RCIGBT Thermal Management via Estimated Temperature Comparison
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Solution Overview
Problem
In power supply systems using reverse-conducting IGBTs (RCIGBTs) as converter arms, it is challenging to determine which component, the IGBT device or the diode, generates more heat, making it difficult to effectively suppress overheating, as they are integrated into a single chip, and thus, appropriate control measures to curb heat generation are hindered.
Innovation Solution
A power supply system configuration that includes temperature sensors and an electronic control unit to calculate temperature estimated values based on control conditions, allowing for the restriction of battery discharge or charge power to manage heat generation, specifically targeting the IGBT device or diode depending on detected temperature values, thereby curbing overheating in RCIGBTs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If temperature sensor is used to detect chip temperature, then temperature monitoring capability is improved, but inability to distinguish heat source between IGBT device and diode worsens control precision
Solution Approach 1:
The patent divides the heat management function into two independent control modes: one for IGBT device overheating and one for diode overheating. By segmenting the protection logic based on the relationship between detected temperature and estimated temperature, the system can identify which component is the heat source and apply appropriate control measures, thus resolving the information loss problem while maintaining temperature monitoring capability.
Solution Approach 2:
The patent introduces an estimated temperature value as an intermediary parameter to bridge the gap between the single temperature sensor reading and the need to identify specific heat sources. By comparing the detected temperature with the estimated temperature of the IGBT device, the system can infer which component (IGBT or diode) is generating excessive heat, thus recovering the lost information without adding physical sensors.
2Device complexity
If RCIGBT with integrated IGBT and diode is used, then device integration is improved, but heat source identification capability deteriorates
Solution Approach 1:
The estimated temperature value serves as an intermediary that enables heat source identification in the integrated RCIGBT structure. By calculating the expected IGBT temperature based on operating conditions and comparing it with the actual chip temperature, the system can infer the diode's thermal state without physically separating the components, thus maintaining integration while enabling detection.
Solution Approach 2:
The patent implements a feedback mechanism where the detected temperature and estimated temperature are continuously compared to determine the heat source. This feedback loop enables real-time identification of whether the IGBT or diode is overheating, allowing the control system to adjust operating parameters accordingly, thus overcoming the detection difficulty imposed by integration.
3Quantity of substance
If single temperature sensor is used for chip temperature detection, then sensor quantity is reduced, but temperature control precision for individual components deteriorates
Solution Approach 1:
The estimated temperature acts as a virtual sensor that provides component-level temperature information without requiring physical sensors for each component. By using operating parameters (current, voltage, switching frequency) to calculate the expected IGBT temperature, the system generates an intermediary value that, when compared with the actual chip temperature, reveals the thermal state of individual components within the integrated structure.
Solution Approach 2:
The patent replaces physical temperature sensors with a computational approach. Instead of using mechanical/physical sensing elements for each component, the system uses mathematical models and parameter calculations to estimate temperatures and identify heat sources, thus reducing sensor quantity while maintaining measurement precision through virtual sensing.
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 approach effectively suppresses overheating in RCIGBTs by accurately determining the heat generation source and adjusting power limits, ensuring that heat generation is managed appropriately, thus preventing overheating in both the upper and lower arms of the converter.
Implementation Method 1
a temperature sensor configured to detect a temperature of the chip
Implementation Method 2
when electric current flows through each part (each IGBT device and each diode) of the converter in accordance with charge/discharge of the battery, heat is generated in the part
Data Source
AI summary
A converter includes one chip constituted a switching device and a diode. An electronic control unit is configured to calculate a temperature estimated value of the switching device from control conditions of the converter, restrict a control upper-limit value of charge power or discharge power of a battery, when a detection value of a temperature sensor is higher than the temperature estimated value of the switching device, and the detection value of the temperature sensor exceeds a protection temperature of the diode, and restrict a control upper-limit value of charge power or discharge power of the battery, when the detection value of the temperature sensor is lower than the temperature estimated value of the switching device, and the detection value of the temperature sensor exceeds a protection temperature of the switching device.