IGBT Gate Driving Circuit With Two-Stage Turn-On Control
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Solution Overview
Problem
Existing driving circuits for insulated gate bipolar transistors (IGBTs) face issues with prolonged turn-on time due to gradual gate voltage increase from start to finish, which affects the efficiency of IGBT operation and inverter dead time.
Innovation Solution
A driving circuit with dual charging capabilities, where the gate voltage increases steeply until reaching a threshold voltage and then ramps up gradually, allowing for faster turn-on and reduced turn-off losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the gate voltage is gradually increased from the beginning to the end of turning on the IGBT, then the IGBT can be driven safely, but the turn-on time is prolonged
Solution Approach 1:
The gate voltage charging process is segmented into two distinct phases: a first charging capability phase that charges the gate voltage up to the threshold voltage, and a second charging capability phase that charges the gate voltage beyond the threshold voltage. This segmentation allows each phase to be optimized independently for its specific function.
Solution Approach 2:
The charging capability is made dynamic by switching between two different charging rates based on the gate voltage level. The first charging capability operates at a higher rate to quickly reach the threshold voltage, then transitions to the second charging capability at a lower rate for the remaining voltage increase, creating an adaptive charging profile.
2Loss of time
If the gate voltage increases steeply to reduce turn-on time, then the turn-on time is reduced, but the collector-emitter voltage decrease is delayed
Solution Approach 1:
The charging parameter (charging capability) is changed based on the gate voltage level. By adjusting the charging capability from high (first charging capability) to low (second charging capability) as the gate voltage increases, the system optimizes both the turn-on time and the collector-emitter voltage decrease speed at different stages of the switching process.
Data Source
AI summary
The object is to provide a technology enabling appropriate driving of an IGBT. A driving circuit is a driving circuit that drives an IGBT by controlling the gate voltage of the IGBT, and includes a first charging capability and a second charging capability. The first charging capability increases the gate voltage up to a threshold voltage of the IGBT, and a second charging capability increases the gate voltage beyond the threshold voltage. An increase in the gate voltage with the first charging capability per unit time is higher than an increase in the gate voltage with the second charging capability per unit time.