Isolated Gate Driver Voltage Switching for Transient Stress Control
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Solution Overview
Problem
Conventional power semiconductor devices like MOSFET and IGBT face increased damage risk and reduced reliability due to parasitic inductances causing voltage spikes and reverse recovery current, which existing solutions fail to address without affecting normal operation performance.
Innovation Solution
A drive circuit that switches between a preset and normal voltage without permanently adjusting resistance, using isolation modules and power supplies to manage voltage stress during transient processes, reducing circuit complexity and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If drive resistances are adjusted permanently to reduce voltage stress and current stress, then reliability of power semiconductor devices is improved, but performance during normal operation deteriorates
Solution Approach 1:
The patent applies dynamics by making the drive resistance adjustable rather than fixed. The drive circuit can dynamically change the resistance value based on operating conditions: using a first resistance value during transient processes to reduce stress, and a second resistance value during normal operation to maintain performance. This dynamic adjustment resolves the contradiction between reliability and productivity.
Solution Approach 2:
The patent changes the resistance parameter of the drive circuit based on operating state. By switching between different resistance values (first resistance value for transient processes, second resistance value for normal operation), the system optimizes both reliability during stress conditions and productivity during normal operation, eliminating the need for permanent resistance adjustment.
2Object-affected harmful factors
If drive resistances are adjusted permanently to reduce voltage stress, then damage risk is reduced, but turn-on and turn-off speeds deteriorate
Solution Approach 1:
The drive circuit dynamically adjusts resistance based on the switching state. During transient processes when devices are turning on or off, a first resistance value is used to reduce voltage stress and damage risk. During normal operation, a second resistance value is used to maintain fast turn-on and turn-off speeds, thus resolving the contradiction between reducing harmful factors and maintaining speed.
Solution Approach 2:
The patent applies periodic action by alternating between different resistance values according to the switching cycle. During each transient process (turn-on or turn-off), the circuit switches to a protective resistance value, then returns to the performance-optimized resistance value, creating a periodic pattern that reduces stress while maintaining speed.
Data Source
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AI summary
The present invention provides a driver circuit of a power conversion device and an application device thereof. The driver circuit comprises: at least one power supply switching circuit, N isolation modules, and at least one isolation power supply. A power supply sequentially provides drive voltages for the isolation modules by means of the power supply switching circuit and a corresponding isolation power supply. Output ends of the isolation modules are respectively connected to control ends of corresponding power semiconductor devices by means of corresponding drive resistors. The power supply switching circuit is used for changing an output thereof according to a drive voltage control signal received by a control end of the power supply switching circuit, so that the drive voltages of the isolation modules are equal to normal voltages when the power conversion device is in a normal operating state, and are equal to preset voltages when the power conversion device is in a transient transition process so as to avoid the risk of the damage to the power semiconductor devices. Moreover, it is unnecessary to permanently adjust resistance values of the drive resistors, and the influence on the performance during the normal operation of the power conversion device is avoided.