Grid-Side Transformer Windings for Compact AC Grid Stabilization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing grid stabilization devices with air-core reactors require significant space and incur high electromagnetic compatibility (EMC) issues due to their external installation, leading to high costs and complex infrastructure needs.
Innovation Solution
Integrating inductors as secondary windings of the grid-side transformer, allowing for a compact design within a transformer housing, and using a modular multi-level power converter with delta-connected branches and magnetically coupled windings for efficient current management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If air-core reactors are used as inductors for current limiting, then the device can effectively limit circulating currents, but the device requires significant external space and generates high electromagnetic compatibility issues
Solution Approach 1:
The patent combines the inductor function with the transformer by integrating the inductors as secondary windings of the grid-side transformer. This merging eliminates the need for separate external air-core reactors, reducing space requirements while maintaining current limiting capability through the transformer's integrated magnetic circuit
Solution Approach 2:
The inductors are nested within the transformer housing as secondary windings, placing one functional element (inductor) inside another (transformer). This nesting approach allows the inductors to be housed within the existing transformer structure, significantly reducing the external space needed for separate reactor installations
2Reliability
If air-core reactors are installed externally, then the device can provide current limiting function, but the electromagnetic compatibility loads in the surroundings increase significantly
Solution Approach 1:
By merging the inductor and transformer into a single integrated unit where inductors serve as secondary windings, the patent reduces electromagnetic interference to the surroundings. The magnetic fields are contained within the transformer housing and core structure, preventing the high EMC loads generated by external air-core reactors
Solution Approach 2:
The patent converts the potentially harmful electromagnetic radiation from external reactors into a beneficial contained magnetic field within the transformer. The magnetic flux is directed through the transformer core and windings to perform useful current limiting while preventing harmful electromagnetic emissions to the surrounding environment
3Reliability
If external air-core reactors are used, then the device can limit currents, but foundations, insulators, steel beams and other complex infrastructure components are required
Solution Approach 1:
The patent merges the inductor support structure with the transformer housing, eliminating the need for separate foundations, steel beams, and mounting infrastructure. The transformer's existing mechanical structure serves as the support for the inductors, significantly simplifying the overall device complexity and infrastructure requirements
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
Reduces space requirements, lowers costs, improves EMC compatibility, and enhances versatility by enabling installation in urban areas while maintaining efficient voltage stabilization.
Implementation Method 1
a grid-side transformer (3), the primary-side transformer windings (4-6) of which can be connected to the AC voltage network (2)... The grid-side transformer (3) transforms a high voltage from the AC network (e.g., > 100 kV) to a voltage between 5 kV and 100 kV
Implementation Method 2
at least one of the winding pairs, preferably all of the winding pairs, is designed as magnetically coupled windings with a center tap... the secondary windings assigned to one and the same winding pair suitably have opposite winding directions to achieve a phase shift of the currents
Data Source
AI summary
The invention relates to a device (1) for stabilizing an alternating voltage grid (2), comprising: a grid-side transformer (3), the primary-side transformer windings (4-6) of which can be connected to the alternating voltage grid; and a power converter (21), which has power converter branches (22-24) and can be connected to the alternating voltage grid by means of the grid-side transformer, current-limiting inductors (11-16) being associated with the power converter. The invention is characterized in that the inductors are designed as secondary windings of the grid-side transformer. The invention further relates to a method for stabilizing the alternating voltage grid by means of the device according to the invention.