Pyrotechnic Network Shutdown for Fault-Independent Isolation
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Solution Overview
Problem
Existing shutdown devices for electrical energy storage systems in motor vehicles face challenges in reliably isolating the supply network from faults, particularly due to the varying current range and potential failure of control electronics, which can lead to incomplete separation during external short circuits.
Innovation Solution
A shutdown device with a pyrotechnic separating element, an ignition device, and a trigger control device that generates a trigger signal based on error events, ensuring independent triggering regardless of electrical conditions, using separate power converters for reliable operation and voltage detection to manage quiescent current optimization and fault responses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a high-current relay is used for overcurrent control, then galvanic isolation can be achieved at lower short-circuit currents, but the relay requires additional power supply and cannot operate when the on-board power supply is interrupted
Solution Approach 1:
The patent extracts the energy storage function from the power supply system by introducing a dedicated capacitor that stores energy independently. This extracted energy storage capability allows the pyrotechnic device to operate independently of the on-board power supply, eliminating power supply dependency while maintaining overcurrent protection capability
Solution Approach 2:
The system uses a simple capacitor and pyrotechnic separating element instead of a complex, expensive high-current relay. The capacitor charges during normal operation and provides a single-use discharge to trigger the pyrotechnic device when needed, offering a cost-effective solution that doesn't require continuous power supply
2Loss of energy
If the power supply to the shutdown device is completely switched off for quiescent current optimization, then energy consumption is reduced in normal operation, but the device cannot respond to faults when in shutdown state
Solution Approach 1:
The capacitor is charged in advance during normal operation when the power supply is available. This preliminary energy storage ensures that when the power supply is switched off for quiescent current optimization, the capacitor still has sufficient energy to trigger the pyrotechnic separating element in response to faults, thus maintaining fault response capability while reducing energy consumption
Solution Approach 2:
The system operates in periodic cycles: during normal operation, the power supply charges the capacitor and the shutdown device monitors for faults; when switched off, the capacitor holds the energy ready for immediate fault response. This periodic charging and monitoring approach balances energy consumption with fault response capability
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
Ensures reliable and independent triggering of pyrotechnic separating elements across varying electrical conditions, maintaining safety and functionality even in fault scenarios, such as short-circuit-related voltage drops or power converter failures, allowing for comprehensive error detection and defined separation processes.
Implementation Method 1
at least one pyrotechnic separating element (5a, 5b) arranged in one or more of the supply lines (4a, 4b)
Implementation Method 2
an ignition device (6) which is designed to trigger the at least one pyrotechnic separating element (5a, 5b) in a defined manner depending on a trigger signal
Data Source
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AI summary
The invention relates to a switch-off device for a supply network (1), in particular for a supply network (1) of an electrical drive system of a motor vehicle, comprising: at least one pyrotechnic disconnecting element (5a, 5b) for arranging in one or more supply lines (4a, 4b) of the supply network (1); an igniting apparatus (6), which is designed to trigger the at least one pyrotechnic disconnecting element (5a, 5b) in accordance with a triggering signal; a triggering control unit (8), which is designed to generate the triggering signal in accordance with one or more failure events.