Frequency Converter Intermediate Circuit Segmentation
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Solution Overview
Problem
Existing electrical energy supply network arrangements suffer from suboptimal electrical properties, including undesired circulating currents due to shared intermediate circuits in frequency converters, which limit their performance and efficiency.
Innovation Solution
The arrangement employs electrically isolated frequency converters with separate intermediate circuits, each with its own control device, allowing for multilevel voltage generation through vector or phasor addition of partial voltages, and controlled pulse width modulation to match the mains voltage, while preventing circulating currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If frequency converters share a common intermediate circuit, then device complexity is reduced, but circulating currents occur causing harmful effects
Solution Approach 1:
The patent divides the common intermediate circuit into separate, isolated intermediate circuits for each frequency converter. Each converter has its own independent DC voltage intermediate circuit, eliminating the shared circuit that causes circulating currents. This segmentation resolves the contradiction by accepting increased device complexity to eliminate harmful circulating currents.
2Object-generated harmful factors
If separate intermediate circuits are used for each frequency converter, then circulating currents are prevented, but device complexity increases
Solution Approach 1:
The patent implements segmentation by creating separate intermediate circuits for each frequency converter, with each converter having its own isolated DC voltage intermediate circuit. This structural division prevents circulating currents while managing the inherent increase in complexity through modular design.
Solution Approach 2:
The patent introduces an intermediary coupling mechanism (inductive coupling through transformers or magnetic coupling) that allows multiple frequency converters with separate intermediate circuits to be connected to the same energy supply network without direct electrical connection between their intermediate circuits. This intermediary approach enables isolation while maintaining functional connectivity.
3Reliability
If multiple frequency converters are used for multilevel voltage generation, then electrical properties improve, but device complexity increases
Solution Approach 1:
The patent merges multiple frequency converters with separate intermediate circuits into a coordinated system that generates multilevel voltage output. By combining the outputs of multiple converters through inductive coupling and synchronized control, the system achieves improved electrical properties and multilevel voltage generation while managing complexity through integrated control.
Solution Approach 2:
The patent makes each frequency converter multi-functional by enabling them to operate independently with separate intermediate circuits while simultaneously working together as a coordinated multilevel system. Each converter can function autonomously yet contributes to the overall multilevel voltage generation, improving reliability and electrical properties.
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 enhances electrical properties by preventing circulating currents and enabling efficient multilevel control, improving power quality and reducing the need for complex filtering, thus optimizing energy supply network performance.
Implementation Method 1
a generator (20) with electrically isolated winding systems (30), wherein the frequency converters (40, 41, 42) are directly or indirectly connected to a winding system (30) of the generator (20)
Implementation Method 2
the control device (80) is connected to the inverters (70) of the frequency converters (40, 41, 42) for their activation with individual control signals (ST1 to ST3)
Data Source
AI summary
The invention relates to an arrangement (10) for feeding electrical energy into an energy supply network (100). According to the invention, the arrangement has a generator (20) having potential-separated winding systems (30), the arrangement has at least two frequency converters (40, 41, 42) having separated intermediate circuits (60), wherein each frequency converter is connected indirectly or directly to a winding system (30) of the generator, the arrangement has at least one control device (80), to which the frequency converters are connected in order for the frequency converters to be controlled, and the frequency converters feed current into the energy supply network (100) by means of a voltage having a multi-level characteristic when controlled by the control device.