Electrolytic cell with normally operated bypass

Abstract

The invention relates to a bypass normal operation electrolytic cell. Systems and methods for operating an electrolyzer are provided. The systems and methods include the operations of: determining that a first cell in a first electrolyzer stack is associated with a first set of performance criteria that fail to meet one or more operating conditions; identifying a second cell associated with a second set of performance criteria that meet the one or more operating conditions; and responsive to determining that a first cell in the first electrolyzer stack is associated with a first set of performance criteria that does not satisfy the one or more operating conditions, and based on determining that the second cell is associated with a second set of performance criteria that satisfies the one or more operating conditions, and bypassing the first electrolytic cell and the second electrolytic cell.

Description

Technical Field

[0001] This document relates generally to, but is not limited to, electrolytic cells. Background Art

[0002] Fuel cells are used to convert chemical energy (usually from hydrogen) into electrical energy. Since each fuel cell typically produces a voltage of 1 to 2 volts, such fuel cells are often stacked in series to produce high power at relatively low currents. Similar devices can also produce hydrogen. Instead of hydrogen and oxygen as inputs and electrons as the desired output, the inputs are electricity and water and hydrogen is the desired output. Summary of the invention

[0003] Among other things, this disclosure describes techniques for operating electrolytic cells.

[0004] In some examples, the technology described herein relates to a system comprising: a first electrolyzer stack comprising a first plurality of electrolytic cells; and control circuitry coupled to the first electrolytic cell and configured to perform operations comprising: determining that a first electrolytic cell in the first electrolyzer stack is associated with a first set of performance criteria that fails to satisfy one or more operating conditions; identifying a second electrolytic cell associated with a second set of performance criteria that satisfies the one or more operating conditions; and bypassing the first electrolytic cell and the second electrolytic cell in response to determining that the first electrolytic cell in the first electrolyzer stack is associated with the first set of performance criteria that fails to satisfy the one or more operating conditions and based on determining that the second electrolytic cell is associated with the second set of performance criteria that satisfies the one or more operating conditions.

[0005] In some aspects, the technology described herein relates to a system wherein the second electrolytic cell is located in the first electrolytic cell stack and is adjacent to the first electrolytic cell on a first side of the first electrolytic cell.

[0006] In some aspects, the technology described herein relates to a system wherein the operations further include: in response to determining that a first electrolytic cell in the first electrolytic cell stack is associated with a first set of performance criteria that do not satisfy the one or more operating conditions, identifying a third electrolytic cell in the first electrolytic cell stack that is adjacent to the first electrolytic cell on a second side of the first electrolytic cell.

[0007] In some aspects, the technology described herein relates to a system wherein operation further comprises: determining that the third electrolytic cell is associated with a third set of performance criteria that satisfies the one or more operating conditions; and in response to determining that a first electrolytic cell in the first electrolytic cell stack is associated with a first set of performance criteria that does not satisfy the one or more operating conditions, and based on identifying a third electrolytic cell in the first electrolytic cell stack that is adjacent to the first electrolytic cell on a second side of the first electrolytic cell, bypassing the third electrolytic cell as well as the first electrolytic cell and the second electrolytic cell.

[0008] In some aspects, the technology described herein relates to a system wherein operations further include: in response to determining that a first electrolysis cell in the first electrolyzer stack is associated with a first set of performance criteria that do not satisfy the one or more operating conditions, bypassing a plurality of adjacent electrolysis cells and the first electrolysis cell, the plurality of adjacent electrolysis cells being located on a same side relative to the first electrolysis cell and being associated with respective sets of performance criteria that satisfy the one or more operating conditions.

[0009] In some aspects, the technology described herein relates to a system wherein an operation for bypassing the first electrolytic cell and the second electrolytic cell includes closing a single switch associated with the first electrolytic cell to direct current from a first bipolar plate of the second electrolytic cell around a second bipolar plate of the first electrolytic cell to a third bipolar plate of the first electrolytic cell, wherein when the single switch is closed, the single switch prevents current from passing through a single bipolar plate of the second electrolytic cell to the second bipolar plate.

[0010] In some aspects, the technology described herein relates to a system further comprising: a second electrolyzer stack comprising a second plurality of electrolytic cells coupled to the control circuit, the second plurality of electrolytic cells including the second electrolytic cell, and the first electrolyzer stack electrically coupled in parallel with the second electrolyzer stack.

[0011] In some aspects, the technology described herein relates to a system wherein operations further include: determining that the first electrolyzer stack is aging at a different rate than the second electrolyzer stack, wherein the first electrolysis cell and the second electrolysis cell are bypassed to balance aging across the first and second electrolyzer stacks.

[0012] In some aspects, the technology described herein relates to a system wherein operations further include determining that the first electrolyzer stack is associated with a different amount of current or voltage from the second electrolyzer stack, wherein the first electrolytic cell and the second electrolytic cell are bypassed to balance the current or voltage across the first and second electrolyzer stacks.

[0013] In some aspects, the technology described herein relates to a system wherein operations further include: determining that the second electrolysis cell has been bypassed by the first electrolysis cell for a threshold time period; and in response to determining that the second electrolysis cell has been bypassed by the first electrolysis cell for a threshold time period: identifying a third electrolysis cell in the second electrolysis stack that is associated with a third set of performance criteria that satisfies the one or more operating conditions; and in response to determining that a first electrolysis cell in the first electrolysis stack is associated with a first set of performance criteria that does not satisfy the one or more operating conditions, bypassing the third electrolysis cell instead of the second electrolysis cell to bypass the first electrolysis cell and the third electrolysis cell.

[0014] In some aspects, the technology described herein relates to a system wherein operations further include selecting a second electrolysis cell from a second plurality of electrolysis cells of the second electrolyzer stack for bypass based on one or more electrolysis cell selection criteria.

[0015] In some aspects, the technology described herein relates to a system wherein the one or more electrolytic cell selection criteria include at least one of a voltage or current associated with the second electrolytic cell relative to voltages or currents of other electrolytic cells, an alignment characteristic associated with the first and second electrolyzer stacks, or an aging curve of the second electrolytic cell.

[0016] In some aspects, the technology described herein relates to a system wherein operation further comprises: determining that a third electrolytic cell of a second plurality of electrolytic cells of the second electrolytic cell stack is associated with a third set of performance criteria that fails to meet the one or more operating conditions; and in response to determining that a third electrolytic cell of a second plurality of electrolytic cells of the second electrolytic cell stack is associated with a third set of performance criteria that fails to meet the one or more operating conditions: bypassing the third electrolytic cell instead of the second electrolytic cell to bypass the first electrolytic cell and the third electrolytic cell.

[0017] In some aspects, the technology described herein relates to a system wherein operation further comprises: initializing operation of the first and second electrolyzer stacks by bypassing a first good electrolyzer (and / or a first set of good electrolyzers) in the first electrolyzer stack and bypassing a second good electrolyzer (and / or a second set of good electrolyzers) in the second electrolyzer stack; after initializing operation of the first and second electrolyzer stacks, determining that a first electrolyzer in the first electrolyzer stack is associated with a first set of performance criteria that fails to meet the one or more operating conditions; and in response to determining that a first electrolyzer in the first electrolyzer stack is associated with a first set of performance criteria that fails to meet the one or more operating conditions, replacing a bypass of the first good electrolyzer of the first electrolyzer stack with a bypass of the first electrolyzer while maintaining a bypass of the second good electrolyzer of the second electrolyzer stack.

[0018] In some aspects, the technology described herein relates to a system wherein the first set of performance criteria includes at least one of pinhole formation, catalyst degradation or dissolution, porous transport layer (PTL) coating degradation, current passing through the first electrolytic cell, or bipolar plate degradation; and wherein the one or more operating conditions include at least one of a pinhole formation threshold, a maximum catalyst degradation or dissolution value, a porous transport layer (PTL) coating degradation threshold, a maximum current threshold, or a bipolar plate degradation threshold.

[0019] In some aspects, the technology described herein relates to a method comprising: determining that a first electrolytic cell in a first electrolytic cell stack is associated with a first set of performance criteria that fails to meet one or more operating conditions; identifying a second electrolytic cell associated with a second set of performance criteria that meets the one or more operating conditions; and in response to determining that the first electrolytic cell in the first electrolytic cell stack is associated with the first set of performance criteria that fails to meet the one or more operating conditions, and based on determining that the second electrolytic cell is associated with the second set of performance criteria that meets the one or more operating conditions, bypassing the first electrolytic cell and the second electrolytic cell.

[0020] In some aspects, the technology described herein relates to a method wherein the second electrolytic cell is located in the first electrolytic cell stack and is adjacent to the first electrolytic cell on a first side of the first electrolytic cell.

[0021] In some aspects, the technology described herein relates to a method that also includes: in response to determining that a first electrolytic cell in the first electrolytic cell stack is associated with a first set of performance criteria that does not satisfy the one or more operating conditions, identifying a third electrolytic cell in the first electrolytic cell stack that is adjacent to the first electrolytic cell on a second side of the first electrolytic cell.

[0022] In some aspects, the technology described herein relates to an apparatus comprising: components for determining that a first electrolytic cell in a first electrolytic cell stack is associated with a first set of performance criteria that fails to meet one or more operating conditions; components for identifying a second electrolytic cell associated with a second set of performance criteria that meets the one or more operating conditions; and components for bypassing the first electrolytic cell and the second electrolytic cell in response to determining that the first electrolytic cell in the first electrolytic cell stack is associated with the first set of performance criteria that fails to meet the one or more operating conditions, and based on determining that the second electrolytic cell is associated with the second set of performance criteria that meets the one or more operating conditions.

[0023] In some aspects, the technology described herein relates to an apparatus wherein the second electrolytic cell is located in the first electrolytic cell stack and is adjacent to the first electrolytic cell on a first side of the first electrolytic cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In the accompanying drawings, which are not necessarily drawn to scale, the same numerals may describe similar components in different views. Similar numerals with different letter suffixes may represent different instances of similar components. The accompanying drawings generally illustrate various examples discussed in this document by way of example and not limitation.

[0025] Figure 1 is a block diagram of an example of an electrolyzer system including electrolyzer cells connected in parallel according to various examples.

[0026] Figure 2 is a block diagram of an example of an electrolyzer system including electrolyzer cells connected in parallel according to various examples.

[0027] Figure 3 is a block diagram of an example of an electrolyzer system including a plurality of parallel-connected electrolyzer cell stacks with bypass switches according to various examples.

[0028] Figure 4 is a block diagram of an example of an electrolyzer system including a plurality of parallel-connected electrolyzer cell stacks with bypass switches according to various examples.

[0029] Figure 5 is a block diagram of an example of an electrolyzer system including a single parallel-connected electrolyzer cell stack with a bypass switch according to various examples.

[0030] Figure 6 is a flow chart depicting an example method for operating an electrolyzer according to various examples.

[0031] Figure 7 is a block diagram illustrating an example of a machine upon which one or more examples may be implemented. DETAILED DESCRIPTION

[0032] Among other things, this disclosure describes techniques for configuring an electrolyzer or hydrolyzer to produce hydrogen and / or oxygen.

[0033] An electrolyzer typically consists of one or more electrolytic cells. Each electrolytic cell has three components: an electrolyte and two electrodes (a cathode and an anode). The electrolyte is typically a solution of water or other solvent with ions dissolved in it. Molten salts such as sodium chloride are also electrolytes. When driven by an external voltage applied to the electrodes, the ions in the electrolyte are attracted to the electrode with the opposite charge, where a charge transfer (also called Faradaic or redox) reaction can occur. Only an external potential (e.g., voltage) of the correct polarity and sufficient magnitude can allow an electrolytic cell to decompose normally stable or inert compounds in solution. The electrical energy provided can produce chemical reactions that would not otherwise occur spontaneously. Water, especially when ions are added (brine or acidic water), can be electrolyzed (subjected to electrolysis). When driven by an external voltage source, H +The ions flow to the cathode to combine with the electrons to produce hydrogen in a reduction reaction. - ions flow to the anode to release electrons, and H + The ions produce oxygen in an oxidation reaction.

[0034] Systems that produce hydrogen by electrolysis are called electrolyzers or hydrolyzers. The power generation system produces high voltage (e.g., between 50V and 200V) and high current (e.g., 100A to 4000A) that are supplied to an electrolyzer stack that includes electrolytic cells, each of which includes an electrolyte and two electrodes. With water as another input, the electrolyzer stack produces hydrogen and oxygen as outputs. If the energy source is a renewable energy source, such as solar, wind, or hydroelectric power, then the entire cycle is completely carbon-free. The electrolytic cells are usually electrically connected in series. However, this configuration has several disadvantages. For example, one challenge with electrolyzers is durability. There is a specific voltage across the electrolytic cells that produces the best combination of efficiency and durability. If the supply voltage is too high, corrosion in the electrodes can lead to increased impedance and shortened electrolyzer life. An increase in impedance in one electrolytic cell changes the voltage in other electrolytic cells and can reduce efficiency and / or durability.

[0035] Additionally, configuring electrolyzers in series limits the scalability of the entire system, as adding or replacing electrolyzers introduces additional challenges. For example, if one electrolyzer in the electrolyzer fails, the distribution of power to other electrolyzers through the system may be affected, and the entire system may also stop operating. That is, when electrolyzers are in a series configuration, when one electrolyzer fails, the entire stack also fails.

[0036] Some systems provide multiple electrolyzer stacks, each with its own set of electrolytic cells connected in series. That is, a first stack of electrolytic cells that is part of a first electrolyzer stack may be connected in series with each other, but connected in parallel with a second stack of electrolytic cells that is part of a second electrolyzer stack. While this improves the functionality of the entire electrolyzer, managing the operation of two or more separate electrolyzer stacks also presents other challenges. In particular, the output of one electrolyzer stack needs to be balanced with the output of another electrolyzer stack to ensure that the stacks age at a similar rate.

[0037] The electrolyzer stack may include multiple electrolytic cells electrically coupled in series, each having some minimum (e.g., thermoneutral) voltage at which water splits and produces increasing current at higher voltages; depending on the cell structure and chemistry (e.g., the thermoneutral voltage for a proton exchange membrane cell is about 1.5 V). Initially, the stack may be "balanced" with respect to some desired operating regime (e.g., the amount of current flowing through each stack is similar, i.e., a nominal amount of current per square centimeter of cell area (e.g., current density)).

[0038] In some examples, an electrolyzer plant includes a number of electrolyzer stacks that can be connected and operated in parallel. In a parallel configuration, the constituent stacks share a single power supply, so the stack voltages are the same. At the start, the stacks can initially be balanced so that the voltage and stack current reach some target levels, where the current flowing through each stack is approximately equal. Over time, the performance of the stacks will deviate from these target levels, which may be caused by differences between the stacks in terms of cell aging or cell failure. This may be caused by degradation of the constituent electrolytic cells, which changes the current-voltage relationship of the electrolytic cells (and the stacks). Alternatively, this may occur if the current and / or voltage of one stack is higher than another stack, perhaps due to wiring or mismatching. It may also be due to the operator intentionally bypassing a particular electrolytic cell that has failed, and the number of these electrolytic cells may be unbalanced across the stack. This may cause the parallel stacks to operate in an unbalanced manner, where one or more stacks begin to operate at currents that deviate significantly from the target current. The plant operator has little control over the performance of the individual stacks. That is, the operator can control the stack voltage of all the stacks in parallel, but has little differential control over the operation of the individual stacks in the parallel configuration.

[0039] While parallel stacks operate at the same voltage, the stack's operating current may vary depending on the number of constituent electrolytic cells and their performance. More current may be directed through some stacks and less in others, which may push some stacks outside of their desired operating regime. For example, at higher current densities, electrolytic cells degrade faster and become less efficient. In some cases, individual electrolytic cells in an electrolyzer stack may fail, resulting in the need to replace the stack. If the electrolytic cell impedance increases as a result of these failures, bypassing the defective electrolytic cell may allow the stack to continue operating without replacement, with slightly reduced efficiency, and without safety issues. Specifically, by bypassing one or more electrolytic cells in certain stacks, operators can fine-tune the operation of parallel stacks. When electrolytic cells within a stack are bypassed, the overall voltage of the stack remains the same, but drops on fewer electrolytic cells; this increases the stack current. Conversely, if a stack already contains bypassed cells, removing the bypass may increase the number of electrolytic cells within that stack and reduce the stack current.

[0040] Bypassing a faulty electrolyzer implicitly assumes that the electrolyzer resistance is much higher than bypassing, and / or that there are no adverse effects from shunting current through the bipolar plates, and / or that there are no adverse effects from leakage current through the electrolyzer. When these assumptions are not true, bypassing a defective electrolyzer may be ineffective. Electrolyzer bypassing has been considered for shunting stack current around a defective electrolyzer, thereby allowing continued operation in the event of a single point failure in an electrolyzer. However, bypassing one electrolyzer in a stack without considering the effect on the output or balance of the other stack can result in inefficiencies and damage to the entire electrolyzer plant.

[0041] According to the disclosed examples, a novel and resource-efficient method for operating and configuring an electrolyzer is provided. The disclosed method uses a bypass circuit to bypass one or more good electrolytic cells (e.g., bypass an electrolytic cell that has not failed), providing an operator with additional control over the operating conditions of a single stack within a parallel configuration. Bypassing a good electrolytic cell can achieve power balance across the stack, and operating conditions can be modified to reduce degradation of the electrolytic cell. When used in conjunction with bypassing of a faulty or failed electrolytic cell, the disclosed examples allow the stack to continue to operate safely and stably, regardless of the distribution of the faulty electrolytic cells (e.g., where they are concentrated within a single stack). As described herein, a faulty electrolytic cell or a faulty electrolytic cell can correspond to an electrolytic cell associated with a corresponding set of performance criteria that fails to meet one or more operating conditions. As described herein, a good electrolytic cell or a non-faulty electrolytic cell can correspond to an electrolytic cell associated with a corresponding set of performance criteria that meets one or more operating conditions.

[0042] There are multiple schemes for selecting good (non-faulty) electrolyzers to be bypassed. The bypassing can be cycled around all the good electrolyzers to balance the aging of the electrolyzers across the stack. For example, the first good electrolyzer might be bypassed one day, and the second good electrolyzer would be bypassed the next day; eventually, over the course of many days, all good electrolyzers will be bypassed at least once, and the cycle can repeat. Alternatively, the good electrolyzers can be selected for bypassing based on the parameters of the electrolyzers (e.g., bypassing is more desirable when one electrolyzer has a different voltage or aging profile). Another example is when the properties of the electrolyzers result in better alignment across the stack when the electrolyzer is bypassed compared to other candidate electrolyzers.

[0043] Bypassing a failed individual electrolytic cell and bypassing selected one or more healthy (e.g., good or non-failed) electrolytic cells (in the same electrolyzer stack and / or different electrolyzer stacks) can improve and optimize the performance of the electrolyzer system and increase the durability of the electrolytic cells and the electrolyzer system.

[0044] Figure 1 1 is a block diagram of an example of an electrolyzer system 100 including electrolytic cell stacks coupled in parallel to each other according to various examples. That is, in this example, the electrolytic cell stacks are electrically connected in parallel, and each electrolytic cell stack is driven by a common voltage source. Each electrolytic cell stack includes a corresponding plurality of electrolytic cells. The electrolyzer system 100 includes a main high-voltage power distribution device 110 configured to provide an intermediate voltage to a load point voltage converter 120. For example, the high-voltage power distribution device 110 can provide a voltage between 10 and 50 volts. The intermediate voltage converter 120 reduces (steps down) the voltage to a range of 1 volt and 2 volts.

[0045] The intermediate voltage converter 120 (common voltage converter) can generate a voltage between 1-2V and distribute the power in parallel to multiple electrolyzer electrolytic cell stacks 140. Each electrolyzer electrolytic cell stack 140 includes multiple electrolytic cells, each electrolytic cell having an electrolyte and two bipolar plates connected to receive a solution (e.g., water). The bipolar plates can be connected to the intermediate voltage converter 120. Each electrolyzer electrolytic cell stack 140 outputs oxygen and hydrogen through its respective electrolytic cells. The output rate depends on the power received by the bipolar plates of the electrolyzer electrolytic cell stack 140. In some cases, higher powers can produce oxygen and hydrogen faster, but this reduces the durability of the system. On the other hand, lower powers can produce oxygen and hydrogen at a slower rate, but can improve the durability of the system.

[0046] Each electrolyzer cell stack 140 is electrically coupled in parallel to each other and to the intermediate voltage converter 120. A monitoring control circuit 130 (e.g., a local monitoring circuit) is associated with (and implemented by) each electrolyzer cell stack 140. The monitoring control circuit 130 collects parameters of each electrolyzer cell 140 individually. For example, the monitoring control circuit 130 associated with the first electrolyzer cell stack 140 implements an analog-to-digital converter (ADC) to measure the voltage across various cell stack components to collect any combination of one or more parameters, including voltage, electrical impedance spectroscopy (EIS), current, temperature, and gas or fluid flow across one or more of the multiple cells. In some cases, the monitoring control circuit 130 includes a processor that implements a model for each cell stack that predicts or determines the performance of the cell stack and / or predicts or determines its failure. The monitoring control circuit 130 can disable the associated cell stack in response to determining that the current parameters are indicative and associated with an impending failure of the cell stack.

[0047] Figure 2 2 is a block diagram of an example of an electrolyzer system 200 according to various examples. The operation of the electrolyzer system 200 is similar to the operation of the electrolyzer system 100. Instead of providing the same power and voltage to all electrolyzer cell stacks 140 in parallel, each electrolyzer electrolytic cell stack 140 includes an independent power supply and monitoring circuit 210. Specifically, the intermediate voltage converter 120 provides a voltage of 10 to 50 volts in parallel to each independent power supply and monitoring circuit 210. The independent power supply and monitoring control circuit 210 then converts the voltage of 10 volts and 50 volts into a separate power supply voltage between 1 volt and 2 volts for a given electrolytic cell. In this way, one of the electrolyzer electrolytic cell stacks 140 can receive a first voltage (e.g., 1 volt) and operate at it, while the second one of the electrolyzer electrolytic cell stacks 140 can receive a different second voltage (e.g., 2 volts) and operate with it.

[0048] According to this configuration, when the monitoring control circuit 210 of a given electrolyzer cell stack 140 predicts that the given electrolyzer cell stack 140 is operating under conditions associated with an impending failure based on measured parameters of the given electrolyzer cell stack 140, the independent power supplies and monitoring control circuits 210 of the electrolyzer cell stack 140 may reduce the power and voltage delivered to the corresponding electrolyzer cell stack 140 to improve the durability and life of the cell stack, or temporarily disable the operation of the electrolyzer cell stack 140. At the same time, when the associated monitoring circuit 210 predicts that the given electrolyzer cell stack 140 has parameters that indicate or are associated with low performance, the independent power supplies and monitoring circuits 210 of the electrolyzer cell stack 140 may increase the power and voltage delivered to the corresponding electrolyzer cell stack 140 to improve performance without reducing the durability and life of the electrolyzer cell stack 140.

[0049] Figure 3 is a block diagram of an example of an electrolyzer system 300 according to various examples. The electrolyzer system 300 operates in a similar manner to the electrolyzer systems 100 and 200. The electrolyzer system 300 includes a first electrolyzer stack 310 (which corresponds to one of the electrolyzer cell stacks 140), and includes a second electrolyzer stack 320 (which corresponds to the second of the electrolyzer cell stacks 140). The second electrolyzer stack 320 and the first electrolyzer stack 310 are connected in parallel to a common power source (voltage / current) 340 (corresponding to the intermediate voltage converter 120 and / or the main high voltage distribution device 110).

[0050] The first electrolyzer stack 310 includes a first plurality of electrolytic cells, such as electrolytic cell 312 and electrolytic cell 316. The second electrolyzer stack 320 includes a second plurality of electrolytic cells, such as electrolytic cell 322 and electrolytic cell 332. The first electrolyzer stack 310 includes a first set of bypass switches 314 (e.g., a first bypass circuit). The first set of bypass switches 314 enables a control circuit (e.g., monitoring control circuit 130) to selectively bypass any one or more of the first plurality of electrolytic cells of the first electrolyzer stack 310. For example, a first switch in the first set of bypass switches 314 can be enabled (closed), which causes the current / voltage to be routed around the electrolytic cell associated with the first switch. In this case, the current / voltage connected to the first bipolar plate of the electrolytic cell is shunted to the second bipolar plate of the electrolytic cell to avoid or prevent the current / voltage from passing through internal components (e.g., solution) contained between the first and second bipolar plates. When a first switch in the first set of bypass switches 314 is disabled (open), current / voltage is routed from the first bipolar plate of the electrolytic cell through the components of the electrolytic cell to the second bipolar plate.

[0051] Similarly, the second electrolyzer stack 320 includes a second set of bypass switches 324 (e.g., a second bypass circuit). The second set of bypass switches 324 enables a control circuit (e.g., monitoring control circuit 130) to selectively bypass any one or more of the second plurality of cells of the second electrolyzer stack 320. For example, a first switch in the second set of bypass switches 324 can be enabled (closed), which causes current / voltage to be routed around the electrolytic cell of the second electrolyzer stack 320 associated with the first switch. In this case, the current / voltage connected to the first bipolar plate of the electrolytic cell is shunted to the second bipolar plate of the electrolytic cell to avoid or prevent the current / voltage from passing through the internal components (e.g., solution) contained between the first and second bipolar sheets. When the first switch of the second set of bypass switches 324 is disabled (open), the current / voltage is routed from the first bipolar plate of the electrolytic cell through the components of the electrolytic cell to the second bipolar plate.

[0052] The bypass circuit may be implemented external or external to the components of a given electrolytic cell. The bypass circuit may be configured to bypass the components of a given cell when the switch is closed. This results in the given electrolytic cell being electrically removed from the series of electrolytic cells of a particular electrolyzer stack as the current is shunted from one bipolar plate to another. Multiple bypass circuits may be associated, each associated with a given electrolytic cell among the many electrolytic cells of the electrolyzer. The bipolar plates may be circular or any suitable shape, such as rectangular or octagonal.

[0053] In some implementations, a bypass circuit is integrated within each electrolytic cell to avoid implementing or running physical wiring around the electrolytic cell. In this case, the bipolar plates are extended to make room for the bypass circuit. For example, the bypass circuit can be set around the electrolytic cell to avoid interfering with the flow of water and gas between the electrolytic cell components. The bypass circuit can include a printed circuit board (PCB), a system on a chip, an integrated circuit, or other device with an integrated processing element. The PCB (processing element) is coupled to wiring, such as copper or other conductive metal. The PCB (processing element) controls whether current flows from one bipolar plate to another through the copper. That is, when the PCB (processing element) closes the switch, the current flows from one bipolar plate to another through the copper, avoiding flowing through other components of the electrolytic cell.

[0054] In some cases, multiple bypass circuits may be arranged around the electrolytic cell. When the switches of the bypass circuits are closed, this causes the current between the bipolar plates to be distributed among the multiple bypass circuits. In this case, the first set of bypass circuits may be configured to allow a certain amount of current to flow between the bipolar plates, while the remaining amount of current continues to flow through other elements of the electrolytic cell. Specifically, a given bipolar plate may receive a given amount of current, and each bypass circuit is configured only to allow a maximum portion of the current less than the total given amount received to flow. In this case, the total given amount of current is divided so that an amount equal to the maximum portion accumulated on the enabled subset of bypass circuits (e.g., bypass circuits with switches closed) flows directly between the bipolar plates, while the remaining portion of the given amount of current flows through other elements of the electrolytic cell. In this way, the electrolytic cell can be partially removed from the series connection of the electrolytic cell.

[0055] In some examples, the control circuit determines that electrolytic cell 322 is a bad or failed electrolytic cell. This can be determined by comparing a set of performance criteria for electrolytic cell 322 to one or more operating conditions. If the performance criteria match or meet the operating conditions, the electrolytic cell is good or has no faults. If the performance criteria do not match or do not meet the operating conditions, the electrolytic cell is bad or faulty. The first set of performance criteria may include at least one of pinhole formation, catalyst degradation or dissolution, PTL coating degradation, current through the first electrolytic cell, and / or bipolar plate degradation. One or more operating conditions may include at least one of a pinhole formation threshold, a maximum catalyst degradation or dissolution value, a PTL coating degradation threshold, a maximum current threshold, and / or a bipolar plate degradation threshold.

[0056] For example, the control circuit may determine that the amount of current drawn by the electrolytic cell 322 exceeds a threshold, indicating that some current is being shunted across the electrolytic cell. As another example, the control circuit may determine that pinhole formation on or associated with the electrolytic cell 322 exceeds a pinhole formation threshold (e.g., a maximum allowable size). As another example, the control circuit may determine that catalyst degradation or dissolution associated with the electrolytic cell 322 exceeds a maximum catalyst degradation or dissolution value. As another example, the control circuit may determine that PTL coating degradation associated with the electrolytic cell 322 exceeds a PTL coating degradation threshold. As another example, the control circuit may determine that bipolar plate degradation associated with the electrolytic cell 322 exceeds a bipolar plate degradation degree threshold. Any other criteria may also be used in conjunction with or in lieu of these criteria to determine whether the electrolytic cell 322 has failed, such as aging of the electrolytic cell 322.

[0057] In some examples, in response to determining that electrolytic cell 322 has failed, the control circuit can enable or close a switch in the second set of bypass switches 324 associated with electrolytic cell 322. This causes electrolytic cell 322 to be bypassed and removed from the second electrolyzer stack 320. In order to balance the output, aging, current, and / or voltage associated with the second electrolyzer stack 320 relative to the first electrolyzer stack 310, the control circuit can select a good electrolytic cell, such as electrolytic cell 312 from the first electrolyzer stack 310, to also be bypassed. In this way, the number of electrolytic cells active and operating between the first electrolyzer stack 310 and the second electrolyzer stack 320 remains unchanged or balanced. For example, the control circuit can enable or close a switch in the first set of bypass switches 314 associated with electrolytic cell 312. This causes electrolytic cell 312 to be bypassed and removed from the first electrolyzer stack 310, while electrolytic cell 322 is also bypassed.

[0058] In some examples, the following combination Figure 5 As discussed in more detail, when electrolytic cell 322 is bypassed, one or more adjacent electrolytic cells 330 and / or 332 may be automatically bypassed. This may prevent pinhole leakage of current through electrolytic cell 322 when electrolytic cell 322 is bypassed. That is, by preventing current from reaching any bipolar plate or certain bipolar plates of a faulty electrolytic cell (e.g., electrolytic cell 322), current may not leak through (e.g., shunted through) any portion of electrolytic cell 322 when electrolytic cell 322 is bypassed.

[0059] The control circuitry may select electrolytic cell 312 from the various electrolytic cells of first electrolyzer stack 310 based on various criteria. For example, the control circuitry may randomly select electrolytic cell 312 from the various electrolytic cells of first electrolyzer stack 310. As another example, the control circuitry may select a first electrolytic cell in first electrolyzer stack 310 at a first point in time. After a specified period of time (e.g., one hour, one day, one week, one month, etc.) has passed, the control circuitry may select a different electrolytic cell, such as electrolytic cell 316, to bypass from first electrolyzer stack 310 instead of electrolytic cell 312. In this way, electrolytic cell 316 may be bypassed while electrolytic cell 322 is bypassed instead of electrolytic cell 312. The control circuitry may continue to traverse first electrolyzer stack 310, periodically switching which good electrolytic cells are bypassed, until the last electrolytic cell in first electrolyzer stack 310 is bypassed. Then, after the last electrolytic cell is bypassed for a specified period of time, the control circuitry may loop back to bypass electrolytic cell 312.

[0060] As another example, the control circuit may search for performance criteria of each electrolytic cell of the first electrolyzer stack 310. The control circuit may select the weakest good electrolytic cell as the good electrolytic cell while bypassing the faulty electrolytic cell 322. That is, the control circuit may select the good electrolytic cells to bypass and bypass the faulty electrolytic cell 322 based on the aging curves of the good electrolytic cells. When bypassing, the good electrolytic cells may also or alternatively be selected based on alignment across the stack compared to other good electrolytic cells.

[0061] In some examples, after bypassing the good electrolytic cell (e.g., after electrolytic cell 312 is bypassed along with electrolytic cell 322), the control circuitry may determine that electrolytic cell 316 has begun to fail and is now a bad or failing electrolytic cell. In response to determining that electrolytic cell 316 has begun to fail and is now a bad or failing electrolytic cell, the control circuitry may select electrolytic cell 316 to be bypassed from first electrolyzer stack 310 instead of electrolytic cell 312. Thus, electrolytic cell 316 may be bypassed as a failed electrolytic cell when electrolytic cell 322 is bypassed instead of electrolytic cell 312.

[0062] like Figure 4 As shown in the diagram 400 of FIG. 400 , the control circuit may initially balance the first electrolyzer stack 310 and the second electrolyzer stack 320 by bypassing good electrolyzers 410 and 420 from each of the first electrolyzer stack 310 and the second electrolyzer stack 320. For example, the control circuit may bypass the first good electrolyzer 410 of the first electrolyzer stack 310 and may bypass the second good electrolyzer 420 of the second electrolyzer stack 320. This may be used to balance the voltage and / or current consumed by and through the first electrolyzer stack 310 and the second electrolyzer stack 320.

[0063] At some later point, the control circuit may determine that the second electrolyzer stack 320 includes a faulty electrolytic cell 430. In this case, the control circuit may keep the good electrolytic cells 410 bypassed in the first electrolyzer stack 310. The control circuit may switch from bypassing the good electrolytic cells 420 in the second electrolyzer stack 320 to bypassing the faulty electrolytic cells 430. Specifically, the operation of the electrolyzer may be initialized by bypassing one or more "good" electrolytic cells in each stack. If a non-bypassed electrolytic cell fails, the non-bypassed electrolytic cell may now be bypassed while removing the bypass of the "good" electrolytic cell in the same stack. In this way, current balance between the stacks is maintained while maintaining the desired stack voltage.

[0064] As previously mentioned, failure of a single electrolytic cell within an electrolyzer stack can be caused by a variety of mechanisms, such as pinhole formation, catalyst degradation or dissolution, PTL coating degradation, bipolar plate degradation, etc. Directing the stack current around the defective cell via a bypass switch or other equivalent mechanism connected to the bipolar plates sandwiching the membrane electrode assembly (MEA) can allow the stack to continue to operate without the need to replace the stack due to such failures.

[0065] Typically, when an electrolyzer develops a pinhole defect (or a thinning of the film that has the potential to develop into a pinhole), continuing to operate the electrolyzer within the stack may result in continued growth of the pinhole in the outlet stream and / or mixing of H2 and O2, with the potential risk of a safety incident. In this case, the stack is typically taken offline and replaced unless the defective electrolyzer has a bypass function to prevent a safety incident. Similarly, when an electrolyzer develops defects such as catalyst degradation, PTL coating degradation, or bipolar plate degradation, the reduction in electrolyzer efficiency creates a positive feedback loop that accelerates electrolyzer degradation and ultimately leads to stack failure. This can be prevented / delayed by using the bypass function to shut down the defective electrolyzer.

[0066] However, if the impedance of the bypassed cell at low voltage is similar to the bypass path due to any internal cell / MEA defects, some shunt current may continue to flow through the cell. Depending on the defect type, this may cause continued or accelerated degradation of the cell and may lead to cell failure. Certain defects manifest as membrane shorts, which can cause pinhole growth if not controlled. If the bypass cell current is shorted, the continued leakage current through the cell membrane can cause resistive heating and further pinhole growth, resulting in a safety incident. If the bipolar plates have mechanical discontinuities due to impurities / cracks, etc., the shunt current path to the switch may be more resistive or inaccessible, resulting in unsuccessful bypass of a single defective cell.

[0067] To address these challenges, Figure 5 As shown in Figures 500 and 501, in addition to the defective electrolytic cell itself, the disclosed technology also bypasses one or two electrolytic cells adjacent to the defective (faulty) electrolytic cell to more completely and robustly prevent current flow within the electrolytic cell. In a typical case, the resistance provided by the switch is several orders of magnitude lower than the resistance of the bipolar plate, so that the shunt current flows through the switch path, avoiding the defective electrolytic cell including the bipolar plate. In some cases, any number of electrolytic cells adjacent to the defective electrolytic cell can be used for effective bypass. This may be just one good electrolytic cell adjacent to the defective electrolytic cell, or it may be two or more good electrolytic cells. In some cases, a stack-level alternative to reduce switch-related costs and achieve effective bypassing may include implementing a switching mechanism that bypasses two or more good electrolytic cells and bad electrolytic cells at a time, rather than allowing bypassing at the individual electrolytic cell level.

[0068] For example, as shown in diagram 500, a single electrolyzer stack (e.g., second electrolyzer stack 320) including a plurality of electrolytic cells 540, 520, 510, 530, and 546 is shown. The control circuit may determine that electrolytic cell 510 is a bad electrolytic cell that has failed and needs to be bypassed. In some cases, the control circuit determines that electrolytic cell 510 has failed due to a certain type of defect (e.g., pinhole formation) that exceeds a threshold amount. In this case, in addition to electrolytic cell 510, the control circuit may also select one or more good electrolytic cells adjacent to the electrolytic cell 510 that failed to be bypassed. For example, in addition to bypassing the faulty electrolytic cell 510, the control circuit may also bypass the good electrolytic cell 520 adjacent to the first side of the faulty electrolytic cell 510 (e.g., on top thereof) and / or the good electrolytic cell 530 adjacent to the faulty electrolytic cell 510 on the second side (e.g., below the faulty electrolytic cell) of the faulty electrolytic cell 510. The control circuit can close switch 522 to route current from the top bipolar plate 542 of good electrolytic cell 520 to the bottom bipolar plate 544 of good electrolytic cell 530 via another switch 524. In this way, the current passes through good electrolytic cell 540; bypasses electrolytic cells 520, 510, and 530; and passes through good electrolytic cell 546.

[0069] In some cases, as shown in diagram 501, a single switch can be associated with multiple electrolytic cells, such as electrolytic cells 510 and 520. In this case, a single switch can be closed to bypass the current around electrolytic cells 520 and 510 at the same time, rather than closing two switches 522 and 524 to direct the current to bypass electrolytic cells 520, 510. A single switch can be associated with any number or quantity of electrolytic cells, so that when the single switch is closed or enabled, all associated electrolytic cells are bypassed at the same time. In some cases, by providing a switch between every two electrolytic cells, rather than (or in addition to) each electrolytic cell in the plurality of electrolytic cells, the complexity / design challenges of the switch can be saved.

[0070] In some examples, as shown in diagram 501, a first number of good electrolytic cells (e.g., two or more good electrolytic cells) on a first side of a faulty electrolytic cell 510 may be bypassed by a control circuit, while a second number of good electrolytic cells 530 (e.g., one or less) on a second side of the faulty electrolytic cell 510 are bypassed. This results in an uneven number of good electrolytic cells on the first and second sides of the faulty electrolytic cell.

[0071] Figure 6 600 is a flowchart depicting an example process or method 600 for operating or configuring an electrolyzer according to various examples. The operations of the process or method 600 may be performed in parallel or in a different order, or may be omitted entirely. In some examples, some or all of the operations of the process or method 600 may be embodied on a computer-readable medium and executed by one or more processors.

[0072] At operation 610 , control circuitry determines that a first electrolysis cell in a first electrolyzer stack is associated with a first set of performance criteria that fails to satisfy one or more operating conditions, as described above.

[0073] At operation 610, the control circuit identifies a second electrolytic cell associated with a second set of performance criteria that satisfies one or more operating conditions, as described above. The second electrolytic cell can be located in the same electrolytic cell stack as the first electrolytic cell, or can be located in a different stack than the first electrolytic cell that is proximate to the second electrolytic cell (e.g., near a threshold).

[0074] At operation 610, control circuitry bypasses the first electrolytic cell and the second electrolytic cell in response to determining that a first electrolytic cell in a first electrolyzer stack is associated with a first set of performance criteria that does not satisfy one or more operating conditions and based on identifying a second electrolytic cell associated with a second set of performance criteria that satisfies one or more operating conditions, as described above.

[0075] Figure 7 700 is a block diagram of an example machine 700, on which any one or more of the techniques (e.g., methods) discussed herein can be performed. In alternative examples, the machine 700 can be run as a standalone device or can be connected (e.g., networked) to other machines. In a networked deployment, the machine 700 can be run as a server machine, a client machine, or both in a server-client network environment. In one example, the machine 700 can act as a peer machine in a peer-to-peer (P2P) (or other distributed) network environment. The machine 700 can be a personal computer (PC), a tablet computer, a set-top box (STB), a personal digital assistant (PDA), a mobile phone, a network device, an Internet of Things device, an automotive system, an aerospace system, or any machine capable of executing instructions (sequentially or otherwise) specifying the actions to be taken by the machine. In addition, although only a single machine is shown, the term "machine" should also be deemed to include any machine collection that executes a set (or multiple sets) of instructions individually or jointly to perform any one or more of the methods discussed herein, such as through cloud computing, software as a service (SaaS) or other computer cluster configurations.

[0076] As described herein, examples may include logic, components, devices, packages, or mechanisms, and may also be operated by them. A circuit is a collection (e.g., a group) of circuits implemented in a tangible entity, including hardware (e.g., simple circuits, gates, logic, etc.). Circuit membership may be flexible over time and as the underlying hardware changes. A circuit includes members that can perform specific tasks individually or in combination when in operation. In one example, the hardware of the circuit may be invariably designed to perform a specific operation (e.g., hardwired). In one example, the hardware of the circuit may include variably connected physical components (e.g., execution units, transistors, simple circuits, etc.), including physically modified computer-readable media (e.g., by magnetic, electrical, movable placement of invariant aggregate particles, etc.) to encode instructions for specific operations. When connecting physical components, the underlying electrical properties of the hardware components change, for example, from an insulator to a conductor, or vice versa. These instructions enable the participating hardware (e.g., execution units or loading mechanisms) to create members of the circuit in hardware through variable connections to perform a portion of a specific task when in operation. Thus, when the device is operating, the computer-readable medium is communicatively coupled to other components of the circuit. In one example, any physical component can be used in multiple members of multiple circuits. For example, under operation, an execution unit can be used in a first circuit of a first circuit at one point in time and reused by a second circuit of the first circuit or a third circuit of the second circuit at a different time.

[0077] The machine (e.g., computer system) 700 may include a hardware processor 702 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof, such as a memory controller, etc.), a main memory 704, and a static memory 706, some or all of which may communicate with each other via an interconnect (e.g., a bus) 708. The machine 700 may also include a display device 710, an alphanumeric input device 712 (e.g., a keyboard), and a user interface (UI) navigation device 714 (e.g., a mouse). In one example, the display device 710, the alphanumeric input device 712, and the UI navigation device 714 may be a touch screen display. The machine 700 may also include a storage device 722 (e.g., a drive unit); a signal generating device 718 (e.g., a speaker); a network interface device 720; one or more sensors 716, such as a global positioning system (GPS) sensor, a wing sensor, a mechanical device sensor, a temperature sensor, a bridge sensor, an audio sensor, an industrial sensor, a compass, an accelerometer, or other sensor; and one or more electrolyzer stacks 790. The electrolyzer stack 790 may implement some or all of the functions of the electrolyzer system described above. The machine 700 may include an output controller 728, such as a serial (e.g., universal serial bus (USB)), parallel or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate with or control one or more peripheral devices (e.g., printers, card readers, etc.).

[0078] The storage device 722 may include a machine-readable medium on which is stored one or more sets of data structures or instructions 724 (e.g., software) embodying or used by any one or more of the techniques or functions described herein. The instructions 724 may also reside, completely or at least partially, within the main memory 704, within the static memory 706, or within the hardware processor 702 during execution of the instructions 724 by the machine 700. In one example, one or any combination of the hardware processor 702, the main memory 704, the static memory 706, or the storage device 722 may constitute a machine-readable medium.

[0079] Although the machine-readable medium is illustrated as a single medium, the term “machine-readable medium” may include a single medium or multiple media (eg, a centralized or distributed database, or associated caches and servers) configured to store one or more instructions 724 .

[0080] The term "machine-readable medium" may include any transient or non-transient medium capable of storing, encoding or carrying transient or non-transient instructions executed by the machine 700 and causing the machine 700 to perform any one or more of the techniques disclosed herein, or any transient and non-transient medium capable of storing, encrypting or carrying data structures used by or associated with these instructions. Non-limiting machine-readable medium examples may include solid-state memory and optical and magnetic media. In one example, the aggregated machine-readable medium includes a machine-readable medium having a plurality of particles with a constant (e.g., stationary) mass. Therefore, the aggregated computer-readable medium is not a transient propagation signal. Specific examples of mass machine-readable media may include non-volatile memory, such as semiconductor storage devices (e.g., electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM)) and flash memory devices; disks, such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD-ROM optical disks.

[0081] Instructions 724 (e.g., software, programs, operating systems (OS), etc.) or other data stored on storage devices 721 may be accessed by main memory 704 for use by hardware processors 702. Main memory 704 (e.g., DRAM) is typically fast, but volatile, and is therefore a different type of storage device than storage devices 721 (e.g., SSDs) and is suitable for long-term storage, including in an "off" state. Instructions 724 or data used by a user or machine 700 are typically loaded into main memory 704 for use by hardware processors 702. When main memory 704 is full, virtual space from storage devices 721 may be allocated to supplement main memory 704; however, because storage devices 721 are typically slower than main memory 704, and write speeds are typically at least twice as fast as read speeds, using virtual memory can significantly reduce the user experience due to storage device latency (compared to main memory 704, such as DRAM). In addition, using storage devices 721 for virtual memory can significantly shorten the useful life of storage devices 721.

[0082] The instructions 724 may also be transmitted or received using a transmission medium via the network interface device 720 over a communication network 726 using any of a variety of transmission protocols (e.g., frame relay, Internet Protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), hypertext transfer protocol (HTTP), etc.). Example communication networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), a mobile telephone network (e.g., a cellular network), a plain old telephone service (POTS) network, and a wireless data network (e.g., a wireless network such as a cellular network). The Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards, known as IEEE 802.16 family of standards, IEEE 802.15.4 family of standards, P2P networks, etc. In one example, the network interface device 720 may include one or more physical jacks (e.g., Ethernet, coaxial cable, or telephone jacks) or one or more antennas to connect to the communication network 726. In one example, the network interface device 720 may include multiple antennas to wirelessly communicate using at least one of single-input multiple-output (SIMO), multiple-input multiple-input (MIMO), or multiple-input single-output (MISO) technology. The term "transmission medium" should be deemed to include any tangible or intangible medium that can store, encode, or carry instructions executed by the machine 700, and includes digital or analog communication signals or other tangible or intangible media to facilitate the communication of such software.

[0083] Each non-limiting aspect or example described herein may stand alone or in various permutations or combinations with one or more of the other examples.

[0084] The above detailed description includes references to the accompanying drawings that form a part of the detailed description. The accompanying drawings show specific examples in which the subject matter of the present invention can be practiced by way of illustration. These examples are also referred to as "examples" in this article. These examples may include elements other than those shown or described. However, the inventors also consider examples that only provide the shown or described elements. In addition, the inventors also consider examples using any combination or permutation of those elements (or one or more aspects thereof) shown or described, whether with respect to a specific example (or another one or more aspects thereof), or with respect to other examples (or two or more aspects thereof) shown or described herein.

[0085] In the event of an inconsistency in usage between this document and any document incorporated by reference, the usage in this document shall control.

[0086] In this document, the terms "a" or "an" are used, as is common in patent documents, to include one or more, independent of any other instance or usage of "at least one" or "one or more." In this document, the term "or" is used to refer to non-exclusivity, or "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise noted. In this document, the terms "including" and "wherein" are used as the plain-English equivalents of the respective terms "comprising" and "wherein." In addition, in the following aspects, the terms "comprising" and "comprising" are open-ended; that is, a system, apparatus, article, composition, formulation, or process that includes additional elements in addition to the elements listed after the term in an aspect is still considered to be within the scope of that aspect. In addition, in the following aspects, the terms "first," "second," "third," etc. are used merely as labels and are not intended to impose numerical requirements on their objects.

[0087] The method examples described herein may be implemented at least in part by a machine or computer. Some examples may include a computer-readable medium or a machine-readable medium, which is encoded with transient or non-transient instructions, operable to configure an electronic device to perform the method described in the above example. The implementation of this method may include code, such as microcode, assembly language code, higher-level language code, etc. Such code may include transient or non-transient computer-readable instructions for executing various methods. The code may form part of a computer program product. In addition, in one example, the code may be tangibly stored on one or more volatile, non-transient or non-volatile tangible computer-readable media, such as during execution or at other times. Examples of these tangible computer-readable media may include, but are not limited to, a hard disk, a removable disk, a removable optical disk (e.g., an optical disk and a digital video disk), a cassette, a memory card or a memory stick, a random access memory (RAM), a read-only memory (ROM), etc.

[0088] The above description is intended to be illustrative rather than limiting. For example, the above examples (or one or more aspects thereof) may be used in combination with each other. Other examples may be used, such as those used by a person of ordinary skill in the art after reading the above description. The abstract is provided to comply with regulations so that the reader can quickly determine the nature of the technical disclosure. The premise of submitting this document is that this document shall not be used to interpret or limit the scope or meaning of the claims. In addition, in the above detailed description, various features may be combined together to simplify the present disclosure. This should not be interpreted as meaning that the disclosed features not listed in the claim list are essential to any aspect. On the contrary, the subject matter of the present invention may lie in the partial features of a specific disclosed example. Therefore, the following aspects are incorporated into the detailed description as examples or instances, each claim exists separately as a separate example, and it is conceivable that these examples can be combined with each other in various combinations or arrangements. The scope of the subject matter of the present invention should be determined with reference to the attached claims and the full scope of equivalents enjoyed by these claims.

Claims

1. A system comprising: a first electrolyzer stack comprising a first plurality of electrolytic cells; and A control circuit coupled to the first electrolyzer stack and configured to perform operations including: determining that a first electrolysis cell in the first electrolyzer stack is associated with a first set of performance criteria that fails to satisfy the one or more operating conditions; determining that a second electrolytic cell is associated with a second set of performance criteria that satisfies the one or more operating conditions; and In response to determining that a first electrolytic cell in the first electrolyzer stack is associated with a first set of performance criteria that does not satisfy the one or more operating conditions, and based on determining that the second electrolytic cell is associated with a second set of performance criteria that satisfies the one or more operating conditions, bypassing the first electrolytic cell and the second electrolytic cell.

2. The system of claim 1, wherein the second electrolytic cell is located in the first electrolytic cell stack and is adjacent to the first electrolytic cell on a first side of the first electrolytic cell.

3. The system of claim 2, wherein the operations further comprise: In response to determining that a first electrolytic cell in the first electrolytic cell stack is associated with a first set of performance criteria that does not satisfy the one or more operating conditions, a third electrolytic cell in the first electrolytic cell stack adjacent to the first electrolytic cell on a second side of the first electrolytic cell is identified.

4. The system of claim 3, wherein the operations further comprise: determining that the third electrolytic cell is associated with a third set of performance criteria that satisfies the one or more operating conditions; and In response to determining that a first electrolytic cell in the first electrolytic cell stack is associated with a first set of performance criteria that does not satisfy the one or more operating conditions, and based on identifying a third electrolytic cell in the first electrolytic cell stack that is adjacent to the first electrolytic cell on a second side of the first electrolytic cell, bypassing the third electrolytic cell and the first and second electrolytic cells.

5. The system of claim 2, wherein the operations further comprise: In response to determining that a first electrolysis cell in the first electrolyzer stack is associated with a first set of performance criteria that do not satisfy the one or more operating conditions, bypassing a plurality of adjacent electrolysis cells and the first electrolysis cell, the plurality of adjacent electrolysis cells being located on a same side relative to the first electrolysis cell and being associated with a respective set of performance criteria that satisfy the one or more operating conditions.

6. The system of claim 2, wherein the operation for bypassing the first electrolytic cell and the second electrolytic cell comprises closing a single switch associated with the first electrolytic cell to direct current from the first bipolar plate of the second electrolytic cell around the second bipolar plate of the first electrolytic cell to the third bipolar plate of the first electrolytic cell, wherein when the single switch is closed, the single switch prevents current from passing through the single bipolar plate of the second electrolytic cell to the second bipolar plate.

7. The system of claim 1, further comprising: A second electrolyzer stack includes a second plurality of electrolytic cells coupled to the control circuit, the second plurality of electrolytic cells including the second electrolytic cell, and the first electrolyzer stack is electrically coupled in parallel with the second electrolyzer stack.

8. The system of claim 7, wherein the operations further comprise: It is determined that the first electrolyzer stack is aging at a different rate than the second electrolyzer stack, wherein the first electrolysis cell and the second electrolysis cell are bypassed to balance aging across the first and second electrolyzer stacks.

9. The system of claim 7, wherein the operations further comprise: The first electrolyzer stack is determined to be associated with a different amount of current or voltage from the second electrolyzer stack, wherein the first and second electrolyzer cells are bypassed to balance the current or voltage across the first and second electrolyzer stacks.

10. The system of claim 7, wherein the operations further comprise: determining that the second electrolytic cell has been bypassed by the first electrolytic cell for a threshold period of time; and In response to determining that the second electrolytic cell has been bypassed by the first electrolytic cell for a threshold period of time: identifying a third electrolytic cell in the second electrolyzer stack associated with a third set of performance criteria that satisfies the one or more operating conditions; and In response to determining that a first electrolytic cell in the first electrolyzer stack is associated with a first set of performance criteria that does not satisfy the one or more operating conditions, bypassing the third electrolytic cell instead of the second electrolytic cell to bypass the first and third electrolytic cells.

11. The system of claim 7, wherein the operations further comprise: A second electrolysis cell is selected from a second plurality of electrolysis cells of the second electrolyzer stack for bypassing based on one or more electrolysis cell selection criteria.

12. The system of claim 11, wherein the one or more electrolytic cell selection criteria include at least one of a voltage or current associated with the second electrolytic cell relative to voltages or currents of other electrolytic cells, an alignment characteristic associated with the first and second electrolyzer stacks, or an aging curve of the second electrolytic cell.

13. The system of claim 7, wherein the operations further comprise: determining that a third electrolytic cell of the second plurality of electrolytic cells of the second electrolyzer stack is associated with a third set of performance criteria that fails to satisfy the one or more operating conditions; and In response to determining that a third electrolytic cell of the second plurality of electrolytic cells of the second electrolyzer stack is associated with a third set of performance criteria that fails to satisfy the one or more operating conditions: The third electrolytic cell is bypassed instead of the second electrolytic cell to bypass the first electrolytic cell and the third electrolytic cell.

14. The system of claim 7, wherein the operations further comprise: initializing operation of the first and second electrolyzer stacks by bypassing a first good electrolyzer in the first electrolyzer stack and bypassing a second good electrolyzer in the second electrolyzer stack; after initiating operation of the first and second electrolyzer stacks, determining that a first electrolytic cell in the first electrolyzer stack is associated with a first set of performance criteria that fails to satisfy the one or more operating conditions; and In response to determining that a first electrolysis cell in the first electrolysis cell stack is associated with a first set of performance criteria that fails to meet the one or more operating conditions, a bypass of a first good electrolysis cell of the first electrolysis cell stack is replaced with a bypass of the first electrolysis cell while maintaining a bypass of a second good electrolysis cell of the second electrolysis cell stack.

15. The system of claim 1 , wherein the first set of performance criteria includes at least one of pinhole formation, catalyst degradation or dissolution, porous transport layer (PTL) coating degradation, current flow through the first electrolytic cell, or bipolar plate degradation; and The one or more operating conditions include at least one of a pinhole formation threshold, a maximum catalyst degradation or dissolution value, a porous transport layer (PTL) coating degradation threshold, a maximum current threshold, or a bipolar plate degradation threshold.

16. A method comprising: determining that a first electrolytic cell in a first electrolyzer stack is associated with a first set of performance criteria that fails to satisfy one or more operating conditions; identifying a second electrolytic cell associated with a second set of performance criteria that satisfies the one or more operating conditions; and In response to determining that a first electrolytic cell in the first electrolyzer stack is associated with a first set of performance criteria that does not satisfy the one or more operating conditions, and based on determining that the second electrolytic cell is associated with a second set of performance criteria that satisfies the one or more operating conditions, bypassing the first electrolytic cell and the second electrolytic cell.

17. The method of claim 16, wherein the second electrolytic cell is located in the first electrolytic cell stack and is adjacent to the first electrolytic cell on a first side of the first electrolytic cell.

18. The method according to claim 17, further comprising: In response to determining that a first electrolytic cell in the first electrolytic cell stack is associated with a first set of performance criteria that does not satisfy the one or more operating conditions, a third electrolytic cell in the first electrolytic cell stack adjacent to the first electrolytic cell on a second side of the first electrolytic cell is identified.

19. A device comprising: means for determining that a first electrolytic cell in a first electrolyzer stack is associated with a first set of performance criteria that fails to satisfy one or more operating conditions; means for identifying a second electrolytic cell associated with a second set of performance criteria satisfying the one or more operating conditions; and means for bypassing a first electrolytic cell in the first electrolytic cell stack in response to determining that the first electrolytic cell is associated with a first set of performance criteria that does not satisfy the one or more operating conditions and based on determining that the second electrolytic cell is associated with a second set of performance criteria that satisfies the one or more operating conditions, the first electrolytic cell and the second electrolytic cell.

20. The apparatus of claim 19, wherein the second electrolytic cell is located in the first electrolytic cell stack and is adjacent to the first electrolytic cell on a first side of the first electrolytic cell.

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