Power Converter Gate Driving Circuit Short-Circuit Protection
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Solution Overview
Problem
Conventional power converters experience delays in protecting power semiconductor devices due to signal isolators, which are necessary for electrical isolation but introduce signal transmission delays, making it difficult to effectively manage short-circuit faults with high time rates of change.
Innovation Solution
A power converter design that connects both ends of the output inductor directly to the gate driving circuit without signal isolators, allowing the circuit to monitor voltage changes and immediately turn off the power semiconductor devices in case of a short-circuit fault, thereby reducing the delay in eliminating short-circuit current conduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a signal isolator is provided between the controller and gate driving circuit to electrically isolate signals, then electrical isolation is achieved, but signal transmission delay increases
Solution Approach 1:
The patent removes the signal isolator from the protection signal transmission path. The gate driving circuit directly monitors the voltage across the output inductor and generates protection signals autonomously without requiring signal isolation, thereby eliminating the signal transmission delay caused by signal isolators while maintaining system reliability
Solution Approach 2:
The gate driving circuit is designed to autonomously monitor the voltage across the output inductor and generate protection signals on its own without external controller intervention. This self-service capability eliminates the need for signal isolators in the protection path, resolving the contradiction between electrical isolation and signal transmission speed
2Reliability
If a signal isolator is provided in the protection circuit, then electrical isolation is maintained, but the protection response time becomes too slow to prevent power semiconductor device breakage
Solution Approach 1:
The signal isolator is removed from the protection circuit path. The gate driving circuit directly detects voltage across the output inductor and immediately generates protection signals, eliminating the delay that prevents effective protection against high dI/dt short-circuit currents
Solution Approach 2:
The gate driving circuit continuously monitors the voltage across the output inductor in advance, ready to immediately generate protection signals when abnormal voltage indicating short-circuit conditions is detected, enabling preemptive protection before damage occurs
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
This design enables faster detection and response to short-circuit abnormalities, reducing the time it takes to protect the power semiconductor devices and preventing device breakage.
Implementation Method 1
a first gate driving circuit connected to a first control gate terminal and a first control source terminal in the first power semiconductor device, to supply a charge to the first power semiconductor device to drive; and a second gate driving circuit connected to a second control gate terminal and a second control source terminal in the second power semiconductor device, to supply a charge to the second power semiconductor device to drive, wherein a first main current source terminal of the first power semiconductor device is connected to a second main current drain terminal of the second power semiconductor device, and an end of the connection is connected to a load by an output line, and the first gate driving circuit monitors a first voltage developed by an output inductor between the connection end and the load
Data Source
AI summary
In a power converter including at least one bridge circuit configured to have upper and lower arms in which a first power semiconductor device and a second power semiconductor device are connected in series, a first gate driving circuit that supplies a charge to the first power semiconductor device of an upper arm to drive the first power semiconductor device monitors a voltage developed by an output inductor between a connection end between the first power semiconductor device and the second power semiconductor device and a load, and performs control to protect the first power semiconductor device based on a value of the monitored voltage.