Power converter system and method in power-to-x applications

Abstract

The present disclosure relates to a power converter system for supplying and controlling power to a plurality of electrolysis cell stack units, the system comprising: a plurality of DC / DC power converters, each connectable to one of the electrolysis cell stack units, wherein at least two of the DC / DC power converters are serially connected; a primary DC link comprising a capacitance; a distributed DC link comprising a plurality of DC links that distribute the capacitance of the primary DC link to at least one of the electrolysis cell stack units through the plurality of DC / DC power converters, wherein at least one DC / DC converter is connected to a DC link from the distributed DC, and wherein a first DC link and a last DC link of the distributed DC link are connected to the primary DC link, wherein each of the plurality of DC / DC power converters are configured to operate at a fraction of a primary voltage of the primary DC link. The present disclosure further relates to a method for controlling a power converter system for a plurality of electrolysis cell stack units.

Description

[0001] P6845PC00

[0002] Power Converter System and Method in Power-to-X Applications

[0003] The present disclosure relates to the field of power conversion systems and control architectures for applications in power-to-X technologies. It relates to a scalable, modular power converter system that enables optimized power supply and individual control of multiple electrolysis cell stack units.

[0004] Background

[0005] Power-to-X is a term used to describe technologies that convert electricity into ideally carbon-neutral fuels, such as hydrogen, synthetic natural gas, liquid fuels, or chemicals. These technologies offer a solution paradigm that may be key in the green transition, in which fossil fuel energy sources are continuously replaced by renewable energy sources.

[0006] In power-to-X technologies, particularly in electrolysis-based systems for hydrogen production and other chemical synthesis processes, conventional power supply and control architectures usually involve centralized DC links and a limited degree of control over individual electrolysis cell stacks. These systems often rely on centralized capacitors and power converters, which supply and regulate power to the entire electrolysis process as a unified load. While such architectures are effective under stable power supply conditions, they lack the flexibility and adaptability to efficiently handle fluctuations in power, especially those associated with renewable energy sources like solar or wind power, where output is inherently variable.

[0007] Current systems are further limited in their capacity to control individual electrolysis cell stack units, which hampers optimization opportunities in operational efficiency. Without control at the level of each cell stack, these architectures are unable to adjust power supply parameters such as voltage, current, or temperature based on the specific needs of individual units. As a result, these systems are prone to inefficiencies, as the entire electrolysis array must operate within a fixed set of parameters even when individual cell stacks may have differing operational requirements. This centralized approach also limits the adaptability of electrolysis systems, making it difficult to scale or modify the system without substantial structural adjustments.

[0008] The inability of conventional architectures to effectively manage power fluctuations from renewable sources introduces additional challenges, including increased wear onP6845PC00

[0009] system components and reduced reliability. Large centralized capacitors in these systems are subjected to substantial stresses during power surges or drops, which can lead to premature component degradation. Furthermore, traditional architectures often require extensive infrastructure and higher material costs to accommodate renewable power sources, making these systems less economically viable for large-scale, renewable-integrated applications.

[0010] There is thus a need for improved power converter and control architectures that enable efficient and adaptable control over a plurality of electrolysis cell stack units, allowing for optimized power distribution and improved stability, even under fluctuating power conditions.

[0011] Summary

[0012] The present disclosure relates to a power converter system for supplying and controlling power to a plurality of electrolysis cell stack units, the system comprising: a plurality of DC / DC power converters, each connectable to one of the electrolysis cell stack units, wherein at least two of the DC / DC power converters are serially connected; a primary DC link comprising a capacitance; a distributed DC link comprising a plurality of DC links that distribute the capacitance of the primary DC link to at least one of the electrolysis cell stack units through the plurality of DC / DC power converters, wherein at least one DC / DC converter is connected to a DC link from the distributed DC link, and wherein a first DC link and a last DC link of the distributed DC link are connected to the primary DC link,

[0013] wherein each of the plurality of DC / DC power converters are configured to operate at a fraction of a primary voltage of the primary DC link.

[0014] The system’s architecture enables precise and individualized control of each electrolysis cell stack unit, allowing the system to maintain stable operation under varying load conditions and to accommodate fluctuations in power input, such as from renewable energy sources. By distributing the capacitance from the main DC link across a distributed DC link comprising multiple DC links, the present disclosure minimizes the need for large, centralized capacitors, which often pose limitations in traditional systems. This distributed DC link configuration also enhances resilience to voltage fluctuations, thus improving the stability and efficiency of the entire electrolysis process.P6845PC00

[0015] The system’s architecture may support various DC / DC converter configurations, allowing it to optimize the voltage, current, and power supplied to each cell stack unit based on specific operational demands. This level of control over individual cell stacks facilitates the efficient and adaptable use of the system across different capacities and applications, from small-scale hydrogen production to larger industrial power-to-X processes. The scalability of the architecture makes it suitable for diverse energy sources, including renewable DC sources such as photovoltaic and hydroelectric power or conventional AC sources, where integration is achieved through AC / DC and DC / AC conversion modules.

[0016] The present disclosure further relates to a method for controlling a power converter system for a plurality of electrolysis cell stack units, the method comprising: providing a plurality of DC / DC power converters, each connected to one of the electrolysis cell stack units, wherein at least two of the DC / DC power converters are serially connected, a primary DC link, and a distributed DC link comprising a plurality of DC links that distribute the capacitance of the primary DC link to at least one of the electrolysis cell stack units, wherein at least one DC / DC converter is connected to a DC link from the distributed DC link, and wherein the first and the last DC links from the distributed DC link are connected to the primary DC link; monitoring directly or indirectly a current and / or voltage and / or power and / or temperature of at least one of the plurality of electrolysis cell stack units; controlling directly or indirectly a current and / or voltage and / or power and / or temperature of at least one of at least one of the plurality of electrolysis cell stack units.

[0017] This method supports the reliable and continuous operation of the electrolysis process, even under fluctuating power supply conditions, making it suitable for renewable energy integration in hydrogen production and related power-to-X applications.

[0018] Brief description of figures

[0019] Various embodiments are described hereinafter with reference to the drawings. The drawings are non-limiting examples of embodiments and are intended to illustrate some of the features of the presently disclosed method and system for power conversion and control architectures in power-to-X technologies.P6845PC00

[0020] FIG. 1 shows an example of a power converter system for supplying and controlling power to a plurality of electrolysis cell stack units, comprised by the present disclosure. FIG. 2 shows a detailed example of a power converter system for supplying and controlling power to a plurality of electrolysis cell stack units comprising a transformer, a distribution BUS, a power-to-hydrogen BUS, and an AC / DC power converter, comprised by the present disclosure.

[0021] FIG. 3 shows a flowchart for the presently disclosed method for controlling a power converter system for a plurality of electrolysis cell stack units.

[0022] Detailed description

[0023] Definitions

[0024] “Power-to-X”: This refers to technologies that convert electrical energy, which may be derived from renewable or conventional sources, into other forms of energy, fuels, or chemical products. The term “X” can represent various outputs, such as gases, liquids, or solids, depending on the process and end application. Examples may include the conversion of electricity into hydrogen through electrolysis (Power-to-Hydrogen), methane (Power-to-Methane), synthetic fuels like methanol, diesel, or kerosene (Power-to-Liquid), or ammonia (Power-to-Ammonia). Power-to-X may further comprise processes for energy storage, chemical synthesis, or carbon capture and utilization, supporting decarbonization and the integration of renewable energy into various sectors. Power-to-X is sometimes denoted by PtX or P2X.

[0025] “Electrolysis cell stack unit”: This refers to a modular assembly of at least one electrolysis cell, such as to facilitate the electrochemical splitting of water or other compounds into constituent elements using electricity. If multiple cells, they may be arranged electrically in series, in parallel, or in a combination thereof. The unit may comprise electrodes, an electrolyte, an anode, a cathode, membranes, and supporting structural components configured to operate under specific electrical and thermal conditions. Electrolysis cell stack units can be designed for various applications, such as producing hydrogen through water electrolysis, extracting or purifying metals, or generating chemical intermediates. The configuration and design of the unit may vary depending on the required production capacity, operational efficiency, and integration within a larger power-to-X system.P6845PC00

[0026] “DC link”: This refers to an electrical connection or intermediate circuit that transfers direct current (DC) power between components or subsystems within a power conversion system. The DC link may comprise energy storage elements, such as capacitors or inductors, to stabilize voltage, filter ripples, or buffer power fluctuations. It can serve as an interface between power converters, such as AC / DC and DC / DC converters, and may be used to distribute power efficiently within the system. The voltage level of the DC link can be configured based on the operational requirements of the connected components. FIG. 1 shows an example of a primary DC link (105).

[0027] “Distributed DC link”: This term refers to a configuration in which the capacitance or energy storage of a primary DC link is divided and distributed across multiple smaller DC links within a system. Each of the smaller DC links may be electrically connected to specific components, such as power converters or loads, enabling localized power stabilization and buffering. This arrangement can improve system efficiency, reduce losses, and enhance voltage stability, particularly in systems with multiple power conversion stages or distributed loads, such as electrolysis cell stack units. In the example of FIG. 1, the smaller DC links (106, 107) belong to a distributed DC link.

[0028] “distribute the capacitance of the primary DC link to at least one of the electrolysis cell stack units through the plurality of DC / DC power converters”: This term defines the electrical pathway of the capacitance. The primary DC link is not directly connected to the electrolysis cell stack units. The primary DC link capacitance is functionally distributed along the chain of distributed DC links. The DC / DC power converters act as intermediate stages that receive the stabilized and buffered DC potentials from their associated distributed DC links and then process, regulate, and forward that conditioned power to the electrolysis cell stack units. Thus, the capacitance is “distributed” to the electrolysis cell stack units only in the sense that the stabilizing and buffering effect of the primary link capacitance propagates forward through the distributed DC links and the DC / DC power converters. In one non-limiting example, the primary DC link includes a DC-link capacitor bank connected across the positive and negative DC buses. This capacitance is divided into multiple smaller, local capacitances within the distributed DC links, each associated with one DC / DC converter.P6845PC00

[0029] Further details

[0030] Embodiments of the presently disclosed system and method are associated with various advantages and / or technical effects.

[0031] The present disclosure relates to a power converter system for supplying and controlling power to a plurality of electrolysis cell stack units, the system comprising: a plurality of DC / DC power converters, each connected to one of the electrolysis cell stack units, wherein at least two of the DC / DC power converters are serially connected; a primary DC link comprising a capacitance; a distributed DC link comprising a plurality of DC links that distribute the capacitance of the primary DC link to at least one of the electrolysis cell stack units, wherein at least one DC / DC converter is connected to a DC link from the distributed DC link, and wherein the first and the last DC links from the distributed DC link are connected to the primary DC link. Each of the plurality of DC / DC power converters may be configured to operate at a fraction of a primary voltage of the primary DC link. Each DC / DC power converter may be supplied from a reduced local DC voltage level originating from its corresponding distributed DC link rather than the full primary DC-link voltage. The distributed DC link divides the primary DC-link voltage into multiple smaller voltage segments, and each DC / DC power converter is electrically referenced to one of these segments. Thus, each converter operates at only a part - or fraction - of the overall primary DC-link voltage, rather than being exposed to the full high voltage.

[0032] The system of the present disclosure enables precise and individualized control of each electrolysis cell stacks. The control architecture facilitates stable operation under varying load conditions and to accommodate fluctuations in power input. An advantage of the present disclosure is associated with distributing the capacitance from the main DC link across a distributed DC link comprising multiple DC links. As such, the present disclosure minimizes the need for large, centralized capacitors. This distributed DC link configuration also enhances resilience to voltage fluctuations, thus improving the stability and efficiency of the entire electrolysis process.

[0033] The presently disclosed power converter system is suitable for use in any type of electrolysis process. Examples of such electrolysis processes are Alkaline Water Electrolysis (AWE), Proton Exchange Membrane (PEM) electrolysis, Solid OxideP6845PC00

[0034] Electrolysis (SOE), Anion Exchange Membrane (AEM) electrolysis, Molten Salt Electrolysis, or any combinations thereof.

[0035] In one embodiment of the presently disclosed power converter system, the system further comprises a control unit configured to allocate power to the plurality of electrolysis cell stack units based on load conditions. The control unit may monitor operational parameters such as current, voltage, temperature, or power demand for each electrolysis cell stack unit and dynamically adjust the output of the corresponding DC / DC power converters to ensure balanced and efficient distribution of available power. By reallocating power according to real-time load conditions, the control unit enables stable operation of the system even under varying input power levels and ensures that each electrolysis cell stack unit operates within its optimal operating window.

[0036] The control unit may further be configured to carry out any suitable task described in the present disclosure, including monitoring functions, protective actions, failure detection, lifetime prediction, or regulation tasks associated with individual DC / DC power converters or electrolysis cell stack units.

[0037] In one embodiment, the primary DC link comprises a positive DC bus and a negative DC bus. The primary DC link may comprise, but is not limited to, any suitable DC-link capacitor bank or equivalent configured to stabilize, buffer, and smooth the DC voltage supplied to the distributed DC links and the plurality of DC / DC power converters. The primary DC link 105 with the positive DC bus 111, the negative DC bus 112 and the DC-link capacitor bank 110 is shown as a schematic example in FIG. 1.

[0038] The primary DC link may be understood as any electrical interface that establishes and maintains a stable DC operating voltage for the power converter system. The primary DC link may include any suitable arrangement of conductors, rails, plates, or busbars capable of carrying high DC currents and supporting the connection of one or more energy-storage elements such as capacitors or other charge-storing components. The primary DC link may take various physical forms and is not limited to any particular mechanical design, enclosure type, or topology.P6845PC00

[0039] The primary DC link may be implemented as a physical installation designed for high-power industrial use. In one non-limiting example, the primary DC link comprises a pair of busbars, such as substantial copper or aluminium busbars, forming positive and negative DC rails, arranged with low inductance and high thermal stability to accommodate switching events and load transients. These busbars may be laminated, stacked, plate-type, or bar-type, depending on the installation requirements. The busbars may be mounted inside a dedicated power-electronics enclosure, cabinet, or containerized module.

[0040] In one example, the primary DC link comprises a DC-link capacitor bank, which may comprise multiple high-voltage polypropylene film capacitors connected in series and / or parallel to achieve the required voltage and energy-storage characteristics. In industrial-scale power-to-X applications, the capacitor bank may be physically sizeable — potentially comprising several rows of capacitor modules installed in a rack or multi-rack arrangement. Such a capacitor bank may reach total capacitances on the order of several millifarads or more, with physical dimensions resembling one or more floor-standing cabinets. However, the DC-link capacitor bank is not limited to film capacitors; it may include any suitable capacitor technology, such as metallized film capacitors, hybrid capacitor units, or combinations thereof, provided that they meet the voltage, ripple-current, and lifetime requirements of the system.

[0041] In another example, the primary DC link may additionally comprise auxiliary components such as pre-charge circuits, discharge resistors, surge-suppression devices, temperature sensors, or voltage-monitoring units integrated into or adjacent to the capacitor bank. These additional components may help protect the DC link during energization, mitigate transient conditions, or provide operational data to the control unit. However, the primary DC link is not limited to any particular set of auxiliary components, and such additions may be omitted or replaced depending on system design preferences.

[0042] It should be appreciated that the primary DC link can be realized in a variety of configurations and physical implementations. It may be a single consolidated assembly, or it may be distributed across more than one enclosure. It may be air-cooled, liquid-cooled, or cooled by any suitable method. It may be constructed using any suitable materials and capacitor technologies. The examples described herein are non-limiting, and any arrangement capable of providing a stable high-power DCP6845PC00

[0043] backbone with a positive DC bus, a negative DC bus, and DC-link capacitor bank falls within the scope of the present disclosure.

[0044] In one embodiment, each distributed DC link comprises a positive local DC bus, a negative local DC bus, and a local capacitor unit arranged between the two buses. More broadly, a distributed DC link may be any localized portion of the overall DC link structure that provides a stabilized, buffered DC potential to one or more downstream power converters or loads. The positive and negative local DC buses may be implemented using conductors, plates, rails, or busbars suitable for the expected current level, and the local capacitor unit may include one or more capacitors configured to provide localized energy storage, voltage smoothing, or ripple reduction. In one non-limiting example, each local capacitor unit may be a smaller capacitor module mounted physically near a corresponding DC / DC power converter to minimize inductance and improve dynamic response. However, the local capacitor unit is not limited to any specific capacitor technology or size. An example of a distributed DC link, wherein each DC link 106 / 107 comprises a positive local DC bus 114 / 116, a negative local DC bus 115 / 117 and a local capacitor unit 113 is shown in FIG. 1.

[0045] In a further embodiment, the positive DC bus of the primary DC link is connected to the positive local DC bus of the first DC link, and the negative DC bus of the primary DC link is connected to the negative local DC bus of the last DC link. This arrangement establishes a series-connected chain of distributed DC links across which the capacitance of the primary DC link is effectively distributed. In one non-limiting example, the first local DC link may receive the highest potential relative to the positive DC bus, while the last local DC link is referenced closest to the negative DC bus, allowing intermediate DC links to operate at progressively lower potentials. The interconnection scheme is not limited to any specific physical layout or mechanical design and may be implemented using busbars, cables, laminated conductors, or any suitable low-inductance connection method. An example of this arrangement is shown in FIG. 1 , in which the positive DC bus 111 of the primary DC link 105 is connected to the positive local DC bus 114 of the first DC link 106. Accordingly, the negative DC bus 112 of the primary DC link 105 is connected to the negative local DC bus 117 of the last DC link 107. Each remaining local DC bus may connected to a local positive DC bus of a neighbouring DC link, as shown in FIG. 1P6845PC00

[0046] In one embodiment, the positive bus of each distributed DC link is electrically connected to a positive input terminal of a corresponding DC / DC power converter, and the negative bus of each distributed DC link is connected to the negative input terminal of the same DC / DC power converter.

[0047] One embodiment of the presently disclosed system is shown in FIG. 1. In this embodiment, a plurality of electrolysis cell stack units are connected to a primary DC link via a distributed DC link comprising a plurality of DC links connected in series, each respectively connecting to one electrolysis cell stack unit.

[0048] In other embodiments of the of the presently disclosed system, the power converters, such as the DC / DC power converters, may comprise further electrical components internally, such as capacitors. An internally comprised capacitor in a power converter may partially or fully serve the same purpose as connecting the power converter to a DC link from the distributed DC link.

[0049] In one embodiment of the present disclosure, the DC / DC power converters are configured to independently regulate the voltage and / or power and / or current and / or temperature, or any combination thereof as supplied to the corresponding electrolysis cell stack unit based on operational requirements. This independent regulation can be achieved through the use of sensors and control algorithms that monitor real-time operational parameters of each electrolysis cell stack and dynamically adjust the output of the corresponding DC / DC converter. By tailoring the energy delivery to the specific needs of each stack, as enabled by the distributed DC link, the system can ensure that optimal conditions are maintained for each unit, regardless of variations in operating efficiency, ambient temperature, or degradation over time.

[0050] The ability to regulate these parameters independently provides several technical advantages. For example, voltage regulation can be used to adapt to changes in the electrolysis process, ensuring that for example hydrogen production remains efficient across varying input power conditions. Similarly, temperature regulation at the stack level can prevent overheating, which might otherwise lead to reduced lifespan or safety risks. This granularity in control also supports the integration of renewable energy sources, where fluctuations in power input are common. Variations of this embodimentP6845PC00

[0051] may include the use of predictive algorithms to forecast changes in stack performance, further enhancing the system's adaptability and reliability.

[0052] In one embodiment of the present disclosure, the system further comprises a power source for supplying the power converter, the power source being a DC power source such as batteries, photovoltaic power stations, hydroelectric power stations, fuel cells, medium-voltage DC sources, high-voltage DC sources, or combinations thereof. This embodiment allows the system to interface with a diverse range of power sources, offering flexibility for integration into different operational contexts. For instance, photovoltaic power stations can provide renewable energy during daytime, while batteries can store excess energy for use during periods of low solar generation.

[0053] The modular design of the system enables seamless integration of multiple DC sources. For example, a hybrid setup might combine photovoltaic arrays with fuel cells to provide both sustainable energy input and long-term storage capacity. This flexibility supports both grid-connected and off-grid applications, ensuring that the system can be deployed in a variety of industrial and remote settings. The ability to handle diverse DC sources enhances the system’s resilience and adaptability, making it suitable for fluctuating or intermittent energy inputs.

[0054] In one embodiment of the present disclosure, the power source is connected to the primary DC link via a DC / DC converter. This configuration allows precise control over the energy supplied from the DC power source to the primary DC link, ensuring that the distributed DC link and electrolysis cell stacks receive stable and optimized power. The DC / DC converter can adjust voltage, current, power, and temperature to match the specific requirements of the system, compensating for variability in the power source.

[0055] The use of a DC / DC converter enhances the efficiency of power delivery, protects components, and optimizes losses. Advanced converter topologies, for example comprising buck-boost or bidirectional converters, may be implemented to handle a broader range of input and output conditions.

[0056] In one embodiment of the present disclosure, the power source is connected to the primary DC link via a DC / AC converter and an AC / DC converter. This configuration allows a DC power source to undergo an intermediate conversion to AC, followed byP6845PC00

[0057] reconversion to DC, ensuring that the power delivered to the primary DC link is conditioned and optimized for the system’s requirements. The DC / AC converter acts as an inverter, transforming direct current into alternating current, which can then be processed further, such as through voltage adjustment or electrical isolation. The AC / DC converter subsequently rectifies the alternating current back to direct current, ensuring compatibility with the primary DC link.

[0058] This dual conversion approach provides several advantages. The DC / AC conversion stage enables integration with intermediate AC networks, transformers, or other components that require or benefit from alternating current. For example, the intermediate AC stage may allow voltage stepping through a transformer to align with the operating range of the downstream system. Additionally, the AC / DC converter ensures that the final power delivered to the primary DC link is stable and free from irregularities, supporting the reliable operation of the distributed DC link and electrolysis cell stacks.

[0059] The inclusion of this dual conversion pathway enhances system flexibility, making it adaptable to a variety of power sources and infrastructure requirements. For instance, a high-voltage DC power source could undergo DC / AC conversion for compatibility with an existing AC distribution system or transformer, and the resulting AC can then be rectified for use in the electrolysis process.

[0060] In one embodiment of the present disclosure, the power conversion system further comprises an AC power source, such as power plants, wind turbines, power grids, or combinations thereof, for supplying the power converter wherein the power source is connected to the primary DC link via an AC / DC converter. This embodiment facilitates the integration of AC power sources into the system by converting alternating current to direct current suitable for distribution through the primary and distributed DC link. The AC / DC converter may use rectification circuits with advanced topologies, such as pulse-width modulation (PWM) rectifiers, to achieve high efficiency and low harmonic distortion during the conversion process.

[0061] This feature enables the system to harness a wide range of AC power sources, from large-scale power grids to smaller renewable sources such as wind turbines. By connecting to an AC power grid, the system can benefit from reliable and consistentP6845PC00

[0062] energy supply, while energy sources such as wind turbines can provide sustainable energy with fluctuating availability. The presently disclosed system can accommodate any type of AC-produced power source. Using AC / DC converters also allows for dynamic adjustments, such as power factor correction and harmonic compensation, which enhance grid compatibility and ensure stable operation. Variations may include single-phase or three-phase AC / DC converters, depending on the specific source and application.

[0063] In one embodiment of the present disclosure, the system further comprises a transformer connected between the AC power source and the AC / DC converter. An example demonstrating this embodiment is shown in FIG. 2. The transformer facilitates the adjustment of the AC power source’s voltage to levels compatible with the AC / DC converter and any further downstream components. In the case of power grids or wind turbines, where voltage levels may be inconsistent or significantly high, the transformer can step down the voltage to protect the system’s components. Conversely, for systems requiring higher voltage levels for efficient power transmission, a step-up transformer can be employed.

[0064] The inclusion of a transformer also provides galvanic isolation, which protects the system and its connected loads from electrical disturbances or faults in the power source. Advanced transformer designs, such as those employing solid-state technology, may offer reduced size and weight while maintaining high efficiency and reliability. This feature ensures safe and effective operation of the power conversion system across a variety of AC power sources, making it adaptable to diverse industrial and renewable energy applications.

[0065] In one embodiment of the present disclosure, at least one of the plurality of DC / DC power converters are controllable DC power converters, such as buck, buck-boost, flyback, bidirectional, or combinations thereof. Controllable DC power converters provide enhanced flexibility in managing voltage and current levels across the electrolysis cell stacks. For instance, a buck converter may be used to step down voltage from a higher source, while a buck-boost converter could handle both stepping up and stepping down based on dynamic power requirements.P6845PC00

[0066] Bidirectional converters add further functionality by enabling power flow in both directions, which may be advantageous in systems with energy storage components such as batteries. Flyback converters, on the other hand, can be useful in low-power applications where electrical isolation may be required. The ability to select and combine different converter topologies allows the system to be customized for a wide range of operational needs, enhancing its adaptability and efficiency. This flexibility also supports better integration with diverse power sources and end-use applications.

[0067] In one embodiment of the present disclosure, the system further comprises switching modules such as MOSFETs, SiC, GaN, IGBT, thyristors, or combinations thereof. These components may be used to enable high-efficiency power conversion and control within the system. Switching modules such as MOSFETs, SiC, or GaN transistors provide high-speed switching with minimal losses, which can help maintaining the efficiency of DC / DC and AC / DC converters. Variations of this embodiment concern comprising inductors and capacitors to filter noise, store energy, and ensure smooth power delivery and that the system operates reliably also under fluctuating input conditions.

[0068] The choice of switching components may be tailored to specific system requirements. For instance, silicon carbide (SiC) and gallium nitride (GaN) transistors may be suitable in high-frequency and high-voltage applications due to their thermal and electrical properties. Thyristors and IGBTs, on the other hand, may be preferable in high-power industrial settings where robustness and reliability are prioritized.

[0069] In one embodiment of the present disclosure, the power conversion unit further comprises a distribution BUS and a power-to-X BUS. An example of this embodiment is shown in FIG. 2. The distribution BUS provides a centralized pathway for distributing power from the primary DC link to the various DC / DC power converters associated with the electrolysis cell stacks. This arrangement ensures efficient and organized power delivery, reducing losses and enhancing the reliability of the system. The power-to-X BUS serves as a specialized interface for managing energy flows specifically related to downstream power-to-X applications, such as hydrogen production or other chemical synthesis processes. The power-to-X BUS may be a power-to-hydrogen BUS in cases of hydrogen electrolysis.P6845PC00

[0070] The inclusion of a distribution BUS allows the system to manage power delivery more effectively by consolidating and streamlining connections between the primary DC link and the distributed DC link. This reduces the complexity of wiring and facilitates modular expansion, enabling additional components to be added without disrupting existing connections. The power-to-X BUS, on the other hand, provides a dedicated channel for directing energy to specific processes, ensuring that power is allocated according to the requirements of different power-to-X applications. This separation of energy pathways enhances system flexibility and allows for tailored optimization of each operational aspect.

[0071] By incorporating both a distribution BUS and a power-to-X BUS, the system gains improved scalability and adaptability, supporting diverse industrial applications. For example, in a hydrogen production facility, the power-to-X BUS may ensure precise energy delivery to hydrogen synthesis units, while the distribution BUS maintains overall system balance.

[0072] In one embodiment of the present disclosure, the system comprises at least 3 electrolysis cell stack units. This configuration ensures sufficient modularity and scalability to address varying production requirements in power-to-X applications. Each electrolysis cell stack unit can be independently controlled by its corresponding DC / DC power converter, allowing the system to optimize performance based on the specific needs of individual electrolysis cell stack units. For instance, in a hydrogen production system, having multiple stacks enables optimal individual operation, which can increase overall production capacity while maintaining efficiency.

[0073] The use of at least three electrolysis cell stack units also allows for redundancy and fault tolerance. If one electrolysis cell stack unit or its associated converter encounters an issue, the remaining electrolysis cell stack units can continue operating, minimizing system downtime. Variations in this embodiment may include configurations where additional electrolysis cell stack units are added to meet higher production demands or to provide flexibility for different chemical synthesis processes. This modular approach ensures that the system can be adapted to changing operational and energy requirements. The at least three electrolysis cell stack units may either all be connected in series, as shown in the example of FIG. 1, or two electrolysis cell stackP6845PC00

[0074] units may be connected in series and the third in parallel with any of the preceding two cell stack units.

[0075] In one embodiment of the present disclosure, a third DC / DC power converter is connected to a third DC link from the distributed DC link which in turn is serially connected to a second DC link from the distributed DC link, wherein the third DC / DC converter is connected to the third electrolysis cell stack unit. This configuration demonstrates the scalability of the distributed DC link architecture, allowing additional electrolysis cell stack units to be integrated into the system seamlessly. The third DC link in series with the second DC link distributes the primary DC link capacitance effectively while ensuring that power delivery remains stable and balanced across all connected stacks.

[0076] This feature provides flexibility in designing systems for varying production scales and allows modular expansion without significant redesigns. For example, additional converters and stacks can be added to increase hydrogen production capacity or adapt the system for different chemical synthesis processes. By maintaining the distributed DC link’s architecture, voltage regulation and power stability are preserved even as more components are integrated. This modular scalability supports diverse industrial applications, from small-scale research setups to large-scale power- to-X facilities.

[0077] In one embodiment of the present disclosure, at least one of the plurality of DC / DC converters are connected to an output filter, wherein the output filter is connected in parallel with a DC / DC converter and an electrolysis cell stack unit. The output filter may include passive components such as capacitors, inductors, or resistors designed to smooth voltage and current fluctuations before they reach the electrolysis cell stack. This ensures that the power delivered to the stack is stable and free of high-frequency noise, which could otherwise affect the efficiency or lifespan of the electrolysis process.

[0078] The output filter also protects the electrolysis cell stack from transient voltage spikes or ripples that may occur during power conversion. Variations in this embodiment could include active filters for more precise control, or combinations of active and passive elements tailored to specific operational requirements. By providing clean and stable power delivery, this feature enhances the reliability and efficiency of the overall system,P6845PC00

[0079] making it suitable for sensitive or high-precision applications in hydrogen production and other power-to-X processes.

[0080] In one embodiment of the present disclosure, the voltage across the primary DC link is greater than 800V and less than 1500V. This voltage range is chosen to optimize the balance between power delivery efficiency and safety. Operating within this range allows for reduced transmission losses while keeping the voltage within limits that are manageable with existing insulation and safety technologies. For large-scale industrial systems, such as those involved in hydrogen production or chemical synthesis, maintaining this voltage range ensures high efficiency in energy delivery to the electrolysis cell stacks.

[0081] The specified voltage range also supports compatibility with various power sources, including high-voltage DC grids, photovoltaic systems, and battery banks. The system’s design can accommodate this range through appropriate selection of components such as capacitors, converters, and transformers. Variations may include systems designed for operation at lower or higher voltage ranges depending on specific application needs. This flexibility ensures that the system remains adaptable to diverse operational environments while maintaining safety and efficiency.

[0082] In one embodiment of the present disclosure, the system further comprises a power source for supplying the power converter, the power source being a variable power source. A variable power source refers to an energy source whose output, in terms of voltage, current, or power, fluctuates over time. Such sources may comprise renewable power sources, such as photovoltaic solar panels, wind turbines, or hydroelectric systems, where the power output varies based on environmental factors such as sunlight, wind speed, or water flow. Such a power source may also comprise a conventional or non-renewable power source in which the output fluctuates over time. Additionally, variable power sources may encompass energy storage systems, such as batteries, that discharge power at fluctuating rates depending on demand and capacity.

[0083] The inclusion of a variable power source, which may be renewable, enables the system to harness sustainable energy inputs, making it well-suited for power-to-X applications with a focus on reducing carbon emissions. The system’s power conversion architecture, comprising the primary DC link, the distributed DC link, and the DC / DCP6845PC00

[0084] power converters, may be configured to stabilize and condition the fluctuating power from the variable source. For instance, the DC / DC power converters can dynamically adjust output parameters such as voltage and current to match the real-time requirements of the electrolysis cell stacks, thereby maintaining stable and efficient operation despite variations in power input.

[0085] Variations in this embodiment may include incorporating buffering components, such as capacitors or battery storage, to smooth out power variations before delivery to the electrolysis stacks. This capability makes the system ideal for grid-independent installations, renewable energy hubs, and industrial applications, contributing to sustainability and the global transition toward cleaner energy solutions.

[0086] In one embodiment of the present disclosure, at least one electrolysis stack unit is configured for using electricity and / or heat to primarily generate hydrogen as an intermediate for producing chemical substances or green byproducts such as E-Methanol, E-Dimethyl Ether, E-Kerosene, E-Diesel, E-Ammonia, or E-Methane. The hydrogen generated through electrolysis serves as a feedstock in power-to-X applications, enabling the synthesis of sustainable fuels and chemicals that can reduce dependence on fossil fuels and help achieve carbon-neutral energy cycles. The process facilitates the production of green hydrogen, which can be further processed into the mentioned byproducts.

[0087] E-Methanol is a liquid chemical that can be produced through the combination of hydrogen and captured carbon dioxide (CO2). It serves as a versatile fuel and feedstock for the chemical industry, with applications ranging from energy storage to blending with gasoline as a cleaner fuel alternative. Similarly, E-Dimethyl Ether (E-DME), derived from hydrogen and methanol, can be used as a sustainable substitute for diesel fuel in transportation or as a propane replacement in heating and cooking applications. These fuels provide reduced emissions of particulates and greenhouse gases compared to conventional fossil fuels.

[0088] E-Kerosene and E-Diesel are synthetic fuels produced through processes such as Fischer-Tropsch synthesis, where hydrogen and CO2are combined to form liquid hydrocarbons. E-Kerosene is particularly relevant for aviation, providing a sustainable alternative to conventional jet fuel, while E-Diesel can be used in existing dieselP6845PC00

[0089] engines without requiring modifications. E-Ammonia, produced by combining hydrogen and nitrogen, is a key feedstock in fertilizer production and can also be used as a carbon-free energy carrier or fuel for shipping and industrial applications. E-Methane, a synthetic form of natural gas, can be generated through the methanation of hydrogen and CO2, providing a renewable substitute for conventional natural gas in power generation, heating, and transportation.

[0090] The system may be integrated with downstream processing units that utilize the hydrogen output for chemical reactions, such as the synthesis of methanol or ammonia. Variations in this embodiment may include operating conditions optimized for specific green byproducts, such as higher temperatures or pressures for certain reactions. By supporting the production of a wide range of green chemicals, this feature enhances the system’s utility in advancing sustainable energy and chemical production goals, aligning with global efforts to mitigate climate change.

[0091] In one embodiment of the present disclosure, at least one electrolysis stack unit is configured for extraction or purification of metals from ores or compounds or in deposition of metals from solution. This configuration enables the system to support industrial processes where electrochemical methods are used for metal refining, extraction, or deposition. For example, in hydrometallurgy, electrolysis can be employed to extract metals such as copper, nickel, or zinc from their ores or solutions. Similarly, the system may be used in electrodeposition processes to coat or refine metals for use in electronics, automotive, or aerospace applications.

[0092] The ability to adapt an electrolysis stack for metal processing offers advantages in terms of process efficiency and environmental impact. The system’s precise power control capabilities allows for optimizing parameters such as current density and voltage to achieve high-purity metal extraction or deposition with minimal energy consumption. Variations in this embodiment could include configurations tailored for specific metals or industrial applications, such as using specialized electrolytes or electrode materials.

[0093] The present disclosure also relates to a method for controlling a power converter system for a plurality of electrolysis cell stack units, the method comprising: providing a plurality of DC / DC power converters, each connected to one of the electrolysis cellP6845PC00

[0094] stack units, wherein at least two of the DC / DC power converters are serially connected, a primary DC link, and a distributed DC link comprising a plurality of DC links that distribute the capacitance of the primary DC link to at least one of the electrolysis cell stack units, wherein at least one DC / DC converter is connected to a DC link from the distributed DC link, and wherein the first and the last DC links from the distributed DC link are connected to the primary DC link; monitoring directly or indirectly a current and / or voltage and / or power and / or temperature of at least one of the plurality of electrolysis cell stack units; controlling directly or indirectly a current and / or voltage and / or power and / or temperature of at least one of at least one of the plurality of electrolysis cell stack units.

[0095] In one embodiment of the presently disclosed method for controlling a power converter system for a plurality of electrolysis cell stack units, the method comprises: providing a plurality of DC / DC power converters, each connected to one of the electrolysis cell stack units, wherein at least two of the DC / DC power converters are serially connected, a primary DC link comprising a DC-link capacitor bank, and a distributed DC link comprising a plurality of DC links that distribute the capacitance of the primary DC link to at least one of the electrolysis cell stack units, wherein at least one DC / DC converter is connected to a DC link from the distributed DC link, and wherein the first and the last DC links from the distributed DC link are connected to the primary DC link; monitoring directly or indirectly a current and / or voltage and / or power and / or temperature of at least one of the plurality of electrolysis cell stack units; controlling directly or indirectly a current and / or voltage and / or power and / or temperature of at least one of the plurality of electrolysis cell stack units.

[0096] In this embodiment, the method enables the control system to individually govern the operating conditions of each electrolysis cell stack unit based on real-time measurements. By providing a plurality of serially connected DC / DC power converters and a distributed DC link that divides and allocates the primary DC link capacitance among several localized DC links, the method ensures that each DC / DC converter receives a stabilized and appropriately referenced DC potential. The monitoring step may include direct sensing through current, voltage, power, or temperature sensors, or indirect inference methods such as state estimation, derived parameters, or algorithmic reconstruction.P6845PC00

[0097] The subsequent controlling step may involve adjusting converter switching behavior, modifying output voltage or current limits, or initiating protective or corrective actions such as derating, throttling, or temporarily isolating a specific electrolysis cell stack. In one non-limiting example, if a monitored temperature exceeds a predefined threshold, the corresponding DC / DC converter may reduce its output current to maintain stable operation. However, the method is not limited to any particular control technique and may include conventional closed-loop control, predictive control, distributed control, or supervisory algorithms.

[0098] This embodiment reflects a flexible framework in which the distributed DC link and the associated plurality of DC / DC converters enable localized, adaptable control at the level of each individual electrolysis cell stack unit, thereby enhancing system stability, efficiency, and robustness during fluctuating or variable power supply conditions.

[0099] In one embodiment of the presently disclosed method for controlling a power converter system, the method further comprises:

[0100] obtaining measurement signals indicative of at least one of current, voltage, power and temperature at the level of individual DC / DC power converters and / or electrolysis cell stack units; predicting a long-term failure by analyzing temporal trends of the measurement signals using historical operating data, by trend analysis and / or a machine-learning algorithm.

[0101] In this embodiment, the method incorporates advanced diagnostic and

[0102] predictive-maintenance functionality by continuously capturing measurement signals associated with each DC / DC power converter and / or each electrolysis cell stack unit. The measurement signals may be obtained directly from embedded current, voltage, power, or temperature sensors, or indirectly through derived quantities, estimators, or converter-internal monitoring circuits. The signals may be sampled at fixed or variable intervals and stored locally or forwarded to a supervisory control unit.

[0103] Based on these signals, the method predicts long-term failure modes by identifying gradual changes in operating behavior. In one non-limiting example, temporal trends such as slowly increasing temperature, rising internal resistance, voltage imbalance, or recurring current deviations may serve as indicators of component aging or degradation within a DC / DC converter or an electrolysis cell stack. The analysis mayP6845PC00

[0104] rely on historical operating data collected over hours, days, or months, enabling the system to detect patterns that would not be visible through instantaneous measurements alone.

[0105] In some embodiments, trend analysis may be performed using conventional statistical techniques such as moving averages, exponential smoothing, or threshold-based deviation detection. In other embodiments, the predictive step may employ machine-learning algorithms trained on historical or simulated datasets to classify anomalies, forecast degradation rates, or estimate remaining useful lifetime. Examples may include neural-network models, regression models, or anomaly-detection algorithms, although the method is not limited to any particular analytical approach. By integrating predictive failure analysis into the control method, the system can autonomously identify developing issues before they result in operational instability, reduced hydrogen production efficiency, or component failure. This enables proactive maintenance strategies, improves system reliability, and enhances the overall safety and availability of the power-to-X installation.

[0106] In one embodiment of the presently disclosed method for controlling a power converter system, the method further comprises: obtaining measurement signals indicative of at least one of current, voltage, power and temperature at the level of individual DC / DC power converters and / or electrolysis cell stack units; estimating a remaining operational lifetime of one or more electrolysis cell stack units based on the measurement signals, wherein the estimating comprises analyzing trends and / or deviations of at least one of current, voltage, power and temperature over time, optionally in combination with stress factors including thermal cycling, over voltage events and / or irregular power inputs.

[0107] In this embodiment, the method enables the control system to evaluate long-term performance and expected degradation of electrolysis cell stack units by continuously or periodically collecting measurement signals at the level of the individual DC / DC power converters and / or electrolysis cell stacks. The measurement signals may originate from dedicated sensors or converter-integrated monitoring circuitry, and may include values such as stack temperature, operating current, voltage behavior, and instantaneous or averaged power consumption.P6845PC00

[0108] The method estimates the remaining operational lifetime of one or more electrolysis cell stack units by examining how these measurement signals evolve over time. In one non-limiting example, the system may track gradual increases in voltage drop across a stack, changes in temperature response under fixed load conditions, or recurring current deviations that indicate increased internal resistance. Such trends or deviations can be compared with historical operating data, baseline performance curves, or predictive health models to identify signs of wear or degradation.

[0109] The estimation process may further take into account stress factors that influence long-term aging of electrolysis units. These stress factors may include thermal cycling resulting from fluctuating renewable power input, over-voltage events during transient operation, and irregular or rapidly varying power delivery associated with intermittent renewable sources. By correlating measured trends with these stress conditions, the system can generate a more accurate prediction of the remaining useful lifetime of the affected stacks.

[0110] The method is not limited to any particular analytical technique. For example, lifetime estimation may be performed through simple trend-tracking, threshold-based deviation detection, regression-based models, or more advanced predictive methods such as machine-learning algorithms trained to identify early signs of stack degradation. By incorporating lifetime estimation into the control strategy, the system supports predictive maintenance, reduces unplanned downtime, and improves reliability in industrial power-to-X installations.

[0111] The presently disclosed method enables precise monitoring and control at the level of individual electrolysis cell stack units. The method facilitates dynamic adjustments to operating conditions, optimizing energy input and enhancing the efficiency of hydrogen production or related power-to-X processes. This approach supports improved system reliability by mitigating the risks of overloading, overheating, or inefficient power delivery to the electrolysis units. Additionally, the method enables the system to adapt to variable power inputs, such as from renewable energy sources, ensuring stable and continuous operation under fluctuating conditions.

[0112] An example of a flowchart for the presently disclosed method is shown in FIG. 3. The flowchart exemplifies a control loop serving to monitor (301) and control (305) powerP6845PC00

[0113] and / or current and / or voltage and / or temperature at the level of the individual electrolysis cell stack units. The control loop regularly or continuously checks measurements values (302) for the individual electrolysis cell stack units against a predefined malfunction threshold (303) and an operational threshold (304). If the measurement values exceed the malfunction threshold, the electrolysis cell stack unit is stopped or disconnected (306) without causing a malfunction or disruption for the remaining electrolysis cell stack units. If the measurement values exceed the operation threshold (305), parameters and / or control settings are adjusted to ensure stable operation by maintaining the measurement values within the desired thresholds.

[0114] In one embodiment of the present disclosure, the method further comprises using active and / or passive filters. The inclusion of filters enhances the stability and quality of the power delivered to the electrolysis cell stack units by mitigating undesired fluctuations, noise, or distortions in current and voltage. Passive filters, which may include inductors, capacitors, and resistors, can smooth out high-frequency ripple components that arise during power conversion processes. These filters are particularly useful for ensuring that the output from the DC / DC power converters remains stable and free from harmonics, protecting the electrolysis cell stacks from voltage stress and improving their long-term reliability.

[0115] Active filters, on the other hand, can provide dynamic and real-time compensation for power quality issues such as transient voltage spikes or harmonic distortions. These filters employ advanced power electronics and control techniques to actively detect and counteract disturbances in the power supply. For example, active filters may include switching components such as MOSFETs or IGBTs controlled through feedback loops to adjust output parameters. The use of active filters enables greater precision and adaptability, which is advantageous in scenarios where the power supply is variable, such as when integrating renewable energy sources.

[0116] In one embodiment of the present disclosure, the method further comprises autonomous short and / or long term failure detection and / or prediction by using directly or indirectly the measured current and / or voltage and / or power and / or temperature at the level of the individual DC / DC converters and / or electrolysis cell stack units. This feature allows the system to identify anomalies or deviations in real time that may indicate potential failures or performance degradation in the electrolysis cell stacks orP6845PC00

[0117] power converters. By continuously monitoring operational parameters, such as voltage instability, abnormal current draw, or rising temperatures, the system can detect shortterm issues, such as transient faults, that may require immediate intervention to prevent further damage or operational downtime.

[0118] For long-term failure prediction, the method may leverage historical data combined with advanced analytical techniques, such as machine learning algorithms or trend analysis, to identify gradual changes in system performance that could lead to failure. For example, increasing temperature patterns over time might indicate deterioration of electrolysis cell stack components, while voltage instabilities could signal wear or faults in the DC / DC converters. By using predictive methods, the system can estimate the remaining operational lifetime of components and recommend maintenance or replacement before failure occurs, enhancing reliability and reducing unplanned downtime. This embodiment thus serves to minimize the risk of failures, reduce repair costs, and improve the overall availability and uptime of the system.

[0119] In one embodiment of the present disclosure, the method further comprises using monitoring to predict a lifetime of one or more of the electrolysis cell stack units. This feature leverages the continuous measurement and analysis of operational parameters, such as current, voltage, power, and temperature, to assess the condition and performance of the electrolysis cell stacks overtime. By analyzing trends and deviations in these parameters, the system can identify patterns indicative of component aging, wear, or degradation. For instance, increasing internal resistance, abnormal temperature rises, or voltage instability may suggest gradual performance deterioration, allowing the system to estimate the remaining useful life of the electrolysis cell stacks.

[0120] The lifetime prediction may be implemented using advanced algorithms or machine learning models that correlate historical operating conditions with known failure modes of electrolysis cell stacks. Such analysis may include stress factors like thermal cycling, overvoltage events, or irregular power inputs, all of which contribute to accelerated aging. Predictive monitoring enables operators to forecast when specific cell stacks may require maintenance, refurbishment, or replacement, allowing for more effective maintenance scheduling and resource allocation.P6845PC00

[0121] The presently disclosed method enhances the overall reliability, efficiency, and costeffectiveness for controlling a power converter system for a plurality of electrolysis cell stack units. In the present embodiment, early identification of aging components reduces the risk of unexpected failures and costly unplanned downtime while extending the operational lifespan of the system as a whole. This capability may be beneficial in industrial-scale power-to-X applications, where maximizing the longevity and performance of electrolysis units can be important for achieving sustainable and uninterrupted production of hydrogen or other green byproducts.

[0122] The present disclosure also relates to any combination of any of the embodiments relating to both method and system described herein.

[0123] Reference numeral list

[0124] 100 power converter system for supplying and controlling power to a plurality of electrolysis cell stack units

[0125] 101 power source such as a renewable energy source

[0126] 102 input AC power grid line

[0127] 103 power transformer

[0128] 104 AC / DC power converter

[0129] 105 primary DC link

[0130] 106 first DC link as part of the distributed DC link

[0131] 107 last DC link as part of the distributed DC link

[0132] 108 DC / DC power converter

[0133] 109 first electrolysis cell stack unit

[0134] 110 DC-link capacitor bank

[0135] 111 positive DC bus

[0136] 112 negative DC bus

[0137] 113 local capacitor unit

[0138] 114 positive local DC bus (of first DC link)

[0139] 115 negative local DC bus (of first DC link)

[0140] 116 positive local DC bus (of first DC link)

[0141] 117 negative local DC bus (of first DC link)

[0142] 200 power converter system for supplying and controlling power to a plurality of electrolysis cell stack units comprising a transformer, a distribution BUS, a power-to-hydrogen BUS, and an AC / DC power converterP6845PC00

[0143] 201 power source such as a renewable energy source

[0144] 202 power grid line

[0145] 203 transformer

[0146] 204 distribution BUS

[0147] 205 power-to-hydrogen BUS

[0148] 206 AC / DC power converter

[0149] 207 primary DC link

[0150] 208 distributed DC link comprising a plurality of DC links

[0151] 209 first DC link as part of the distributed DC link

[0152] 210 DC / DC power converter

[0153] 211 output filter, such as a lowpass filter comprising an inductor and a capacitor connected to ground

[0154] 212 first electrolysis cell stack unit

[0155] 213 DC-link capacitor bank

[0156] 300 flowchart for the presently disclosed method for controlling a power converter system for plurality of electrolysis cell stack units 301 monitoring power and / or current and / or voltage and / or temperature at the level of the individual electrolysis cell stack units

[0157] 302 compare measurement values against predefined thresholds to determine whether defined thresholds are exceeded

[0158] 303 measurement value is greater than or equal to malfunction threshold 304 measurement value is greater than or equal to operational threshold 305 adjust control parameters to ensure stable operation since measurement values are greater than or equal to operational threshold

[0159] 306 stop operation and / or disconnect relevant electrolysis cell stack unit

[0160] Examples

[0161] A non-limiting example of the presently disclosed system is shown in FIG. 2. Here, we elaborate on this example and explain its features and advantages.

[0162] In the system illustrated in FIG. 2, a plurality of DC / DC power converters are all serially connected. Each DC / DC power converter is individually connected to one DC link from the distributed DC link, via one output filter, to one electrolysis cell stack unit. The first and the last DC link from the distributed DC link are connected to the primary DC link, such that the primary DC link distributes its capacitance across the plurality of DC linksP6845PC00

[0163] in the distributed DC link and facilitates control over the individual electrolysis cell stack units.

[0164] The power converter system is configured to interface with a renewable energy resource, such as wind turbines or photovoltaic systems. The system includes an AC power source connected to the power grid, followed by a transformer that adjusts the voltage to appropriate levels. The output of the transformer is fed through a distribution BUS and a dedicated PtH (Power-to-Hydrogen) BUS, which deliver power to an AC / DC power converter. The AC / DC power converter rectifies the incoming AC power into DC power, which is subsequently supplied to a main DC BUS. The main DC BUS then distributes power to a distributed DC links comprising one DC link for each of the electrolysis cell stack units, each of which is connected to a DC / DC power converter. These DC / DC power converters regulate and stabilize power delivery to individual electrolysis cell stack units through output filters, ensuring high power quality and efficient operation.

[0165] The described architecture achieves high efficiency through its modular design and distributed power regulation. The AC / DC power conversion step ensures minimal energy loss during rectification, while the DC / DC converters allow for precise voltage and current control at the level of each electrolysis stack. By distributing the primary DC link capacitance across multiple smaller capacitances in the distributed DC link, the system reduces transmission losses and stabilizes power delivery across the electrolysis cell stack units. The inclusion of output filters further minimizes high-frequency noise and harmonics, which enhances the efficiency of the electrolysis process. These features collectively ensure that energy drawn from the renewable power sources is used optimally for hydrogen production.

[0166] This embodiment offers lower cost, loss, and complexity compared to centralized power architectures. The modularity of the system simplifies the integration of additional electrolysis cell stack units or renewable power sources, avoiding the need for extensive redesigns. The distributed DC link configuration reduces the reliance on large, costly capacitors and minimizes energy losses associated with centralized power transmission. Additionally, the use of standardized DC / DC power converters allows for cost-effective scalability while maintaining system performance. By managing powerP6845PC00

[0167] regulation locally at each electrolysis stack, the system reduces complexity in power distribution and control.

[0168] The system delivers high reliability and power quality, particularly in scenarios where power input from renewable energy sources is highly variable. The distributed DC link and individual DC / DC converters provide redundancy, ensuring that the failure of one converter or electrolysis cell stack does not disrupt the operation of the entire system. The use of output filters and regulated converters ensures that clean and stable power is delivered to each stack, reducing the risk of voltage fluctuations or component degradation. This architecture enhances system resilience and ensures continuous operation under fluctuating grid conditions or renewable energy inputs.

[0169] Furthermore, the system provides higher controllability and flexibility through the independent regulation of each electrolysis cell stack unit. The DC / DC converters are capable of adjusting voltage, current, power, or temperature delivery in real time based on the operational needs of each stack. This allows the system to optimize power delivery for efficiency and performance, even when individual cell stacks operate under differing conditions or are at varying stages of wear. The modular design also supports seamless expansion, enabling additional electrolysis units to be integrated as production demands increase or energy availability improves.

[0170] The described embodiment opens for a different approach to protection and maintenance compared to traditional centralized systems. The modular and distributed nature of the system achieves protection mechanisms at multiple levels, including the primary DC link, distributed DC link, and individual power converters. Advanced monitoring and failure detection systems may be implemented to detect anomalies in current, voltage, or temperature at the level of each electrolysis cell stack unit and power converter. This ensures rapid fault isolation and reduces the risk of cascading failures. Predictive maintenance techniques can also be applied to monitor the condition of system components and estimate their remaining operational lifetime, further enhancing reliability and reducing downtime.

[0171] This embodiment, therefore, provides a highly efficient, reliable, and scalable solution for integrating renewable energy sources with electrolysis-based power-to-XP6845PC00

[0172] applications, supporting high-quality power delivery while reducing costs, losses, and system complexity.

[0173] Items

[0174] 1. A power converter system for supplying and controlling power to a plurality of electrolysis cell stack units, the system comprising:

[0175] a plurality of DC / DC power converters, each connected to one of the electrolysis cell stack units, wherein at least two of the DC / DC power converters are serially connected;

[0176] a primary DC link comprising a capacitance;

[0177] a distributed DC link comprising a plurality of DC links that distribute the capacitance of the primary DC link to at least one of the electrolysis cell stack units, wherein at least one DC / DC converter is connected to a DC link from the distributed DC link, and wherein the first and the last DC links from the distributed DC link are connected to the primary DC link.

[0178] 2. The system according to item 1, wherein the DC / DC power converters are configured to independently regulate the voltage and / or power and / or current and / or temperature, or any combination thereof as supplied to the corresponding electrolysis cell stack unit based on operational requirements.

[0179] 3. The system according to any one of the preceding items, further comprising a power source for supplying the power converter, the power source being a DC power source such as batteries, photovoltaic power stations, hydroelectric power stations, fuel cells, medium-voltage DC sources, high-voltage DC sources, or combinations thereof.

[0180] 4. The system according to item 3, wherein the power source is connected to the primary DC link via a DC / DC converter.

[0181] 5. The system according to item 3, wherein the power source is connected to the primary DC link via a DC / AC converter and an AC / DC converter.

[0182] 6. The system according any one of the preceding items 1-2, further comprising an AC power source, such as power plants, wind turbines, power grids, orP6845PC00

[0183] combinations thereof, for supplying the power converter wherein the power source is connected to the primary DC link via an AC / DC converter.

[0184] 7. The system according to item 6, wherein the system further comprises a transformer connected between the AC power source and the AC / DC converter.

[0185] 8. The system according to any one of the preceding items, wherein at least one of the plurality of DC / DC power converters are controllable DC power converters, such as buck, buck-boost, flyback, bidirectional, or combinations thereof.

[0186] 9. The system according to any one of the preceding items, the system further comprising switching modules such as MOSFETs, SiC, GaN, IGBT, thyristors, or combinations thereof.

[0187] 10. The system according to any one of the preceding items, wherein the power conversion unit further comprises a distribution BUS and a power-to-X BUS.

[0188] 11. The system according to any one of the preceding items, comprising at least 3 electrolysis cell stack units.

[0189] 12. The system according to item 11 , wherein a third DC / DC power converter is connected to a third DC link from the distributed DC link which in turn is serially connected to a second DC link from the distributed DC link, wherein the third DC / DC converter is connected to the third electrolysis cell stack unit.

[0190] 13. The system according to any one of the preceding items, wherein at least one of the plurality of DC / DC converters are connected to an output filter, wherein the output filter is connected in parallel with a DC / DC converter and an electrolysis cell stack unit.

[0191] 14. The system according to any one of the preceding items, wherein the voltage across the primary DC link is greater than 800V and less than 1500V.P6845PC00

[0192] 15. The system according to any one of the preceding items, further comprising a power source for supplying the power converter, the power source being a variable power source.

[0193] 16. The system according to any one of the preceding items, wherein at least one electrolysis stack unit is configured for using electricity and / or heat to primarily generate hydrogen as an intermediate for producing chemical substances or green byproducts such as E-Methanol, E-Dimethyl Ether, E-Kerosene, E- Diesel, E-Ammonia, or E-Methane.

[0194] 17. The system according to any one of the preceding items, wherein at least one electrolysis stack unit is configured for extraction or purification of metals from ores or compounds or in deposition of metals from solution.

[0195] 18. A method for controlling a power converter system for a plurality of electrolysis cell stack units, the method comprising:

[0196] providing a plurality of DC / DC power converters, each connected to one of the electrolysis cell stack units, wherein at least two of the DC / DC power converters are serially connected, a primary DC link, and a distributed DC link comprising a plurality of DC links that distribute the capacitance of the primary DC link to at least one of the electrolysis cell stack units, wherein at least one DC / DC converter is connected to a DC link from the distributed DC link, and wherein the first and the last DC links from the distributed DC link are connected to the primary DC link; monitoring directly or indirectly a current and / or voltage and / or power and / or temperature of at least one of the plurality of electrolysis cell stack units;

[0197] controlling directly or indirectly a current and / or voltage and / or power and / or temperature of at least one of at least one of the plurality of electrolysis cell stack units.

[0198] 19. The method according to item 18, wherein the method further comprises using active and / or passive filters.P6845PC00

[0199] 20. The method according to any one of preceding items 18-19, wherein the method further comprises

[0200] autonomous short and / or long term failure detection and / or prediction by using directly or indirectly the measured current and / or voltage and / or power and / or temperature at the level of the individual DC / DC converters and / or electrolysis cell stack units.

[0201] 21. The method according to any one of the preceding items 18-20, further comprising using monitoring to predict a lifetime of one or more of the electrolysis cell stack units.

Claims

34P6845PC00Claims1. A power converter system for supplying and controlling power to a plurality of electrolysis cell stack units, the system comprising:a plurality of DC / DC power converters, each connectable to one of the electrolysis cell stack units, wherein at least two of the DC / DC power converters are serially connected;a primary DC link comprising a capacitance;a distributed DC link comprising a plurality of DC links that distribute the capacitance of the primary DC link to at least one of the electrolysis cell stack units through the plurality of DC / DC power converters, wherein at least one DC / DC converter is connected to a DC link from the distributed DC link, and wherein a first DC link and a last DC link of the distributed DC link are connected to the primary DC link,wherein each of the plurality of DC / DC power converters are configured to operate at a fraction of a primary voltage of the primary DC link.

2. The system according to claim 1 , comprising a control unit configured to allocate power to the plurality of electrolysis cell stack units based on load conditions.

3. The system according to any one of the preceding claims, wherein the DC / DC power converters are configured to independently regulate the voltage and / or power and / or current and / or temperature, or any combination thereof as supplied to the corresponding electrolysis cell stack unit based on operational requirements.

4. The system according to any one of the preceding claims, wherein the primary DC link comprises a positive DC bus, and a negative DC bus, and a DC link capacitor bank.

5. The system according to any one of the preceding claims, wherein each distributed DC link comprises a positive local DC bus, a negative DC bus, and a local capacitor unit.35P6845PC006. The system according to claims 4-5, wherein the positive DC bus is connected to the positive local DC bus of the first DC link, the negative DC bus is connected to the negative local DC bus of the last DC link.

7. The system according to claims 6, wherein each remaining local DC bus is connected to a local positive DC bus of a neighbouring DC link.

8. The system according to claims 6-7, wherein the positive bus of each of the plurality of DC links is connected to a positive input of a corresponding DC / DC power converter, and the negative bus of each of the plurality of DC links is connected to a negative input of a corresponding DC / DC power converter.

9. The system according to any one of the preceding claims, further comprising a power source for supplying the power converter, the power source being a DC power source such as batteries, photovoltaic power stations, hydroelectric power stations, fuel cells, medium-voltage DC sources, high-voltage DC sources, or combinations thereof.

10. The system according to claim 9, wherein the power source is connected to the primary DC link via a DC / DC converter.

11. The system according to claim 9, wherein the power source is connected to the primary DC link via a DC / AC converter and an AC / DC converter.

12. The system according any one of the preceding claims 1-9, further comprising an AC power source, such as power plants, wind turbines, power grids, or combinations thereof, for supplying the power converter wherein the power source is connected to the primary DC link via an AC / DC converter.

13. The system according to claim 12, wherein the system further comprises a transformer connected between the AC power source and the AC / DC converter.

14. The system according to any one of the preceding claims, wherein at least one of the plurality of DC / DC power converters are controllable DC powerP6845PC00converters, such as buck, buck-boost, flyback, bidirectional, or combinations thereof.

15. The system according to any one of the preceding claims, the system further comprising switching modules such as MOSFETs, SiC, GaN, IGBT, thyristors, or combinations thereof.

16. The system according to any one of the preceding claims, wherein the power conversion unit further comprises a distribution BUS and a power-to-X BUS.

17. The system according to any one of the preceding claims, wherein at least one of the plurality of DC / DC converters are connected to an output filter, wherein the output filter is connected in parallel with a DC / DC converter and an electrolysis cell stack unit.

18. A method for controlling a power converter system for a plurality of electrolysis cell stack units, the method comprising:providing a plurality of DC / DC power converters, each connected to one of the electrolysis cell stack units, wherein at least two of the DC / DC power converters are serially connected, a primary DC link comprising a capacitance, and a distributed DC link comprising a plurality of DC links that distribute the capacitance of the primary DC link to at least one of the electrolysis cell stack units, wherein at least one DC / DC converter is connected to a DC link from the distributed DC link, and wherein the first and the last DC links from the distributed DC link are connected to the primary DC link;monitoring directly or indirectly a current and / or voltage and / or power and / or temperature of at least one of the plurality of electrolysis cell stack units;controlling directly or indirectly a current and / or voltage and / or power and / or temperature of at least one of at least one of the plurality of electrolysis cell stack units.

19. The method according to claim 18, wherein the method further comprises:P6845PC00obtaining measurement signals indicative of at least one of current, voltage, power and temperature at the level of individual DC / DC power converters and / or electrolysis cell stack units;detecting a short-term fault condition by identifying a deviation of at least one of said measurement signals from an expected operating range and / or a threshold.

20. The method according to any one of claims 18-19, wherein the method further comprises:obtaining measurement signals indicative of at least one of current, voltage, power and temperature at the level of individual DC / DC power converters and / or electrolysis cell stack units;predicting a long-term failure by analyzing temporal trends of the measurement signals using historical operating data, by trend analysis and / or a machine-learning algorithm.

21. The method according to any one of the preceding claims 18-20, further comprising:obtaining measurement signals indicative of at least one of current, voltage, power and temperature at the level of individual DC / DC power converters and / or electrolysis cell stack units;estimating a remaining operational lifetime of one or more electrolysis cell stack units based on the measurement signals, wherein the estimating comprises analyzing trends and / or deviations of at least one of current, voltage, power and temperature over time, optionally in combination with stress factors including thermal cycling, over voltage events and / or irregular power inputs.

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