Multi-Switch Solid-State Assembly for Fast High-Current Turn-Off
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Solution Overview
Problem
Existing high-voltage, high-current electromechanical relays are bulky, slow, prone to contact welding, and noisy, while solid-state switches struggle with high energy absorption during turn-off under shorted or overload conditions, necessitating a lightweight, fast, reliable, and compact solution for efficient bidirectional control.
Innovation Solution
An electronic solid-state switch assembly featuring a base plate with a heat exchanger, insulating layer, power transistors, gate drivers, a communication interface, current sensor, and snubber circuit, controlled by a controller, which includes a heat sink and liquid-cooled base for thermal management, and uses power transistors like Si IGBT, SiC JFET, or GaN FETs arranged in parallel for scalable current ratings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If electromechanical relays are used for high-voltage high-current switching, then the switching capability is achieved, but the device becomes bulky and slow with contact welding issues
Solution Approach 1:
The patent replaces electromechanical relay contacts with solid-state power transistors (IGBTs, MOSFETs, or BJTs) that perform the switching function electronically without mechanical moving parts. This eliminates contact bounce and welding issues while achieving microsecond-level switching speeds, directly resolving the contradiction between switching speed and reliability.
Solution Approach 2:
The invention changes the fundamental operating parameters of the switching device by transitioning from mechanical contact-based switching to semiconductor-based switching. This parameter change enables switching speeds in the microsecond range (10-1000 times faster than electromechanical relays) while eliminating contact welding through the solid-state nature of the transistors.
2Speed
If solid-state switches are used for high energy absorption during turn-off, then switching speed improves, but the device requires complex protection circuits and high power consumption
Solution Approach 1:
The patent incorporates snubber circuits (RC networks) and clamp circuits that are pre-configured to absorb and dissipate the high energy spikes generated during transistor turn-off. These protection circuits are designed beforehand to handle the voltage and current transients, preventing damage to the power transistors while keeping gate driver power consumption low through efficient energy management.
Solution Approach 2:
The invention uses clamp diodes and snubber circuits as intermediary elements between the power transistors and the load. These intermediaries absorb the high energy during turn-off transients, protecting the solid-state switches from voltage spikes and current surges, thereby enabling fast switching without requiring excessive gate driver power.
3Adaptability or versatility
If bidirectional control is implemented for fault tolerant applications, then control versatility improves, but the device complexity increases
Solution Approach 1:
The patent implements bidirectional control capability in the gate driver circuits, allowing them to control power transistors in both forward and reverse directions. This multi-functionality enables the same hardware to handle both charging and discharging modes, as well as normal operation and fault protection, without requiring separate dedicated circuits for each function, thereby managing complexity while enhancing versatility.
Solution Approach 2:
The invention employs dynamically controllable gate driver circuits that can adapt their control parameters based on operating conditions. The bidirectional control is achieved through dynamic switching of control signals, allowing the system to flexibly respond to different operational modes (charging/discharging) and fault conditions, managing complexity through adaptive control rather than fixed dedicated circuits.
4Weight of stationary object
If compact heat management is implemented, then device size reduces, but thermal dissipation capability may be compromised
Solution Approach 1:
The patent incorporates liquid cooling systems with coolant channels integrated into the heat sink structure. The liquid coolant flows through these channels to actively remove heat from the power transistor mounting area, enabling effective thermal dissipation in a compact package. This hydraulic cooling approach allows significant weight reduction compared to air-cooled systems while maintaining adequate thermal management.
Solution Approach 2:
The invention uses thermally conductive materials with high thermal conductivity (such as copper or aluminum alloys) for the heat sink and mounting structures. These materials efficiently conduct heat away from the power transistors to the cooling surfaces, enabling compact design with effective thermal dissipation by maximizing heat transfer per unit volume and weight.
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 provides fast switching speeds, reliable operation, quiet performance, and efficient current handling with low voltage drop, capable of managing high currents and temperatures, while being compact and lightweight, suitable for high-voltage applications like electrified powertrain operation.
Implementation Method 1
a heat sink portion and a liquid cooled base, and the heat sink portion being thermally coupled to the base plate
Implementation Method 2
liquid cooled base
Data Source
AI summary
An electronic solid-state switch assembly includes a base plate and a heat exchanger; an electrically insulating layer and a direct bonded substrate affixed to the base plate; a first terminal and a second terminal; a plurality of power transistors; a plurality of gate drivers; a communication interface, a current sensor, and a snubber circuit; and a controller. The plurality of gate drivers are operatively coupled to the plurality of power transistors. The plurality of power transistors are arranged in parallel on the direct bonded substrate between the first terminal and the second terminal. The plurality of power transistors are electrically connected to the first terminal and to the second terminal. The controller is in communication with the plurality of gate drivers, the current sensor, and the communication interface. The controller is configured to control, via the plurality of gate drivers, the plurality of power transistors.