Electrolyzer Power Supply With Tap-Changing Transformer and IGBT Converter

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Solution Overview

Problem

Existing electrolysis systems face inefficiencies and require multiple converters, including thyristor-based converters for pre-charge operations, leading to increased complexity and harmonics feedback into the electrical grid.

Innovation Solution

An electrolyzer power supply system incorporating an on-load tap changing transformer and a self-commutated converter, such as an IGBT converter, which reduces the need for additional converters by adjusting voltage levels to match the electrolyzer's requirements, ensuring safe operation during ramp-up, ramp-down, and compensating for aging effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple converters including thyristor-based converters are used for pre-charge operations, then the electrolyzer can be charged safely during startup, but the system complexity increases and harmonics feedback into the electrical grid increases

Engineering Contradiction:
Improvesafe operation during startupVSAvoidnumber of converters
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the pre-charge function and voltage conversion function into a single self-commutated converter. This converter integrates the capabilities of both the traditional thyristor-based pre-charge converter and the main voltage converter, eliminating the need for separate devices and reducing overall system complexity while maintaining safe startup operations

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The self-commutated converter is designed to perform multiple functions: it serves as both the pre-charge converter during startup and as the main voltage converter during normal operation. This multi-functional design replaces multiple specialized converters with a single versatile device, reducing harmonics feedback and simplifying the system architecture

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Device complexity

If traditional voltage conversion methods are used without on-load tap changing transformer, then the system structure is simpler, but the efficiency decreases and additional converters are needed for extended pre-charge operation

Engineering Contradiction:
Improveconverter configurationVSAvoidsystem efficiency
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The on-load tap changing transformer enables dynamic adjustment of voltage ratios during operation. The transformer can change tap positions while loaded, allowing optimal voltage matching between the electrical grid and electrolyzer throughout the system's operational lifetime, including compensation for aging effects, thereby maintaining high efficiency without requiring additional converters

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system utilizes parameter changes in the transformer's turn ratio through on-load tap changing to adapt to varying operational conditions. By adjusting the transformation ratio dynamically, the system maintains optimal efficiency across different operational phases without needing complex converter configurations or extended pre-charge operations

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration minimizes the number of converters needed over the electrolyzer's lifetime, enhances efficiency, reduces harmonics feedback, and ensures safe operation by dynamically adjusting voltage levels to match the electrolyzer's current-voltage characteristics.

Implementation Method 1

the transformer is adapted to receive an electrical power output from an electrical power source and to provide the electrical power output to the converter

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the converter is adapted to convert the alternating current electrical power output from the electrical power source, which is received by the converter from the on-load tap changing transformer, into a direct current electrical power input for the electrolyzer

Methodology Applied
Scientific EffectRectification: Diode

Implementation Method 3

The electrolyzer may be adapted to transform the electrical power input into an energy carrier by means of an electrolysis process. The energy carrier may be hydrogen, for instance.

Methodology Applied
Scientific EffectElectrolysis: Electrolysis

Data Source

PatentEP4672583A1An electrolyzer power supply system, a method for operating an electrolysis system, a computer program, a computer-readable storage medium, a controller and an electrolysis system
Publication Date: 2025.12.31 SIEMENS ENERGY GLOBAL GMBH & CO KG
  • EP4672583A1 patent drawingFigure 1
  • EP4672583A1 patent drawingFigure 2
  • EP4672583A1 patent drawingFigure 3

AI summary

The present invention relates to an electrolyzer power supply system (1) which comprises a transformer (2), particularly a medium to low voltage transformer (2), and a converter (3) which is electrically connected to the transformer (2), wherein the transformer (2) is adapted to receive an electrical power output (4) from an electrical power source (5) and to provide the electrical power output (4) to the converter (3), wherein the converter (3) is adapted to convert the electrical power output (4) into an electrical power input (6) for an electrolyzer (7). According to the invention, the transformer (2) is an on-load tap changing transformer (2) and the converter (3) is a self-commutated converter (3), wherein a tap selection of the on-load tap changing transformer (2), particularly between a first tap and a second tap, is only changed at a tap changing voltage (UTap) of the electrolyzer (7).