H-Bridge Gate Control Using Coil-Phase Signals for Low-Loss WPT
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Solution Overview
Problem
High power wireless power transfer systems face challenges in achieving reliable and high efficiency due to increased power demands, requiring a simple and efficient gate drive control apparatus for H-bridge switching circuits in wireless power transfer systems.
Innovation Solution
A gate control apparatus is introduced that includes a rectifier with a first and second leg, where the gate drive signals for switches are derived from signals in phase with the voltages at the terminals of a coil, and an auxiliary coil is used to control high-side switches of the H-bridge, simplifying the driver circuit and improving reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If resonant converters are used to reduce switching losses, then power efficiency is improved, but system complexity increases due to the need for reliable high power operation
Solution Approach 1:
The gate control apparatus uses the coil voltage signals themselves to generate the gate drive signals for the switches. The first and second signals are derived directly from the voltage on the first and second terminals of the coil, eliminating the need for external control circuits and making the system self-controlling while maintaining zero voltage switching for reduced losses
Solution Approach 2:
The gate control apparatus introduces an intermediary control mechanism that derives gate drive signals from the coil voltage through signal derivation circuits. This intermediary approach allows the system to maintain resonant operation for efficiency while adding controlled complexity only where needed for reliable high power operation
2Device complexity
If gate drive signals are derived from coil voltage signals, then driver circuit complexity is reduced, but control precision under varying operating conditions may worsen
Solution Approach 1:
The gate control apparatus dynamically adapts to varying operating conditions by deriving gate drive signals directly from the instantaneous coil voltage signals. The first and second signals track the coil voltage in real-time, automatically adjusting to changing operating conditions without requiring external control intervention, thus maintaining precision while simplifying the driver circuit
Solution Approach 2:
The system implements inherent feedback by deriving gate drive signals from the coil voltage signals. The gate drive signals are directly coupled to the coil voltage, creating a natural feedback mechanism that maintains control precision under varying operating conditions without adding complex external control circuits
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 simple and reliable gate control mechanism for H-bridge switching circuits, enhancing the efficiency and reliability of wireless power transfer systems by reducing switching losses and improving power transfer efficiency.
Implementation Method 1
an auxiliary coil is used to control high-side switches of the H-bridge, simplifying the driver circuit and improving reliability
Data Source
AI summary
An apparatus includes a rectifier coupled to a coil of a wireless power transfer system, the rectifier comprising a first leg and a second leg, wherein the first leg comprises a first switch and a second switch connected in series between a first voltage bus and a second voltage bus, and the second leg comprise a third switch and a fourth switch connected in series between the first voltage bus and the second voltage bus, and wherein a gate drive signal of the first switch is derived from a signal in phase with a voltage on a first terminal of the coil, and a gate drive signal of the third switch is derived from a signal in phase with a voltage on a second terminal of the coil.