SiC Oscillation Suppression Circuit with Parallel Capacitor
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Solution Overview
Problem
High-frequency voltage oscillations in SiC devices used in power conversion devices lead to increased switching losses, which hinder the utilization of low switching loss characteristics.
Innovation Solution
A semiconductor oscillation suppression circuit incorporating a wide-bandgap semiconductor element and a capacitor with a larger capacity than the junction capacitance, connected in parallel to suppress voltage oscillations with minimal loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If gate resistance of the SiC device is increased to suppress voltage oscillation, then voltage oscillation is suppressed, but switching loss increases
Solution Approach 1:
A capacitor is introduced as an intermediary component connected in parallel with the SiC device. This capacitor acts as a mediator that absorbs high-frequency voltage oscillations without requiring increased gate resistance, thereby suppressing voltage oscillation while maintaining low switching loss characteristics
Solution Approach 2:
The invention changes the electrical parameters of the circuit by adding a capacitor with specific capacitance value. This parameter change provides an alternative pathway for oscillation suppression that does not rely on increasing gate resistance, thus avoiding the trade-off between oscillation suppression and switching loss
2Loss of energy
If switching speed is maintained high in SiC devices, then low switching loss characteristics are achieved, but high-frequency voltage oscillation is generated
Solution Approach 1:
The capacitor serves as an intermediary that specifically targets and absorbs high-frequency voltage oscillations generated during fast switching operations. This allows the SiC device to maintain its high switching speed and low switching loss characteristics while the capacitor handles the oscillation suppression function
Solution Approach 2:
The invention segments the functions by separating oscillation suppression from the gate control mechanism. The capacitor is dedicated to absorbing oscillations, while the gate resistance can be kept low for fast switching, thus dividing the problem into independent functional components
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 effectively reduces voltage oscillations and switching losses in SiC devices, allowing for more efficient power conversion while maintaining low loss characteristics.
Implementation Method 1
a first capacitor connected to the first wide-bandgap semiconductor element in parallel and having a larger capacity than a junction capacitance of the first wide-bandgap semiconductor element
Data Source
AI summary
An object of the present invention is to provide a semiconductor oscillation suppression circuit capable of suppressing voltage oscillation of a switching element with low loss. A semiconductor oscillation suppression circuit includes a wide-bandgap semiconductor element and a capacitor connected to the wide-bandgap semiconductor element in parallel and having a larger capacity than a junction capacitance of the wide-bandgap semiconductor element.