Power supply system, controller and control method thereof

Abstract

A power supply system for an electrolyzer module is provided. The electrolyzer module includes a plurality of electrolyzer cells, wherein a first electrolyzer cell and a second electrolyzer cell of the plurality of electrolyzer cells are connected in series. The power supply system includes a DC / DC converter including a first switch coupled with the first electrolyzer cell and a second switch coupled with the second electrolyzer cell, the first switch and the second switch being configurable to independently operate to obtain individual control of power supply to the first electrolyzer cell and the second electrolyzer cell, and a controller configured to receive a difference measurement indicative of a performance difference between the first electrolyzer cell and the second electrolyzer cell, and to control operation of at least one of the first electrolyzer cell and the second electrolyzer cell by controlling switching operation of at least one of the first switch and the second switch based on the difference measurement.

Description

Technical Field

[0001] The present invention relates to a power supply system for an electrolytic cell module comprising electrolytic cells connected in series, and a method for controlling the power supply system. Background Technology

[0002] By exploring solutions for converting AC to DC using IGBT modules in the electrolysis process of green hydrogen applications, a two-stage power conversion (i.e., AC / DC conversion and DC / DC conversion) combined with a series-connected electrolyzer structure (also known as a bipolar configuration structure of the electrolyzer) is considered the optimal solution from a semiconductor cost perspective. However, series-connected electrolyzers may exhibit asymmetrical characteristics, possibly due to different aging conditions or parameter drift in the electrolyzer. In such cases, severely aged electrolyzers generally consume more electrical energy, further accelerating their aging process and leading to a shortened lifespan. Summary of the Invention

[0003] According to one aspect of the present invention, a power supply system for an electrolytic cell module is provided. The electrolytic cell module includes a plurality of electrolytic cells, wherein a first electrolytic cell and a second electrolytic cell are connected in series. The power supply system includes: a DC / DC converter including a first switch coupled to a first electrolytic cell and a second switch coupled to a second electrolytic cell, the first and second switches being configurable to operate independently to obtain separate control of power supply to the first and second electrolytic cells; and a controller configured to receive a difference measurement indicating a performance difference between the first and second electrolytic cells, and to control the operation of at least one of the first and second electrolytic cells by controlling the switching operation of at least one of the first and second switches based on the difference measurement.

[0004] In one embodiment, when the difference measurement indicates that the performance of the first electrolyzer is different from that of the second electrolyzer, the controller is configured to control the first switch with a first duty cycle and control the second switch with a second duty cycle different from the first duty cycle.

[0005] In one embodiment, the controller is configured to operate at least one of a first switch and a second switch to supply power to at least one of a first electrolyzer and a second electrolyzer, such that the total hydrogen production of the first electrolyzer and the second electrolyzer reaches a target total hydrogen production within a predetermined time period, and that the total power loss in the first electrolyzer and the second electrolyzer is reduced within the predetermined time period.

[0006] In one embodiment, when the difference measurement indicates that the performance of the first electrolyzer is the same as that of the second electrolyzer, the controller is configured to control the duty cycle of each switch so that the first and second electrolyzers are operated synchronously to have the same hydrogen production duration within a predetermined time period.

[0007] In one embodiment, the difference measurement is related to the aging state of each of the first and second electrolytic cells; and the controller is configured to determine whether the first and second electrolytic cells are in a balanced or unbalanced state based on the difference measurement.

[0008] In one embodiment, when the difference measurement indicates that the first electrolyzer and the second electrolyzer are in an unbalanced state, the controller is configured to: control the duty cycle of each of the first switch and the second switch such that each of the first electrolyzer and the second electrolyzer is powered to produce hydrogen at a predetermined percentage corresponding to the aging state of the electrolyzer, and such that the total amount of hydrogen produced by the multiple electrolyzers together is the target total hydrogen production.

[0009] In one embodiment, when the difference measurement indicates that the first electrolytic cell and the second electrolytic cell are in an unbalanced state, the controller is configured to adjust the duty cycle of at least one of the first switch and the second switch to compensate for performance loss in either the first electrolytic cell or the second electrolytic cell.

[0010] In one embodiment, when the difference measurement indicates that the first electrolytic cell and the second electrolytic cell are in an unbalanced state, the controller is configured to dynamically adjust the duty cycle of at least one of the first switch and the second switch within a predetermined time period until the difference measurement indicates that the first electrolytic cell and the second electrolytic cell are in a balanced state.

[0011] In one embodiment, when one of the first and second electrolytic cells fails, the controller is configured to control at least one of the first and second switches to bypass the faulty electrolytic cell.

[0012] In one embodiment, the difference measurement is determined based on one or more difference measurements to quantitatively represent the difference between the current measurement state of the first electrolyzer and the current measurement state of the second electrolyzer.

[0013] In one embodiment, the difference measurement is determined based on one or more difference measurements to quantitatively represent the difference between the current measurement state of at least one of the first and second electrolytic cells and the previous measurement state of the at least one electrolytic cell.

[0014] In one embodiment, the difference measurement is determined based on the voltage difference between the first voltage of the first electrolytic cell and the second voltage of the second electrolytic cell.

[0015] In one embodiment, the difference measurement is determined based on the current difference between a reference current and a measuring circuit, wherein the measuring current is measured in a branch between the series node of the first and second electrolytic cells and the connection node of the first and second switches.

[0016] In one embodiment, the difference measurement is determined based on the voltage difference between a reference voltage and a measured voltage, which is measured at the series node of the first electrolytic cell and the second electrolytic cell.

[0017] In one embodiment, the DC / DC converter includes: a first output terminal coupled to one end of a first electrolytic cell, a second output terminal coupled to one end of a second electrolytic cell, and a third output terminal coupled to the series node of the first and second electrolytic cells.

[0018] In one embodiment, the DC / DC converter is a boost DC / DC converter, and further includes a first capacitor coupled to a first electrolytic cell and a second capacitor coupled to a second electrolytic cell. The first capacitor has a predetermined first capacitance to meet the ripple requirements of the first electrolytic cell, and the second capacitor has a predetermined second capacitance to meet the ripple requirements of the second electrolytic cell.

[0019] In one embodiment, the DC / DC converter is a step-down DC / DC converter, and further includes a first inductor coupled to a first electrolytic cell and a second inductor coupled to a second electrolytic cell. The first inductor has a predetermined first inductance to meet the ripple requirements of the first electrolytic cell, and the second inductor has a predetermined second inductance to meet the ripple requirements of the second electrolytic cell.

[0020] According to another aspect of the present invention, a method for controlling a power supply system as described above is provided. The method includes: obtaining a difference measurement indicating a performance difference between a first electrolyzer and a second electrolyzer; determining, based on the difference measurement, whether the first electrolyzer and the second electrolyzer are in a balanced state or an unbalanced state; if it is determined that the first electrolyzer and the second electrolyzer are in a balanced state, controlling a first switch and a second switch to synchronize the operation of the two electrolyzers; and if it is determined that the first electrolyzer and the second electrolyzer are in an unbalanced state, controlling the first switch and the second switch with different duty cycles to achieve a target total hydrogen production in the first electrolyzer and the second electrolyzer over a predetermined time period, and reducing the total power loss in the first electrolyzer and the second electrolyzer over the predetermined time period.

[0021] In one embodiment, controlling the first switch and the second switch with different duty cycles includes: determining, based on a difference measurement, which of the first and second electrolyzers has a more severe aging condition; controlling the first switch and the second switch with different duty cycles to reduce the hydrogen production duration of the more severely aging electrolyzer within a predetermined time period and increase the hydrogen production duration of the other electrolyzer within the predetermined time period; and dynamically adjusting the duty cycle of each switch according to real-time acquired difference measurements to compensate for the performance loss of the electrolyzer with a more severe aging condition and to minimize the performance difference between the first and second electrolyzers.

[0022] According to another aspect of the present invention, a controller for controlling a power supply system is provided, comprising one or more processors configured with processor-executable instructions to perform the method described above. Attached Figure Description

[0023] The following description of the accompanying drawings of the embodiments or implementations further illustrates and explains various aspects of the conversion system and control method. Devices, apparatuses, modules, and blocks having the same structure and effects appear with equivalent reference numerals. In different drawings, descriptions of each of the devices, apparatuses, modules, and blocks will not be repeated in the following drawings as long as they correspond to each other in their functionality.

[0024] Figure 1 This is a block diagram of a power supply system for an electrolytic cell module according to an embodiment of the present invention.

[0025] Figure 2 Examples Figure 1 An example of an electrolytic cell module.

[0026] Figure 3 This is an exemplary circuit of a boost DC / DC converter according to an embodiment of the present invention.

[0027] Figure 4A ~4D shows Figure 3 An exemplary operating mode of a boost DC / DC converter.

[0028] Figure 5 This is an exemplary circuit of a buck DC / DC converter according to an embodiment of the present invention.

[0029] Figure 6A ~6F shows Figure 5 An exemplary operating mode of a step-down DC / DC converter.

[0030] Figure 7 This is a flowchart of a method for controlling a power supply system according to an embodiment of the present invention.

[0031] Figure 8 and Figure 9 It shows Figure 7 Here are some examples of the main steps of the method. Detailed Implementation

[0032] Embodiments of the present invention provide a solution for controlling a DC / DC power converter (hereinafter referred to as a DC / DC converter) based on differential measurements to control the operation of electrolytic cells connected in series in a bipolar configuration, wherein the differential measurements indicate the performance differences between the series-connected electrolytic cells. The DC / DC converter can be a boost DC / DC converter or a buck DC / DC converter. The solution according to embodiments of the present invention can be applied to both boost DC / DC converters and buck DC / DC converters.

[0033] According to embodiments of the present invention, the operation of each electrolyzer can be individually controlled based on its SOH / aging state. This allows for flexible adjustment of the electrolyzer operation. Furthermore, while ensuring that the same amount of hydrogen is produced by the electrolyzer within a predetermined time period, the overall power loss of the electrolyzer can be reduced.

[0034] According to embodiments of the present invention, aging balance between electrolyzers can be achieved by releasing the hydrogen production load of the aged electrolyzer, for example by adjusting the duty cycle of the DC / DC converter switch so that the healthy electrolyzer produces more hydrogen than the aged electrolyzer.

[0035] According to an embodiment of the present invention, the difference measurement value is used as an indicator for quantitatively measuring the performance differences between electrolyzers, thereby enabling the control of electrolyzer operation to be accurately guided by this indicator.

[0036] It is worth noting that, in embodiments of the present invention, the electrolyzer refers to a hydrogen electrolyzer. For example, the electrolyzer uses electricity to decompose water into hydrogen and oxygen during the electrolysis process. The electrolyzer produces hydrogen through such an electrolysis process.

[0037] The embodiments of the present invention will now be described with reference to the accompanying drawings.

[0038] Figure 1 A power supply system according to an embodiment of the present invention is shown. The power supply system includes a DC / DC converter 1 and a controller 2 for controllinglably supplying power to an electrolytic cell module 3. The electrolytic cell module 3 may include a plurality of electrolytic cells connected in series. Figure 1 The image shows two of the multiple electrolytic cells, namely, the first electrolytic cell ELE1 and the second electrolytic cell ELE2.

[0039] Figure 2An embodiment of the electrolyzer module 3 is shown. Each of the first electrolyzer ELE1 and the second electrolyzer ELE2 may include one or more electrolytic stacks. According to an embodiment of the invention, when both the first and second electrolyzers are in the beginning-of-life (BOL) state, they have the same internal resistance and the same hydrogen production rate. However, after the first and second electrolyzers have been operating to produce hydrogen for a period of time, they may have different internal resistances, resulting in different degrees of aging. According to an embodiment of the invention, the first and second electrolyzers may be two electrolyzer products of the same model, or two symmetrical portions of a single electrolyzer product.

[0040] like Figure 2 As shown, the first electrolytic cell ELE1 has a first terminal 311 (e.g., a positive terminal) and a second terminal 312 (e.g., a negative terminal). The second electrolytic cell ELE2 has a first terminal 321 (e.g., a positive terminal) and a second terminal 322 (e.g., a negative terminal). The second terminal 312 of the first electrolytic cell ELE1 is coupled to the first terminal 321 of the second electrolytic cell ELE2. That is, the second terminal 312 of the first electrolytic cell ELE1 and the first terminal 321 of the second electrolytic cell ELE2 are coupled to form a series connection node of the two electrolytic cells ELE1 and ELE2. The series connection node of the two electrolytic cells ELE1 and ELE2 can be grounded or coupled to a reference potential V. REF Reference node.

[0041] Return to reference Figure 1 The DC / DC converter 1 has two input terminals IN1 and IN2 and three output terminals OUT1 to OUT3. The two input terminals IN1 and IN2 of the DC / DC converter 1 are coupled to an AC power supply via an AC / DC converter. Additionally, although... Figure 1 Although not shown in the diagram, the two input terminals IN1 and IN2 of DC / DC converter 1 can also be coupled to a DC power supply via another DC / DC converter or directly coupled to a DC power supply. The first output terminal OUT1 of DC / DC converter 1 is coupled to the first terminal of the first electrolytic cell ELE1. The second output terminal OUT2 of DC / DC converter 1 is coupled to the second terminal of the second electrolytic cell ELE2. The third output terminal OUT3 of DC / DC converter 1 is coupled to the series connection node of the two electrolytic cells.

[0042] The controller 2 controls the switching of the DC / DC converter 1 based on a difference measurement indicating the performance difference between the first electrolyzer ELE1 and the second electrolyzer ELE2 (e.g., the difference between the aging states of the two electrolyzers) to control the operation of at least one electrolyzer, thereby reducing the total power loss of the electrolyzers while achieving the target total hydrogen production within a predetermined time period.

[0043] It should be understood that, according to embodiments of the present invention, the controller 2 can be implemented in hardware, software, or a combination of both. For the hardware implementation, it can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), data signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, electronic units designed to perform their functions, or combinations thereof. For the software implementation, it can be implemented using microcode, program code, or code segments, and can also be stored in a machine-readable storage medium such as a storage component.

[0044] According to an embodiment of the present invention, the DC / DC converter 1 can be implemented as a boost DC / DC power converter (hereinafter referred to as a boost DC / DC converter) or a buck DC / DC power converter (hereinafter referred to as a buck DC / DC converter).

[0045] Figure 3 An exemplary circuit is shown that implements DC / DC converter 1 as a boost DC / DC converter 11. Figure 3 As shown, the boost DC / DC converter 11 includes a first switch SW1 and a second switch SW2, a first diode 111 and a second diode 112, a first capacitor 113 and a second capacitor 114, and an inductor 115. Each of the first and second switches can be implemented to include one or more switching devices (e.g., multiple IGBTs or multiple IGCTs). The first switch SW1 is coupled to a first electrolytic cell ELE1 and the second switch SW2 is coupled to a second electrolytic cell ELE2. Independent control of the operation of each electrolytic cell can be achieved by individually controlling the on / off state or duty cycle of the two switches. Each of the first and second diodes is implemented as a reverse current protection diode. Each of the first and second capacitors is implemented as a DC-link capacitor. The first capacitor 113 is coupled to the first electrolytic cell ELE1 to smooth and filter the DC current supplied to the first electrolytic cell ELE1. The capacitance of the first capacitor is predetermined to meet the ripple requirements of the first electrolytic cell ELE1. Similarly, a second capacitor 114 is coupled to the second electrolytic cell ELE2 to smooth and filter the DC current supplied to the second electrolytic cell ELE2. The capacitance of the second capacitor is predetermined to meet the ripple requirements of the second electrolytic cell ELE2.

[0046] Figures 4A to 4D The diagram schematically illustrates various combinations of the on and off states of the first and second switches of the boost DC / DC converter 11, as well as the corresponding operating modes of the first and second electrolytic cells.

[0047] Figure 4A An example is shown where controller 2 controls both the first and second switches to be off. In this case, both the first and second electrolyzers operate to produce hydrogen. Current flows from the first input terminal IN1 of the boost DC / DC converter 11 into the power supply circuit, flows sequentially through the first and second electrolyzers, and then flows out of the power supply circuit from the second input terminal IN2 of the boost DC / DC converter 11. The current direction in the power supply circuit is as follows: Figure 4A As shown by the arrow in the image.

[0048] Figure 4B An example is shown where controller 2 controls both the first and second switches to be ON. In this case, neither the first nor the second electrolyzer is producing hydrogen. Current flows only through the first and second switches, and not through either the first or second electrolyzer. The direction of current in the power supply circuit is as follows: Figure 4B As shown by the arrow in the image.

[0049] Figure 4C An example is shown where controller 2 controls the first switch to be ON and the second switch to be OFF. In this case, only the second electrolyzer operates to produce hydrogen. Current flows from the first input terminal IN1 of the boost DC / DC converter 11 into the power supply circuit, flows sequentially through the first switch and the second electrolyzer, and then flows out of the power supply circuit from the second input terminal IN2 of the boost DC / DC converter 11. The current direction in the power supply circuit is as follows: Figure 4C As shown by the arrow in the image.

[0050] Figure 4D An example is shown where controller 2 controls the first switch to be off (OFF) and the second switch to be on (ON). In this case, only the first electrolyzer operates to produce hydrogen. Current flows from the first input terminal IN1 of the boost DC / DC converter 11 into the power supply circuit, flows sequentially through the first electrolyzer and the second switch, and then flows out of the power supply circuit from the second input terminal IN2 of the boost DC / DC converter 11. The current direction in the power supply circuit is as follows: Figure 4D As shown by the arrow in the image.

[0051] Figure 5 An exemplary circuit is shown that implements DC / DC converter 1 as a buck DC / DC converter 12. Figure 5As shown, the step-down DC / DC converter 12 includes first and second switches SW1 and SW2, first and second diodes 121 and 122, first to fourth capacitors 125-128, and first and second inductors 123 and 124. Each of the first and second switches can be implemented to include one or more switching devices (e.g., multiple IGBTs or multiple IGCTs). The first switch SW1 is coupled to the first electrolytic cell ELE1 and the second switch SW2 is coupled to the second electrolytic cell ELE2. Independent control of the operation of each electrolytic cell can be achieved by individually controlling the on / off state or duty cycle of the two switches. Each of the first and second diodes is implemented as a reverse current protection diode. Each of the first to fourth capacitors is implemented as a DC-link capacitor for smoothing and filtering the DC current supplied to one or both of the first and second electrolytic cells. The first inductor 123 is coupled to the first electrolytic cell ELE1 and has a predetermined inductance to meet the ripple requirements of the first electrolytic cell ELE1. Similarly, the second inductor 124 is coupled to the second electrolytic cell ELE2 and has a predetermined inductance to meet the ripple requirements of the second electrolytic cell ELE2.

[0052] Figures 6A to 6F Examples of various combinations of the on and off states of the first and second switches of the buck DC / DC converter 12 and the corresponding operating modes of the first and second electrolytic cells are shown.

[0053] Figure 6A An example is shown where controller 2 controls both the first and second switches to be off. In this case, both the first and second electrolyzers operate to produce hydrogen by utilizing the electrical energy stored in the inductors. Current flows from the first inductor into the power supply circuit, sequentially through the first and second electrolyzers, the second inductor, and the second and first diodes. The direction of the current in the power supply circuit is as follows: Figure 6A As shown by the arrow in the image.

[0054] Figure 6B An example is shown where controller 2 controls both the first and second switches to be ON. In this case, both the first and second electrolyzers operate to produce hydrogen. Current flows into the power supply circuit from the first input terminal IN1 of the buck DC / DC converter 12, flows sequentially through the first and second electrolyzers, and then flows out of the power supply circuit from the second input terminal IN2 of the buck DC / DC converter 12. The direction of current in the power supply circuit is... Figure 6B The arrow in the image indicates this.

[0055] Figure 6CAn example is shown where controller 2 controls the first switch to be ON and the second switch to be OFF. In this case, only the first electrolyzer operates to produce hydrogen. Current flows from the first input terminal IN1 of the buck DC / DC converter 12 into the power supply circuit, through the first electrolyzer, and then out of the power supply circuit from the second input terminal IN2 of the buck DC / DC converter 12. The direction of the current in the power supply circuit is... Figure 6C The arrow in the image indicates this.

[0056] Figure 6D An example is shown where controller 2 controls both the first and second switches to be off. In this case, only the first electrolyzer operates to produce hydrogen using the electrical energy stored in the first inductor. This situation may occur if the second electrolyzer malfunctions or if there is no stored electrical energy in the second inductor. Current flows from the first inductor into the power supply circuit, sequentially through the first electrolyzer and the first diode. The direction of the current in the power supply circuit is as follows: Figure 6D As shown by the arrow in the image.

[0057] Figure 6E An example is shown where controller 2 controls the first switch to be off (OFF) and the second switch to be on (ON). In this case, only the second electrolyzer operates to produce hydrogen. Current flows from the first input terminal IN1 of the buck DC / DC converter 12 into the power supply circuit, through the second electrolyzer, and then out of the power supply circuit from the second input terminal IN2 of the buck DC / DC converter 12. The direction of current in the power supply circuit is... Figure 6E The arrow in the image indicates this.

[0058] Figure 6F An example is shown where controller 2 controls both the first and second switches to be off. In this case, only the second electrolyzer operates to produce hydrogen by utilizing the electrical energy stored in the second inductor. This situation may occur when the first electrolyzer malfunctions or when there is no stored electrical energy in the first inductor. Current flows sequentially through the second electrolyzer, the second inductor, and the second diode. The direction of current in the power supply circuit is as follows... Figure 6F As shown by the arrow in the image.

[0059] It is worth noting that, in Figure 3 , Figure 4A ~4D, Figure 5 and Figure 6A In ~6F, although the series node of the two electrolytic cells is grounded, it can also be connected to the reference point, especially when only one voltage sensor is used to obtain the differential measurement value.

[0060] Further relating to the above-described power system example, an example of obtaining a differential measurement value is now described. According to an example of the invention, the differential measurement value can be used to determine whether the first electrolytic cell and the second electrolytic cell are in a balanced or unbalanced state. This differential measurement value can also be used to indicate a change in the aging state of either the first or second electrolytic cell. This differential measurement value can be obtained based on a voltage difference or a current difference. An example of measuring a voltage difference or a current difference to obtain a differential measurement value is described below. Note that these examples apply to both the above-described boost DC / DC converter 11 and buck DC / DC converter 12. It should be noted that the following measurement methods can be used in combination.

[0061] In the following descriptions of some examples, exemplary arrangements of one or more current sensors and exemplary arrangements of one or more voltage sensors are described, but the invention is not limited thereto. Voltage or current sensors can be arranged in any manner capable of measuring the desired voltage or current.

[0062] In the first embodiment, two voltage sensors, namely a first voltage sensor and a second voltage sensor, are used to measure two current voltages. The current state of the two electrolyzers can be determined from these two current voltages. In this embodiment, the voltage difference is obtained by calculating the voltage difference based on the two measured voltages. The measurement method of this embodiment is applicable to situations where the first and second electrolyzers are operating simultaneously to produce hydrogen, for example... Figure 4A or Figure 6A The situation is shown.

[0063] According to one embodiment of the first embodiment, a first voltage sensor measures a first DC voltage across a first electrolytic cell, and a second voltage sensor measures a second DC voltage across a second electrolytic cell. A controller 2 calculates the voltage difference between the two measured voltages, for example, by subtracting the first DC voltage from the second DC voltage. When the voltage difference is zero, the controller 2 determines that the two electrolytic cells have the same degree of aging and are in a balanced state. When the voltage difference is greater than zero, the controller 2 determines that the first electrolytic cell is more severely aged than the second electrolytic cell and is in a non-balanced state. When the voltage difference is less than zero, the controller 2 determines that the second electrolytic cell is more severely aged than the first electrolytic cell and is in a non-balanced state.

[0064] According to another embodiment of the first embodiment, a first voltage sensor measures a first DC voltage across the first electrolytic cell, and a second voltage sensor measures the total DC voltage across the first and second electrolytic cells. The controller 2 calculates a second DC voltage across the second electrolytic cell based on the two measured voltages, and then uses a method similar to the one described above to determine whether the two electrolytic cells are in a balanced or unbalanced state based on the first and second DC voltages.

[0065] According to another embodiment of the first embodiment, a first voltage sensor measures a second DC voltage across the second electrolytic cell, and a second voltage sensor measures the total DC voltage across the first and second electrolytic cells. The controller 2 calculates a first DC voltage across the first electrolytic cell based on the two measured voltages, and then uses a method similar to the one described above to determine whether the two electrolytic cells are in a balanced or unbalanced state based on the first and second DC voltages.

[0066] In the second embodiment, a current sensor is used to measure the current in a branch. That is, the current sensor is located in that branch. Figure 3 In the case of the boost DC / DC converter 11 shown, this branch is the branch between the connection node of the two switches SW1 and SW2 and the series connection node of the two electrolytic cells ELE1 and ELE2. Figure 5 In the case of the step-down DC / DC converter 12 shown, this branch is the branch between the connection node of the two diodes 121 and 122 and the series connection node of the two electrolyzers ELE1 and ELE2. If the two electrolyzers are in a balanced state, no current should flow through this branch; and if the two electrolyzers are in a non-balanced state, current should flow through this branch. In this embodiment, the difference measurement value can be obtained based on the current difference between the measured current and the zero current. When the value of this current difference is zero, the controller 2 determines that the two electrolyzers are in a balanced state. When the value of this current difference is not equal to zero, the controller 2 determines that the two electrolyzers are in a non-balanced state. The measurement method of this embodiment is applicable to the case where the first electrolyzer and the second electrolyzer are operating simultaneously to produce hydrogen, for example, Figure 4A or Figure 6A The situation is shown.

[0067] In the second embodiment, when the current difference is not zero and the two electrolyzers are in a non-equilibrium state, the difference measurement value can also be the current difference between the currently measured current and the previously measured current. In this case, the difference measurement value can indicate whether the difference in aging state between the two electrolyzers is decreasing or increasing. For example, if the difference measurement value increases, it means that the difference in aging state between the two electrolyzers is increasing. If the difference measurement value decreases, it means that the difference in aging state between the two electrolyzers is decreasing.

[0068] In the third embodiment, a voltage sensor is used to measure the voltage between the series node and the reference node of the electrolyzer. This measurement method is applicable when the series node is not grounded. When the two electrolyzers are in equilibrium, the voltage value between the series node and the reference node (i.e., the measured voltage) should be equal to a preset value. In this embodiment, the difference measurement value can be obtained based on the voltage difference between the measured voltage and a reference voltage with a predetermined value. When the difference voltage value is zero, the controller 2 determines that the two electrolyzers are in equilibrium. When the difference voltage value is not equal to zero, the controller 2 determines that the two electrolyzers are in an unbalanced state. This measurement method is applicable to situations where the first and second electrolyzers are operating simultaneously to produce hydrogen, for example... Figure 4A or Figure 6A The situation is shown.

[0069] In the third embodiment, when the voltage difference is not zero and the two electrolyzers are in an unbalanced state, the difference measurement value can also be the voltage difference between the current measured voltage and the previously measured voltage or reference voltage. In this case, the difference measurement value can indicate whether the difference in aging state between the two electrolyzers is decreasing or increasing. For example, if the difference measurement value increases, it means that the difference in aging state between the two electrolyzers is increasing. If the difference measurement value decreases, it means that the difference in aging state between the two electrolyzers is decreasing.

[0070] Additionally, in the case of producing hydrogen by operating one of the first and second electrolyzers (e.g., Figure 4A , 4B (As shown in cases 6C, 6D, 6E, or 6F), the difference measurement value can be obtained based on the voltage difference between the measured voltage and the reference voltage of the electrolytic cell, or based on the current difference between the measured current and the reference current of the electrolytic cell. In this case, the aging rate of the electrolytic cell can be represented by the rate of change of the difference measurement value. For example, an increase in the rate of change of the difference measurement value means an increase in the aging rate of the electrolytic cell. A decrease in the rate of change of the difference measurement value means a decrease in the aging rate of the electrolytic cell.

[0071] Figure 7 This is a flowchart of a method 700 for controlling a power supply system according to an embodiment of the present invention. Method 700 can be executed by the controller 2 described above and can be applied to the power supply system described above; therefore, various features of the power supply system described above are also applicable to method 700.

[0072] In block 702, controller 2 acquires a difference measurement indicating the performance difference between the first electrolytic cell and the second electrolytic cell. For an embodiment of acquiring the difference measurement, please refer to the related description above.

[0073] In block 704, controller 2 determines whether the first and second electrolytic cells are in a balanced or unbalanced state based on the difference measurement. An embodiment of this determination step is described in the related embodiments above.

[0074] If it is determined that the first electrolytic cell and the second electrolytic cell are in a balanced state, then method 700 proceeds to block 706.

[0075] In block 706, controller 2 controls the first switch and the second switch to synchronize the operation of the two electrolyzers. For example, controller 2 controls the first switch and the second switch with the same duty cycle, so that the two electrolyzers have the same hydrogen production duration within a predetermined time period.

[0076] If it is determined that the first electrolytic cell and the second electrolytic cell are in an unbalanced state, then method 700 proceeds to block 708.

[0077] In block 708, controller 2 controls at least one of the first and second switches based on the difference measurement value, so that the total hydrogen production of the first electrolyzer and the second electrolyzer reaches the target total hydrogen production within a predetermined time period, and the total power loss in the first electrolyzer and the second electrolyzer is reduced within the predetermined time period.

[0078] The following describes an embodiment of the control steps in box 70 8.

[0079] Figure 8 This is a flowchart 800 of an exemplary implementation of the control steps in box 708.

[0080] In block 802, controller 2 determines, based on the difference measurement, the electrolytic cell with a more severe aging condition between the first and second electrolytic cells. For an embodiment of this determination step, please refer to the description of the related embodiments above.

[0081] In box 804, controller 2 controls the first and second switches with different duty cycles to reduce the hydrogen production time of the more severely aged electrolyzer and increase the hydrogen production time of the other electrolyzer during a predetermined time period. In this way, the performance loss of the severely aged electrolyzer can be compensated by the mildly aged electrolyzer.

[0082] For example, when using a boost DC / DC converter 11 and the first electrolytic cell is severely aged, the controller 2 controls the first switch with a large duty cycle (e.g., 70%) and the second switch with a small duty cycle (e.g., 30%), so that the electrolytic cell is in a state of... Figure 4C The situation is better than being in Figure 4D The duration of this situation is longer.

[0083] For example, when using a step-down DC / DC converter 12 and the first electrolytic cell is a severely aged electrolytic cell, the controller 2 controls the second switch with a larger duty cycle (e.g., 70%) and the first switch with a smaller duty cycle (e.g., 30%), so that the electrolytic cell is in the condition shown in FIG4E compared to the condition shown in FIG4E. Figure 6C The duration of this situation is longer.

[0084] In box 806, controller 2 dynamically adjusts the duty cycle of each switch and detects the difference measurement value in real time.

[0085] In block 808, once controller 2 detects a difference measurement indicating that the first electrolytic cell and the second electrolytic cell are in a balanced state, controller 2 controls the first switch and the second switch with the same duty cycle.

[0086] Figure 9 This is a flowchart of another exemplary implementation method 900 of the control steps in block 708.

[0087] In block 902, controller 2 determines a first average current of the first electrolyzer and a second average current of the second electrolyzer such that, within a predetermined time period, the sum of the first average current and the second average current equals the total current corresponding to the target total hydrogen, and the total power loss in the first and second electrolyzers based on the first and second average currents and the internal resistance of the first and second electrolyzers is minimized.

[0088] In box 904, controller 2 determines the duty cycle of the first switch and the second switch based on the first average current and the second average current.

[0089] In box 906, controller 2 controls the first switch and the second switch according to the determined duty cycle.

[0090] Furthermore, when operating only one electrolyzer to produce hydrogen, if the aging rate of the electrolyzer is determined to be increasing based on differential measurements, controller 2 can control the corresponding switch to reduce the DC voltage supplied to the electrolyzer. This reduces the load rate of the electrolyzer, thereby slowing down its aging.

[0091] In addition, if one of the two electrolytic cells malfunctions, the faulty electrolytic cell can be bypassed by controlling the switch.

[0092] The above description is provided to enable any person skilled in the art to implement the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Therefore, the claims are not intended to be limited to the aspects shown herein. All structural and functional equivalents of the elements of the various aspects described herein, as known or forthcoming to those skilled in the art, are expressly incorporated herein by reference and are intended to be covered by the claims.

Claims

1. A power supply system for an electrolytic cell module, the electrolytic cell module comprising a plurality of electrolytic cells, wherein a first electrolytic cell and a second electrolytic cell of the plurality of electrolytic cells are connected in series, the power supply system comprising: A DC / DC converter includes a first switch coupled to a first electrolytic cell and a second switch coupled to a second electrolytic cell, the first and second switches being configurable to operate independently to obtain separate control of the power supply to the first and second electrolytic cells. as well as A controller is configured to receive a difference measurement indicating a performance difference between a first electrolytic cell and a second electrolytic cell, and to control the operation of at least one of the first and second electrolytic cells by controlling the switching operation of at least one of a first switch and a second switch based on the difference measurement.

2. The power supply system as claimed in claim 1, wherein, When the difference measurement indicates that the performance of the first electrolytic cell is different from that of the second electrolytic cell, the controller is configured to control the first switch with a first duty cycle and control the second switch with a second duty cycle different from the first duty cycle.

3. The power supply system as described in claim 1, wherein, The controller is configured to operate at least one of a first switch and a second switch to supply power to at least one of a first electrolyzer and a second electrolyzer, such that the total hydrogen production of the first electrolyzer and the second electrolyzer reaches a target total hydrogen production within a predetermined time period, and that the total power loss in the first electrolyzer and the second electrolyzer is reduced within the predetermined time period.

4. The power supply system as claimed in claim 1, wherein, When the difference measurement indicates that the performance of the first electrolytic cell is the same as that of the second electrolytic cell, the controller is configured to: The first and second switches are controlled with the same duty cycle so that the first and second electrolyzers are operated synchronously to have the same hydrogen production duration within a predetermined time period.

5. The power supply system as described in claim 1, wherein, The difference measurement value is related to the aging state of each of the first and second electrolytic cells; Furthermore, the controller is configured to determine whether the first and second electrolytic cells are in a balanced or unbalanced state based on the difference measurement value.

6. The power supply system as described in claim 5, wherein, When the difference measurement indicates that the first and second electrolytic cells are in an unbalanced state, the controller is configured to: The duty cycle of each of the first and second switches is controlled so that each of the first and second electrolyzers is powered, thereby producing hydrogen at a predetermined percentage corresponding to the aging state of the electrolyzer, and the total amount of hydrogen produced by the multiple electrolyzers together is the target total hydrogen production.

7. The power supply system as described in claim 5, wherein, When the difference measurement indicates that the first and second electrolytic cells are in an unbalanced state, the controller is configured to: Adjust the duty cycle of at least one of the first and second switches to compensate for performance loss in either the first or second electrolytic cell.

8. The power supply system as described in claim 5, wherein, When the difference measurement indicates that the first and second electrolytic cells are in an unbalanced state, the controller is configured to: The duty cycle of at least one of the first and second switches is dynamically adjusted over a period of time until the difference measurement indicates that the first and second electrolytic cells are in equilibrium.

9. The power supply system as described in any one of claims 1-8, wherein, In the event of a malfunction in either the first or second electrolytic cell, the controller is configured to: Control at least one of the first and second switches to bypass the faulty electrolytic cell.

10. The power supply system as described in any one of claims 1-9, wherein, The difference measurement is determined based on one or more difference measurements and is used to quantitatively represent the difference between the current measurement state of the first electrolyzer and the current measurement state of the second electrolyzer.

11. The power supply system as claimed in any one of claims 1-9, wherein, The difference measurement is determined based on one or more difference measurements and is used to quantitatively represent the difference between the current measurement state of at least one of the first and second electrolytic cells and the previous measurement state of the at least one electrolytic cell.

12. The power supply system as described in any one of claims 1-9, wherein, The difference measurement value is determined based on the voltage difference between the first voltage of the first electrolytic cell and the second voltage of the second electrolytic cell.

13. The power supply system as described in any one of claims 1-9, wherein, The difference measurement value is determined based on the current difference between the reference current and the measured current, which is measured in the branch between the series node of the first electrolytic cell and the second electrolytic cell and the connection node of the first switch and the second switch.

14. The power supply system according to any one of claims 1-9, wherein, The difference measurement value is determined based on the voltage difference between the reference voltage and the measured voltage, which is measured at the series node between the first electrolytic cell and the second electrolytic cell.

15. The power supply system as claimed in claim 1, wherein, The DC / DC converter includes: a first output terminal coupled to a terminal of a first electrolytic cell, a second output terminal coupled to a terminal of a second electrolytic cell, and a third output terminal coupled to the series node of the first and second electrolytic cells.

16. The power supply system according to any one of claims 1-15, wherein, The DC / DC converter is a boost DC / DC converter, and also includes a first capacitor coupled to a first electrolytic cell and a second capacitor coupled to a second electrolytic cell. The first capacitor has a predetermined first capacitance to meet the ripple requirements of the first electrolytic cell; and The second capacitor has a predetermined second capacitance to meet the ripple requirements of the second electrolytic cell.

17. The power supply system according to any one of claims 1-15, wherein, The DC / DC converter is a step-down DC / DC converter, and also includes a first inductor coupled to a first electrolytic cell and a second inductor coupled to a second electrolytic cell. The first inductor has a predetermined first inductance to meet the ripple requirements of the first electrolytic cell, and The second inductor has a predetermined second inductance to meet the ripple requirements of the second electrolytic cell.

18. A method for controlling a power supply system as described in any one of claims 1-17, comprising: Obtain the difference measurement value indicating the performance difference between the first electrolytic cell and the second electrolytic cell; The difference measurement value determines whether the first and second electrolytic cells are in a balanced or unbalanced state. When it is determined that the first electrolyzer and the second electrolyzer are in a balanced state, the first switch and the second switch are controlled to make the two electrolyzers operate synchronously, so as to have the same hydrogen production within a predetermined time period. as well as When it is determined that the first electrolyzer and the second electrolyzer are in an unbalanced state, the first switch and the second switch are controlled with different duty cycles so that the total hydrogen production of the first electrolyzer and the second electrolyzer within a predetermined time period reaches the target total hydrogen production, and the total power loss in the first electrolyzer and the second electrolyzer within the predetermined time period is reduced.

19. The method of claim 18, wherein, Controlling the first and second switches with different duty cycles includes: Based on the difference measurement values, the electrolytic cell with a more severe aging condition was determined between the first and second electrolytic cells. The first and second switches are controlled with different duty cycles to reduce the hydrogen production duration of the more severely aged electrolyzer within a predetermined time period, and to increase the hydrogen production duration of the other electrolyzer within the predetermined time period; and The duty cycle of each switch is dynamically adjusted based on the real-time difference measurement value to compensate for the performance loss of the electrolyzer with more severe aging and to minimize the performance difference between the first and second electrolyzers.

20. A controller for controlling a power supply system, comprising one or more processors configured with processor-executable instructions to perform the method according to any one of claims 18-19.

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