EV Charger PWM Control for Stable Battery Input Power
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Solution Overview
Problem
Existing charge control devices for electric vehicles extend the charging time of batteries due to power differences between supply and input, leading to decreased input power to the battery when in-vehicle devices are in use.
Innovation Solution
A charge control device with a controller that adjusts the in-vehicle charger's power conversion based on detected current differences between supply and input power, increasing the on-duty ratio to maintain consistent battery charging through PWM control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the in-vehicle charger converts external power to supply power for both battery and in-vehicle devices, then the in-vehicle devices can operate, but the input power to the battery decreases due to power difference between supply and input
Solution Approach 1:
The controller detects the difference between supply power and input power, and based on this feedback, adjusts the on-duty ratio of the PWM signal to the in-vehicle charger. This closed-loop feedback mechanism ensures that when in-vehicle devices consume power, the controller compensates by adjusting the charger's duty cycle to maintain consistent battery charging power.
Solution Approach 2:
The controller changes the on-duty ratio parameter of the PWM signal based on the detected power difference. By dynamically adjusting this parameter, the system optimizes the power conversion process to ensure that battery charging power remains stable even when in-vehicle devices are operating and consuming power.
2Productivity
If the supply power is insufficient due to power difference, then the charging time of the battery is extended
Solution Approach 1:
The controller continuously monitors the power difference between supply and input, and uses this feedback to dynamically adjust the PWM on-duty ratio. This ensures that the in-vehicle charger compensates for power consumed by in-vehicle devices, maintaining optimal charging speed and preventing charging time extension.
Solution Approach 2:
The system transitions from a static power conversion approach to a dynamic one where the on-duty ratio is continuously adjusted based on real-time power difference detection. This dynamic adjustment allows the charger to adapt to changing power demands and maintain efficient charging performance.
3Power
If the controller increases the on-duty ratio to compensate for power difference, then the input power to battery is maintained, but the in-vehicle charger operates at higher duty cycle
Solution Approach 1:
The controller implements a feedback mechanism that detects the power difference and automatically adjusts the PWM on-duty ratio accordingly. This automated feedback control simplifies the overall system complexity by using a straightforward detect-and-adjust approach rather than requiring complex multi-parameter optimization algorithms.
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 configuration suppresses the decrease in input power to the battery, thereby preventing the extension of charging time and ensuring efficient battery charging even when in-vehicle devices are in use.
Implementation Method 1
an in-vehicle charger configured to convert external power supplied from an external power source into supply power
Implementation Method 2
the controller increases the on-duty ratio when there is a difference between the supply power and the input power
Data Source
AI summary
A charge control device includes a controller configured to control an in-vehicle charger. The in-vehicle charger is configured to convert external power supplied from an external power source into supply power to provide the supply power to a battery and an in-vehicle device which are attached to an electric vehicle.