Wireless Charging Power Topology With Series-Parallel Battery Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rapid wireless charging of portable electronic devices results in increased current losses due to inefficiencies in power consumption, necessitating improved power system topologies for faster charging with reduced losses.
Innovation Solution
A wireless power system for portable electronic devices featuring a bi-directional three-level buck-boost converter and a 2S/2P battery configuration, where cells can be connected in series for charging and in parallel for discharging, along with a balancer circuit to equalize state of charge, utilizing a ladder of switching devices and a flyback or switched capacitor-based balancer to manage power distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wireless power transfer uses increased currents for rapid charging, then charging speed is improved, but power consumption efficiency deteriorates due to losses
Solution Approach 1:
The battery is divided into multiple cells that can be independently controlled and switched between series and parallel configurations. This segmentation allows the system to optimize charging by using series connection for efficient power delivery and parallel connection for balanced current distribution, thereby maintaining both charging speed and efficiency
Solution Approach 2:
The system dynamically switches between series and parallel battery configurations based on charging requirements. During rapid charging, cells are connected in series to handle higher power efficiently; during normal operation or when balancing is needed, cells are connected in parallel to reduce current density and losses. This dynamic reconfiguration resolves the contradiction between charging speed and efficiency
2Loss of energy
If cells are connected in series for charging, then power delivery efficiency is improved, but current capacity for power delivery deteriorates
Solution Approach 1:
The switching circuit dynamically changes battery configuration based on operational mode. During charging, cells are connected in series to minimize conduction losses and maximize power delivery efficiency. During power delivery to the power management unit, cells are switched to parallel connection to increase current capacity. This dynamic switching resolves the contradiction between efficiency and power capacity
3Adaptability or versatility
If cells have different capacities or chemistries, then system adaptability is improved, but cell balancing complexity increases
Solution Approach 1:
A balancer circuit acts as an intermediary between battery cells with different capacities or chemistries. The circuit includes switching devices and control logic that monitor individual cell states and redistribute charge to maintain balance. This intermediary mechanism enables the system to accommodate diverse battery configurations while managing the complexity of cell balancing through automated control
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 configuration reduces conduction losses by allowing higher charge currents while maintaining efficiency, enabling faster charging with minimized power consumption losses and ensuring balanced cell states through continuous balancer operation.
Implementation Method 1
wireless power transfer, in which power is delivered via magnetic/inductive coupling between a power transmitter (PTx) and a power receiver (PRx)
Implementation Method 2
a converter coupled to the wireless power system that converts a voltage from the wireless power system to a battery charging voltage
Data Source
AI summary
A battery powered electronic device can include a wireless power system configured to receive power from a wireless power transmitter, a converter coupled to the wireless power system that converts a voltage from the wireless power system to a battery charging voltage, a battery comprising at least two cells, a power management unit that delivers power from one or more of the at least two cells to one or more subsystems of the electronic device, and a plurality of switching devices connecting the at least two cells, the converter, and the power management unit. The plurality of switching devices can be arranged so that a first switching configuration connects the cells in series for charging from the converter and a second switching configuration connects the cells in parallel for delivering power to the power management unit.