IGBT with Integrated Overvoltage and Temperature Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Transistor devices, particularly IGBTs, are prone to damage from overcurrent, overvoltage, and overtemperature conditions in induction heating applications, leading to system failures and inefficiencies due to the lack of effective integrated protection mechanisms.
Innovation Solution
Integration of an overvoltage protection circuit, current limiter circuit, and temperature sensor with the IGBT, which monitors the junction temperature and regulates the voltage across the load path to prevent damage by clamping the voltage below the breakdown voltage and limiting peak currents, thereby protecting the transistor from excessive conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If transistor devices are used in induction heating applications without integrated protection mechanisms, then device complexity is reduced, but reliability deteriorates due to susceptibility to overcurrent, overvoltage, and overtemperature damage
Solution Approach 1:
The patent integrates overvoltage protection, current limiting, and temperature monitoring circuits directly into the transistor device structure. The protection circuit shares common elements with the main transistor, such as using the collector-emitter path for both power transmission and protection functions, and integrating temperature sensors within the device package rather than as separate external components.
Solution Approach 2:
The transistor device is designed to perform multiple functions simultaneously: it acts as the main power switching element while also serving as the platform for integrated protection functions. The same physical structure supports both high-power transmission and sensitive protection measurements, eliminating the need for separate dedicated protection devices.
2Reliability
If integrated protection mechanisms are added to transistor devices, then reliability is improved, but device complexity increases
Solution Approach 1:
The protection circuits are nested within the transistor device structure, with temperature sensors positioned inside or adjacent to the power semiconductor die, and protection circuitry integrated into the same package. This nested arrangement allows the protection functions to be embedded within the existing device footprint rather than adding external complexity.
3Reliability
If voltage regulation is implemented to clamp voltage below breakdown level, then transistor protection is improved, but energy loss increases due to continuous voltage regulation
Solution Approach 1:
The overvoltage protection operates periodically rather than continuously. The circuit monitors voltage conditions and activates clamping only when overvoltage events are detected, allowing the transistor to operate in its normal high-efficiency mode during standard operation. The protection engages in discrete intervals when needed rather than maintaining constant regulation.
4Reliability
If current limiting is implemented to prevent overcurrent damage, then transistor reliability is improved, but productivity decreases due to restricted current flow
Solution Approach 1:
The current limiting function dynamically adjusts its characteristics based on operating conditions. The protection circuit allows high current flow during normal operation to maintain productivity, while automatically limiting current only when overcurrent conditions are detected. The limiting threshold and response are adaptive rather than fixed, optimizing both performance and protection.
Data Source
AI summary
In accordance with an embodiment, a method of operating a transistor includes: switching the transistor on and off based on a control signal; monitoring a voltage of a collector node of the transistor; detecting whether the voltage of the collector node of the transistor is above a first threshold; and after detecting the voltage of the collector node of the transistor above the first threshold, regulating a voltage across a load path of the transistor to a first target voltage.