Dynamic Deadtime Control in Wireless Power Transmitter
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Solution Overview
Problem
Wireless power transfer systems experience inefficiency due to power loss caused by deadtime configuration in wireless power transmitters, which affects the overall efficiency of charging processes.
Innovation Solution
A wireless power transmitter dynamically adjusts the deadtime by using a controller to monitor and adjust the switching voltages at the transistor circuit, incrementing or decrementing the deadtime based on the presence of negative voltages to optimize power transfer and minimize losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a fixed deadtime is used in the wireless power transmitter switching circuit, then the circuit operation is simple and stable, but power loss increases due to hard switching and diode mode operations
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed deadtime to a dynamically adjustable deadtime in the switching circuit. The controller modifies the deadtime duration based on real-time detection of voltage polarities at the transistor switches, enabling the system to adapt to varying operating conditions and minimize power loss while maintaining manageable complexity through automated control.
Solution Approach 2:
The patent implements parameter changes by adjusting the deadtime parameter based on the operating state of the switching circuit. The controller detects voltage polarities and modifies the deadtime duration accordingly, changing this critical timing parameter to optimize power transfer efficiency and reduce losses from hard switching and diode mode operations.
2Loss of energy
If the deadtime is increased to prevent hard switching, then switching losses are reduced, but power transfer efficiency decreases due to extended diode mode operation
Solution Approach 1:
The patent employs feedback by having the controller continuously monitor the voltage polarities at the transistor switches during the deadtime period. This feedback mechanism enables the system to detect when hard switching occurs or when diode mode operation extends too long, allowing the controller to adjust the deadtime dynamically to balance switching loss reduction with maintaining power transfer efficiency.
Solution Approach 2:
The patent uses dynamics to adjust the deadtime duration based on real-time operating conditions. Rather than using a static deadtime value, the system dynamically modifies the deadtime to prevent hard switching while avoiding excessive diode mode operation, thereby optimizing both switching loss and power transfer efficiency simultaneously.
3Productivity
If the deadtime is decreased to improve power transfer efficiency, then productivity increases, but power loss increases due to hard switching
Solution Approach 1:
The patent applies feedback by monitoring voltage polarities at the transistor switches and using this information to adjust the deadtime. This feedback loop prevents hard switching by extending the deadtime when necessary while keeping it short enough to maintain power transfer efficiency, thereby reducing switching losses without significantly impacting productivity.
Solution Approach 2:
The patent implements dynamics by making the deadtime adjustable rather than fixed. The controller dynamically modifies the deadtime duration based on detected operating conditions, enabling the system to prevent hard switching when needed while maintaining short deadtimes for efficient power transfer, thus balancing switching loss and productivity.
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 dynamic adjustment of deadtime reduces power loss by optimizing the switching process, leading to improved efficiency in wireless power transfer and minimizing both hard switching and diode mode operations.
Implementation Method 1
a transmitter coil that is driven by an alternate current to produce a time-varying magnetic field and a receiver coil, which can be part of a device such as a cell phone, PDA, computer, or other device, that is positioned relative to the transmitter coil to receive the power transmitted in the time-varying magnetic field
Data Source
AI summary
Embodiments described herein provide a wireless power transmitter that dynamically adjusts the deadtime to reduce power loss. Specifically, the wireless power transmitter includes a transistor circuit for switching a first voltage at a first node and a second voltage at a second node, and a LC circuit coupled between the first node and the second node. The wireless power transmitter further includes a controller coupled to the transistor circuit. The controller is configured to determine whether either of the first voltage and the second voltage is negative during a deadtime of switching. The controller is configured to increment or decrement the deadtime by an adjustment amount depending on whether negative voltage is detected.