EV Charging System Current Sensor Failure Protection
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Solution Overview
Problem
Conventional vehicle charging systems face issues with motor rotation and potential vehicle driving due to current sensor failures during battery charging, leading to dangerous situations and motor burning.
Innovation Solution
A charging system with an inverter and controller configuration that detects abnormal current sensors, maintains switching duties according to a previous command, and linearly decreases switching duties to zero, ensuring battery charging stops and preventing motor torque generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the inverter is operated in boosting mode to charge the battery, then the charging system can charge batteries of various specifications, but if a current sensor fails, the motor rotates causing vehicle driving and potential motor burning
Solution Approach 1:
The controller performs preliminary detection of current sensor status before the motor rotation issue occurs. When a current sensor failure is detected during battery charging, the controller proactively determines the inductance value using voltage and current data from other functional sensors, and stops the inverter operation before motor rotation can cause vehicle driving or motor burning.
Solution Approach 2:
The system continuously monitors current sensor outputs during charging operation. When an abnormal value is detected, the controller receives feedback about the sensor failure, calculates the inductance value using available data, and adjusts the inverter switching duty accordingly to prevent motor rotation while maintaining safe charging operation.
2Reliability
If the inverter switching duty is abruptly stopped upon current sensor failure, then motor rotation is prevented, but the charging process is interrupted
Solution Approach 1:
Instead of abruptly stopping the charging process, the controller changes the switching duty parameter of the inverter based on the calculated inductance value. By adjusting the switching duty to an appropriate level that prevents motor rotation while maintaining power flow, the system continues charging operation safely without complete interruption.
Solution Approach 2:
The controller applies partial action by maintaining inverter operation at a reduced switching duty level rather than complete shutdown. This partial operation is sufficient to prevent motor rotation while still allowing charging to continue, thus maintaining productivity while ensuring safety.
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
Prevents vehicle driving and motor burning by stopping battery charging upon current sensor failure, maintaining system stability and safety.
Implementation Method 1
an inverter which is mounted between the motor and the battery and configured to control a flow of a current between the motor and the battery
Implementation Method 2
controller which is connected to the inverter and configured to control a switching duty of the inverter according to a previous duty command transmitted to the inverter just before an abnormal current sensor occurs, and then linearly decreases the switching duty of the inverter to reach zero
Implementation Method 3
current sensors, which are connected to the inverter and detect the amount of the current applied to a three-phase coils of the motor
Implementation Method 4
When the imbalance of the current applied to the three-phase coils 131, 132, 133 occurs, the inductance value of the three-phase coils 131, 132, 133 is changed by the magnetic flux of a permanent magnet of a motor rotor, and as a result, the motor 130 rotates
Data Source
AI summary
A charging system for a vehicle and a battery charging stop method thereof may provide a charging system for a vehicle and a battery charging stop method thereof, which may stop the charging of a battery upon failure of a current sensor applied to a three-phase coils of a motor configured for driving a vehicle, preventing the occurrence of the torque caused by operation of the motor.