Resonant DC-DC Converter Coil Segmentation for Charger Efficiency
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Solution Overview
Problem
Existing DC-DC converters for motor vehicle chargers face inefficiencies due to changing operating parameters such as temperature and current, leading to increased internal resistance and reduced charging efficiency.
Innovation Solution
A method for optimizing the DC-DC converter efficiency by using a resonant converter with multiple primary side transformation coils and semiconductor switches, where the number of active coils is adjusted based on operating parameters like temperature and current, using a computing unit to control the switches and maintain resonance, thereby reducing losses and enhancing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of active transformation coils is increased to maintain resonance and improve efficiency at low loads, then charging efficiency is improved, but device complexity increases
Solution Approach 1:
The primary side transformation coil is divided into multiple independent coil segments that can be individually switched on or off. This segmentation allows the system to adjust the number of active coils based on operating conditions, maintaining resonance and efficiency without requiring a completely different transformer design for each load condition.
Solution Approach 2:
The system dynamically adjusts the number of active transformation coils based on real-time operating parameters such as temperature, current, and power level. This dynamic reconfiguration allows the charger to optimize efficiency across different operating conditions while managing thermal characteristics through controlled coil activation.
2Reliability
If the DC-DC converter operates continuously to maintain power supply, then reliability is improved, but energy loss increases due to internal resistance at low loads
Solution Approach 1:
Instead of operating all transformation coils continuously, the system activates only the necessary number of coils based on current power demands. This partial action approach maintains sufficient power supply reliability while significantly reducing energy losses from internal resistance that would occur if all coils remained active at low load conditions.
Solution Approach 2:
The system changes operational parameters by adjusting the number of active coils based on temperature, current, and power level thresholds. This parameter adaptation allows the converter to maintain reliability across different operating conditions while minimizing energy losses through optimized coil configuration.
3Productivity
If the charger operates at high power levels to meet demand, then productivity is improved, but temperature increases leading to reduced efficiency
Solution Approach 1:
The system employs periodic monitoring and adjustment of operating parameters, switching between different coil configurations based on temperature and power level thresholds. This periodic adaptation allows the charger to maintain high productivity when conditions permit while preventing excessive temperature buildup through timely reconfiguration.
Solution Approach 2:
The control unit continuously monitors temperature, current, and power level parameters, using this feedback to dynamically adjust the number of active transformation coils. This feedback mechanism ensures that productivity is maximized within safe thermal limits, automatically reducing active coils when temperature thresholds are approached.
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 method improves the charger's efficiency across the entire operating range by dynamically adjusting the number of active coils and resonant frequency, reducing heat generation and internal resistance, and maintaining optimal power transmission.
Implementation Method 1
All active primary side transformation coils generate an electromagnetic field if a current in the form of an AC current flows through them. The electromagnetic field induces an AC current in the secondary side transformation coil arranged alongside.
Implementation Method 2
A resonant frequency of the DC-DC converter is influenced by the number of active primary side transformation coils.
Data Source
AI summary
A method is provided for operating a DC-DC converter (22) of a charger (20). The DC-DC converter has on a primary side a first transformation coil (28) and at least one second transformation coil (30) that are arranged in series one behind another and also alongside a secondary side transformation coil (48). A respective semiconductor switch is connected in parallel with the at least one second primary side transformation coil (30). The at least one second primary side transformation coil (30) is switched either on or off by the semiconductor switch depending on a present value of at least one operating parameter of the charger (20).