Safety Switching Device for High-Voltage Battery Heating
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Solution Overview
Problem
High-voltage batteries in electric vehicles face reduced drive and charging power at low temperatures due to decreased battery performance, and existing heating solutions lack safety features to prevent overheating and overvoltage transmission.
Innovation Solution
A safety switching device with a controllable switching element and disconnection apparatus is used to control the heating current and isolate the high-voltage battery from the low-voltage on-board power supply, ensuring safe heating of battery cells by interrupting the heating current in case of faults and preventing overvoltage transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a heating unit is connected directly to the power supply terminal without safety switching device, then the heating procedure is simple and device complexity is reduced, but the reliability is worsened due to risk of overheating and overvoltage transmission
Solution Approach 1:
The patent introduces a safety switching device as an intermediary component between the power supply terminal and the heating unit. This device includes controllable switching elements and disconnection apparatus that mediate the power transmission, enabling safe heating control while isolating faults. The intermediary structure allows the system to maintain reliability without requiring complete redesign of the heating system.
Solution Approach 2:
The heating control system is segmented into distinct functional modules: controllable switching elements for normal operation, disconnection apparatus for fault isolation, and transmission apparatus for signal isolation. This segmentation allows each component to perform its specific safety function independently, improving overall reliability while keeping the added complexity manageable through modular design.
2Object-affected harmful factors
If galvanic isolation is implemented between high-voltage battery and low-voltage on-board power supply, then overvoltage transmission is prevented, but the signal transmission complexity increases
Solution Approach 1:
The transmission apparatus acts as an intermediary for signal transmission between the high-voltage battery control and low-voltage on-board power supply. It provides galvanic isolation through optical or magnetic coupling, preventing overvoltage transmission while maintaining controlled signal transmission. This mediator approach protects against harmful voltage transmission without requiring direct electrical connection.
Solution Approach 2:
The patent replaces direct electrical (mechanical) connection with optical or magnetic coupling in the transmission apparatus. This substitution eliminates galvanic isolation requirements while maintaining signal transmission capability, reducing the complexity associated with galvanic isolation design and implementing overvoltage protection more elegantly.
3Manufacturing precision
If controllable switching elements are used to control heating current, then heating control precision is improved, but the risk of switching element failure and overheating increases
Solution Approach 1:
The disconnection apparatus is configured to detect switching element failure conditions and automatically disconnect the heating unit before overheating can occur. This preliminary action prevents the harmful effect of overheating by anticipating potential switching element failure and taking preventive disconnection action.
Solution Approach 2:
The system implements feedback monitoring of the controllable switching elements to detect abnormal conditions such as failure states. When faults are detected, the feedback signal triggers the disconnection apparatus to interrupt heating current, preventing overheating. This feedback mechanism allows precise heating control while mitigating the risks associated with switching element failure.
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
The safety switching device provides a safe and controlled heating procedure for high-voltage battery cells, preventing overheating and overvoltage transmission, thus ensuring reliable drive and charging performance even at low temperatures.
Implementation Method 1
a heating unit (6) for heating at least one battery cell (5) of the high-voltage battery (3)
Implementation Method 2
a transmission apparatus (18) arranged in the signal transmission path (14), that is designed to transmit the control signal without potential to the first switching element (9) in order to galvanically isolate the high-voltage battery (3) and the apparatus (15)
Data Source
AI summary
A safety switch device connects a heating unit for at least one battery cell of a high-voltage battery of a motor vehicle to a power supply connection that provides a heating current for the heating unit. The device includes: a first controllable switching element arranged in a heating current transmission path, which is designed to receive a control signal supplied by a unit external to the high-voltage battery via a signal transmission path of the safety switch device and to generate heating current transmission between the heating unit and the power supply connection according to the received control signal; a separating unit arranged in the heating current transmission path, for interrupting the heating current transmission in the event of failure of the first switching element; and a transmission unit arranged in the signal transmission path, which is designed to transmit the control signal potential-free to the first switching element, for the galvanic separation of the high-voltage battery and the unit.