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EP-4736308-A1 - ELECTROLYSIS DEVICE

EP4736308A1EP 4736308 A1EP4736308 A1EP 4736308A1EP-4736308-A1

Abstract

The invention relates to an electrolysis device (1) comprising a converter (2), an electrolyzer (3), and network connections (4). In order to improve the properties of the electrolysis, the electrolysis device (1) comprises two converters (2), wherein the converters (2) are arranged in a parallel circuit on the DC voltage side, the electrolyzer (3) is electrically connected to the DC voltage side of the converter (2), each phase (21) of the converters (2) is electrically connected to one of the network connections (4) via a choke (5), and the electrolysis device (1) has a controller (6) which is designed to clock the converters (2) with time offsets. The invention additionally relates to a method for operating such an electrolysis device (1), wherein the converters (2) are clocked with time offsets.

Inventors

  • Lobmeyer, Stefan
  • SCHWIMMBECK, FRANZ

Assignees

  • Innomotics GmbH

Dates

Publication Date
20260506
Application Date
20240514

Claims (5)

  1. 1. Electrolysis device (1), comprising two self-commutated power converters (2), an electrolyzer (3) and mains connections (4), wherein the power converters (2) are arranged in a parallel circuit on the DC voltage side, wherein the electrolyzer (3) is electrically connected to the DC voltage side of the power converter (2), wherein each phase (21) of the power converters (2) is electrically connected to one of the mains connections (4) via a choke (5), wherein the electrolysis device (1) has a control device (6) which is set up to clock the power converters (2) in an offset manner.
  2. 2. Electrolysis device (1) according to claim 1, wherein the choke (5) has two windings (50) and three connections (51, 52, 53), wherein a first of the windings (50) is arranged between a first connection (51) of the three connections (51, 52, 53) and a second connection (52) of the three connections (51, 52, 53), wherein a second of the windings (50) is arranged between the first connection (51) of the three connections (51, 52, 53) and a third connection (53) of the three connections (51, 52, 53), wherein the first connection (51) is electrically connected to one of the mains connections (4), wherein the second connection (52) is electrically connected to a phase (21) of a first power converter of the two power converters (2), wherein the third connection (53) is electrically connected to a phase (21) of a second power converter of the two power converters (2), wherein the windings (50) are magnetically coupled in such a way that magnetic fields caused by a current in a direction from the first terminal (51) to the second terminal (52) of the choke (5) and by a current in the direction from the first terminal (51) to the third terminal (53) at least partially compensate each other.
  3. 3. Electrolysis device (1) according to one of claims 1 or 2, wherein a further choke (7) is arranged between the respective mains connections (4) and the choke (5).
  4. 4. Electrolysis device (1) according to one of claims 1 to 3, wherein a transformer (8) is arranged between the mains connections (4) and choke (5).
  5. 5. Method for operating an electrolysis device (1) according to one of claims 1 to 4, wherein the power converters (2) are clocked in an offset manner.

Description

Description electrolysis device The invention relates to an electrolysis device with a power converter, an electrolyzer and mains connections. Furthermore, the invention relates to a method for operating such an electrolysis device. With the help of an electrolyzer, a material conversion can be brought about as a chemical reaction. This involves electrolysis. The electrolyzer is supplied with electrical energy from an energy source or a power grid. An alternating voltage from the energy source or the power grid is converted into a direct voltage for the electrolyzer by means of a power converter. This power converter is therefore also referred to as a rectifier. Mains-commutated power converters such as diode rectifiers or thyristor power converters, also known as thyristor-controlled power converters, are used as power converters. Self-commutated power converters, for example those based on IGBT semiconductors, are also known. These self-commutated power converters are also referred to as pulse power converters due to their pulsed operation. Chokes can be designed as common mode chokes. The choke has several windings that are magnetically coupled. The magnetic coupling results in common mode currents being suppressed. In contrast, a choke can also be designed as a differential mode choke. The coupling then results in differential mode currents being suppressed. In the future, electrolysis will become increasingly important for the economical and environmentally friendly production of hydrogen, for example as a synthetic fuel. In this case, an electrolyzer or a corresponding Electrolysis device produces hydrogen. This hydrogen-based fuel can significantly contribute to reducing climate-damaging C02 emissions. From the publication “Control methods for self-commutated power converters” (Felix Jenni, Dieter Wüest; Zurich: vdf, Hoch- schulverl. at the ETH Zurich; Stuttgart: Teubner, 1995) a staggered timing of power converters is known. The invention is based on the object of improving an electrolysis device. This object is achieved by an electrolysis device having two power converters, an electrolyzer and mains connections, wherein the power converters are arranged in a parallel circuit on the DC voltage side, wherein the electrolyzer is electrically connected to the DC voltage side of the power converter, wherein each phase of the power converter is electrically connected to one of the mains connections via a choke, wherein the electrolysis device has a control device which is set up to clock the power converters in an offset manner. Furthermore, the object is achieved by a method for operating such an electrolysis device, wherein the power converters are clocked in an offset manner. Further advantageous embodiments of the invention are specified in the dependent claims. The invention is based, among other things, on the realization that the operation of an electrolyzer can be significantly improved if the voltage on the DC side of the converter, which is used to feed the electrolyzer, is ideally free of harmonics. Even a reduction in harmonics leads to a partially significant increase in the efficiency of the electrolysis. The formation of harmonics is prevented or at least suppressed. The use of self-commutated converters allows the pulse frequency of these converters to be specified and varied. It is also possible to clock converters arranged in parallel in an offset manner. A large proportion of harmonics, particularly low-frequency harmonics below 1 kHz, can be eliminated by designing the power converter as a self-commutated power converter. In other words, the power converter is designed as a pulse-controlled power converter. It has proven to be advantageous for uniform energy absorption from the power supply network and simple transmission of electrical energy if the power converter is designed as a three-phase system and thus the energy transfer between the network connections and the power converter is designed as a three-phase system. To further reduce the harmonics, at least two converters are arranged in the electrolysis device to convert the alternating voltage of an energy source or an energy supply network (the energy source can also be part of the energy supply network) into the direct voltage for feeding the electrolyzer. The converters are arranged in parallel on the direct voltage side. The mains connections of the electrolysis device are used to connect the electrolysis device to an energy supply network. Pulse converters with a DC intermediate circuit typically work with capacitors in the intermediate circuit as energy storage. The switching processes in the converter load these capacitors with an alternating current. The resulting losses and the permissible current carrying capacity of the capacitors are an important dimensioning criterion. The individual phases of the converters are each connected to one of the mains connections via a choke. The choke serves to decouple the two conver