Power Converter Temperature Estimation for Semiconductor Hotspots
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power conversion devices struggle to accurately detect the maximum surface temperature of switching elements, leading to unnecessary output limitations due to uneven temperature distribution and heat generation.
Innovation Solution
A power conversion device with a control unit that calculates the loss in a detection target power semiconductor element based on surface temperature and inter-terminal voltage, and estimates the maximum surface temperature at the hottest point, allowing for more precise overheating protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a temperature sensor is arranged on a chip of the switching element to detect temperature, then the temperature of the switching element can be detected, but the detected temperature differs from the maximum temperature point on the surface due to non-uniform temperature distribution
Solution Approach 1:
The patent introduces an intermediary calculation method that uses the detected temperature at the sensor position, the inter-terminal voltage, and pre-stored thermal resistance data to estimate the maximum temperature. This intermediary approach bridges the gap between the easily measurable sensor position temperature and the difficult-to-measure maximum temperature point.
Solution Approach 2:
The patent replaces the direct physical measurement approach (placing sensor at maximum temperature point) with a computational method. By substituting the mechanical/physical measurement system with a calculation system that uses thermal resistance models and voltage measurements, the patent achieves accurate maximum temperature estimation without direct contact at the hottest point.
2Reliability
If a temperature margin based on maximum temperature difference is set to protect the switching element, then overheating protection is achieved, but the output of the switching element is unnecessarily limited even when not required
Solution Approach 1:
The patent implements a dynamic temperature margin adjustment mechanism. Instead of using a fixed temperature margin, the system dynamically calculates the appropriate margin based on real-time conditions including the detected temperature, inter-terminal voltage, and thermal resistance characteristics. This allows the output to be maintained at maximum levels when safe, while providing protection when necessary.
Solution Approach 2:
The patent changes the parameter used for temperature margin calculation from a fixed maximum temperature difference to a dynamically calculated value based on thermal resistance and real-time operating conditions. This parameter change enables more flexible and accurate output control that adapts to varying thermal 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
This solution enables more appropriate protection of power semiconductor elements from overheating, preventing unnecessary output limitations and improving the efficiency of power conversion devices.
Implementation Method 1
a temperature sensor configured to detect a surface temperature of the detection target element as a sensor position temperature
Implementation Method 2
a voltage sensor configured to detect an inter-terminal voltage of the detection target element
Implementation Method 3
the control unit being configured to calculate, when a position at which the temperature is highest on a surface of the detection target element is defined as a maximum temperature position, a loss in the detection target element based on the sensor position temperature and the inter-terminal voltage
Data Source
AI summary
A power conversion device includes a power conversion unit and a control unit. The power conversion unit includes a first semiconductor module. The first semiconductor module includes a plurality of power semiconductor elements. Some of the plurality of power semiconductor elements are detection target elements. The power conversion unit further includes a temperature sensor and a voltage sensor. The temperature sensor detects a surface temperature of the detection target element as a sensor position temperature. The voltage sensor detects an inter-terminal voltage of the detection target element. The control unit calculates a loss in the detection target element based on the sensor position temperature and the inter-terminal voltage, and estimates a maximum temperature based on the calculated loss.