Gate Driving Circuit Dynamic Resistance Control
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Solution Overview
Problem
Conventional gate driving circuits fail to achieve a balanced reduction of switching loss and voltage overshoot in a simple configuration.
Innovation Solution
A gate driving circuit with a control circuit that adjusts the resistance values of resistors and switching devices based on the ON period and current magnitude to optimize switching conditions, using voltage-controlled resistors and switching devices to manage the gate driving of main switching devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional gate driving circuits use fixed resistance values, then the configuration is simple, but switching loss and voltage overshoot cannot be reduced with good balance
Solution Approach 1:
The patent applies dynamics by making the gate resistance values variable rather than fixed. The control circuit dynamically adjusts the resistance values of the first and second resistors based on the ON period of the main switching device. This allows the circuit to adapt its resistance characteristics to different operating conditions, achieving both switching loss reduction and voltage overshoot suppression without requiring an overly complex fixed configuration.
Solution Approach 2:
The patent changes the resistance parameter dynamically based on the ON period. The control circuit modifies the resistance values of the gate resistors according to whether the ON period is long or short, enabling optimal performance across different operating conditions. This parameter change approach resolves the contradiction by allowing the system to maintain simplicity while achieving reduced losses through adaptive resistance control.
2Object-affected harmful factors
If the resistance value of the second resistor is increased for longer ON periods, then voltage overshoot is reduced, but switching loss may increase
Solution Approach 1:
The patent applies local quality by using separate first and second resistors with different resistance values connected to different potentials (positive and negative). The control circuit independently adjusts the resistance of each resistor based on the ON period, allowing localized optimization for different parts of the gate driving circuit. This enables the circuit to suppress voltage overshoot in one path while managing switching loss in another path simultaneously.
Solution Approach 2:
The patent makes the resistance values dynamic rather than fixed. The control circuit adjusts the resistance of the first and second resistors based on the detected ON period, enabling the circuit to adapt to different operating conditions. This dynamic adjustment allows the system to reduce voltage overshoot when needed while minimizing switching loss, resolving the contradiction between these two performance parameters.
3Loss of energy
If the resistance value of the first resistor is decreased for shorter ON periods, then switching loss is reduced, but voltage overshoot may increase
Solution Approach 1:
The patent uses separate first and second resistors that can be independently controlled, applying local quality to different parts of the gate driving circuit. The control circuit adjusts each resistor's value based on the ON period, allowing localized optimization. This enables the circuit to reduce switching loss through the first resistor while the second resistor manages voltage overshoot, achieving both goals simultaneously.
Solution Approach 2:
The patent dynamically adjusts the resistance values of both resistors based on the ON period detected by the control circuit. This dynamic control allows the system to optimize for switching loss reduction when the ON period is short, while still maintaining voltage overshoot suppression through coordinated adjustment of both resistors, resolving the apparent contradiction.
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 solution effectively reduces switching loss and voltage overshoot by dynamically adjusting resistance values according to the ON period and current magnitude, improving the balance of switching performance.
Implementation Method 1
At least one of the first resistor and the second resistor is a voltage-controlled resistor having a resistance value that is continuously changeable according to an input voltage
Data Source
AI summary
A gate driving circuit that drives a gate of a main switching device is provided, where the gate driving circuit includes: a first resistor connected between a first potential and the gate of the main switching device; a second resistor connected between a second potential being lower than the first potential and the gate of the main switching device; a first switching device connected in series with the first resistor between the first potential and the gate of the main switching device; a second switching device connected in series with the second resistor between the second potential and the gate of the main switching device; and a control circuit that changes at least one resistance value of a resistance value of the first resistor and a resistance value of the second resistor according to a length of an ON period during which the main switching device is turned on.