IGBT Gate Capacitance Control for High-Temperature Switching Loss
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Solution Overview
Problem
There is a trade-off relationship between radiation noise and loss in switching elements like IGBTs, with recovery voltage change rate decreasing at higher temperatures, leading to increased loss without a corresponding increase in radiation noise.
Innovation Solution
A semiconductor device with a capacitance adjustment unit that adjusts the capacitance between the gate and emitter of the switching element based on temperature detection, using a temperature detection element and a capacitance adjustment unit to manage capacitance according to detected temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the recovery voltage change rate is increased to reduce radiation noise, then radiation noise is suppressed, but loss in the switching element increases
Solution Approach 1:
The patent applies dynamics by making the capacitance value adjustable based on operating conditions. The capacitance adjustment unit dynamically changes the capacitance value in response to temperature changes or switching frequency variations, allowing the system to optimize the balance between radiation noise suppression and loss reduction under different operating conditions
Solution Approach 2:
The patent applies parameter changes by modifying the capacitance value as a key parameter. The capacitance adjustment unit changes the capacitance value according to temperature or switching frequency, thereby adjusting the recovery voltage change rate to achieve optimal performance across different operating conditions
2Object-affected harmful factors
If a fixed capacitance value is used to suppress radiation noise at room temperature, then radiation noise is reduced, but loss increases at high temperature
Solution Approach 1:
The patent transforms the fixed capacitance system into a dynamic one by introducing temperature detection and capacitance adjustment mechanisms. The system automatically adapts the capacitance value based on real-time temperature measurements, ensuring optimal performance across the full operating temperature range
Solution Approach 2:
The patent implements feedback control by using the temperature detection element to monitor operating conditions and feed this information to the capacitance adjustment unit, which then adjusts the capacitance value accordingly. This closed-loop control ensures the system maintains optimal balance between noise suppression and loss reduction
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
Suppresses loss in switching elements at high temperature without increasing radiation noise.
Implementation Method 1
IGBT modules and IPMs use negative temperature characteristics of the diode to detect whether the IGBT chip is overheating or not
Data Source
AI summary
An object of the present invention is to provide a semiconductor device capable of suppressing loss in a switching element at high temperature without increasing radiation noise of the switching element. A semiconductor device includes an IGBT including a gate to which a gate signal is input, a temperature detection element that detects temperature of the IGBT, and a capacitance adjustment unit that is arranged between the gate of the IGBT and a reference potential terminal and that adjusts a capacitance between the gate and an emitter of the IGBT according to a detection temperature detected by the temperature detection element.