Semiconductor Device Switching Loss Reduction via Local Quality
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor devices in power conversion apparatuses face challenges in reducing switching losses, particularly when the lower-arm switching element's switching speed is increased to match or exceed that of the upper-arm switching element, leading to insufficient improvement in overall loss reduction.
Innovation Solution
The semiconductor device employs a configuration where the first semiconductor element has a lower switching loss and the second semiconductor element has a lower conduction loss, with specific semiconductor elements like N-channel type MOSFETs and IGBTs used in series, along with freewheeling diodes, to optimize switching and conduction losses in the upper and lower arms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the lower-arm switching element uses a faster switching speed semiconductor element (e.g., wide band gap semiconductor), then the switching speed is improved, but the switching loss when turning-on is not sufficiently reduced
Solution Approach 1:
The patent applies different semiconductor element types to different positions in the circuit: N-channel MOSFETs (with low switching loss) are used for upper-arm switching elements, while IGBTs (with low conduction loss) are used for lower-arm switching elements. This local differentiation of component characteristics resolves the contradiction by optimizing each position for its specific functional requirements rather than using a uniform high-speed semiconductor throughout.
Solution Approach 2:
The patent changes the key parameter of semiconductor element type between upper and lower arms. By selecting MOSFETs for upper arms and IGBTs for lower arms, the patent optimizes the switching loss parameter for upper arms and conduction loss parameter for lower arms, thereby resolving the contradiction between switching speed and switching loss through parameter optimization at different locations.
2Speed
If the lower-arm switching element uses a faster switching speed semiconductor element, then the switching speed is improved, but the total loss is not sufficiently reduced
Solution Approach 1:
The patent applies different semiconductor element types to different positions in the circuit: N-channel MOSFETs (with low switching loss) are used for upper-arm switching elements, while IGBTs (with low conduction loss) are used for lower-arm switching elements. This local differentiation of component characteristics resolves the contradiction by optimizing each position for its specific functional requirements rather than using a uniform high-speed semiconductor throughout.
Solution Approach 2:
The patent changes the key parameter of semiconductor element type between upper and lower arms. By selecting MOSFETs for upper arms and IGBTs for lower arms, the patent optimizes the switching loss parameter for upper arms and conduction loss parameter for lower arms, thereby resolving the contradiction between switching speed and switching loss through parameter optimization at different locations.
3Speed
If the lower-arm switching element uses a faster switching speed semiconductor element, then the switching speed is improved, but the switching loss when turning-on of the lower-arm element increases
Solution Approach 1:
The patent applies different semiconductor element types to different positions in the circuit: N-channel MOSFETs (with low switching loss) are used for upper-arm switching elements, while IGBTs (with low conduction loss) are used for lower-arm switching elements. This local differentiation of component characteristics resolves the contradiction by optimizing each position for its specific functional requirements rather than using a uniform high-speed semiconductor throughout.
Solution Approach 2:
The patent changes the key parameter of semiconductor element type between upper and lower arms. By selecting MOSFETs for upper arms and IGBTs for lower arms, the patent optimizes the switching loss parameter for upper arms and conduction loss parameter for lower arms, thereby resolving the contradiction between switching speed and switching loss through parameter optimization at different locations.
Data Source
AI summary
There is provided a semiconductor device capable of decreasing a switching loss. The semiconductor device has first semiconductor elements (Su)-(Sw) and second semiconductor elements (Sx)-(Sz) connected in series, in which the first semiconductor element includes a low switching loss semiconductor element having a switching loss which is smaller than a switching loss of the second semiconductor element and the second semiconductor element includes a low conduction loss semiconductor element having a conduction loss which is smaller than a conduction loss of the first semiconductor element.