Power Converter Voltage Control for Low-Temperature Interface Withstand
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Solution Overview
Problem
High-frequency driving voltage applied to power converters with semiconductor elements leads to reduced withstand voltage at the interface between the semiconductor and the sealing material due to delayed electric field relaxation, with the effect being more pronounced at lower temperatures.
Innovation Solution
A power conversion device and method that includes a temperature sensor and a driving circuit to control the voltage steepness or crest value applied to the semiconductor element based on temperature measurements, thereby improving the withstand voltage at the interface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high-frequency driving voltage is applied to the power converter, then the efficiency is improved, but the withstand voltage at the interface between the semiconductor element and sealing material is reduced
Solution Approach 1:
The patent changes the voltage application parameters (voltage steepness and voltage crest value) based on temperature conditions. By adjusting these parameters dynamically, the system maintains high-frequency driving efficiency while preventing excessive electric field stress that would reduce withstand voltage at the semiconductor-sealing material interface.
Solution Approach 2:
The patent implements dynamic control of voltage parameters based on real-time temperature measurements. The driving circuit adjusts voltage steepness and crest value according to temperature conditions, making the system adaptive to thermal states and preventing withstand voltage degradation during high-frequency operation.
2Productivity
If high-frequency driving voltage is applied, then the power conversion efficiency is improved, but the electric field relaxation area formation is delayed
Solution Approach 1:
The patent modifies voltage application parameters (steepness and crest value) based on temperature to compensate for delayed electric field relaxation. By controlling these parameters, the system maintains efficient power conversion while allowing sufficient time for electric field relaxation to occur, preventing accumulation of excessive electric stress.
3Reliability
If the temperature is lowered, then the withstand voltage reduction is more remarkable, but the heat generation from switching element operation is reduced
Solution Approach 1:
The patent implements temperature-dependent voltage parameter control. When temperature is low, the system reduces voltage steepness and/or voltage crest value to prevent excessive withstand voltage reduction. When temperature increases, the system can apply higher voltage parameters, allowing the switching element to self-heat to optimal operating temperature ranges.
Solution Approach 2:
The patent uses temperature sensors to provide feedback on the thermal state of the semiconductor element and sealing material. This feedback enables the driving circuit to dynamically adjust voltage parameters, creating a closed-loop control system that maintains reliability across varying temperature conditions.
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 enhances the withstand voltage at the interface between the semiconductor element and the sealing material by controlling voltage parameters in response to temperature, mitigating the reduction in withstand voltage caused by high-frequency driving.
Implementation Method 1
The temperature sensor measures temperatures of the semiconductor element and the sealing material
Implementation Method 2
The driving circuit controls a voltage steepness or a voltage crest value to be applied to the semiconductor element, on the basis of temperature information measured by the temperature sensor
Implementation Method 3
warming the switching element through heat generation by itself
Implementation Method 4
an AC-DC power converter including a semiconductor device is used
Data Source
AI summary
A power conversion device includes a semiconductor element, a temperature sensor, a sealing material sealing the semiconductor element, and a driving circuit for the semiconductor element. The temperature sensor measures the temperature of either or both of the semiconductor element and the sealing material. The driving circuit controls a voltage steepness or a voltage crest value to be applied to the semiconductor element, on the basis of temperature information measured by the temperature sensor.