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EP-4736306-A1 - ELECTROLYSIS DEVICE WITH PULSE POWER CONVERTER AND TRANSFORMER

EP4736306A1EP 4736306 A1EP4736306 A1EP 4736306A1EP-4736306-A1

Abstract

The invention relates to an electrolysis device (1) having precisely one pulse power converter (2), an electrolyzer (3), a transformer (4), and connections (6) for supplying with electric energy, wherein the transformer (4) is electrically connected to the connections (6) on the primary side in order to supply the transformer with electric energy, the pulse power converter (2) is electrically connected to the electrolyzer (3) on the DC voltage side, the pulse power converter (2) is electrically connected to a secondary side (42) of the transformer (4) on the AC voltage side, and the pulse power converter is designed to be operated with a pulse frequency (f P ). In order to reduce the harmonic currents of the electrolysis device (1), the electrolysis device (1) is designed without a network filter. A stray inductance (L σ ) and/or a short circuit voltage (u K ) of the transformer (4) is dimensioned such that harmonic currents between the transformer (4) and the connections (6) fall below a specifiable limit. The invention additionally relates to the use of a stray inductance (L σ ) of a transformer (4) of such an electrolysis device in order to reduce harmonic currents between the electrolysis device (1) and an energy supply network (7) and to a method for operating such an electrolysis device (1), the pulse power converter being operated with a pulse frequency (f P ) at which the resulting harmonic currents between the transformer (4) and the connections (6) fall below the specified limit.

Inventors

  • Lobmeyer, Stefan
  • SCHWIMMBECK, FRANZ

Assignees

  • Innomotics GmbH

Dates

Publication Date
20260506
Application Date
20240514

Claims (9)

  1. 1. Electrolysis device (1) comprising exactly one pulse converter (2), an electrolyzer (3), a transformer (4) and connections (6) for supplying electrical energy, wherein the transformer (4) is electrically connected on the primary side to the connections (6) for supplying electrical energy, wherein the pulse converter (2) is electrically connected on the DC side to the electrolyzer (3), wherein the pulse converter (2) is electrically connected on the AC side to a secondary side (42) of the transformer (4), wherein the pulse converter (2) is designed to be operated with a pulse frequency (f P ), characterized in that the electrolysis device (1) is designed to be free of a mains filter, wherein a leakage inductance (L o ) and/or a short-circuit voltage (u K ) of the transformer (4) is dimensioned such that harmonic currents between the transformer (4) and the connections (6) exceed a predeterminable limit below.
  2. 2. Electrolysis device (1) according to claim 1, wherein the leakage inductance (L o ) and/or a short-circuit voltage (u K ) of the transformer (4) is dimensioned such that a current in the range of the pulse frequency (f P ) and/or in the range of a multiple of the pulse frequency (f P ) between the transformer (4) and the terminals (6) falls below the predeterminable limit.
  3. 3. Electrolysis device (1) according to one of claims 1 or 2, wherein a capacitor (5) is arranged between the terminals (6) for the supply of electrical energy and the pulse converter (2) in parallel with the transformer (4).
  4. 4. Electrolysis device (1) according to claim 3, wherein the leakage inductance (L o ) of the transformer (4) and the capacitor (5) form a blocking circuit with a resonance frequency (w R ) in range of the pulse frequency (f P ) or in the range of a multiple of the pulse frequency (f P ).
  5. 5. Electrolysis device (1) according to one of claims 1 to 4, wherein the electrolysis device has a control device (11) for controlling the pulse converter (2), which is designed to clock the pulse converter (2) with a higher pulse frequency when undesirable interference currents occur.
  6. 6. Use of a leakage inductance (L o ) of a transformer (4) of an electrolysis device (1) according to one of claims 1 to 4 for reducing harmonic currents between the electrolysis device (1) and a power supply network (7).
  7. 7. Method for operating an electrolysis device (1) according to one of claims 1 to 6, wherein the pulse converter (2) is operated with a pulse frequency (f P ) at which the harmonic currents which develop between the transformer (4) and the terminals (6) fall below the predetermined limit.
  8. 8. Method according to claim 7, wherein the pulse converter is operated with a pulse frequency (f P ) at which the currents which develop in the range of the pulse frequency (f P ) and/or in the range of a multiple of the pulse frequency (f P ) between the transformer (4) and the terminals (6) fall below the predeterminable limit.
  9. 9. Method according to one of claims 7 or 8, wherein the pulse converter (2) is clocked at a higher pulse frequency when undesirable interference currents occur.

Description

Description ELECTROLYSIS DEVICE WITH PULSE CONVERTER AND TRANSFORMER The invention relates to an electrolysis device, having a pulse current converter, an electrolyzer, a transformer and connections for supplying electrical energy, the transformer being electrically connected on the primary side to the connections for supplying electrical energy, the pulse current converter being electrically connected on the DC side to the electrolyzer, the pulse current converter being electrically connected on the AC side to a secondary side of the transformer, the pulse current converter being designed to be operated at a pulse frequency. The invention further relates to the use of a stray inductance of a transformer of such an electrolysis device for reducing harmonic currents between the electrolysis device and a power supply network. The invention further relates to a method for operating such an electrolysis device. For electrolysis, power converters are used to generate a direct voltage. These convert an alternating voltage from an energy source or a power supply network into a direct voltage, which can be used for electrolysis in the electrolyzer. The power converter generates harmonics. These lead to currents on the alternating voltage side of the power converter, which are particularly undesirable for the power supply network. These currents are also referred to as harmonic currents. They are usually filtered out using filter circuits. These filters are used to prevent or suppress harmonics in the mains current and are therefore also referred to as mains filters. The mains current is the current between a power supply network and the electrolysis device. This can be measured, for example, at the connections of the electrolysis device. The mains filter has at least one inductance and one capacitance which are arranged together in a structural unit . By staggering the timing of several pulse converters, it is possible for some of the harmonics to compensate for each other, i.e. to cancel each other out. The invention is based on the object of reducing the harmonic currents of the electrolysis device. This object is achieved by an electrolysis device having exactly one pulse current converter, an electrolyzer, a transformer and connections for the supply of electrical energy, wherein the transformer is electrically connected on the primary side to the connections for the supply of electrical energy, wherein the pulse current converter is electrically connected on the DC side to the electrolyzer, wherein the pulse current converter is electrically connected on the AC side to a secondary side of the transformer, wherein the pulse current converter is set up to be operated with a pulse frequency, wherein the electrolysis device is designed without a mains filter, wherein a stray inductance and/or a short-circuit voltage of the transformer is dimensioned such that harmonic currents between the transformer and the connections fall below a predefinable limit. Furthermore, this object is achieved by using a stray inductance of a transformer of such an electrolysis device to reduce harmonic currents between the electrolysis device and a power supply network. This object is further achieved by a method for operating such an electrolysis device, wherein the pulse converter is operated with a pulse frequency at which the harmonic currents formed between the transformer and the terminals fall below the predetermined limit. Further advantageous embodiments of the invention are specified in the dependent claims. The invention is based, among other things, on the knowledge that the behavior of the pulse converter of an electrolyzer can be improved with regard to the harmonic currents in the mains current by selecting a stray inductance of the transformer that is high enough to sufficiently reduce the harmonic currents. This means that a mains filter is not required. In other words, the electrolysis device is designed to be mains filter-free. Mains filter-free means that there is no mains filter in which a current is kept away from the mains in a structural unit via a combination of inductance and capacitance. The electrolysis device is designed to be connected to a power supply network or an energy source at the connections for supplying electrical energy. For an electrolysis output of around 5 MVA, a medium-voltage supply from the power supply network with a voltage in the range of 1 kV to 30 kV has proven advantageous. This results in nominal currents of around 100A to 300A between the power supply network and the transformer or electrolysis device. For the electrolysis, a direct voltage of around 800V (+/- 20%) can be generated in a particularly efficient manner by the power converter. To adequately suppress the harmonics using the transformer, a short-circuit voltage u K in the range of 10% to 25%, and particularly in the range of 10% to 15%, has proven to be particularly effective. It has been shown that the additional exp