Solid-State Transformer Auxiliary Power Without 10 kV Insulation
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Solution Overview
Problem
The high cost and weight of power frequency transformers in conventional solid-state transformers lead to increased use costs, and the requirement for 10 kV medium-voltage insulation further complicates the issue.
Innovation Solution
The proposed solid-state transformer design eliminates the need for a power frequency transformer by using the low-voltage direct current output to power the low-voltage side auxiliary power supply, thereby reducing costs and eliminating the need for 10 kV medium-voltage insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a power frequency transformer is used to power the low-voltage side auxiliary power supply, then the auxiliary power supply can be powered reliably, but the cost and weight of the solid-state transformer increase significantly
Solution Approach 1:
The patent extracts and removes the power frequency transformer from the solid-state transformer system. Instead of using a separate power frequency transformer to power the auxiliary power supply, the invention uses the output of the solid-state transformer itself (low-voltage AC or DC) to power the auxiliary power supply, thereby eliminating the additional weight and cost of the power frequency transformer while maintaining reliable power supply to auxiliary circuits
Solution Approach 2:
The patent makes the solid-state transformer output serve multiple functions: it not only provides power to the main load but also powers the low-voltage side auxiliary power supply. This multi-functionality eliminates the need for separate dedicated power frequency transformers for auxiliary power, reducing overall system weight and cost while maintaining reliability
2Reliability
If a power frequency transformer is used to power the low-voltage side auxiliary power supply, then the auxiliary power supply can be powered reliably, but the use cost of the solid-state transformer increases
Solution Approach 1:
The invention removes the power frequency transformer component from the system architecture, eliminating its associated manufacturing costs. The auxiliary power supply is instead powered directly from the solid-state transformer output, reducing the bill of materials and manufacturing complexity while maintaining reliable power supply to auxiliary functions
Solution Approach 2:
The patent merges the auxiliary power supply function into the main solid-state transformer output system. By using the same power conversion system to serve both main load and auxiliary power needs, the invention reduces the total number of separate components and their associated manufacturing costs, while maintaining reliable power supply through the integrated design
3Adaptability or versatility
If 10 kV medium-voltage insulation is implemented, then the transformer can handle medium-voltage inputs, but the device complexity and cost increase
Solution Approach 1:
The patent segments the voltage handling function across multiple power units connected in series at the medium-voltage side. Each power unit handles a portion of the voltage, and their series connection achieves the required 10 kV medium-voltage capability without requiring each individual component to handle the full voltage, thereby reducing insulation complexity and cost while maintaining voltage handling capability
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 design reduces the use costs of the solid-state transformer and improves the reliability of power supply to the low-voltage side auxiliary power supply by eliminating the need for a costly power frequency transformer and associated insulation.
Implementation Method 1
The SST is a medium-voltage to low-voltage power conversion system that uses high-frequency isolation
Implementation Method 2
The transformer can implement voltage level conversion (for example, conversion from a high-voltage alternating current to a low-voltage alternating current, or conversion from a low-voltage alternating current to a high-voltage alternating current) and electrical isolation
Data Source
AI summary
A solid-state transformer includes a first phase circuit and a low-voltage side auxiliary power supply. The first phase circuit has an input end connected to a single-phase medium-voltage alternating current, and an output end connected to an output end of a low-voltage direct current. The first phase circuit includes N power units. Input ends of the N power units in the first phase circuit are connected in series and are connected to the single-phase medium-voltage alternating current. Output ends the N power units are connected in parallel and are connected to the output end of the low-voltage direct current. The low-voltage side auxiliary power supply is connected to the output end of the low-voltage direct current. First direct currents output from the output ends of the N power units are used to supply power to the low-voltage side auxiliary power supply.