Parallel Semiconductor Switch Shutdown Using a Delay Circuit
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Solution Overview
Problem
Existing semiconductor switches in battery-electric vehicles face challenges in efficiently switching off during critical currents without the need for expensive suppressor circuits, which occupy space and weight, and mechanical safeguards have limited durability.
Innovation Solution
An electronic circuit with a delay circuit connected in parallel to semiconductor switches, absorbing a part of the critical current during the switching-off process, allowing simultaneous switching-off of multiple semiconductor switches, reducing circuit energy without a massive suppressor circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a suppressor circuit is used to reduce circuit energy during switching-off, then the semiconductor switches are protected from critical current, but the device complexity, cost, weight, and installation space increase significantly
Solution Approach 1:
The invention extracts only the essential function of the suppressor circuit (absorbing critical current during switching-off) and implements it through a simplified delay circuit with a capacitor and resistor, eliminating the need for complex electronic components while maintaining protection functionality
Solution Approach 2:
The delay circuit uses simple, inexpensive passive components (capacitor and resistor) that can be easily replaced or integrated, replacing expensive suppressor circuits with affordable components that achieve the same protective effect
2Reliability
If a suppressor circuit is used to absorb critical current, then the semiconductor switches are protected, but the weight and installation space increase
Solution Approach 1:
The invention changes the parameters of the circuit by introducing a delay element (capacitor-resistor network) that modifies the switching-off timing, allowing the semiconductor switches themselves to handle the critical current reduction without requiring additional heavy suppressor components
3Reliability
If semiconductor switches switch off simultaneously, then the critical current is distributed evenly, but the switching-off process remains highly dynamic and energy-intensive
Solution Approach 1:
The delay circuit performs a preliminary action by delaying the switching-off signal for a controlled period, allowing the critical current to be reduced before the semiconductor switches fully turn off, thereby reducing the energy loss during the switching process
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 solution enables cost-effective, space-efficient, and weight-reduced switching-off of semiconductor switches, utilizing robust semiconductors like SiC MOSFETs, while managing highly dynamic processes and extending their service life.
Implementation Method 1
a delay circuit, which is switched in parallel with the at least two semiconductor switches, and is configured to absorb, during a not-exactly-simultaneous switching-off of the at least two semiconductor switches, a part of the critical current
Data Source
AI summary
An electronic circuit for a battery-electric vehicle for the switching-off of semiconductor switches in the event of critical currents, the electronic circuit includes at least two semiconductor switches that are connectable in parallel with one another between an energy supply source and a load. The electronic circuit includes a control unit configured to detect a current flowing through the at least two semiconductor switches, and, based on reaching a critical current, to switch off the at least two semiconductor switches. The electronic circuit includes a delay circuit connected in parallel with the at least two semiconductor switches and is configured, in the event of a not-exactly-simultaneous switching-off of the at least two semiconductor switches, to absorb a part of the critical current that switches over from at least one first-switching-off semiconductor switch to another one of the at least two semiconductor switches.