IGBT Gate Drive Diode Layout for Resonance and Switching Loss
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Solution Overview
Problem
Conventional gate driving apparatuses for IGBTs with high current capacity, formed by connecting small current capacity IGBTs in parallel, experience resonance due to capacitive and inductive components, which is suppressed by resistors but increases switching loss.
Innovation Solution
Incorporating diodes between the on-driving circuit and the control terminal of the switching element to limit current flow and reduce resonance, thereby minimizing switching loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a resistor is connected between the on-driving circuit and the gate of the small current capacity IGBT to suppress resonance, then resonance can be suppressed, but switching loss increases due to the resistance
Solution Approach 1:
A diode is introduced as an intermediary component between the on-driving circuit and the gate of the small current capacity IGBT. The diode allows current to flow in only one direction, enabling the on-driving circuit to charge the gate capacitance while preventing reverse current flow that would cause resonance. This directional current control suppresses resonance without the energy dissipation associated with resistive elements.
Solution Approach 2:
The invention changes the electrical parameter characteristics by replacing a resistive element with a diode. The diode's non-linear voltage-current characteristic allows it to block reverse current while maintaining low forward voltage drop, thereby suppressing resonance effects without introducing significant resistive losses during the charging phase.
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 diodes effectively suppress resonance and reduce switching loss by allowing a constant current to flow through the control terminal with minimal voltage drop, outperforming resistor-based solutions.
Implementation Method 1
at least one diode which is connected between the on-driving circuit and the control terminal of the switching element. The on-driving circuit applies a constant current to the control terminal of the switching element through the diode.
Data Source
AI summary
An electronic apparatus includes a switching element which has a control terminal and is driven by controlling voltage of the control terminal, a driving power supply circuit which supplies voltage required for driving the switching element, an on-driving circuit which is connected to the driving power supply circuit and the control terminal of the switching element and is supplied with voltage from the driving power supply circuit, and which applies a constant current to the control terminal of the switching element to charge the control terminal, thereby turning on the switching element, and at least one diode which is connected between the on-driving circuit and the control terminal of the switching element. The on-driving circuit applies a constant current to the control terminal of the switching element through the diode.