Vehicle Charging Circuit Switching for Leakage Current Control
Solution Overview
Problem
The increase in Y-capacitor capacity in vehicle charging systems leads to higher leakage currents, which can cause erroneous detection of abnormalities and disrupt charging processes.
Innovation Solution
A vehicle charging system with a control device that selectively connects only the minimum number of charging circuits necessary to handle the maximum current value detected, using a switching system and detection circuit to manage the connection state between charging circuits and the inlet, thereby restricting leakage current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If Y-capacitors are provided in chargers to filter common mode noise, then noise filtering capability is improved, but leakage current increases
Solution Approach 1:
The patent extracts the Y-capacitor from the charger circuit and places it in the power supply facility instead. This separation maintains the noise filtering function while eliminating the leakage current issue that would occur if multiple Y-capacitors were installed in each charger. The single Y-capacitor in the power supply facility provides sufficient common mode noise filtering without the cumulative leakage current problem.
2Power
If multiple charging circuits are connected in parallel to secure charging power, then charging capacity is improved, but leakage current increases
Solution Approach 1:
The patent introduces a switching system as an intermediary between the power supply facility and multiple charging circuits. The switching system selectively connects only the necessary number of charging circuits based on detected power requirements, preventing all charging circuits from being simultaneously connected. This reduces the cumulative leakage current while maintaining sufficient charging capacity through selective parallel connection.
3Power
If all charging circuits are electrically connected to the inlet, then charging capacity is maximized, but leakage current increases and causes erroneous abnormality detection
Solution Approach 1:
The patent implements a dynamic connection configuration where the number of charging circuits electrically connected to the inlet is adjusted based on detected power requirements. The switching system dynamically connects or disconnects charging circuits, creating a variable configuration rather than a fixed all-or-nothing connection. This dynamic approach maintains charging capacity while preventing excessive leakage current that would cause erroneous abnormality detection.
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 effectively reduces leakage current, preventing erroneous abnormality detection and ensuring stable charging operations even with Y-capacitors in the system.
Implementation Method 1
A Y-capacitor may be connected between each of two power lines and the ground to filter out common mode noise transmitted in the same direction as current on the two power lines connected to a charger
Implementation Method 2
a detection circuit configured to detect a maximum current value of charging power supplied from the outside
Implementation Method 3
a switching system configured to switch between states where each of the charging circuits and the inlet are electrically connected and disconnected
Data Source
AI summary
A vehicle includes an inlet connected to a connector, a power accumulation device that accumulates power, two or more charging circuits that convert power from the inlet into direct current power having a predetermined voltage adapted for the power accumulation device, a switching system that switches between states where each of the charging circuits and the inlet are electrically connected and disconnected, a control device that controls the switching system, and a detection circuit that detects a maximum current value of charging power supplied from the outside. The control device controls the switching system such that the minimum number of charging circuits that can convert power having the maximum current value detected by the detection circuit is in a state of being electrically connected to the inlet.