EV Contactor Control Apparatus Voltage Time Counter
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing contactor control systems for electric vehicles cannot safely operate when an auxiliary battery with a higher rated voltage is connected, leading to excessive heat generation and potential damage to the contactor coils, and they often stop the vehicle due to voltage fluctuations, even with suitable batteries.
Innovation Solution
A contactor control apparatus that uses a controller to count and manage counter values based on reference voltages and time limits, ensuring the contactors remain conductive until a voltage-applicable time limit is reached and then set to a non-conductive state to prevent overheating, using timers to increment or reset counter values when voltage thresholds are exceeded or lowered.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the auxiliary battery voltage is monitored and contactors are immediately disconnected when voltage exceeds the reference value, then the contactor coil is protected from excessive heat generation, but the vehicle operation is unnecessarily interrupted even when the high voltage condition is temporary
Solution Approach 1:
The control system dynamically adjusts the response to voltage deviations by introducing a time-based counter mechanism. When voltage exceeds the reference value, the system counts the duration of the deviation and only triggers disconnection after a predetermined time threshold is reached. This dynamic approach allows temporary voltage fluctuations without unnecessary shutdowns while still protecting against sustained overvoltage conditions.
Solution Approach 2:
The system performs preliminary monitoring and counting of the voltage deviation duration before taking the protective action of disconnecting the contactor. By counting the time duration first and comparing it against a predetermined threshold, the system prepares for disconnection only when necessary, avoiding premature interruption of vehicle operation while ensuring protection when the high voltage condition persists.
2Productivity
If the contactor is allowed to remain conductive longer when voltage exceeds the reference value, then vehicle operation continuity is maintained, but the contactor coil is at risk of excessive heat generation and damage
Solution Approach 1:
The system continuously monitors the voltage condition and uses feedback from the counter mechanism to determine when to disconnect the contactor. The counter provides feedback on the duration of voltage deviation, and when this feedback exceeds the predetermined time threshold, the system triggers disconnection. This feedback loop ensures the contactor remains conductive only as long as safe, while automatically protecting against excessive heat generation when the duration limit is reached.
3Device complexity
If a simple voltage threshold comparison is used for control, then the control system is simple, but it cannot distinguish between temporary and sustained high voltage conditions
Solution Approach 1:
The system adds a time dimension to the voltage control decision-making process. Instead of making disconnection decisions based solely on voltage magnitude (one dimension), the system incorporates time duration as an additional dimension through the counter mechanism. This dimensional expansion allows the system to distinguish between temporary and sustained high voltage conditions while maintaining relatively simple control logic.
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 effectively prevents excessive heat generation and reduces vehicle stoppages by maintaining contactor conductivity until the voltage limit is exceeded, then safely disconnecting to prevent damage, thereby enhancing operational reliability and reducing unnecessary vehicle shutdowns.
Implementation Method 1
the controller counts a first counter value when a control voltage for controlling each contactor is higher than a first reference voltage, and holds the first counter value when the control voltage is lower than or equal to the first reference voltage
Data Source
AI summary
A contactor control apparatus is provided for controlling contactors connected to a battery assembly. A contactor control apparatus includes a controller for turning on and off a first contactor connected to one end of a battery assembly having at least one secondary battery connected in series and a second contactor connected to another end of the battery assembly. The controller counts a first counter value when a control voltage for controlling each contactor is higher than a first reference voltage, and holds the first counter value when the control voltage is lower than or equal to the first reference voltage. The controller turns off at least one of the first contactor and the second contactor when the first counter value is equal to or higher than a first threshold value.