Solid State Fuse Control for Predictable EV Fault Isolation
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Solution Overview
Problem
Conventional fuses in electric vehicles have variable and often slow response times to high current faults, leading to unreliable protection and the need for physical replacement, which can result in catastrophic failures and downtime.
Innovation Solution
A solid state fuse system that includes a power switch, a DC-DC converter, sensors, and a fuse controller to selectively open the power switch based on sensed voltage and current ripple thresholds, providing predictable response times and enabling pulse width modulation for fault management without physical replacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional fuse is used to protect against high current faults, then the system structure remains simple, but the response time is slow and variable leading to unreliable protection
Solution Approach 1:
The patent replaces the mechanical fuse system with an electronic solid state fuse system. The solid state fuse uses electronic components (power switch, controller, sensors) to detect and respond to fault conditions, eliminating the mechanical melting process of conventional fuses. This substitution enables predictable response times and reliable protection while maintaining system simplicity.
2Reliability
If a conventional fuse blows to protect the system, then fault protection is achieved, but the vehicle cannot be driven until the fuse is physically replaced
Solution Approach 1:
The patent implements a recoverable protection mechanism where the solid state fuse can be reset after a fault condition is cleared. The controller monitors fault conditions and can reclose the power switch once conditions normalize, allowing the vehicle to continue operation without physical fuse replacement. This enables 'limp home mode' functionality where the vehicle can be driven to a service location.
Solution Approach 2:
The solid state fuse system provides self-diagnosis and self-recovery capabilities. The controller automatically detects fault conditions, opens the power switch for protection, and can automatically reclose the switch when fault conditions are resolved, without requiring external intervention or physical replacement. The system serves itself through automated monitoring and control.
3Reliability
If a solid state fuse with complex control circuitry is implemented, then predictable response times and reliable protection are achieved, but the device complexity increases
Solution Approach 1:
The solid state fuse controller performs multiple functions: fault detection, power switch control, system monitoring, and communication. By consolidating these functions into a single controller unit, the patent achieves predictable response times and reliable protection while managing device complexity through functional integration rather than proliferation of separate components.
Solution Approach 2:
The patent combines the fuse control functionality with existing power control system components. The solid state fuse controller integrates with the power inverter control architecture, sharing sensors, processors, and communication interfaces. This merging approach enables reliable fault protection without adding significant complexity to the overall system.
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 solid state fuse system provides reliable and predictable fault management, reducing the risk of catastrophic failures and eliminating the need for physical replacement, while enabling a limp home mode to maintain vehicle functionality during faults.
Implementation Method 1
A DC-DC converter is configured to convert a first voltage output by the RESS of the electric vehicle to a second voltage
Implementation Method 2
One or more sensors configured to sense one or more operating parameters of the RESS
Data Source
AI summary
A power control system includes a power inverter comprising a first side, a second side, and a plurality of power switches. The second side is configured to connect to an electric machine. A solid state fuse includes a power switch including a first terminal in communication with the first terminal of a rechargeable energy storage system (RESS) of the electric vehicle and a second terminal in communication with the first side of the power inverter. A DC-DC converter is configured to convert a first voltage output by the RESS of the electric vehicle to a second voltage. One or more sensors configured to sense one or more operating parameters of the RESS. A fuse controller is configured to receive power from the DC-DC converter, to communicate with the one or more sensors and to cause the power switch to selectively change state in response to changes in the one or more operating parameters.