Motor Driver Switch Frequency Hysteresis Control for Thermal Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-density and high-efficiency motor drivers face heat dissipation challenges, leading to potential failure and safety risks due to the discrepancy between substrate and junction temperatures, which existing thermal protection mechanisms fail to address effectively.
Innovation Solution
A hysteresis control method is implemented to adjust the switch frequency of the power module based on motor rotation speed and current switch frequency, evaluating the junction temperature to prevent overheating and ensure safe operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the motor driver is designed with high density and high efficiency to increase power output, then the power output is improved, but the heat dissipation becomes more difficult and the risk of thermal damage increases
Solution Approach 1:
The patent implements dynamic adjustment of switch frequency based on real-time temperature monitoring. When temperature exceeds thresholds, the system dynamically changes frequency ratios between first and second power modules, allowing the motor driver to adapt its operating characteristics to thermal conditions while maintaining high power output capability
Solution Approach 2:
The system changes operational parameters (switch frequency, duty cycle) based on temperature conditions. By adjusting the frequency ratio of power modules according to thermal state, the patent optimizes heat dissipation while preserving power output performance across different operating conditions
2Measurement precision
If the switch frequency is increased to improve motor response and performance, then the motor control precision is improved, but the heat generation in the power module increases
Solution Approach 1:
The patent employs periodic modulation of switch frequency between first and second power modules. By alternating the operating frequency based on temperature thresholds, the system maintains precise motor control through high-frequency operation when cool, while periodically reducing frequency to dissipate heat when temperature rises
Solution Approach 2:
The system implements temperature feedback control where the monitored temperature of the power module directly influences the switch frequency selection. When temperature exceeds thresholds, the feedback mechanism triggers frequency adjustment to reduce heat generation, creating a closed-loop control that balances precision and thermal management
3Device complexity
If a simple thermal protection mechanism is used to prevent overheating, then the device complexity is reduced, but the protection effectiveness is insufficient due to substrate-junction temperature discrepancy
Solution Approach 1:
The patent implements preliminary thermal protection by monitoring substrate temperature and predicting junction temperature conditions before actual thermal damage occurs. The system proactively adjusts switch frequency when substrate temperature approaches critical thresholds, preventing junction temperature from reaching damaging levels
Solution Approach 2:
The substrate temperature serves as an intermediary measurement that indirectly reflects junction temperature conditions. By using substrate temperature as a proxy and implementing frequency adjustment based on this intermediate measurement, the system achieves effective junction temperature protection without requiring direct junction temperature sensing
Data Source
AI summary
An operation method and an operation device of a motor driver for driving a motor are provided. The operation method includes: establishing a hysteresis control method; and adjusting a switch frequency of a power module for operating the motor by using the hysteresis control method according to a change of rotation speed of the motor and a current switch frequency.