Power source device

Abstract

Provided is a power source device comprising: a positive electrode terminal that is connected to an anode of an electrolytic cell; a negative electrode terminal that is connected to a cathode of the electrolytic cell; a conversion circuit that is connected to the positive electrode terminal and the negative electrode terminal and is connected to a power source, and that has a switching element and converts power supplied from the power source into DC power corresponding to the electrolytic cell by switching the switching element, and outputs the converted DC power to the positive electrode terminal and the negative electrode terminal; a reference potential setting unit that is set to a reference potential; a first charge storage element that is provided between the positive electrode terminal and the reference potential setting unit, and that suppresses fluctuations in voltage between the positive electrode terminal and the reference potential setting unit; and a second charge storage element that is provided between the negative electrode terminal and the reference potential setting unit, and that suppresses fluctuations in voltage between the negative electrode terminal and the reference potential setting unit. Due to this configuration, a power source device is provided which is capable of suppressing the application of a voltage exceeding a withstand voltage to each of a pair of electrodes of an electrolytic cell.

Description

Power supply device

[0001] An embodiment of the present invention relates to a power supply device.

[0002] There is a power supply device that converts the power supplied from a power source into DC power according to an electrolytic cell and supplies the converted DC power to the electrolytic cell. The power supply device has a switching element, and by switching the switching element, the power supplied from the power source is converted into DC power according to the electrolytic cell.

[0003] The electrolytic cell has a pair of electrodes immersed in an electrolyte solution, and by supplying the DC power supplied from the power supply device to the pair of electrodes, electrolysis of the electrolyte solution is performed. Thereby, the electrolytic cell generates a predetermined product from the electrolyte solution.

[0004] In such a power supply device, due to the potential fluctuation generated during the switching of the switching element, there is a possibility that a voltage exceeding the withstand voltage is applied to one of the electrodes of the electrolytic cell. Such a voltage exceeding the withstand voltage is feared to cause factors such as failure or deterioration of the electrolytic cell.

[0005] Therefore, in a power supply device that supplies DC power to an electrolytic cell, it is desired to be able to suppress the application of a voltage exceeding the withstand voltage to each of the pair of electrodes of the electrolytic cell.

[0006] Japanese Patent No. 5728626

[0007] An embodiment of the present invention provides a power supply device capable of suppressing the application of a voltage exceeding the withstand voltage to each of the pair of electrodes of an electrolytic cell.

[0008] According to an embodiment of the present invention, a power supply device is provided for use in an electrolytic cell having a pair of electrodes, an anode and a cathode, which are provided to be immersed in an electrolyte solution, the power supply device comprising: a positive electrode terminal connected to the anode of the electrolytic cell; a negative electrode terminal connected to the cathode of the electrolytic cell; a conversion circuit connected to the positive electrode terminal and the negative electrode terminal, and also connected to a power supply, having a switching element, which converts power supplied from the power supply into DC power corresponding to the electrolytic cell by switching the switching element, and outputs the converted DC power to the positive electrode terminal and the negative electrode terminal; a reference potential setting unit set to a reference potential; a first charge storage element provided between the positive electrode terminal and the reference potential setting unit to suppress voltage fluctuations between the positive electrode terminal and the reference potential setting unit; and a second charge storage element provided between the negative electrode terminal and the reference potential setting unit to suppress voltage fluctuations between the negative electrode terminal and the reference potential setting unit.

[0009] According to an embodiment of the present invention, a power supply device is provided that can suppress the application of a voltage exceeding the withstand voltage to each of the pair of electrodes of an electrolytic cell.

[0010] This is a schematic block diagram of a power supply device according to the embodiment. This is a schematic block diagram of a reference power supply device. This is a schematic graph showing an example of the operation of a reference power supply device. This is a schematic graph showing an example of the operation of a power supply device according to the embodiment. This is a schematic block diagram showing a modified version of the power supply device according to the embodiment.

[0011] The embodiments will be described below with reference to the drawings. Note that the drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the ratio of the sizes of the parts, etc., are not necessarily the same as those of actual objects. Furthermore, even when representing the same part, the dimensions and ratios may be shown differently in different drawings. In this specification and in each drawing, elements similar to those described above are denoted by the same reference numerals, and detailed explanations are omitted as appropriate.

[0012] Figure 1 is a schematic block diagram of a power supply device according to an embodiment. As shown in Figure 1, the power supply device 10 includes a positive terminal 12a, a negative terminal 12b, a conversion circuit 14, a reference potential setting unit 16, a first charge storage element 21, and a second charge storage element 22.

[0013] The power supply unit 10 is used in the electrolytic cell 2. The electrolytic cell 2 has a tank body for storing an electrolyte solution and a pair of electrodes, an anode 2a and a cathode 2b, which are provided to be immersed in the electrolyte solution stored in the tank body.

[0014] The positive terminal 12a is connected to the anode 2a of the electrolytic cell 2. The negative terminal 12b is connected to the cathode 2b of the electrolytic cell 2. The conversion circuit 14 is connected to the positive terminal 12a and the negative terminal 12b, as well as to the power supply 4. In other words, the conversion circuit 14 is connected to the electrolytic cell 2 via the positive terminal 12a and the negative terminal 12b.

[0015] The conversion circuit 14 converts the power supplied from the power supply 4 into DC power corresponding to the electrolytic cell 2, and outputs the converted DC power to the positive terminal 12a and the negative terminal 12b. In this way, the conversion circuit 14 supplies the converted DC power to the electrolytic cell 2 connected to the positive terminal 12a and the negative terminal 12b.

[0016] The electrolytic cell 2 performs electrolysis of the electrolyte solution by supplying DC power, which is supplied from the conversion circuit 14 (power supply unit 10), to the anode 2a and cathode 2b. As a result, the electrolytic cell 2 produces a predetermined product from the electrolyte solution.

[0017] The power supplied from the power source 4 to the conversion circuit 14 is, for example, AC power. The conversion circuit 14 includes, for example, a first converter 31, a second converter 32, a charge storage element 33, and a pair of reactors 34a and 34b.

[0018] The first converter 31 converts the AC power supplied from the power source 4 into DC power and inputs the converted DC power to the second converter 32. The first converter 31 is, for example, a diode rectifier.

[0019] The second converter 32 converts the DC power input from the first converter 31 into DC power corresponding to the electrolytic cell 2. The second converter 32 converts the DC power input from the first converter 31 into DC power corresponding to the electrolytic cell 2 by, for example, stepping down the voltage of the DC power input from the first converter 31 to a voltage corresponding to the electrolytic cell 2. The second converter 32 has a pair of output terminals and outputs the converted DC power from the pair of output terminals.

[0020] The second converter 32 has switching elements 32s, and by switching the switching elements 32s, it converts the DC power input from the first converter 31 into DC power corresponding to the electrolytic cell 2. The second converter 32 is, for example, a chopper circuit having multiple switching elements 32s, and performs power conversion by switching the multiple switching elements 32s. The switching elements 32s are, for example, self-excited switching elements such as IGBTs and MOSFETs. However, the switching elements 32s are not limited to these, and can be any switching elements that can appropriately convert power by switching.

[0021] The charge storage element 33 is provided between the first converter 31 and the second converter 32. The charge storage element 33 suppresses fluctuations in the DC voltage input from the first converter 31 to the second converter 32. The charge storage element 33 is, for example, a DC capacitor.

[0022] Reactor 34a is provided between one output terminal of the second converter 32 and the positive terminal 12a. Reactor 34b is provided between the other output terminal of the second converter 32 and the negative terminal 12b. Reactors 34a and 34b suppress fluctuations in the DC current supplied from the second converter 32 to the electrolytic cell 2 via the positive terminal 12a and the negative terminal 12b.

[0023] Thus, the conversion circuit 14 has a switching element 32s, and the switching of the switching element 32s converts the power supplied from the power supply 4 into DC power corresponding to the electrolytic cell 2.

[0024] The reference potential setting unit 16 is the part of the power supply unit 10 that is set to a reference potential. The reference potential setting unit 16 is electrically connected to the reference potential setting part of the electrolytic cell 2. The reference potential setting part of the electrolytic cell 2 is, for example, the housing (cell body) of the electrolytic cell 2. The reference potential setting unit 16 is electrically connected to a common potential setting part with the reference potential setting part of the electrolytic cell 2, such as a ground electrode. In other words, the reference potential setting unit 16 is electrically connected to the reference potential setting part of the electrolytic cell 2 via a common potential setting part.

[0025] The reference potential set in the reference potential setting unit 16 is substantially the same as the reference potential of the electrolytic cell 2. However, the reference potential set in the reference potential setting unit 16 does not necessarily have to be exactly the same as the reference potential of the electrolytic cell 2; it may include error components such as errors due to wiring resistance or measurement errors. The reference potential set in the reference potential setting unit 16 can be considered substantially the same as the reference potential of the electrolytic cell 2 by electrically connecting the reference potential setting unit 16 to the reference potential setting part of the electrolytic cell 2.

[0026] The reference potential is, for example, the ground potential (potential of the earth). However, the reference potential is not limited to the ground potential, but may also be, for example, the potential of the frame ground or the potential of the chassis ground. The reference potential may be any potential that serves as the reference for the operation of the electrolytic cell 2 and the power supply unit 10. The reference potential setting unit 16 is, for example, the frame, housing, or terminal connected to the grounding wire of the power supply unit 10. However, the reference potential setting unit 16 is not limited to these, but may be any part that is set as the reference potential.

[0027] The first charge storage element 21 is provided between the positive terminal 12a and the reference potential setting unit 16. More specifically, the first charge storage element 21 is provided between the connection point between the positive terminal 12a and the conversion circuit 14 and the reference potential setting unit 16. The first charge storage element 21 is connected to the positive terminal 12a at a position closer to the positive terminal 12a than the conversion circuit 14.

[0028] The first charge storage element 21 suppresses voltage fluctuations between the positive electrode terminal 12a and the reference potential setting unit 16. In other words, the first charge storage element 21 suppresses voltage fluctuations between the anode 2a of the electrolytic cell 2 and the reference potential setting unit 16. For example, the first charge storage element 21 suppresses fluctuations in the voltage to ground applied to the anode 2a of the electrolytic cell 2.

[0029] The second charge storage element 22 is provided between the negative electrode terminal 12b and the reference potential setting unit 16. More specifically, the second charge storage element 22 is provided between the connection point between the negative electrode terminal 12b and the conversion circuit 14 and the reference potential setting unit 16. The second charge storage element 22 is connected to the negative electrode terminal 12b at a position closer to the negative electrode terminal 12b than to the conversion circuit 14.

[0030] The second charge storage element 22 suppresses voltage fluctuations between the negative electrode terminal 12b and the reference potential setting unit 16. In other words, the second charge storage element 22 suppresses voltage fluctuations between the cathode 2b of the electrolytic cell 2 and the reference potential setting unit 16. For example, the second charge storage element 22 suppresses fluctuations in the voltage to ground applied to the cathode 2b of the electrolytic cell 2.

[0031] Figure 2 is a schematic block diagram of a reference power supply unit. Figure 2 schematically represents a reference power supply unit 10ref in which the first charge storage element 21 and the second charge storage element 22 are omitted. Since the reference power supply unit 10ref is the same as power supply unit 10 except that it does not have the first charge storage element 21 and the second charge storage element 22, a detailed explanation is omitted.

[0032] As shown in Figure 2, in the conversion circuit 14, parasitic capacitances may occur between the conversion circuit 14 and the reference potential setting unit 16, such as the parasitic capacitance PC1 between the first converter 31 and the reference potential setting unit 16, the parasitic capacitance PC2 between the second converter 32 and the reference potential setting unit 16, and the parasitic capacitance PC3 between the reactors 34a and 34b and the reference potential setting unit 16.

[0033] Figure 3 is a schematic graph illustrating an example of the operation of a reference power supply unit. Figure 3 schematically shows an example of the voltage Vpg (positive terminal to ground voltage) between the positive terminal 12a and the reference potential setting unit 16, and an example of the voltage Vng (negative terminal to ground voltage) between the negative terminal 12b and the reference potential setting unit 16 in the reference power supply unit 10ref.

[0034] As shown in Figure 3, when the first charge storage element 21 and the second charge storage element 22 are not present, the voltage Vpg between the positive terminal 12a and the reference potential setting unit 16, and the voltage Vng between the negative terminal 12b and the reference potential setting unit 16, change in a rectangular wave shape according to the operation of the second converter 32 (switching of the switching element 32s).

[0035] In this case, if there is an imbalance between the parasitic capacitance on the positive terminal 12a side and the parasitic capacitance on the negative terminal 12b side, when the switching element 32s is switched, a voltage equivalent to the DC voltage of the conversion circuit 14 may be instantaneously applied to the anode 2a or cathode 2b of the electrolytic cell 2 via the parasitic capacitance of the conversion circuit 14. An imbalance between the parasitic capacitance on the positive terminal 12a side and the parasitic capacitance on the negative terminal 12b side means, in other words, that the parasitic capacitance on the positive terminal 12a side and the parasitic capacitance on the negative terminal 12b side differ by a predetermined value or more. Furthermore, the voltage equivalent to the DC voltage of the conversion circuit 14 means, in other words, the voltage of the charge storage element 33.

[0036] Therefore, if the magnitude of the DC voltage equivalent to the conversion circuit 14 is greater than the withstand voltage of the anode 2a and cathode 2b of the electrolytic cell 2, a voltage exceeding the withstand voltage will be applied to the anode 2a or cathode 2b of the electrolytic cell 2, which may cause malfunction or deterioration of the electrolytic cell 2.

[0037] Figure 4 is a schematic graph illustrating an example of the operation of the power supply device according to the embodiment. Similar to Figure 3, Figure 4 schematically illustrates an example of the voltage Vpg (positive terminal to ground voltage) between the positive terminal 12a and the reference potential setting unit 16, and an example of the voltage Vng (negative terminal to ground voltage) between the negative terminal 12b and the reference potential setting unit 16 in the power supply device 10 according to the embodiment.

[0038] As shown in Figure 4, in a power supply device 10 having a first charge storage element 21 and a second charge storage element 22, the voltage Vpg between the positive terminal 12a and the reference potential setting unit 16, and the voltage Vng between the negative terminal 12b and the reference potential setting unit 16 can be leveled by the first charge storage element 21 and the second charge storage element 22.

[0039] As a result, the power supply unit 10 can suppress the instantaneous application of a voltage equivalent to the DC voltage of the conversion circuit 14 to the anode 2a or cathode 2b of the electrolytic cell 2 via the parasitic capacitance of the conversion circuit 14 when the switching element 32s is switched. The power supply unit 10 can suppress the application of a voltage exceeding the withstand voltage to the anode 2a and cathode 2b of the electrolytic cell 2.

[0040] The capacitance of the second charge storage element 22 is substantially the same as that of the first charge storage element 21. The difference between the capacitance of the first charge storage element 21 and the capacitance of the second charge storage element 22 is, for example, within the manufacturing tolerance range of the first charge storage element 21 and the second charge storage element 22. The capacitance of the second charge storage element 22 is, for example, 0.9 times or more and 1.1 times or less than the capacitance of the first charge storage element 21.

[0041] Furthermore, the capacitance values ​​of the first charge storage element 21 and the second charge storage element 22 are set to a value larger than, for example, the size of the parasitic capacitance that occurs between the conversion circuit 14 and the reference potential setting unit 16. The capacitance values ​​of the first charge storage element 21 and the second charge storage element 22 are set to, for example, 10 times or more the size of the parasitic capacitance that is expected to occur between the conversion circuit 14 and the reference potential setting unit 16.

[0042] In this way, the capacitance of the second charge storage element 22 is set to be substantially the same as the capacitance of the first charge storage element 21, and the capacitance of the first charge storage element 21 and the capacitance of the second charge storage element 22 are set to be larger than the capacitance of the parasitic capacitance generated between the conversion circuit 14 and the reference potential setting unit 16. Thereby, the influence of the imbalance between the parasitic capacitance on the positive electrode terminal 12a side and the parasitic capacitance on the negative electrode terminal 12b side of the conversion circuit 14 is suppressed, and it is possible to more appropriately suppress the application of voltages of magnitudes exceeding the withstand voltage to each of the anode 2a and the cathode 2b of the electrolytic cell 2. In other words, the first charge storage element 21 and the second charge storage element 22 can balance the capacitance on the positive electrode terminal 12a side and the capacitance on the negative electrode terminal 12b side.

[0043] FIG. 5 is a block diagram schematically showing a modified example of the power supply device according to the embodiment. As shown in FIG. 5, in the power supply device 10a, the first converter 31 has a switching element 31s. Note that components that are substantially the same in function and configuration as those in the above embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

[0044] In the power supply device 10a, the first converter 31 converts the AC power supplied from the power source 4 into DC power by the switching element 31s. The first converter 31 has, for example, a plurality of switching elements 31s, and converts the AC power supplied from the power source 4 into DC power by the plurality of switching elements 31s.

[0045] In this way, the first converter 31 is not limited to a diode rectifier, and may be a converter or the like that converts AC power into DC power by the switching element 31s. In this case, the first converter 31 may further have a function of supplying the DC power stored in the charge storage element 33 to the power source 4 side.

[0046] The configuration of the first converter 31 is not limited to the above, and may be any configuration capable of converting the AC power supplied from the power source 4 into DC power.

[0047] Also, in each of the above embodiments, the power supplied from the power source 4 to the conversion circuit 14 is AC power. The power supplied from the power source 4 to the conversion circuit 14 is not limited to AC power and may be DC power. In this case, for example, the first converter 31 and the charge storage element 33 can be omitted. The configuration of the conversion circuit is not limited to the above, and may have at least one switching element, and may have any configuration that can appropriately convert the power supplied from the power source 4 into DC power corresponding to the electrolytic cell 2 by switching at least one switching element.

[0048] This embodiment includes the following aspects. (Supplementary Note 1) A power supply device used in an electrolytic cell having a pair of electrodes, an anode and a cathode, provided so as to be immersed in an electrolyte solution, a positive electrode terminal connected to the anode of the electrolytic cell, a negative electrode terminal connected to the cathode of the electrolytic cell, and a conversion circuit connected to the positive electrode terminal and the negative electrode terminal and also connected to a power source, having a switching element, which converts the power supplied from the power source into DC power corresponding to the electrolytic cell by switching the switching element and outputs the converted DC power to the positive electrode terminal and the negative electrode terminal, a reference potential setting unit set to a reference potential, a first charge storage element provided between the positive electrode terminal and the reference potential setting unit to suppress fluctuations in the voltage between the positive electrode terminal and the reference potential setting unit, and a second charge storage element provided between the negative electrode terminal and the reference potential setting unit to suppress fluctuations in the voltage between the negative electrode terminal and the reference potential setting unit.

[0049] (Supplementary Note 2) The power supply device according to Supplementary Note 1, wherein the reference potential setting unit is electrically connected to a portion for setting the reference potential of the electrolytic cell.

[0050] (Supplementary Note 3) The power supply device according to Supplementary Note 1 or 2, wherein the magnitude of the capacitance of the second charge storage element is 0.9 times or more and 1.1 times or less the magnitude of the capacitance of the first charge storage element, and the magnitudes of the capacitance of the first charge storage element and the capacitance of the second charge storage element are set to values larger than the magnitude of the parasitic capacitance generated between the conversion circuit and the reference potential setting unit.

[0051] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention and in the scope of the invention and its equivalents as described in the claims.

[0052] 2... Electrolytic cell, 2a... Anode, 2b... Cathode, 4... Power supply, 10, 10a, 10ref... Power supply unit, 12a... Positive terminal, 12b... Negative terminal, 14... Conversion circuit, 16... Reference potential setting unit, 21... First charge storage element, 22... Second charge storage element, 31... First converter, 31s... Switching element, 32... Second converter, 32s... Switching element, 33... Charge storage element, 34a, 34b... Reactor

Claims

1. A power supply device for use in an electrolytic cell having a pair of electrodes, an anode and a cathode, which are provided to be immersed in an electrolyte solution, comprising: a positive electrode terminal connected to the anode of the electrolytic cell; a negative electrode terminal connected to the cathode of the electrolytic cell; a conversion circuit connected to the positive electrode terminal and the negative electrode terminal, and also connected to a power supply, having a switching element, which converts power supplied from the power supply into DC power corresponding to the electrolytic cell by switching the switching element, and outputs the converted DC power to the positive electrode terminal and the negative electrode terminal; a reference potential setting unit set to a reference potential; a first charge storage element provided between the positive electrode terminal and the reference potential setting unit to suppress voltage fluctuations between the positive electrode terminal and the reference potential setting unit; and a second charge storage element provided between the negative electrode terminal and the reference potential setting unit to suppress voltage fluctuations between the negative electrode terminal and the reference potential setting unit.

2. The power supply device according to claim 1, wherein the reference potential setting unit is electrically connected to the reference potential setting unit of the electrolytic cell.

3. The power supply device according to claim 1, wherein the capacitance of the second charge storage element is 0.9 times or more and 1.1 times or less the capacitance of the first charge storage element, and the capacitances of the first charge storage element and the second charge storage element are set to be greater than the parasitic capacitance generated between the conversion circuit and the reference potential setting unit.

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