Hybrid Power Switch Gate Timing for Temperature-Dependent Loss Control
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Solution Overview
Problem
Existing hybrid power switches using high and low frequency switching devices face inefficiencies due to predefined static gate signals, leading to high switching losses and potential overheating, particularly in high frequency devices like SiC-based switches.
Innovation Solution
A control method that dynamically adjusts gate signals and delay times based on the temperature of high frequency switching devices, such as SiC MOSFETs, to optimize performance and reduce switching losses by modifying delay times using a reference curve that correlates temperature with percentage adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If predefined static gate signals are used for turning on and turning off the switching devices of the hybrid power switches, then the control method is simple and easy to implement, but the switching losses increase and the high frequency switching device may overheat
Solution Approach 1:
The patent applies dynamics by transitioning from static, predefined gate signals to dynamic gate signals that are adjusted in real-time based on the temperature of the high frequency switching device. The control method modifies delay times dynamically according to temperature conditions, allowing the system to adapt its switching behavior to current thermal states, thereby reducing switching losses while preventing overheating.
2Loss of energy
If the high frequency switching device operates at high switching rates, then the switching losses are reduced and efficiency is improved, but the device temperature increases leading to potential overheating
Solution Approach 1:
The patent implements feedback by continuously monitoring the temperature of the high frequency switching device and using this information to adjust the gate signals dynamically. The control method incorporates temperature-based feedback loops that modify delay times and switching parameters in real-time, creating a closed-loop control system that balances switching efficiency with thermal management.
Solution Approach 2:
The patent applies parameter changes by adjusting switching parameters (delay times, gate signal characteristics) based on temperature conditions. The control method establishes different delay time values corresponding to different temperature ranges, dynamically changing operational parameters to optimize both efficiency and thermal performance under varying load and environmental conditions.
3Loss of energy
If dynamic adjustment of gate signals based on temperature is implemented, then switching losses are reduced and overheating is prevented, but the control system complexity increases
Solution Approach 1:
The patent manages complexity by implementing parameter changes through a structured approach that uses temperature-based lookup tables or predefined delay time values for different temperature ranges. Rather than requiring complex real-time calculations, the system selects from predetermined parameter sets based on measured temperature, simplifying the control logic while still achieving dynamic optimization.
Data Source
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AI summary
A control method of a hybrid power switch having at least a first switching device connected in parallel with a second switching device is provided. The switching losses of the first device are lower than the switching losses of the second device for same current and voltage conditions. A first gate signal is provided to the first switching device for turning on and turning off the first switching device. A second gate signal is provided to the second switching device for turning on and turning off the second switching device. A first delay time is stablished between the turning on of the first switching device and the turning on of the second switching device, and a second delay time is established between the turning off of the first switching device and the turning off of the second switching device. The temperature of the first switching device is determined, and at least one of the first and second delay times is modified depending on such temperature. The temperature is compared with a reference curve which defines a relationship between temperatures of the first switching device and percentage values for modifying the delay time. A percentage value is obtained and applied to the delay time to modify. The reference curve is established between three junction temperatures of the first switching device, wherein below first junction temperature is lineal and takes a constant value, from first to second junction temperature decreases linearly, and from second to third junction temperature further decreases linearly.