Non-Inverted DC-DC Converter with Segmented Inductors
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Solution Overview
Problem
Conventional non-isolated DC-DC converters face challenges in handling fluctuating input voltages from solar panels due to opposite polarity between input and output voltages, leading to noise issues and difficulty in designing stable output voltages for applications like planet explorers.
Innovation Solution
A non-isolated DC-DC converter design featuring an input coil, input capacitor, intermediate coils, output coil, output capacitor, and a switching device, along with a diode, to achieve non-inverted output voltage with reduced noise by controlling ripple currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional non-isolated DC-DC converter is used to step-up/down fluctuating solar panel voltage, then voltage conversion is achieved, but the input and output voltages have opposite polarity and large ripple currents cause high noise
Solution Approach 1:
The patent divides the single inductor into two separate inductors (L1 and L2), allowing independent control of input and output current ripple. This segmentation enables each inductor to smooth its respective current waveform, significantly reducing noise while maintaining voltage conversion capability.
Solution Approach 2:
The patent introduces an intermediary capacitor (C1) connected between the two inductors that acts as a mediator to transfer energy while isolating the ripple currents. This intermediary element allows the input and output sides to operate independently, reducing mutual interference and noise transmission.
2Stability of the object's composition
If the number of solar panels is adjusted to ensure output voltage is always higher than input voltage (stepping-down converter), then voltage stability is improved, but the design becomes difficult when solar panel voltage fluctuates widely
Solution Approach 1:
The patent employs dynamic control of the switching device to adjust the duty cycle based on the instantaneous input voltage level. This allows the converter to adapt to wide fluctuations in solar panel voltage while maintaining stable output, transitioning between step-up and step-down modes as needed.
Solution Approach 2:
The converter circuit is designed with universal functionality to operate in both step-up and step-down modes using the same basic topology. The two inductors and intermediary capacitor configuration allows the circuit to handle both voltage increasing and decreasing scenarios, making it adaptable to wide input voltage ranges.
3Adaptability or versatility
If a stepping-up DC-DC converter is used when solar panel voltage fluctuates largely, then low voltage operation is enabled, but the output voltage becomes very low and design becomes difficult
Solution Approach 1:
The switching control mechanism dynamically adjusts the duty cycle to maintain stable output voltage even when input voltage drops to very low levels. The controller compensates for low input voltage by increasing the on-time of the switching device, ensuring consistent output regardless of input fluctuations.
Solution Approach 2:
The use of two separate inductors allows the first inductor (L1) to handle the low voltage input side while the second inductor (L2) handles the output side independently. This segmentation enables the circuit to process very low input voltages without compromising output stability, as each inductor optimizes its respective side of the conversion.
4Device complexity
If conventional DC-DC converter topology is used, then circuit simplicity is maintained, but opposite polarity between input and output voltages creates handling difficulties
Solution Approach 1:
The patent inverts the conventional approach by using two inductors instead of one, and positioning the switching device and diode in a configuration that produces same-polarity output. This inverted topology naturally generates output voltage with the same polarity as input, eliminating the need for additional polarity correction circuits.
Solution Approach 2:
The intermediary capacitor C1 serves as a mediator that transfers energy between the two inductor circuits while maintaining voltage polarity. This intermediary element enables the circuit to achieve same-polarity output without complex additional components, keeping the overall circuit relatively simple while solving the polarity issue.
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 provides a stable, non-inverted output voltage with reduced noise, making it suitable for applications requiring low noise and flexibility in handling fluctuating input voltages from solar panels.
Implementation Method 1
a coil (or inductor) L
Implementation Method 2
a load capacitor Co
Implementation Method 3
a diode D
Data Source
AI summary
Disclosed is a low noise, non-isolated DC-DC converter for providing a non-inverted (i.e., the same polarity as an input voltage) output voltage of any desired voltage by stepping-up/down the input voltage. It comprises an input coil L1, an input capacitor C1 and a second intermediate coil Lm2 connected in series between both ends of the input voltage source, an output coil L2, an output capacitor C2 and a first intermediate coil Lm1 connected in series between both ends of a load Ro, a switching device S connected between a node a of the L1 and the C1 and a node b of the C2 and the Lm1, and a diode D connected between a node d of the C1 and the Lm2 and a node c of the C2 and the L2.