DC Coupled Converter Transformer Elimination
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Solution Overview
Problem
Existing DC-DC converters require large and expensive transformers for high voltage transformation ratios, leading to increased installation size and costs, and are limited in efficiency and flexibility in generating output voltages.
Innovation Solution
A DC coupled electrical converter design combining a boost converter and an inverting buck-boost converter with a series circuit of two capacitors, eliminating the need for a transformer by reducing the transformation ratio and allowing for high output voltages without a transformer, while enabling separate use of output voltages and flexible control for uniform or different voltage forms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a transformer is used for high voltage transformation ratio, then the output voltage can be achieved, but the installation size and cost increase
Solution Approach 1:
The patent divides the single high-ratio transformation task into two separate conversion stages: first a boost converter increases voltage from a moderate ratio, then an inverting buck-boost converter achieves the remaining transformation. This segmentation allows each converter to operate at lower, more efficient ratios without requiring a large transformer
Solution Approach 2:
The patent replaces the traditional mechanical/electromagnetic transformer system with electronic switching converters. By using semiconductor switches (MOSFETs or IGBTs) to control energy transfer through inductors and capacitors, the system eliminates the need for a large iron-core transformer, significantly reducing installation size and weight while achieving the same voltage transformation function
2Power
If a transformer is used for high voltage transformation ratio, then the output voltage can be achieved, but the cost increases
Solution Approach 1:
The patent segments the voltage transformation into two independent converter modules that can be manufactured and assembled separately. This modular approach reduces the need for expensive custom-made high-ratio transformers and allows use of standard, lower-cost components like off-the-shelf inductors, capacitors, and semiconductor devices
Solution Approach 2:
The patent employs relatively inexpensive semiconductor switches and passive components that can be easily replaced, replacing the need for expensive, custom-wound high-ratio transformers. The electronic components used in the dual-converter architecture are generally more cost-effective than precision transformer manufacturing for high transformation ratios
3Power
If a transformer is used, then voltage transformation is achieved, but efficiency and flexibility in generating output voltages are limited
Solution Approach 1:
The patent employs dynamic switching control where semiconductor devices are turned on and off at optimized timing to maximize energy transfer efficiency. The boost converter and inverting buck-boost converter use pulse-width modulation and synchronized switching to minimize resistive losses and improve overall conversion efficiency compared to static transformer operation
Solution Approach 2:
The patent enables flexible adjustment of output voltage by changing switching duty cycles and timing parameters of the semiconductor devices. This allows continuous optimization of conversion efficiency at different operating points and provides the ability to generate multiple output voltages from the same input, something a fixed-ratio transformer cannot do
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
The solution achieves a smaller installation size, lower costs, and improved efficiency by eliminating the transformer, allowing for high transformation ratios and flexible voltage generation, while supporting both unidirectional and bidirectional energy flow with reduced size and weight of inductive components.
Implementation Method 1
a first inductance (L1), which is connected to the center connection (12B) of the first series circuit and to the positive pole (11A) of the input voltage
Implementation Method 2
a second inductance (L2), which is connected to the center connection (12C) of the second series circuit and to the center connection (12A) between the capacitors (C1, C2)
Implementation Method 3
a series circuit composed of two capacitors (C1, C2), which is connected to the output-side positive pole (13A) of the boost converter and to the output-side negative pole (13B) of the inverting buck-boost converter
Data Source
AI summary
Various embodiments include a DC coupled electrical converter for converting an input voltage applied to first connections to an output voltage comprising: a boost converter connected on the input side to the first connections; an inverting buck-boost converter connected on the input side to the first connections; and a series circuit including two capacitors, the series circuit connected to an output-side positive pole of the boost converter and to an output-side negative pole of the inverting buck-boost converter. An output-side negative pole of the boost converter and an output-side positive pole of the inverting buck-boost converter are connected to a center connection between the capacitors.