Partial Power Boost Converter for High Gain With Low Input Ripple
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional DC-to-DC converters face limitations in stepping up low voltage from renewable energy sources or electrical vehicle batteries due to high input current ripple, nonideal parasitics, and reduced efficiency, especially when high voltage gain is required, leading to reduced duty cycle control margin and component stress.
Innovation Solution
A non-isolated, differential partial power processing DC-to-DC converter with two inverting boost stages and interleaved inductors and switches, configured to reduce input current ripple and stress on components by creating a negative boost converter output and sharing current among multiple components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a traditional boost converter is used to achieve voltage step-up, then the voltage conversion ratio can be increased, but the input current ripple increases and efficiency decreases
Solution Approach 1:
The converter is divided into two separate inverting boost stages (first and second stages) that operate in parallel. Each stage processes a portion of the input power independently, with their outputs combined at the output node. This segmentation allows the ripple currents from each stage to partially cancel each other out, reducing the total input current ripple while maintaining high voltage gain capability.
2Force
If a traditional boost converter operates at high duty cycle to achieve higher voltage gain, then the voltage conversion ratio increases, but the duty cycle control margin decreases
Solution Approach 1:
By dividing the power processing into two stages, each operating at a moderate duty cycle (D1 and D2), the system achieves high overall voltage gain without requiring either stage to operate at extreme duty cycles. This provides sufficient control margin in each stage to handle voltage disturbances and maintain stable operation.
Solution Approach 2:
The patent implements partial power processing where only a portion of the total input power needs to be processed by each individual stage. The first stage processes power with duty cycle D1 and the second stage processes power with duty cycle D2, where neither stage needs to handle the full power load, allowing both to operate within optimal control margins.
3Device complexity
If a traditional boost converter is used, then the structure is simple, but the current and voltage stresses on switches equal the input current and output voltage, reducing efficiency
Solution Approach 1:
The converter uses two separate inverting boost stages, each with its own switch (S1 and S2). The current stress on each switch is reduced compared to a single-stage converter handling the full power, as each switch only needs to handle a portion of the total current. The voltage stress on each switch is managed by the individual stage design, distributing the overall stress across multiple components.
4Force
If nonideal parasitics are present in converter elements, then the converter can operate, but efficiency drastically decreases when higher voltage gain is desired
Solution Approach 1:
The patent implements partial power processing where each stage handles only a portion of the total power conversion task. This allows each stage to operate at moderate duty cycles with lower current densities, reducing the impact of parasitic resistances and other nonideal effects. The combined effect of both stages achieves high voltage gain while maintaining efficiency by avoiding the extreme operating conditions that amplify parasitic losses.
Data Source
AI summary
A step-up, non-isolated, direct current (DC)-to-DC converter includes a first inverting boost stage having (1) a first input terminal configured to be electrically connected to a first terminal of a DC voltage source, and (2) a first common terminal configured to be electrically connected to a second terminal of the DC voltage source, a second inverting boost stage having (1) a first input terminal configured to be electrically connected to the second terminal of the DC voltage source, and (2) a second common terminal configured to be electrically connected to the first terminal of the DC voltage source. An output voltage V0 generated by the first and second inverting boost stages, between the first and second output terminals includes at least a direct voltage contribution from the DC voltage source.