Electric Machine Reconfiguration With Real-Time Speed Thresholds
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Solution Overview
Problem
Existing methods for reconfiguring electric machines in vehicles set fixed angular speed thresholds that can lead to unsafe UGO phenomena, inefficient performance, and comfort issues due to varying supply voltage and rotor parameters during operation.
Innovation Solution
Determine the real-time real speed threshold ω real_th by considering magnet temperature, supply voltage, and rotor current, using predictive logic and analytical models to ensure safe reconfiguration without performance loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fixed angular speed thresholds are used for reconfiguration, then the reconfiguration process is simple and predetermined, but unsafe UGO phenomena occur and performance is lost due to varying supply voltage and rotor parameters
Solution Approach 1:
The patent applies dynamics by transitioning from fixed, predetermined speed thresholds to dynamic, real-time threshold determination. The system continuously monitors supply voltage, rotor current, and magnet temperature to calculate the actual BEMF threshold, allowing the reconfiguration decision boundary to adapt to changing operating conditions. This resolves the contradiction by maintaining simple control logic while improving reliability through dynamic parameter adaptation.
Solution Approach 2:
The patent changes physical parameters (supply voltage, rotor current, magnet temperature) from static design-time values to dynamic run-time measurements. By continuously monitoring these parameters and using them to determine the real-time BEMF threshold, the system avoids UGO phenomena while maintaining operational simplicity. The threshold itself becomes a dynamic parameter rather than a fixed constant.
2Ease of operation
If fixed angular speed thresholds are used for reconfiguration, then the control logic is simple, but inefficient performance and comfort issues arise due to varying operating conditions
Solution Approach 1:
The patent implements feedback by continuously measuring supply voltage, rotor current, and magnet temperature, then using these measurements to dynamically determine the BEMF threshold. This closed-loop approach ensures optimal performance by adapting to actual operating conditions while maintaining simple control logic through automated real-time calculations rather than complex predetermined rules.
Solution Approach 2:
The system performs self-service by automatically monitoring its own operating parameters and adjusting the reconfiguration threshold accordingly. The control system uses built-in sensors and real-time calculations to determine when reconfiguration should occur, eliminating the need for external tuning or complex predetermined logic while optimizing performance for current operating conditions.
3Reliability
If real-time threshold determination is implemented, then safe reconfiguration is ensured by avoiding UGO phenomena, but system complexity and measurement requirements increase
Solution Approach 1:
The patent applies universality by using the existing inverter and sensor infrastructure for multiple purposes: the same voltage and current sensors used for motor control also provide data for BEMF threshold determination. The magnet temperature measurement, already required for thermal management, is additionally used for threshold calculation. This multi-functionality avoids adding dedicated hardware while improving safety.
Solution Approach 2:
The patent uses the existing control system and sensor data as intermediaries to determine the BEMF threshold without requiring direct measurement of BEMF or additional specialized sensors. The control system mediates between available measurements (voltage, current, temperature) and the reconfiguration decision, simplifying the overall system architecture while achieving real-time threshold determination.
4Productivity
If real-time threshold determination is implemented, then optimal performance is maintained under varying conditions, but more sensors and measurements are required
Solution Approach 1:
The patent maximizes the use of existing sensors for multiple functions. The voltage and current sensors already present for motor control provide data for both motor operation and BEMF threshold determination. The magnet temperature sensor, required for thermal management, is additionally utilized for threshold calculation. This approach achieves optimal performance without increasing the sensor count.
Solution Approach 2:
The system uses its own existing measurement infrastructure to determine the BEMF threshold, rather than requiring additional dedicated sensors. The control system processes already-acquired data (voltage, current, temperature) to derive the threshold information, making the system self-sufficient and avoiding additional hardware requirements while maintaining optimal performance.
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
Ensures safe and efficient reconfiguration by avoiding UGO phenomena and maintaining performance and comfort, with a tolerance margin to account for non-linearities.
Implementation Method 1
An electric machine is a machine that comprises a rotor whose rotation generates a back electromotive force (BEMF)
Data Source
Figure 1~2
Figure 3a~3c
Figure 4~6
AI summary
Method for reconfiguring an electric machine including a rotor arranged to rotate with an angular speed (ω), the electric machine being arranged to pass from a first configuration (config1) to a second configuration (config2), the method comprising the steps of: a) determining (100) in real-time a real speed threshold (ωreal_th) depending on the current operating condition of the electric machine; b) checking (102) if the angular speed (ω) of the rotor is greater than said real speed threshold (ωreal_th); c) in positive case, no reconfiguration is performed (104) from the first configuration (config1); d) in negative case: d.1) determining (106) the current configuration of the electric machine; d.2) selecting (108) a reconfiguring decision method; d.3) deciding (110) whether to reconfigure the electric machine or not and, in positive case, reconfiguring (112) the electric machine.