Motor Controller Thermal Data Recovery After Power Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motor controllers fail to accurately maintain and restore thermal monitoring data during power loss, leading to inaccurate thermal content estimation upon restart, which can result in improper motor operation.
Innovation Solution
A motor controller system that saves accumulated thermal values and time stamps to non-volatile memory before power loss and uses these data to calculate an updated thermal value upon restart, incorporating a cooling constant and time difference calculation to estimate the motor's thermal content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the motor controller monitors thermal content continuously, then motor safety is improved, but power consumption increases
Solution Approach 1:
The system performs thermal monitoring and data saving at periodic intervals rather than continuously. The processor saves accumulated thermal values and time stamps to non-volatile memory at specific moments (normal operation, overload, fault conditions), reducing power consumption while maintaining safety through periodic thermal content assessment.
2Measurement precision
If thermal monitoring data is saved to non-volatile memory, then thermal content estimation accuracy is improved, but device complexity increases
Solution Approach 1:
The system saves accumulated thermal values and time stamps to non-volatile memory in advance before power loss occurs. This preliminary action ensures that when power is restored, the thermal monitoring can resume accurately without needing complex real-time thermal sensors, as the thermal history is already recorded.
Solution Approach 2:
The patent uses time stamp data as an intermediary to calculate time differences, which then serve as the basis for calculating thermal content changes during power loss periods. This intermediary approach simplifies the thermal estimation process by using readily available time data rather than requiring complex thermal modeling.
3Measurement precision
If the system calculates thermal content using time difference and cooling constant, then thermal estimation accuracy is improved, but processing time increases
Solution Approach 1:
The system pre-calculates and stores time stamps at key moments (power loss, power restoration, thermal events). When thermal content needs to be estimated after power restoration, the system simply retrieves these pre-stored time stamps and performs a straightforward time difference calculation, avoiding complex real-time thermal analysis and reducing processing time.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method for operating a controller includes receiving a first accumulated thermal value of an electrical machine (107) and an associated first time stamp from a memory (106), initializing a processor (104) of the controller (102) with the first accumulated thermal value and the associated first time stamp (310), determining whether a second time stamp has been received, calculating a difference between the second time stamp and the first time stamp responsive to determining that the second time stamp has been received (314), calculating a second accumulated thermal value as a function of the first accumulated thermal value, the first time stamp (318), and the second time stamp, and updating the first accumulated thermal value with the second accumulated thermal value (320).