Power Converter Controller Thermal Protection
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Solution Overview
Problem
Existing techniques for protecting semiconductor switching devices in power converters fail to effectively manage thermal stress in both average-temperature saturated and transit states, leading to potential device failure due to excessive temperature pulsations.
Innovation Solution
A controller for power converters that calculates average losses and thermal variations, using thermal resistance and time constants to estimate partial temperature variations and extract pulsation envelope temperatures, thereby protecting the device from excessive heat in both saturated and transit states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If average temperature estimation is used in low-speed region, then device protection is achieved in saturated state, but device cannot be protected in transit state where temperature pulsation exceeds average temperature
Solution Approach 1:
The patent applies dynamics by making the temperature estimation method adaptive to different operational states. The controller dynamically switches between average temperature estimation (for saturated state) and peak temperature estimation (for transit state) based on real-time detection of temperature saturation conditions. This dynamic adaptation ensures accurate temperature monitoring and device protection across all operating conditions, resolving the contradiction between reliability and measurement precision.
Solution Approach 2:
The patent changes the estimation parameter from fixed average temperature to variable peak temperature based on operational state. By detecting whether the temperature has reached saturation and adjusting the estimation approach accordingly, the system achieves accurate temperature measurement in both saturated and transient states, thereby improving both device protection reliability and temperature estimation precision.
2Device complexity
If simple average temperature estimation is used, then calculation complexity is low, but temperature pulsation peak cannot be detected in transit state
Solution Approach 1:
The patent segments the temperature estimation process into two distinct methods: average temperature estimation for saturated state and peak temperature estimation for transit state. By dividing the estimation approach based on operational conditions, the system maintains simple calculation in stable states while achieving accurate peak detection in transient states, thus resolving the contradiction between device complexity and measurement precision.
Solution Approach 2:
The system dynamically selects the appropriate estimation method based on real-time detection of temperature saturation. This dynamic switching allows the controller to use simple average temperature calculation when appropriate while transitioning to more sophisticated peak temperature estimation only when needed, balancing computational complexity with measurement accuracy.
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 controller effectively protects semiconductor devices from thermal destruction by accurately estimating and managing temperature variations, ensuring device reliability across various operational states.
Implementation Method 1
while regarding the semiconductor device as a thermal network including at least one combination of a thermal resistance and a thermal time constant, estimate a partial temperature variation of the combination from a loss in the semiconductor device and the combination of the thermal resistance and the thermal time constant
Data Source
AI summary
A controller of a power converter has: an average loss calculator (202) calculating an average loss in a semiconductor device; and a partial temperature variation estimation part (204), while regarding the semiconductor device as a thermal network including at least one combination of a thermal resistance and a thermal time constant, estimating a partial temperature variation of the combination from a loss in the semiconductor device and the combination of the thermal resistance and the thermal time constant. The partial temperature variation estimation part (204) estimates an average temperature from the loss, the thermal resistance, and the thermal time constant; extracts a pulsation envelope temperature exceeding the maximum value of a pulsation temperature dependent on the average loss and the pulsation frequency; and estimates a temperature variation in the semiconductor device by adding the average temperature and the pulsation envelope temperature.