Solid State Relay Module With Integrated Overcurrent Shutdown
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Solution Overview
Problem
Mechanical contactors used in high voltage applications are slow and have a limited lifespan, leading to mechanical or electrical failures and increased warranty costs, whereas traditional solid state relays often require dedicated bypass relays and resistors for overcurrent protection.
Innovation Solution
A solid state relay module with shunt and desaturation overcurrent detection circuits, utilizing MOSFETs for fast and reliable switching, eliminates the need for dedicated bypass relays and resistors by quickly turning off during overcurrent conditions, employing pulsed energy to pre-charge capacitive loads and protect against high peak currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If mechanical contactors are used for high voltage switching, then the device can handle high voltage applications, but the response speed is slow and the lifespan is limited due to mechanical wear
Solution Approach 1:
The patent replaces mechanical contactors with solid state electronic switches (MOSFETs or IGBTs) that have no moving parts. The electronic switch is controlled by a drive circuit that receives commands from a controller, eliminating mechanical wear and significantly improving both response speed and operational lifespan while maintaining high voltage switching capability.
Solution Approach 2:
The solid state relay module incorporates built-in overcurrent protection through shunt detection circuitry and desaturation detection that automatically monitor and protect the electronic switch without external intervention. The system self-detects fault conditions and self-protects by shutting down the electronic switch when overcurrent is detected, eliminating the need for external protective devices.
2Reliability
If traditional solid state relays are used, then the response time is fast and reliability is improved, but dedicated bypass relays and resistors are required for overcurrent protection
Solution Approach 1:
The patent combines the solid state relay functionality with integrated overcurrent protection circuitry into a single unified device. The shunt detection circuit and desaturation detection circuit are integrated within the relay module itself, merging the protective functions that were previously separate components into the main relay unit, thereby reducing overall system complexity.
Solution Approach 2:
The electronic switch serves multiple functions: it performs the primary voltage switching operation and simultaneously provides overcurrent protection through its integrated detection circuits. The drive circuit not only controls the electronic switch but also works in conjunction with the detection circuits to provide comprehensive protection, making the device multi-functional and reducing the need for separate protective components.
3Device complexity
If mechanical contactors are used, then the structure is simple, but the device generates mechanical wear and electrical failures
Solution Approach 1:
The patent replaces the mechanical contactor structure with a solid state electronic switch that uses semiconductor physics rather than mechanical contact. The electronic switch is controlled by electrical signals from the drive circuit, eliminating all mechanical moving parts, contacts, and springs that cause wear and failure in traditional contactors.
Solution Approach 2:
The integrated detection circuits continuously monitor the operational status of the electronic switch and automatically detect fault conditions such as overcurrent and desaturation. The system provides self-diagnosis and self-protection by shutting down the electronic switch when faults are detected, eliminating the need for external protective relays or switches.
Data Source
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AI summary
A solid state relay module (100) includes a first electronic switch (106) configured to establish and break an electrical connection between a first voltage inputs and outputs. The module (100) has a drive circuit (112) connected to the first electronic switch (106) configured to turn the first electronic switch (106) on and off due to commands from an electronic controller (110). The module (100) has a shunt overcurrent detection (OCD) circuit (202) and a desaturation OCD circuit (204) in communication with the electronic controller (110). The electronic controller (100) is configured to command the drive circuit (112) to turn off the first electronic switch (106) when the shunt OCD or the desaturation OCD circuits (202, 204) detect an overcurrent condition.