On-Board Charger Converter Control for High-Voltage EV Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing on-board chargers for electric and hybrid vehicles face challenges with high voltage requirements, leading to increased costs, bulkiness, and efficiency losses due to heating, which necessitate the use of expensive and bulky components and additional cooling devices.
Innovation Solution
The electric system incorporates a DC-DC voltage converter with a first and second H-bridge, each with four switches, and a transformer, controlled by a microcontroller that transitions between two operating modes to manage power variations, thereby reducing voltage stress on components and minimizing heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If the on-board charger is designed to withstand high voltages (400-800 V), then the voltage handling capability is improved, but the cost and size of components (especially the link capacitor) increase significantly
Solution Approach 1:
The patent implements dynamic voltage management by transitioning the DC-DC converter between two operating modes: a first mode for normal operation and a second mode for overvoltage protection. This dynamic switching allows the system to adapt to varying voltage conditions, enabling the use of smaller, less expensive capacitors that don't need to be continuously rated for maximum voltage while still providing adequate protection against voltage spikes and transients.
Solution Approach 2:
The system changes operational parameters by switching between different converter modes based on voltage conditions. The microcontroller monitors voltage levels and adjusts the converter's operating state accordingly, changing parameters such as switching frequency and duty cycle to maintain safe operation without requiring all components to be designed for maximum voltage stress.
2Power
If the on-board charger operates at high voltages above 600 V, then the power conversion capability is improved, but heating occurs causing efficiency loss of 1-3% and requiring additional cooling devices
Solution Approach 1:
The patent employs dynamic operating mode switching to manage thermal conditions. By transitioning between the first operating mode (normal power conversion) and the second operating mode (overvoltage protection), the system dynamically adjusts power handling to prevent excessive heating while maintaining conversion capability when conditions permit.
Solution Approach 2:
The microcontroller periodically monitors voltage levels and switches between operating modes based on detected conditions. This periodic monitoring and switching creates a rhythm of operation that prevents sustained high-voltage operation that would cause excessive heating, while still allowing high power conversion when voltage conditions are favorable.
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 solution allows for more responsive power management, reduces the risk of overvoltage and overheating, and maintains efficiency by quickly adapting to power demand variations without significant voltage fluctuations, thus protecting electronic components and improving overall system performance.
Implementation Method 1
a transformer electrically connecting the first H-bridge and the second H-bridge
Data Source
AI summary
This relates to an electric system for a motor vehicle, the vehicle including at least one power supply battery, the electric system including an electric charger intended to be connected, on the one hand, to the battery and, on the other hand, to an electric network outside the vehicle supplying an AC voltage or to electric equipment, and a microcontroller, the charger being able to charge the battery from an external electric network or to allow the battery to power the equipment, the charger including a power factor corrector circuit and a converter.