Switching Charger Input Voltage Ripple Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional switched power converters face efficiency losses due to high input voltages and conversion ratios, leading to increased power dissipation and size constraints, particularly in battery charging applications where high inductance and switching frequency are required, resulting in reduced mobility and longer charging times.
Innovation Solution
A power converter design that includes an inductor and capacitor cell with a controller managing commutation cycles to regulate output voltage and current, allowing for reduced inductor size and power dissipation by controlling phases to maintain a reference voltage and current, and using interleaved sub-converters to minimize ripple and size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the input voltage Vin is increased to provide higher power for faster battery charging, then the charging power is improved, but the conversion efficiency deteriorates due to increased switch area and reverse recovery losses
Solution Approach 1:
The power converter is divided into multiple phases with separate inductors and switches operating in interleaved fashion. This segmentation allows each phase to operate at lower voltage stress, reducing reverse recovery losses and improving overall conversion efficiency while maintaining high total power output capability
Solution Approach 2:
The controller dynamically adjusts the duty cycle and switching timing of each phase based on real-time operating conditions. This dynamic control optimizes the voltage distribution across switches and inductors, minimizing reverse recovery losses and maintaining high efficiency across varying input voltages and power levels
2Stability of the object's composition
If the inductance L is increased to maintain low current variations at high input voltages, then the current ripple is reduced, but the inductor size increases due to increased number of turns and wire thickness
Solution Approach 1:
The total inductance requirement is segmented across multiple inductors operating in parallel phases. Each inductor carries only a fraction of the total current and requires fewer turns, significantly reducing the volume of each inductor while maintaining the same overall current ripple performance through interleaved operation
Solution Approach 2:
Multiple inductors with smaller individual inductance values are combined through interleaved operation to achieve the effective inductance needed for low current ripple. The phased switching causes current ripples from different inductors to cancel each other out, providing low total current variation without requiring large individual inductors
3Stability of the object's composition
If the switching frequency is increased to achieve predetermined current ripple at high input voltages, then the current ripple is controlled, but the inductor core losses and dissipation power increase
Solution Approach 1:
The switching operation is segmented into multiple phases that are interleaved in time. Each phase operates at a moderate switching frequency, but the combined effect of multiple phases provides the equivalent of a higher frequency response with reduced current ripple, avoiding the core losses associated with truly high-frequency switching
4Reliability
If the number of turns in the inductor is increased to maintain DCR with higher inductance, then the direct current resistance is maintained, but the inductor size grows due to increased number of turns and wire thickness
Solution Approach 1:
The total number of turns required for the inductor is segmented across multiple parallel inductors. Each inductor has fewer turns and uses thinner wire, maintaining acceptable DCR for each component while dramatically reducing the overall volume required compared to a single large inductor with high turn count
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 enables efficient battery charging with reduced power dissipation and size, achieving high conversion efficiency and extended battery life by optimizing power converter design for high input voltages and conversion ratios.
Implementation Method 1
an inductor (i.e. coils) with increased inductance L, due to the relation dIL/dt=VL/L
Implementation Method 2
a capacitor cell (comprising a capacitor or corresponding to a capacitor or comprising a capacitive voltage divider)
Data Source
AI summary
A voltage or current regulated power converter for charging batteries, is described. The power converter comprises an inductor (L), a capacitor cell (C1, C2), switches (S1, S2, S3, S4, S5, S6, S7, S8) and a controller. The controller controls the switches such that a commutation cycle of the power converter comprises a first phase, during which the capacitor cell and the inductor are arranged in series and during which a voltage across the serial arrangement of the capacitor cell and the inductor corresponds to Vin−Vout; a second phase, during which the capacitor cell and the inductor are arranged in series and during which the voltage across the serial arrangement of the capacitor cell and the inductor corresponds to −Vout; and a third phase, during which the capacitor cell is floating and during which the voltage across the inductor corresponds to Vin−Vout or to −Vout.