Hybrid MOSFET-IGBT Topology for Zero-Voltage Power Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High voltage applications require devices with higher breakdown voltage, lower on-resistance, and lower switching losses, which existing IGBT devices and MOSFETs fail to achieve effectively, especially in high power applications like inverters and converters.
Innovation Solution
A hybrid power device configuration comprising a low voltage MOSFET, high voltage MOSFET, IGBT device, and diodes connected in series and parallel, with specific gate drive signal sequencing to achieve zero voltage turn-on and turn-off, reducing switching losses and on-resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If IGBT device is used for high voltage applications, then breakdown voltage is improved, but switching speed deteriorates
Solution Approach 1:
The patent divides the switching function into two separate devices: an IGBT for high voltage blocking and a MOSFET for fast switching. The IGBT handles the high voltage breakdown requirement while the MOSFET handles the fast switching requirement, eliminating the trade-off by segmenting the functions across two devices with complementary characteristics.
2Speed
If MOSFET is used for high switching speed, then switching speed is improved, but breakdown voltage capability deteriorates
Solution Approach 1:
The patent segments the voltage blocking function from the switching function. The MOSFET is optimized for fast switching with low on-resistance, while the IGBT provides the high voltage blocking capability. This segmentation allows each device to excel at its specialized function without compromise.
3Power
If IGBT device is used for high power applications, then current capability is improved, but switching losses increase
Solution Approach 1:
The patent segments the current handling function from the switching function. The IGBT provides high current capability with low saturation voltage, while the MOSFET handles the switching operation with fast transition times. This division reduces switching losses because the MOSFET's fast switching minimizes the time the IGBT spends in high-loss transition states.
4Device complexity
If unidirectional device is used, then device complexity is reduced, but current flow capability deteriorates
Solution Approach 1:
The patent uses antiparallel diodes to enable bidirectional current flow through a unidirectional switching structure. The diodes are connected in opposite directions to allow current to flow in both directions through the switching element, effectively inverting the limitation of unidirectional devices to achieve bidirectional capability while maintaining simpler device structure.
Data Source
AI summary
A device includes a first diode and a second diode connected in series between a first terminal and a second terminal of a switching element, wherein the switching element is a unidirectional device and an anode of the first diode is directly connected to an anode of the second diode, a third diode connected between the first terminal and the second terminal of the switching element and a switch connected in parallel with the first diode.