the primary battery to the load, the shared operation of supplying the electric energy of the primary battery and the electric energy of the storage battery to the load, the charging operation of charging the storage battery with the electric energy of the primary battery, and the storage battery. Depending on the situation, one of the regeneration operations of regenerating the primary battery with the electric energy of the above can be performed.

[12] In the power supply system of the present invention, when the electric energy of the primary battery is supplied to the load, the switching control unit connects the boost control unit and the load and disconnects the bidirectional control unit. In this state, it is preferable to control the drive unit and the constant voltage circuit of the plurality of isolated converters so that the load voltage required for the load and the voltage detected by the total voltage detection unit match. ..

As described above, according to the power supply system of the present invention, normal operation of supplying the electric energy of the primary battery to the load becomes possible.

[13] In the power supply system of the present invention, for example, when the power generation capacity of the primary battery is insufficient due to overload (in this case, the output voltage detected by the microbial fuel cell voltage detection unit is equal to or less than a certain value. , When the stored voltage detected by the stored voltage detection unit is equal to or higher than the rated value), when the electric energy of the primary battery and the electric energy of the storage battery are supplied to the load, the switching control unit is used. By connecting the boost control unit and the bidirectional control unit to the load, it is possible to supply electric energy from the primary battery to the load and to supply electric energy from the storage battery to the load. It is preferable that the control unit switches the current in the direction of supplying electric energy from the storage battery to the load, and converts the voltage into the load voltage required for the load.

According to the power supply system of the present invention, for example, when the power generation capacity of the primary battery is insufficient due to an overload, the shared operation of supplying both the electric energy of the primary battery and the electric energy of the storage battery to the load is performed. Will be possible.

[14] In the power supply system of the present invention, when the voltage detected by the total voltage detection unit is lower than the load voltage required for the load (in this case, the output voltage of the boost control unit becomes insufficient). ), It is preferable that the switching control unit only supplies electrical energy from the storage battery to the load by disconnecting the boost control unit.

As described above, according to the power supply system of the present invention, when the output of the primary battery becomes insufficient, only the electric energy of the storage battery can be supplied to the load.

[15] In the power supply system 60 of the present invention, when the voltage detected by the stored voltage detection unit is equal to or lower than the rated voltage and the current detected by the load current detection unit is zero (that is, whether the load is operating). In the unconnected state), the switching control unit switches to supply electric energy from the boost control unit to the storage battery by connecting the boost control unit and the bidirectional control unit and disconnecting the load. At the same time, the bidirectional control unit can control the charging of the storage battery by switching the current in the direction of supplying electric energy from the boost control unit to the storage battery and converting the voltage to the rated voltage of the storage battery. preferable.

As described above, according to the power supply system of the present invention, it is possible to perform a charging operation of charging the storage battery with the electric energy of the primary battery.

[16] In the power supply system of the present invention, when the voltage detected by the storage battery voltage detection unit reaches the rated voltage during charging of the storage battery (that is, when charging is completed), the switching control unit performs the switching control unit. It is preferable to disconnect the storage battery by disconnecting the bidirectional control unit to stop charging the storage battery.

As described above, according to the power supply system of the present invention, when the storage battery is charged with sufficient power, the charging operation is stopped and the storage battery is disconnected from the primary battery to obtain a stable storage voltage against fluctuations in the primary battery. It will be possible to maintain.

[17] In the power supply system of the present invention, when the primary battery is regenerated, the reverse bias control unit is from the storage battery with the boost control unit and the load separated by the switching control unit. It is preferable to apply a reverse bias voltage to each of the primary batteries.

According to the power supply system of the present invention, the electric energy of the storage battery is effective for the regeneration operation of regenerating the primary battery, particularly the microbial fuel cell.

In the power supply system of the present invention, each input unit (primary side) of the isolated converter is connected to each of the primary batteries, and each insulated output unit (secondary side) is connected in series. Therefore, the power supply system of the present invention is a power supply system capable of stably extracting a high output voltage by allowing a primary battery such as a microbial fuel cell, which cannot be connected in series, to be connected in series by an electric circuit. In this case, by burying a plurality of cathode electrodes and anode electrodes of the microbial fuel cell in the soil, connecting each electrode to each input section of the isolated converter, and connecting each output section of the plurality of isolated converters in series. Higher voltage is possible.

It is a schematic functional block diagram of the power supply system 60 of this invention. It is a schematic diagram of a microbial fuel cell which is a kind of primary cell. It is a figure which shows an example of an isolated type converter. It is a figure which shows an example of the full-bridge type isolated type booster converter (full-bridge type isolated type booster converter A51). It is a figure which shows another example (full bridge type insulation type boost converter B52) of a full bridge type insulation type boost converter. It is a figure which shows a plurality of microbial fuel cells B30-1, 30-2, ..., 30-n connected in series, and a step-up control unit 56. It is a figure which shows the example which made the primary cell connected in series into a microbial fuel cell B30-1, 30-2 and a solar cell 28. It is a block diagram which shows the outline of the power-source system 60 which used the microbial fuel cell part 32. It is a block diagram which shows the structure in the normal operation state which supplies electric energy from the microbial fuel cell part 32 to the load 62. It is a block diagram which shows the structure in the shared operation state which supplies electric energy from a microbial fuel cell part 32 and a storage battery 66 to a load 62. It is a block diagram which shows the structure in the charging operation state which supplies electric energy from the microbial fuel cell part 32 to the storage battery 66. It is a block diagram which shows the structure in the reverse bias application operation state which applies the reverse bias voltage from the storage battery 66 to the microbial fuel cell part 32. It is a figure which shows the switching state in the reverse bias control unit 67 which applies the reverse bias voltage from the storage battery 66 to the microbial fuel cell unit 32. It is a figure which shows the embodiment which takes out the electric energy from the soil. It is a figure which shows the embodiment of the power supply system 60. It is a figure explaining the control of the power-source system by the microcomputer 96. It is a figure which shows the embodiment of the normal operation which supplies the electric energy of a microbial fuel cell 33-1, 33-2, ..., 33-n to a load 62. It is a figure which shows the embodiment of the sharing operation which supplies the electric energy of a microbial fuel cell 33-1, 33-2, ..., 33-n and a storage battery 66 to a load 62. It is a figure which shows the embodiment of the charging operation which charges the electric energy of a microbial fuel cell 33-1, 33-2, ..., 33-n into a storage battery 66. It is a figure which shows the embodiment of the reverse bias operation which applies the reverse bias from the storage battery 66 to the microbial fuel cell 33-1, 33-2, ..., 33-n.

<Power supply system of the present invention>
FIG. 1 is a schematic functional block diagram of the power supply system 60 of the present invention. The power supply system 60 of the present invention is a power supply system using environmental energy, and as shown in FIG. 1, a plurality of primary batteries 2 that convert natural environmental energy into electrical energy to generate electricity, and an input side and an output. It comprises a plurality of isolated converters 4 whose sides are isolated. Each input side of the plurality of isolated converters 4 is connected to each of the plurality of primary batteries 2, and each output side of the plurality of isolated converters 4 is connected in series.

The primary battery 2 is a battery that generates power by using environmental energy, and is one of a vibration power generation battery, a photopower generation battery (solar cell), a temperature difference power generation battery, a metal air battery, a fuel cell, and a microbial fuel cell. A primary battery containing two or more.

As shown in FIG. 1, the power supply system 60 further includes a constant voltage circuit 54 in which the output voltages from both ends of the plurality of isolated converters 4 are connected in series and output by controlling the output voltage to a constant voltage. ..

As shown in FIG. 1, the power supply system 60 further has a boost control having a plurality of the isolated converters 4, a constant voltage circuit 54, and a control unit for controlling the operation of the plurality of isolated converters 4 and the constant voltage circuit 54. The unit 56, the storage battery 66 for storing electric energy, the switching control unit 58 for switching the connection state between the storage battery 66, the boost control unit 56, and the load 62, the charging direction to the storage battery 66, and the electric energy from the storage battery 66. A bidirectional control unit 64 for controlling the supply direction is provided.

The bidirectional control unit 64 has a voltage conversion function, and when the storage battery 66 is charged, the voltage is converted to the rated voltage of the storage battery 66, and when the electric energy is supplied from the storage battery 66, the voltage is converted to the load voltage required for the load. ..

As shown in FIG. 1, the storage battery 66 is connected to the load 62 via the bidirectional control unit 64 and the switching control unit 58, and also includes the bidirectional control unit 64, the switching control unit 58, and the boost control unit 56. It is connected to the primary battery 2 via.

Further, in the power supply system 60, the drive of the insulation converter is stopped, the boost control unit 56 and the 62 load are separated from the storage battery 66 by the switching control unit 58, and the voltage from the storage battery 66 is reversed to each primary battery 2. The reverse bias control unit 67 to be applied is provided. In this case, it is preferable that the reverse bias control unit 67 can adjust the reverse bias voltage applied to the primary battery 2 with the reverse polarity. This is particularly effective when the primary battery 2 is a microbial fuel cell.

Each isolated converter 4 is provided with a drive unit (see FIG. 15 described later) that performs pulse width modulation, phase modulation, or frequency modulation by a switching element (see FIGS. 3 to 5 described later) on the input side. The boost control unit 56 further includes a total voltage detection unit 88 that detects the total voltage on the output side or the input side of the constant voltage circuit 54, and a total current detection unit 90 that detects the current. Further, a storage battery voltage detection unit 82 that detects the voltage of the storage battery 66, a storage battery output voltage detection unit 84 that detects the voltage and current after the voltage of the storage battery 66 is voltage-converted by the bidirectional control unit 64, and a storage battery output current detection unit. In addition to the 86, it also includes a load voltage detecting unit 92 that detects the voltage of the load and a load current detecting unit 94 that detects the current flowing through the load.

In the configuration example shown in FIG. 1, the total voltage detection unit 88 and the total current detection unit 90 are connected to the output side of the constant voltage circuit 54, but the total voltage detection unit 88 and the total current detection unit 90 are connected. It may be configured by connecting to the input side of the constant voltage circuit 54. In this case, the voltage and current of the isolated converter output of the primary battery connected in series by the isolated converter can be detected.

Here, the primary battery using the environmental energy in the natural world is clean energy without emitting carbon dioxide, but the output voltage that can be taken out is as low as about 0.5 to 1.5V, and the high voltage is obtained by the series connection or the booster circuit. Need to be. For example, a photovoltaic cell (solar cell) has a unit cell of about 0.5 V. The metal-air battery includes a magnesium battery and a nickel battery, and the magnesium battery has a voltage of about 1.5 V and the nickel battery has a voltage of about 1 V. These primary batteries can be connected in series to increase the voltage, but the microbial fuel cell cannot be directly connected in series because the electrodes are installed in the soil.

A microbial fuel cell is a battery that produces electric energy from an organic substance by utilizing the catabolic metabolic ability of microorganisms, and uses carbon for an electrode to obtain an output of about 0.5 V. Microbial fuel cells are also a sustainable power generation system because they can use biomass such as sludge and swill as fuel. Since the microorganism itself functions as a biocatalyst for extracting electrons from organic matter, it also has an advantage of low cost.

<Microbial fuel cell>
FIG. 2 is a schematic diagram of a microbial fuel cell, which is a type of primary cell. Of these, FIG. 2A is a schematic diagram showing an example of a microbial fuel cell (microbial fuel cell A10). In the microbial fuel cell A10, the plant 24 grows in the soil layer composed of soil 12 and the water layer composed of water 14. For example, the microbial fuel cell A10 uses a paddy field or a pond. The anode electrode 16 is embedded in the soil 12. The cathode electrode 20 is arranged in the water layer at the boundary between the water 14 and the air, and has an air cathode structure for taking in oxygen in the air.

Geobacter and Shewanella inhabit the soil 12 as current-producing bacteria. Geobacter and Shewanella dislike oxygen in the air and live in environments with almost no oxygen, such as underground, seabed, and swamp bottom. A part of sugar (C ₆ H ₁₂ O ₆ ) produced by photosynthesis of plant 24 is released from root 26 and decomposed by current-generating bacteria in soil 12, hydrogen ions (H +) and electrons (e−). To generate. Electrons move to the anode electrode 16 side, and hydrogen ions move to the cathode electrode 20 side. Therefore, electric energy can be taken out by passing electrons from the anode terminal 18 to the cathode terminal 22. A carbon-based material such as carbon felt is used for the anode electrode 16 and the cathode electrode 20.

FIG. 2B is a schematic view showing another example of a microbial fuel cell (microbial fuel cell B30). The microbial fuel cell B30 utilizes the wilderness and forest where the plant 24 grows. The anode electrode 16 and the cathode electrode 20 use materials having different ionization tendencies. The anode electrode 16 is a metal having a negative ionization tendency, that is, a standard redox potential. The cathode electrode 20 is an electronic conductor containing carbon as a component, or a metal having a positive ionization tendency, that is, a metal having a positive standard redox potential.

Hydrogen ions and electrons are generated by an organic substance and a current-producing bacterium, and electrons are passed from the anode electrode 16 to the cathode electrode 20 by utilizing the difference in ionization tendency. Examples of the metal having a negative standard redox potential include magnesium (standard redox potential: -2.36V) and aluminum (standard redox potential: −1.68V). Examples of the metal having a positive standard redox potential include platinum (standard redox potential: 1.19 V) and gold (standard redox potential: 1.52 V). Examples of the electronic conductor containing carbon as a component include graphite (graphite), charcoal (activated carbon, charcoal), carbon black, carbon felt, carbon nanotubes and the like.

When a metal having a negative standard redox potential is used for the anode electrode 16, electrons are emitted in the soil 12 to be oxidized, and the cathode electrode 20 receives the electrons and is reduced to hydroxylated ions. Since this chemical reaction occurs, the voltage that can be taken out increases depending on the ionization tendency. This phenomenon is the same in the case of the microbial fuel cell A10 shown in FIG. 2A, and the output voltage can be increased by using a metal having a negative standard redox potential for the anode electrode 16.

Although the outline of the microbial fuel cell has been described above, the microbial fuel cell A10 or the microbial fuel cell B30 cannot be structurally electrically connected in series. This is because when two microbial fuel cells A10 are arranged side by side, the anode electrode 20 is commonly present in the soil 12, and the cathode electrode 16 is commonly present at the boundary between the water 14 and the air. Further, when two microbial fuel cells B30 are arranged side by side, the anode electrode 16 and the cathode electrode 20 are commonly present in the soil 12.

Therefore, in the microbial fuel cell A10 or the microbial fuel cell B30, when these are connected in parallel, the current capacity increases due to the increase in the area of each electrode. Therefore, the anode electrode 16 and the cathode electrode 20 are plural. It may be composed of the electrode material of.

However, when the microbial fuel cell A10 or the microbial fuel cell B30 is connected in series, they are in a short-circuited state and no voltage is added. Therefore, in the present invention in which the voltage is increased by series connection using an isolated converter having an insulating function, the primary battery is preferably a microbial fuel cell.

<Insulated converter>
FIG. 3 is a diagram showing an example of an isolated converter. The isolated converter shown in FIG. 3A is a flyback type isolated boost converter A40. The isolated boost converter A40 connects the DC input voltage Vi to the primary side of the isolation transformer 42, and repeats on / off by the switching element 44. When the switching element 44 is turned on, a magnetic flux is generated from the primary winding of the isolation transformer 42, and at this time, countercurrent electrical energy is generated so as to prevent the increase in the magnetic flux. The generated magnetic flux magnetizes the core and stores energy. Since the direction of the diode 46 is opposite to the direction of the current, no induced current flows in the secondary winding.

When the switching element 44 is off, the energy stored in the core of the isolation transformer 42 is released and a current flows through the diode 46. It can be considered that the coil of the isolation transformer 42 plays the role of a choke coil. The current flowing through the diode 46 is charged in the smoothing capacitor 48, and a smoothed DC output voltage Vo is obtained. The output voltage Vo is determined by controlling the input voltage Vi, the winding number ratio of the coils on the primary side and the secondary side of the isolation transformer 42, and the on / off time of the switching element 44.

The isolated converter shown in FIG. 3B is a single-forward isolated boost converter B50. When the switching element 44 is on, electromotive forces (back electromotive force, induced electromotive force) are generated on the primary and secondary sides of the isolation transformer 42, current flows through the diode 46-1, and the smoothing capacitor 48 is charged. do. At this time, energy is stored in the choke coil 49.

When the switching element 44 is turned off, an electromotive force is generated in the choke coil 49 so as to prevent the current change, the stored energy is released, a current flows through the diode 46-2, and the smoothing capacitor 48 is charged. The voltage smoothed by the smoothing capacitor 48 becomes a DC output voltage Vo. The output voltage Vo is determined by the input voltage Vi, the winding ratio of the coils on the primary side and the secondary side of the isolation transformer 42, and the control of the on / off time of the switching element 44, similarly to the isolated boost converter A40.

FIG. 4 is a diagram showing an example of a full-bridge type isolated boost converter (full-bridge type isolated boost converter A51). FIG. 4A is a diagram showing a circuit configuration of a full-bridge type isolated boost converter A51. On the primary side (input side) of the isolation transformer 42, a bridge circuit is composed of four switching elements Q1, Q2, Q3, and Q4. A choke coil 49 is connected in series to the secondary side (output side) of the isolation transformer 42, and a smoothing capacitor 48 is further connected in parallel.

The full-bridge type isolated boost converter A is capable of phase modulation, and in this case, controls the phase between the left and right arms. FIG. 4B is a diagram showing a time chart of phase shift control. The on-time Ton of all switching Q1, Q2, Q3, and Q4 is 1/2 of one cycle T. The switching element Q1 and the switching element Q2 alternately repeat on / off. When the itching element Q1 is on, the switching element Q2 is off, and when the itching element Q1 is off, the switching element Q2 is on. Similarly, the switching element Q3 and the switching element Q4 are alternately turned on and off. The control of the output voltage Vo changes the on / off phase difference θ between the switch elements Q1 and Q2 groups and the switching elements Q3 and Q4 groups. That is, control is performed by shifting the phase.

As shown in FIG. 4B, the duration of each operation mode in the time chart is T1, T2, T3, and T4. At the time of T1, the switching element Q1 and the switching element Q4 are on, at the time of T2, the switching element Q2 and the switching element Q4 are on, and at the time of T3, the switching element Q2 and the switching element Q3 are on. , T4, the switching element Q1 and the switching element Q3 are on. T1 and T3, and T2 and T4 are equal, and the sum of T1, T2, T3, and T4 is one cycle T.

The output voltage Vo is determined by the input voltage Vi, the ratio of T1 in one cycle T, and the turns ratio of the isolation transformer 42. That is, assuming that the number of primary windings of the isolation transformer 42 is n1 and the number of secondary windings of the isolation transformer 42 is n2, the output voltage Vo is represented by Vo = 2 (T1 / T) · (n2 / n1) · Vi. To.

FIG. 5 is a diagram showing another example of a full-bridge type isolated boost converter (full-bridge type isolated boost converter B52). FIG. 5A is a diagram showing a circuit configuration of a full bridge type isolated boost converter B52 in which a full bridge circuit is connected to the primary side (input side) and the secondary side (output side) of the isolation transformer 42. .. On the primary side of the isolation transformer 42, a bridge circuit is composed of four switching elements Q11, Q12, Q13, and Q14 via a choke coil 49. On the secondary side of the isolation transformer 42, a bridge circuit is composed of four switching elements Q21, Q22, Q23, and Q24, and a smoothing capacitor 48 is connected in parallel.

Similar to the full-bridge type isolated boost converter A51, the full-bridge type isolated boost converter B52 is also capable of phase modulation. In this case, the phase is controlled between the primary side and the secondary side full bridge circuits. FIG. 5B is a diagram showing a time chart of phase shift control. The on-time Ton of all the switching elements Q11, Q12, Q13, Q14, Q21, Q22, Q23, and Q24 is 1/2 of one cycle T. The switching element Q11 and the switching element Q14, the switching element Q12 and the switching element Q13, the switching element Q22 and the switching element Q23, and the switching element Q21 and the switching element Q24 are paired and perform on / off operations in synchronization. The control of the output voltage Vo changes the on / off phase difference θ between the primary side full bridge circuit 45 and the secondary side full bridge circuit 47. That is, control is performed by shifting the phase.

The output voltage Vo is determined by the input voltage Vi, the ratio of T1 in one cycle T, and the turns ratio of the isolation transformer 42, as in the case of the full bridge type isolated boost converter A51. That is, assuming that the number of primary windings of the isolation transformer 42 is n1 and the number of secondary windings of the isolation transformer 42 is n2, the output voltage Vo is represented by Vo = 2 (T1 / T) · (n2 / n1) · Vi. To.

The isolated converter is not limited to the flyback system, the single forward system and the full bridge system described above, and may be a self-excited flyback converter, a half bridge system or a push-pull system. Further, the isolated converter may be either a step-down converter or a buck-boost converter in addition to the above-mentioned isolated boost converter, or may have a configuration in which these are combined.

<Multiple microbial fuel cells connected in series and boost control unit>
FIG. 6 is a diagram showing a plurality of microbial fuel cells B30-1, 30-2, ..., 30-n and a boost control unit 56 connected in series. As shown in FIG. 6, the power supply system 60 includes a plurality of microbial fuel cells B30-1, 30-2, ..., 30-n (see the primary battery unit 3 shown in FIG. 1), and a boost control unit 56. To prepare for. The boost control unit 56 is composed of a plurality of isolated boost converters A40-1, 40-2, ..., 40-n (see a plurality of isolated boost converters 4 shown in FIG. 1) and a constant voltage circuit 54. There is. Each output side of a plurality of isolated converters A40-1, 40-2, ..., 40-n is connected in series, both ends are connected to a constant voltage circuit, and the constant voltage circuit 54 controls the output to a constant voltage. .. Each input side of the plurality of isolated converters A40-1, 40-2, ..., 40-n is connected to each of the plurality of microbial fuel cells B30-1, 30-2, ..., 30-n. .. Note that n is a natural number, which means that there are n equivalent components. The same applies hereinafter.

In the microbial fuel cell B30-1, 30-2, ..., 30-n, plants 24-1, 24-2, ..., 24-n grow, and water and sugar produced by organic matter or photosynthesis. , Soil containing hydrogen ions and current-generating bacteria that decompose organic substances or sugars to generate electrons, anode electrodes 16-1, 16-2, ..., 16-n, and cathode electrodes 20-1, 20. -2, ..., 20-n.

Microbial fuel cell B30-1, 30-2, ..., 30-n anode terminals 18-1, 18-2, ..., 18-n and cathode terminals 22-1, 22-2, ..., 22- n is connected to the input side of the isolated boost converters A40-1, 40-2, ..., 40-n, and outputs the boosted voltage from the output side to the output side. The input side and the output side of the isolated boost converters A40-1, 40-2, ..., 40-n are isolated by an isolation transformer. The output sides of the isolated boost converters A40-1, 40-2, ..., 40-n to which a plurality of microbial fuel cells B30-1, 30-2, ..., 30-n are connected are connected in series. There is. As a result, the output voltages V1, V2, ..., Vn from the isolated boost converters A40-1, 40-2, ..., 40-n are added to enable higher voltage.

A constant voltage circuit 54 is connected to the output side to which the isolated boost converters A40-1, 40-2, ..., 40-n are connected in series, and a stable voltage can be supplied. Further, by providing a storage battery 66 for storing electric energy, effective utilization becomes possible.

As described above, in the power supply system 60 of the present invention, each input side of the isolated converter is connected to each of the primary batteries, and each isolated output side is connected in series. Therefore, the power supply system 60 of the present invention is a power supply system capable of stably extracting a high output voltage by allowing a primary battery such as a microbial fuel cell, which cannot be connected in series, to be connected in series by an electric circuit.

The power supply system 60 of the present invention can be applied to primary batteries of various principles utilizing environmental energy in the natural world, for example, vibration power generation batteries, photovoltaic power generation batteries (solar batteries), temperature difference power generation batteries, metal air batteries, and the like. By using a microbial fuel cell or a combination thereof, it becomes possible to construct an energy-efficient power generation system that makes the best use of each characteristic.

Further, in the power supply system 60 of the present invention, particularly when a microbial fuel cell is used as a primary battery, the microbial fuel cell can always generate power regardless of the weather, and when no current is passed through the load. By charging the storage battery, it becomes possible to construct an energy-efficient power supply system. Since a microbial fuel cell is used, a stable output voltage can be obtained, and at the same time, it can be used as a power storage system that takes advantage of the feature of constant power generation.

Further, according to the power supply system 60 of the present invention, a stable output voltage can be obtained by providing a constant voltage circuit on the output side of the isolated converter connected in series.

Further, in the power supply system 60 of the present invention, particularly when a microbial fuel cell is used as a primary battery, the microbial fuel cell can always generate power regardless of the weather, and when no current is passed through the load. By charging the storage battery, it becomes possible to construct an energy-efficient power supply system.

<Example of using solar cells together>
FIG. 7 is a diagram showing an example in which the primary cells connected in series are the microbial fuel cells B30-1 and 30-2 and the solar cell 28. This embodiment is an embodiment in which a solar cell 28 is connected in series in addition to the microbial fuel cells B30-1 and 30-2. The primary battery connected in series is not limited to one type, and is one or two of a vibration power generation battery, a photopower generation battery (solar battery), a temperature difference power generation battery, a metal air battery, a fuel cell, and a microbial fuel cell. It can consist of one or more primary batteries. Hereinafter, the present invention will be described with reference to an example in which a microbial fuel cell is used as the primary battery.

<Power supply system using microbial fuel cell>
FIG. 8 is a block diagram showing an outline of a power supply system 60 using the microbial fuel cell unit 32. In FIG. 8, the arrow indicates the direction in which the current (or electric energy) flows. The same applies to FIGS. 9 to 12, which will be described later.

As shown in FIG. 8, the power supply system 60 includes a boost control unit 56 and a storage battery 66 for charging electric energy, in addition to the microbial fuel cell unit 32 composed of a plurality of microbial fuel cells. A bidirectional control unit 64 is connected to the storage battery 66, and the direction of the current is switched by charging the storage battery 66 and supplying energy from the storage battery 66. The bidirectional control unit 64 further has a voltage conversion function, and can control the voltage when charging the storage battery 66 and supplying energy from the storage battery 66. The switching control unit 58 supplies electric energy from the boost control unit 56 and the bidirectional control unit 64 to the load 62, and supplies electric energy from the boost control unit 56 to the storage battery 66 via the bidirectional control unit 64. can do. Further, electric energy can be supplied from the bidirectional control unit 64 to the reverse bias control unit 67.

The current from the microbial fuel cell unit 32 flows to the load 62 via the boost control unit 56 and the switching control unit 58. When the storage battery 66 also supplies electric energy to the load 62, the bidirectional control unit 64 controls the current from the storage battery 66 to flow in the direction of the switching control unit 58, and the switching control unit 58 is a boost control unit. The current from the 56 and the storage battery 66 is controlled to flow. The switching control unit 58 may control the flow of either the current from the microbial fuel cell unit 32 or the current from the storage battery 66.

When the electric energy from the microbial fuel cell unit 32 is charged to the storage battery 66, the current from the microbial fuel cell unit 32 flows to the storage battery 66 under the control of the boost control unit 56, the switching control unit 58 and the bidirectional control unit 64. ..

When applying a reverse bias to the microbial fuel cell unit 32, the switching control unit 58 disconnects the load 62 from the bidirectional control unit 64, and the bidirectional control unit 64 connects the storage battery 66 via the reverse bias control unit 67. It is controlled to apply a reverse bias to the microbial fuel cell unit 32. The reverse bias control unit 67 is controlled so that the voltage of the storage battery 66 is applied to the anode electrode 20 and the cathode electrode 16 of the microbial fuel cell unit 32 with opposite polarities. When the reverse bias is applied to the microbial fuel cell unit 32, the current from the boost control unit 56 is cut off, and the current flows from the storage battery 66 to the microbial fuel cell unit 32 via the reverse bias control unit 67.

The microbial fuel cell unit 32 may be the plurality of microbial fuel cells A10 shown in FIG. 2A or the plurality of microbial fuel cells B30 shown in FIG. 2B, and is not limited thereto. The current capacity of the microbial fuel cell unit 32 depends on the size and number of electrodes of the microbial fuel cell. The current capacity required by the power supply system 60 can be obtained by appropriately setting the size and number of electrodes.

In the power supply system 60, each isolated converter 4 includes a drive unit on the input side that performs pulse width modulation, phase modulation, or frequency modulation by a switching element (drive units 80-1 to 80-n in FIG. 15 described later). reference.).

The boost control unit 56 further includes a total voltage detection unit 88 that detects the total voltage on the output side of the constant voltage circuit 54 and a total current detection unit 90 that detects the current (see FIG. 1), and is a power supply system. Reference numeral 60 denotes a storage battery output voltage detection unit 84 that detects the output voltage of the storage battery 66, and a storage battery output voltage detection unit 84 that detects the voltage and current after the voltage of the storage battery 66 is voltage-converted by the bidirectional control unit 64. It also includes a storage battery output current detection unit 86, a load voltage detection unit 92 that detects the voltage of the load 62, and a load current detection unit 94 that detects the current flowing through the load 62 (see FIG. 1). The power supply system 60 includes a microbial fuel cell voltage detection unit 70 that detects each output voltage of each microbial fuel cell constituting the microbial fuel cell unit 32, and a storage voltage detection unit 82 that detects the voltage of the storage battery 66 (FIG. 8). reference.). Since the output voltage of the microbial fuel cell is the input voltage of the isolated boost converter 4, the microbial fuel cell voltage detection unit 70 also serves as the input voltage detection unit of the isolated boost converter 4 (see FIG. 1). As shown in FIG. 1, the boost control unit 56 includes a plurality of isolated boost converters 4, a constant voltage circuit 54, and a control unit (not shown) that controls boosting.

With such a configuration, according to the power supply system 60 of the present invention, even when the output of the primary battery is insufficient, stable energy supply can be achieved by using the storage battery together.

Further, according to the power supply system 60 of the present invention, the electric energy of the storage battery can be supplied to the load, and the electric energy of the primary battery can be charged to the storage battery.

Further, according to the power supply system 60 of the present invention, the electric energy of the storage battery can be used for the regeneration of the microbial fuel cell. That is, it is possible to prevent deterioration of the anode electrode and to collect electrons on the anode electrode to prevent deterioration of power generation efficiency.

Further, according to the power supply system 60 of the present invention, the reverse bias voltage applied to the microbial fuel cell unit can be arbitrarily adjusted, and the optimum reverse bias voltage can be applied.

According to the power supply system 60 of the present invention, the voltage and current of the constant voltage circuit, the storage battery and the bidirectional control unit can be monitored, and can be controlled by a computer. As a result, the normal operation of supplying the electric energy of the primary battery to the load, the shared operation of supplying the electric energy of the primary battery and the electric energy of the storage battery to the load, the charging operation of charging the storage battery with the electric energy of the primary battery, and the storage battery. It becomes possible to perform any of the regeneration operations of regenerating the primary battery with the electric energy of.

<Normal operation>
FIG. 9 is a block diagram showing a configuration in a normal operating state in which electric energy is supplied from the microbial fuel cell unit 32 to the load 62. In the normal operating state, the power supply system 60 supplies the electric energy of the microbial battery unit 32 to the load 62 via the boost control unit 56 and the switching control unit 58, as shown in FIG. In the microbial fuel cell unit 32, the output voltage is detected by the microbial fuel cell voltage detection unit 70. The output voltage from the microbial fuel cell unit 32 is boosted to a voltage suitable for the load by the boost control unit 56, and is supplied to the load 62 via the switching control unit 58. At this time, the switching control unit 58 cuts off the connection with the storage battery 66, the bidirectional control unit 64, and the reverse bias control unit 67, and supplies electric energy from only the microbial fuel cell unit 32 to the load 62. The current from the microbial fuel cell unit 32 is passed through the load 62 via the boost control unit 56 and the switching control unit 58.

As described above, according to the power supply system 60 of the present invention, it is possible to perform a normal operation of supplying the electric energy of the microbial fuel cell unit 32 to the load 62.

<Shared operation>
FIG. 10 is a block diagram showing a configuration in a shared operation state in which electric energy is supplied from the microbial fuel cell unit 32 and the storage battery 66 to the load 62. In the power supply system 60 of the present invention, for example, when the power generation capacity of the microbial fuel cell unit 32 is insufficient due to overload, that is, the voltage boosted by the boost control unit 56 does not reach the voltage required for the load, and the microorganisms. When the output voltage detected by the fuel cell voltage detection unit 70 is below a certain value and the storage voltage detected by the storage voltage detection unit 82 is the rated value, the electric energy of the primary battery 2 and the electricity of the storage battery 66 The shared operation of supplying energy to the load 62 is performed.

In such a case, as shown in FIG. 10, the switching control unit 58 connects the boost control unit 56 and the bidirectional control unit 56 to the load 62, so that electricity from the microbial fuel cell unit 32 to the load 62 can be obtained. It enables the supply of energy and the supply of electrical energy from the storage battery 66 to the load 62. The bidirectional control unit 64 is controlled to cut off the connection with the reverse bias control unit 67, switch the current in the direction of supplying electric energy from the storage battery 66 to the load 62, and convert the current into the voltage required for the load. .. The current from the microbial fuel cell unit 32 and the storage battery 66 flows to the load 62 via the switching control unit 58. The bidirectional control unit 64 is controlled in a direction in which the current from the storage battery 66 flows through the switching control unit 58.

As described above, according to the power supply system 60 of the present invention, for example, when the power generation capacity of the microbial fuel cell unit 32 is insufficient due to overload, the electric energy of the microbial fuel cell unit 32 and the electricity of the storage battery 66 are used. It is possible to perform a shared operation of supplying both of the energy to the load 62.

<Disconnecting microbial fuel cell>
In the power supply system 60 of the present invention, when the voltage detected by the total voltage detection unit 88 becomes lower than the load voltage required for the load 62, the switching control unit 58 disconnects the boost control unit 56 and the storage battery 66. Control may be performed so that the electric energy is supplied from only to the load 62.

As described above, according to the power supply system 60 of the present invention, when the output of the microbial fuel cell unit 32 decreases and the power generation capacity becomes insufficient, only the electric energy of the storage battery 66 can be supplied to the load.

<Charging operation>
FIG. 11 is a block diagram showing a configuration in a charging operation state in which electric energy is supplied from the microbial fuel cell unit 32 to the storage battery 66. In the power supply system 60, when the voltage detected by the storage voltage detection unit 82 is equal to or less than the rated value and the current detected by the load current detection unit 94 is zero, that is, the load 62 is disconnected or the load is connected. In the non-existing state, as shown in FIG. 11, with the switching control unit 58 disconnecting the load 62, the electric energy of the microbial fuel cell unit 32 is transferred to the boost control unit 56, the switching control unit 58, and the bidirectional control unit. It is supplied to the storage battery 66 via 64 to charge the storage battery 66.

The bidirectional control unit 64 controls to charge the storage battery 66 by switching the current in the direction of supplying electric energy from the boost control unit 56 to the storage battery 66 and converting the voltage to the rated voltage of the storage battery 66. In this case, the reverse bias control unit 67 is cut off. The current from the microbial fuel cell unit 32 is passed to the storage battery 66 via the bidirectional control unit 64 to charge the storage battery 66.

As described above, according to the power supply system 60 of the present invention, it is possible to perform a charging operation of charging the storage battery with the electric energy of the primary battery.

<End of charging>
In the power supply system 60, when the voltage detected by the storage battery output voltage detection unit 84 reaches the rated value while charging the storage battery 66, that is, when charging is completed, the switching control unit 58 is the bidirectional control unit 64. By disconnecting the voltage booster control unit 56 and the storage battery 66, the microbial fuel cell unit 32 controls to stop charging the storage battery 66.

As described above, according to the power supply system 60 of the present invention, it is possible to stop the charging operation when the storage battery is charged with sufficient electric power. Further, by disconnecting the storage battery 66 from the boost control unit 56, it is possible to prevent leakage in the case of insufficient power generation of the microbial fuel cell unit 32 and maintain the storage state at the rated voltage.

<Playback operation>
FIG. 12 is a block diagram showing a configuration in a reverse bias application operating state in which a reverse bias voltage is applied from the storage battery 66 to the microbial fuel cell unit 32. When the microbial fuel cell unit 32 is regenerated in the power supply system 60, the switching control unit 58 cuts off the electric energy supply from the boost control unit 56 and the electric energy supply to the load 62, and the bidirectional control unit 58. 64 supplies the electric energy of the storage battery 66 to the reverse bias control unit 67. The reverse bias control unit 67 converts the voltage of the storage battery 66 to the reverse polarity, disconnects the electrode of the microbial fuel cell unit 32 from the boost control unit, and applies a voltage of the reverse polarity from the storage battery 66 to the microbial fuel cell unit 32. The electrode connection of the microbial fuel cell unit 32 is switched as described above. The current when the reverse bias voltage is applied to the microbial fuel cell unit 32 is passed from the storage battery 66 to the microbial fuel cell unit 32 via the bidirectional control unit 64 and the reverse bias control unit 67.

FIG. 13 is a diagram showing a switching state in the reverse bias control unit 67 that applies a reverse bias voltage from the storage battery 66 to the microbial fuel cell unit 32. As shown in FIG. 13, the reverse bias control unit 67 includes cathode electrodes 20-1, 20-2 of the microbial fuel cells B30-1, 30-2, ..., 30-n, which constitute the microbial fuel cell unit 32. The reverse bias switching circuits 69-1, 69-2, ..., 69-n are switched so that the voltage of the storage battery 66 is applied to 20-n with the opposite polarity. The anode electrodes 16-1, 16-2, ..., 16-n are used as common electrodes by grounding the anode terminals 18-1, 18-2, ..., 18-n. Hereinafter, the anode electrodes 16-1, 16-2, ..., 16-n may be referred to as an anode electrode 16, and the cathode electrodes 20-1, 20-2, ..., 20-n may be referred to as a cathode electrode 20.

The application of the reverse bias voltage to the microbial fuel cell unit 32 is to apply the voltage of the storage battery 66 to the anode electrode 16 and the cathode electrode 20 of the microbial fuel cell unit 32 with opposite polarities. At this time, the switching control unit 58 cuts off the electric energy supply from the boost control unit 56 and the electric energy supply to the load 62, and the bidirectional control unit 64 supplies the electric energy of the storage battery 66 to the reverse bias control unit 67. do. The reverse bias control unit 67 includes reverse bias switching circuits 69-1, 69-2, ..., 69-n and a reverse bias control circuit (not shown).

The voltage of the storage battery 66 converted to the reverse polarity is connected to the reverse via application terminals 23-1, 23-2, ..., 23-n. The reverse bias control circuit in the reverse bias control unit 67 reverses the cathode terminals 22-1, 22-2, ..., 22-n of the microbial fuel cells B30, 30-1, 30-2, ..., 30-n. Bias application terminals 23, 23-1, 23-2, ..., Controls to switch the connection to 23-n, and is the optimum reverse for the microbial fuel cell B30, 30-1, 30-2, ..., 30-n. It can be adjusted to the bias voltage.

As described above, according to the power supply system 60, it is possible to perform a reproduction operation of regenerating the primary battery with the electric energy of the storage battery.

The reason why the reverse bias voltage is applied to the microbial fuel cell unit 32 is to cause the anode electrode 16 to perform the regeneration operation when the metal electrode is used. For example, when magnesium is used for the anode electrode 16, magnesium emits electrons to become magnesium ions and dissolves in the soil 12.

On the other hand, at the anode electrode 16, oxygen and water receive electrons and become hydroxide ions. As a result, magnesium hydroxide (Mg (OH) ₂ ) is produced from magnesium, oxygen, and water. At the same time as magnesium dissolves, the generated electrons react with hydrogen ions to generate hydrogen, so that a self-discharge phenomenon occurs in which the electrons do not move to the positive electrode and no current flows. In addition, there is also the generation of heat. In addition, residues due to impurities contained in magnesium adhere to the electrode surface. Therefore, it causes a decrease in power generation capacity.

The same phenomenon occurs when aluminum is used for the anode electrode 16. Aluminum hydroxide (Al (OH) ₃ ) is produced from aluminum, oxygen, and water. At the same time as the aluminum melts, the generated electrons react with hydrogen ions to generate hydrogen, so a self-discharge phenomenon occurs in which the electrons do not move to the positive electrode and no current flows, and the residue due to impurities contained in the aluminum is also an electrode. By adhering to the surface, the power generation capacity is reduced.

The application of the reverse bias voltage to the microbial fuel cell unit 32 causes a self-discharge phenomenon by decomposing and diffusing hydrogen generated by melting the metal used in the anode electrode 16 into electrons and hydrogen ions. The effect of suppressing occurs. Residues due to impurities adhering to the electrode surface can also be made finer to suppress the effect on power generation. The suppression of the self-discharge phenomenon and the miniaturization of the residue are the regeneration operations of the microbial fuel cell unit 32 by applying the reverse bias voltage.

In the above, when the bidirectional control unit 64 flows the current from the storage battery 66 to the load 62, the bidirectional control unit 64 is controlled to flow the current from the storage battery 66 in the direction of the load 62, and the current to the reverse bias control unit 67 is controlled. It is blocked. Further, when a reverse bias voltage is applied to the microbial fuel cell unit 32, the current from the boost control unit 56 is cut off, and the current is transmitted from the storage battery 66 via the bidirectional control unit 64 and the reverse bias control unit 67. It is flowed to the microbial fuel cell unit 32.

(Example 1)
FIG. 14 is a diagram showing an embodiment of extracting electrical energy from soil. It is the embodiment which carried out the example of the microbial fuel cell B30 shown in FIG. 2 (B). An aluminum plate is embedded as an anode electrode 20 and carbon felt is embedded as a cathode electrode 16 in the soil 12 in which plants are growing. The output voltage at this time was 1.131V. When a magnesium plate is used as the anode electrode 16, an output voltage of 1.5 to 1.8 V is obtained.

(Example 2)
FIG. 15 is a diagram showing an embodiment of the power supply system 60. The circuit configuration of the power supply system 60 shown in FIG. 8 is shown. Insulated converters 40-1, 40-2, ..., 40-n are connected to the microbial fuel cells 33-1, 33-2, ..., and 33-n, respectively. The microbial fuel cells 33-1, 33-2, ..., 33-n may be either the microbial fuel cell A10 or the microbial fuel cell B30. In FIG. 15, the isolated boost converter is shown as a flyback type isolated boost converter A40 (hereinafter referred to as an isolated boost converter 40), but a single forward type isolated boost converter B50 and a full bridge type isolated boost converter. A51 and a full bridge type isolated boost converter B52 can also be used.

The output voltage of the microbial fuel cells 33-1, 33-2, ..., 33-n is input to the primary side (input side) of the isolated boost converters 40-1, 40-2, ..., 40-n. It becomes a voltage and is detected by the input voltage detection units 74-1, 74-2, ..., 74-n. The input voltage detection units 74-1, 74-2, ..., 74-n correspond to the microbial fuel cell voltage detection unit 70 in FIG.

The isolated boost converters 40-1, 40-2, ..., 40-n are provided with drive units 80-1, 80-2, ..., 80-n on the primary side (input side), and are provided by a switching element 44. A control unit (not shown) that performs pulse width modulation or frequency modulation is provided. The secondary side (output side) includes output voltage detection units 76-1, 76-2, ..., 76-n and output current detection units 78-1, 78-2, ..., 78-n.

The secondary sides of the isolated boost converters 40-1, 40-2, ..., 40-n are connected in series, and both ends are connected to the input side of the constant voltage circuit 54. The constant voltage circuit 54 is composed of a DC / DC converter circuit, and the voltage of the isolated boost converters 40-1, 40-2, ..., 40-n connected in series is boosted to a predetermined constant voltage. That is, it is controlled by a computer so that the voltage is required for the load. The output side of the constant voltage circuit 54 includes a total voltage detection unit 88 and a total current detection unit 90 that detect the output voltage and output current boosted by the constant voltage circuit 54. The isolated boost converters 40-1, 40-2, ..., 40-n, the constant voltage circuit 54, the total voltage detection unit 88, and the total current detection unit 90 constitute a boost control unit 56. ..

The output side of the constant voltage circuit 54 is connected to the load 62 via the switching control unit 58. On the load side of the switching control unit 58, a load voltage detection unit 92 that detects the voltage of the load 62 and a load current detection unit 94 that detects the current of the load 62 are provided.

The storage battery 66 stores electric energy. A storage voltage detection unit 82 is connected to the storage battery 66, and the voltage of the storage battery 66 is detected. The bidirectional control unit 64 is composed of a storage battery bidirectional conversion circuit 98 having a function of switching between an input direction to the storage battery 66 and an output direction from the storage battery 66 and a voltage conversion function by a DC / DC converter. A storage battery bidirectional conversion circuit 98 is connected to the storage battery 66, and the storage battery output voltage detection unit 84 and an output of the storage battery bidirectional conversion circuit 98 detect the output voltage of the storage battery 66 converted by the storage battery bidirectional conversion circuit 98. The storage battery output current detection unit 86 that detects the current is connected.

The storage battery bidirectional conversion circuit 98 is controlled by the microcomputer 96 so that a current flows from the constant voltage circuit 54 in the direction of the storage battery 66 via the switching control unit 58 at the time of charging, and further, the voltage of the constant voltage circuit 54 is DC / It is controlled by the microcomputer 96 so as to be the rated voltage of the storage battery 66 by the voltage conversion function of the DC converter. During the shared operation from the storage battery 66 to the load 62 and when the reverse bias voltage is applied from the storage battery 81 to the microbial fuel cells 33-1, 33-2, ..., 33-n, the microcomputer 96 receives the current from the storage battery 66. The load 62 and the microbial fuel cell 33-1, 33-2, ..., Control in the direction of flow to 33-n.

The reverse bias control unit 67 is composed of reverse bias switching circuits 69, 69-1, 69-2, ..., 69-n and reverse bias control circuits 68-1, 68-2, ..., 68-n. .. The reverse bias switching circuits 69, 69-1, 69-2, ..., 69-n connect the microbial fuel cells 33-1, 33-2, ..., 33-n, and the isolated boost converter 40-1. , 40-2, ..., 40-n is switched to the reverse bias control circuits 68-1, 68-2, ..., 68-n. Further, the reverse bias control circuits 68-1, 68-2, ..., 68-n convert the voltage from the storage battery 66 to the reverse polarity, and the microbial fuel cells 33-1, 33-2, ..., 33. It has a function to adjust and apply the optimum reverse bias voltage to −n, and reverse bias switching circuits 69, 69-1, 69-2, ..., 69-n are reverse bias control circuits 68-1, 68-2. , ..., Controls the connection to 68-n.

The microcomputer 96 drives the reverse bias control circuits 68-1, 68-2, ..., 68-n during the reproduction operation, and applies the reverse bias voltage from the storage battery 66 via the storage battery bidirectional conversion circuit 98. While switching, control is performed so that the optimum voltage is obtained for each of the microbial fuel cells 33-1, 33-2, ..., 33-n.

The switching control unit 58 connects only the constant voltage circuit 54 to the load 62 during normal operation, and connects the constant voltage circuit 54 and the storage battery 66 via the storage battery bidirectional conversion circuit 98 to the load during shared operation. Further, the switching control unit 58 disconnects the load 62 during the charging operation, connects the constant voltage circuit 54 to the storage battery 66 via the storage battery bidirectional conversion circuit 98, and disconnects the constant voltage circuit 54 and the load 62 during the reproduction operation.

FIG. 16 is a diagram illustrating control of a power supply system by a microcomputer. The voltage and current detected by each detection unit are input to the microcomputer 96, and the microcomputer 96 is controlled to appropriately output the voltage. The output voltage of the microbial fuel cells 33-1, 33-2, ..., 33-n is set by the input voltage detection unit 74 as the input voltage of the isolated boost converters 40-1, 40-2, ..., 40-n. The output voltage and output current of the isolated boost converters 40-1, 40-2, ..., 40-n are detected by the output voltage detection unit 76 and the output current detection unit 78. The microcomputer 96 modulates the pulse width or switching frequency of the drive units 80-1, 80-2, ..., 80-n in the isolated boost converters 40-1, 40-2, ..., 40-n. , 40-1, 40-2, ..., 40-n output voltage of the isolated boost converter 40-1, 40-2.

The total voltage detection unit 88 and the total current detection unit 90 detect the voltage and current output from the constant voltage circuit 54, input the voltage and current to the microcomputer 96, and insulate the voltage booster so that the voltage becomes a predetermined voltage by the microcomputer 96. The converters 40-1, 40-2, ..., 40-n and / or the constant voltage circuit 54 are controlled. In this control, for example, the control of the drive units 80-1, 80-2, ..., 80-n is based on the information detected by the total voltage detection unit 88 and the total current detection unit 90. In the case of isolated boost converters 40-1, 40-2, ..., 40-n, the switching pulse width is controlled, and in the case of frequency modulation, isolated boost converters 40-1, 40-2, ..., 40. It controls the switching frequency of −n, optimizes the boosting operation of the boost control unit, and controls with good power conversion efficiency.

In the examples of FIGS. 1 and 15, the total voltage detection unit 88 and the total current detection unit 90 are provided on the output side of the constant voltage circuit 54, but the total voltage detection unit 88 and the total current detection unit 90 are fixed. It may be configured to be provided between the voltage circuit 54 and the isolated boost converters 40-1, 40-2, ..., 40-n, and even in such a configuration, the total voltage detection unit 88 and the total current detection unit 90 are used. Similar control can be performed based on the voltage and current detection information. In that case, since the voltage and current are detected at a position not controlled by the constant voltage circuit 54, the output change of the isolated boost converters 40-1, 40-2, ..., 40-n can be directly detected. , It is possible to control with a higher response speed than the configuration examples of FIGS. 1 and 15.

Further, if the isolated boost converters 40-1, 40-2, ..., 40-n are of the full bridge type, phase modulation is possible, and in this case, the phase between the left and right arms is controlled. Further, if each of the primary and secondary is an isolated converter configured by a full bridge method, phase modulation is possible in this case as well, and in this case, phase control between the primary and secondary is possible. I do.

The voltage and current of the load 62 are detected by the load voltage detecting unit 92 and the load current detecting unit 94, and are monitored by the microcomputer 96, and at the same time, the microcomputer 96 can detect the presence or absence of the load 62. When the load current is zero, the load 62 is not connected or the load is connected but the power is not consumed.

The storage voltage detection unit 82 detects the voltage of the storage battery 66, and controls the voltage by the constant voltage circuit 54 and / or the storage battery bidirectional conversion circuit 98 so as to be the rated voltage of the storage battery 66 by the microcomputer 96. The output voltage and output current from the storage battery 66 via the storage battery bidirectional conversion circuit 98 are detected by the storage battery output voltage detection unit 84 and the storage battery output current detection unit 86, and the state of the storage battery 66 is monitored by the microcomputer 96. To. The voltage and current of the load 62 are detected by the load voltage detection unit 92 and the load current detection unit 94, and the constant voltage circuit 54 and the storage battery bidirectional conversion circuit 98 are controlled by the microcomputer 96 so as to be the voltage required for the load. To.

The storage battery bidirectional conversion circuit 98 uses the microcomputer 96 to transfer the storage battery 66 to the load 62 and the microbial fuel cells 33-1, 33-2, ..., 33-n during normal operation, shared operation, and regeneration operation. It is controlled in the output direction in the input direction from the constant voltage circuit 54 to the storage battery 66 during the charging operation.

The reverse bias control circuit 68 is controlled to be driven by the microcomputer 96 during the reproduction operation. Microbial fuel cells 33-1, 33-2, ..., 33-n are connected to the reverse bias control circuit 68, and from the storage battery 66 to the microbial fuel cells 33-1, 33-2, ..., 33-n. The connection is switched so as to be reverse biased, and is controlled by the microcomputer 96 so as to have an appropriate voltage value depending on the microbial fuel cells 33-1, 33-2, ..., 33-n.

<Normal operation>
FIG. 17 is a diagram showing an embodiment of a normal operation in which the electric energy of the microbial fuel cells 33-1, 33-2, ..., 33-n is supplied to the load 62. When the electric energy of the microbial fuel cells 33-1, 33-2, ..., 33-n (primary battery) is supplied to the load 62, the switching control unit 58 connects the boost control unit 56 and the load 62. At the same time, the storage battery bidirectional conversion circuit 98, which is the bidirectional control unit 64, is separated by the switching control unit 58 so that the load voltage required for the load and the voltage detected by the total voltage detection unit 88 match. , A plurality of isolated converters 40-1, 40-2, ..., 40-n drive units are controlled. The boost control unit 56 includes isolated boost converters 40-1, 40-2, ..., 40-n, a constant voltage circuit 54, a total voltage detection unit 88, and a total current detection unit 90. However, the load voltage required for the load 62 and the voltage detected by the total voltage detection unit 88 are controlled by the microcomputer 96 so as to match the voltage detected by the total voltage detection unit 88.

Inverse bias switching circuits 69-1, 69-2, ..., 69-n are microbial fuel cells 33-1, 33-2, ..., 33-n isolated boost converters 40-1, 40-2, The reverse bias control circuits 68-1, 68-2, ..., 68-n stop driving, and the storage battery 66 and the storage battery bidirectional conversion circuit 98 are connected to 40-n. It is separated by the switching control unit 58.

The normal operation of supplying the electric energy of the microbial fuel cells 33-1, 33-2, ..., 33-n to the load 62 is a plurality of isolated boost converters 40-1, 40-2, ..., 40-n. 80-1, 80-2, ..., Pulse width modulation, phase modulation or frequency modulation by the switching element 44 of 80-n, and the constant voltage circuit 54 are reduced to the voltage required for the load by the microcomputer 96. It is a controlled voltage-driven voltage control. If voltage-driven voltage control is not possible, the electrical energy supply from the microbial fuel cells 33-1, 33-2, ..., 33-n is insufficient, and the shortfall is the electrical energy of the storage battery 81. It will be shared.

As described above, according to the power supply system 60 of the present invention, it is possible to perform a normal operation of supplying the electric energy of the primary battery to the load.

<Shared operation>
FIG. 18 is a diagram showing an embodiment of a shared operation of supplying the electric energy of the microbial fuel cells 33-1, 33-2, ..., 33-n and the electric energy of the storage battery 66 to the load 62. When the electric energy of the storage battery 66 is supplied to the load 62 in addition to the electric energy of the microbial fuel cells 33-1, 33-2, ..., 33-n (primary battery), the switching control unit 58 controls the boosting. By connecting the unit 56, the storage battery bidirectional conversion circuit 98, and the load 62, the microbial fuel cells 33-1, 33-2, ..., From the storage battery 66 for supplying electric energy from the 33-n to the load 62. It enables the supply of electric energy to the load 62. The storage battery bidirectional conversion circuit 98 controls to switch the current in the direction of supplying electric energy from the storage battery 66 to the load 62.

When supplying electric energy from the storage battery 66 to the load 62, the storage battery bidirectional conversion circuit 98 is controlled by a computer so that the voltage of the storage battery 66 becomes the load voltage required for the load 62. At this time, the voltage of the storage battery 66 is detected by the storage voltage detection unit 82, and the converted output voltage and output current are detected by the storage battery output voltage detection unit 84 and the storage battery output current detection unit 86.

The reverse bias switching circuits 69-1, 69-2, ..., 69-n are the isolated boost converters 40-1, 40-2 from the microbial fuel cells 33-1, 33-2, ..., 33-n. The connection to 40-n is set, and the operation of the reverse bias control circuits 68-1, 68-2, ..., 68-n is stopped by the microcomputer 96.

When the voltage detected by the total voltage detection unit 88 is lower than the load voltage required for the load 62, the insulation connected to the microbial fuel cells 33-1, 33-2, ..., 33-n. Type boost converters 40-1, 40-2, ..., The frequency or pulse width of the drive units 80-1, 80-2, ..., 80-n in 40-n is controlled by the microcomputer 96, and a constant voltage is obtained. The output voltage of the circuit 54 is made constant. In the microcomputer 96, the voltage detected by the input voltage detection units 74-1, 74-2, ..., 74-n, which are the inputs of the isolated boost converters 40-1, 40-2, ..., 40-n. From the value, the output of each microbial fuel cell 33-1, 33-2, ..., 33-n is controlled so as to be efficiently taken out.

The outputs of the microbial fuel cells 33-1, 33-2, ..., 33-n vary individually, but each isolated boost converter so that the voltage detected by the total voltage detection unit 88 becomes a constant voltage. 40-1, 40-2, ..., 40-n can be independently controlled by the microcomputer 96. In this case, the drive units 80-1, 80-2, ..., 80 by the microcomputer 96 correspond to the voltage values detected by the input voltage detection units 74-1, 74-2, ..., 74-n. The output voltage from the isolated boost converters 40-1, 40-2, ..., 40-n is controlled by the frequency modulation or the pulse width modulation of −n.

Further, when the voltage detected by the total voltage detection unit 88 is lower than the load voltage required for the load 62, the output voltage of the constant voltage circuit 54 may be controlled by the microcomputer 96. The control of the constant voltage circuit 54 and the control of the isolated boost converters 40-1, 40-2, ..., 40-n may be performed in parallel.

Insulated boost converters 40-1, 40-2, ..., 40-n drive units 80-1, 80-2, ..., 80-n control and constant voltage circuit 54 control by microcomputer 96 If the output voltage of the voltage circuit 54 does not reach a constant voltage, it means that the electrical energy supply from the microbial fuel cells 33-1, 33-2, ..., 33-n is insufficient, and the switching control unit 58 is in a state of insufficient supply. , The constant voltage circuit 54 is disconnected, and the microcomputer 96 controls to supply electric energy from only the storage battery 66 to the load 62. As a result, the shortage of electrical energy from the microbial fuel cells 33-1, 33-2, ..., 33-n is supplied from the storage battery 66.

The reverse bias switching circuits 69-1, 69-2, ..., 69-n are the isolated boost converters 40-1, 40-2 from the microbial fuel cells 33-1, 33-2, ..., 33-n. The connection to 40-n is set, and the operation of the reverse bias control circuits 68-1, 68-2, ..., 68-n is stopped by the microcomputer 96.

In this way, even if the drive units 80-1, 80-2, 80-n of the isolated boost converters 40-1, 40-2, ..., 40-n and the constant voltage circuit 54 are controlled, the load is applied. If the voltage detected by the total voltage detection unit 88 is lower than the load voltage required for 62, the electric energy supply capacity from the microbial fuel cells 33-1, 33-2, ..., 33-n is exceeded. Therefore, by disconnecting the constant voltage circuit 54 in the switching control unit 58, only the electric energy can be supplied from the storage battery 66 to the load 62.

According to the power supply system 60 of the present invention, for example, when the power generation capacity of the primary battery 2 is insufficient due to an overload, both the electric energy of the primary battery 2 and the electric energy of the storage battery 66 are supplied to the load. It becomes possible to perform shared operation. Further, according to the power supply system 60 of the present invention, when the output of the primary battery 2 becomes insufficient, it is possible to supply only the electric energy of the storage battery 66 to the load 62.

<Charging operation>
FIG. 19 is a diagram showing an embodiment of a charging operation for charging the storage battery 66 with the electric energy of the microbial fuel cells 33-1, 33-2, ..., 33-n. When the voltage detected by the storage voltage detection unit 82 is equal to or lower than the rated value of the storage battery 66, the storage battery 66 is charged with the electric energy from the microbial fuel cells 33-1, 33-2, ..., 33-n. At this time, the switching control unit 58 connects the constant voltage circuit 54 and the storage battery bidirectional conversion circuit 98, and disconnects the load 62. In addition, the reverse bias switching circuits 69-1, 69-2, ..., 69-n are isolated boost converters 40-1, 40- from the microbial fuel cells 33-1, 33-2, ..., 33-n. 2. The connection to 40-n is set, and the operation of the reverse bias control circuits 68-1, 68-2, ..., 68-n is stopped by the microcomputer 96.

As a result, electric energy can be supplied from the constant voltage circuit 54 of the boost control unit 56 to the storage battery 66. The storage battery bidirectional conversion circuit 98 switches the current from the constant voltage circuit 54 in the direction of supplying electric energy to the storage battery 66. The output voltage from the constant voltage circuit 54 is detected by the storage battery output voltage detection unit 84, and the voltage is converted to the rated value of the storage battery 66 by the storage battery bidirectional conversion circuit 98. In this case, the storage battery output voltage detection unit 84 detects the output voltage of the constant voltage circuit 54, that is, the input voltage to the storage battery bidirectional conversion circuit 98, and the storage battery output current detection unit 86 detects the storage battery bidirectional conversion circuit. The input current to 98 is detected.

<Stop charging>
The storage battery 66 is charged under the control of the microcomputer 92. When the voltage detected by the storage voltage detection unit 82 reaches the rated value while the storage battery 66 is being charged (or the storage battery output current detection unit 86 may become zero), the switching control unit 58 may use the switching control unit 58. By disconnecting the storage battery bidirectional conversion circuit 98 from the constant voltage circuit 54, the storage battery 66 is disconnected, and charging to the storage battery 66 is stopped. Since the output voltage of the microbial fuel cells 33-1, 33-2, ..., 33-n is unstable, if the battery is continuously charged, the charged electric energy will be consumed if the output voltage is low. This is because it may decrease.

As described above, according to the power supply system 60 of the present invention, it is possible to perform a charging operation of charging the storage battery with the electric energy of the primary battery. Further, according to the power supply system 60 of the present invention, it is possible to stop the charging operation when the charging unit is charged with sufficient electric power or when the electric energy required for charging is insufficient.

<Playback operation>
FIG. 20 is a diagram showing an embodiment of a reverse bias operation in which a reverse bias voltage is applied from the storage battery 66 to the microbial fuel cells 33-1, 33-2, ..., 33-n. When the microbial fuel cells 33-1, 33-2, ..., 33-n (primary battery) are regenerated, the constant voltage circuit 54 and the load 62 are separated by the switching control unit 58, and the reverse bias is performed. The control unit 67 boosts the cathode electrodes of the microbial fuel cells 33-1, 33-2, ..., 33-n by the reverse bias switching circuits 69, 69-1, 69-2, ..., 69-n. The connection is switched from the converters 40-1, 40-2, ..., 40-n to the reverse bias control circuits 68-1, 68-2, ..., 68-n. Thereby, the reverse bias voltage from the storage battery 66 can be applied to each microbial fuel cell 33-1, 33-2, ..., 33-n.

The reverse bias control circuits 68-1, 68-2, ..., 68-n are controlled by the microcomputer 96, convert the voltage of the storage battery 66 to the reverse polarity, and reverse bias switching circuits 69, 69-1, 69-2. , ..., 69-n causes the cathode terminals 22-1, 22-2, ..., 22-n of the microbial fuel cells 33-1, 33-2, ..., 33-n to have the reverse bias application terminal 23-. 1, 23-2, ..., It is controlled to connect 23-n. As a result, a reverse bias voltage is applied to the microbial fuel cells 33-1, 33-2, ..., 33-n. Microbial fuel cells 33-1, 33-2, ..., Anode terminals 18-1, 18-2, ..., 18-n of 33-n are grounded, and microbial fuel cells 33-1, 33-2. , ... It is a common electrode of 33-n.

The switching control unit 58 cuts off the electric energy supply from the constant voltage circuit 54 and the electric energy supply to the load 62. At this time, the isolated boost converters 40-1, 40-2, ..., 40-n drive units 80-1, 80-2, ..., 80-n are turned off, and the isolated boost converter 40-1 ,. 40-2, ..., The drive of 40-n is stopped, and the load 62 is also disconnected by the switching control unit 58. These controls are performed by the microcomputer 96.

Further, the reverse bias control circuits 68-1, 68-2, ..., 68-n are controlled by the microcomputer 96, and the reverse bias voltage converted by the storage battery bidirectional conversion circuit 98 is applied to each microbial fuel cell 33-. Adjust the voltage to a voltage suitable for 1, 33-2, ..., 33-n. The output voltage of each of the microbial fuel cells 33-1, 33-2, ..., 33-n is the input voltage detection unit 74-1 of the edge type boost converter 40-1, 40-2, ..., 40-n. , 74-2, ..., 74-n, so before the playback operation, the voltage values detected by the input voltage detectors 74-1, 74-2, ..., 74-n are measured by the microcomputer. The reverse bias voltage applied to the respective microbial fuel cells 33-1, 33-2, ..., 33-n can be adjusted based on the voltage value stored in 96.

The voltage of the storage battery 66 is detected by the storage voltage detection unit 82, the voltage converted by the storage battery bidirectional conversion unit 98 is detected by the storage battery output voltage detection unit 84, and the current is detected by the storage battery output current detection unit 86. The voltage values detected by the storage battery output voltage detection unit 84 are the reverse bias control circuits 68-1, 68-2, ..., 68-n, and the respective microbial fuel cells 33-1, 33-2, ... It is applied as a reverse voltage to 33-n. The reverse bias voltage can be adjusted to a voltage value suitable for the microbial fuel cells 33-1, 33-2, ..., 33-n, respectively.

For example, for microbial fuel cells 33-1, 33-2, ..., 33-n, which have a large decrease in power generation voltage, the reverse bias voltage is increased, and the microbial fuel cells 33-1, 33, which have a small decrease in power generation voltage. -2, ... For 33-n, the reverse bias voltage is lowered. Further, even in the case of the microbial fuel cells 33-1, 33-2, ..., 33-n, which have a small decrease in the generated voltage, the current capacity may be decreased, and the reverse bias voltage is uniformly increased. It may be applied to the microbial fuel cells 33-1, 33-2, ..., 33-n.

The application of the reverse bias voltage is the regeneration of the microbial fuel cells 33-1, 33-2, ..., 33-n by suppressing the self-discharge phenomenon and miniaturizing the residue. In the reverse bias control circuits 68-1, 68-2, ..., 68-n, the microcomputer 96 relies on the microbial fuel cells 33-1, 33-2, ..., 33-n suitable for regeneration. The bias voltage is controlled so that it can be applied.

As described above, according to the power supply system 60 of the present invention, it is possible to perform a reproduction operation of regenerating the primary battery 2 with the electric energy of the storage battery 66.

Although the embodiments of the present invention have been described above, the present invention includes appropriate modifications that do not impair the purpose and advantages thereof, and is not limited by the above embodiments.

2 Primary battery 3 Primary battery part 4 Insulated converter 10 Microbial fuel cell A
12 Soil 14 Water 16, 16-1, 16-2, ..., 16-n Anode electrode 18, 18-1, 18-2, ..., 18-n Anode terminal 20, 20-1, 20-2, .., 20-n cathode electrodes 22, 22-1, 22-2, ..., 22-n cathode terminals 23, 23-1, 23-2, ..., 23-n reverse bias application terminals 24, 24- 1, 24-2, ..., 24-n plant 26 roots 28 solar cell 30, 30-1, 30-2, ..., 30-n microbial fuel cell B
32 Microbial fuel cell unit 33-1, 33-2, ..., 33-n Microbial fuel cell 40, 40-1, 40-2, ..., 40-n Insulated boost converter 42 Insulated transformer 44 Switching element 45 Primary Side full bridge circuit 46, 46-1, 46-2 Diode 47 Secondary side full bridge circuit 48 Smoothing capacitor 49 Chalk coil 50 Insulated boost converter B
51 Full bridge type isolated boost converter A
52 Full bridge type isolated boost converter B
54 Constant voltage circuit 56 Boost control unit 58 Switching control unit 60 Power supply system 62 Load 64 Bidirectional control unit 66 Storage battery 67 Reverse bias control unit 68, 68-1, 68-2, ..., 68-n Reverse bias control circuit 69 , 69-1, 69-2, ..., 69-n reverse bias switching circuit 70 Microbial fuel cell voltage detector 74, 74-1, 74-2, ..., 74-n Input voltage detector 76, 76- 1,76-2, ..., 76-n output voltage detector 78, 78-1, 78-2, ..., 78-n output current detector 80, 80-1, 80-2, ..., 80 −n Drive unit 82 Storage voltage detection unit 84 Storage battery output voltage detection unit 86 Storage battery output current detection unit 88 Total voltage detection unit 90 Total current detection unit 92 Load voltage detection unit 94 Load current detection unit 96 Microcomputer 98 Both storage batteries Direction conversion circuit

Claims (17)

It is a power supply system that uses environmental energy.
Multiple primary batteries that convert natural environmental energy into electrical energy to generate electricity,
Equipped with multiple isolated converters with isolated inputs and outputs,
A power supply system, wherein each input unit of the plurality of isolated converters is connected to each of the plurality of primary batteries, and each output unit of the plurality of isolated converters is connected in series. The primary battery is a primary battery including any one or more of a vibration power generation battery, a photopower generation battery, a temperature difference power generation battery, a metal air battery, a fuel cell and a microbial fuel cell. Item 1. The power supply system according to Item 1. The power supply system further
The power supply system according to claim 1, wherein each output unit of the plurality of isolated converters includes a constant voltage circuit that controls and outputs an output voltage from both ends connected in series to a constant voltage. The power supply system further
A boost control unit having a plurality of the isolated converters, the constant voltage circuit, the plurality of isolated converters, and a control unit for controlling the operation of the constant voltage circuits.
A storage battery that stores electrical energy and
A switching control unit that switches the connection state between the storage battery, the boost control unit, and the load,
The power supply system according to claim 3, further comprising a bidirectional control unit that controls a charging direction to the storage battery and an electric energy supply direction from the storage battery. The bidirectional control unit has a voltage conversion function, and when the storage battery is charged, the voltage is converted to the rated voltage of the storage battery, and when the electric energy is supplied from the storage battery, the voltage is converted to the load voltage required for the load. The power supply system according to claim 4, wherein the power supply system is characterized by the above. The storage battery is connected to the load via the bidirectional control unit and the switching control unit, and the plurality of primary batteries are connected to the load via the bidirectional control unit, the switching control unit, and the boost control unit. The power supply system according to claim 4 to 5, wherein the power supply system is connected to the above. The power supply system further
A reverse bias control unit that applies the voltage from the storage battery to each primary battery with the opposite polarity while the drive of the isolated converter is stopped and the boost control unit and the load are separated from the storage battery by the switching control unit. 4. The power supply system according to claim 4. The power supply system according to claim 7, wherein the reverse bias control unit can adjust a voltage of a reverse bias voltage applied to the primary battery with a reverse polarity. The power supply system according to claim 7, wherein the primary cell is a microbial fuel cell. The power supply system according to claim 1, wherein the isolated converter is provided with a drive unit that performs pulse width modulation, frequency modulation, or phase modulation by a switching element on the input side. The boost control unit further includes a total voltage detection unit that detects the total voltage on the output side or the input side of the constant voltage circuit, and a total current detection unit that detects the current.
The power supply system further includes a storage battery voltage detection unit that detects the voltage of the storage battery, and a storage battery output voltage detection unit that detects the voltage and current after the voltage of the storage battery is voltage-converted by the bidirectional control unit. The tenth aspect of the present invention is characterized in that it includes a storage battery output current detection unit, a load voltage detection unit that detects the voltage of the load, and a load current detection unit that detects the current flowing through the load. Power system. When supplying the electric energy of the primary battery to the load, the switching control unit connects the boost control unit and the load and disconnects the bidirectional control unit to obtain the load voltage required for the load and the load voltage. The power supply system according to claim 11, wherein the drive unit and the constant voltage circuit of the plurality of isolated converters are controlled so that the voltages detected by the total voltage detection unit match. When supplying the electric energy of the primary battery and the electric energy of the storage battery to the load, the switching control unit connects the boost control unit and the bidirectional control unit to the load, whereby the primary battery is used. The bidirectional control unit switches the current in the direction of supplying the electric energy from the storage battery to the load. The power supply system according to claim 11, further comprising converting a voltage into a load voltage required for the load. When the voltage detected by the total voltage detection unit becomes lower than the load voltage required for the load, the switching control unit disconnects the boost control unit to provide electrical energy from the storage battery to the load. 13. The power supply system according to claim 13, characterized in that it is supplied only. When the voltage detected by the stored voltage detection unit is equal to or lower than the rated voltage and the current detected by the load current detection unit is zero, the switching control unit controls the boost control unit and the bidirectional control unit. By connecting and disconnecting the load, the boost control unit switches to supplying electric energy to the storage battery, and the bidirectional control unit switches the current in the direction of supplying electric energy from the boost control unit to the storage battery. The power supply system according to claim 11, further comprising controlling the charging of the storage battery by converting the voltage into the rated voltage of the storage battery. When the voltage detected by the storage voltage detection unit reaches the rated voltage while charging the storage battery, the switching control unit disconnects the storage battery by disconnecting the bidirectional control unit to charge the storage battery. The power supply system according to claim 15, wherein the power supply system is controlled to stop the operation. When the primary battery is regenerated, the reverse bias control unit applies the reverse bias voltage from the storage battery to each of the primary batteries in a state where the boost control unit and the load are separated by the switching control unit. The power supply system according to claim 11, wherein the power supply system is applied.

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