Impedance Control Device for Vehicular Non-Contact Power
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing impedance control devices for non-contact power transmission systems face inefficiencies in matching the impedance of AC power supplying units with fluctuating loads, limiting the effective supply of AC power to vehicles.
Innovation Solution
An impedance control device with a diode bridge rectifier circuit and capacitance variable units, controlled by a feedback system that adjusts capacitances based on load impedance to optimize power transmission efficiency, eliminating the need for a DC/DC converter and dedicated impedance matching circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a DC/DC converter and dedicated impedance matching circuits are used to match impedance between AC supplying unit and load, then power transmission efficiency is improved, but device complexity and hardware requirements increase
Solution Approach 1:
The patent extracts and eliminates the DC/DC converter and dedicated impedance matching circuits from the power transmission system. By removing these complex components and relying solely on the inherent characteristics of the power receiving coil and diode bridge rectifier circuit, the system achieves impedance matching without additional hardware, thereby reducing device complexity while maintaining power transmission efficiency
Solution Approach 2:
The power receiving coil is designed to serve multiple functions: it acts as both the receiving antenna for electromagnetic power transmission and as the impedance matching element. The diode bridge rectifier circuit simultaneously performs rectification and contributes to impedance matching through its interaction with the power receiving coil, eliminating the need for separate dedicated circuits
2Loss of energy
If capacitance variable units are added to control impedance matching, then power transmission efficiency is improved, but device complexity increases
Solution Approach 1:
The patent employs capacitance variable units that can dynamically adjust their capacitance values based on the impedance characteristics of the load. This dynamic adjustment capability allows the system to maintain optimal impedance matching under varying load conditions, improving power transmission efficiency. The capacitance variable units are integrated into the existing circuit structure, adding functionality without significantly increasing overall device complexity
Solution Approach 2:
The system incorporates feedback control mechanisms where the controller monitors the impedance of the load and adjusts the capacitance of the capacitance variable units accordingly. This feedback loop ensures continuous optimization of impedance matching, maintaining high power transmission efficiency even as load conditions change, while the control is managed through software/firmware rather than complex hardware
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 matching of impedance between the power receiving coil and the battery, enhancing AC power transmission efficiency and allowing for adaptive impedance control to match varying load conditions, thereby improving overall power delivery without additional hardware requirements.
Implementation Method 1
a power receiving coil that is provided on the vehicle and receives AC power transmitted in a non-contact manner from a power transmission coil that is provided outside the vehicle
Implementation Method 2
a diode bridge rectifier circuit that is provided on a vehicle, the diode rectifier circuit including first and second diodes that are coupled in series in a forward direction, third and fourth diodes that are coupled in series in a forward direction
Implementation Method 3
first and second capacitance variable units that are coupled in series, the first capacitance variable unit being coupled to the third diode in parallel, the second capacitance variable unit being coupled to the fourth diode in parallel
Data Source
AI summary
An impedance control device includes a diode bridge rectifier circuit and a controller. The controller is configured to control, based on impedance of a battery that is coupled to output terminals of the diode bridge rectifier circuit, the capacitance of a first capacitance variable unit and capacitance of a second capacitance variable unit of the diode bridge rectifier circuit.