Electric Machine Drive Calibration for Pulsed Torque and NVH Control
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Solution Overview
Problem
Existing electric machines face inefficiencies due to varying operational loads, requiring manual calibration and leading to inaccurate torque measurements and increased power losses, especially in pulsed operations, which are labor-intensive and affect noise, vibration, and harshness (NVH) responses.
Innovation Solution
Implementing a dynamic motor drive (DMD) system with automatic calibration and adaptation capabilities, using pulse width modulation and pulse density modulation to adjust torque delivery, and incorporating an equivalent circuit model to minimize power losses, while monitoring performance in real-time to ensure optimal efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If manual calibration is performed for each vehicle model to reduce NVH, then NVH response is improved, but labor intensity and time consumption increase significantly
Solution Approach 1:
The system performs automatic calibration using the vehicle's existing sensors and actuators to measure frequency response and identify resonances, eliminating the need for external test equipment and manual calibration procedures. The calibration process is self-contained within the vehicle's control system.
Solution Approach 2:
The system changes operational parameters by varying the dynamic motor drive pulsing frequency to identify resonant frequencies and adjust operating conditions to avoid NVH problems, transforming manual parameter tuning into an automated parameter optimization process.
2Use of energy by moving object
If pulsed operation is used to improve motor efficiency, then energy conversion efficiency is improved, but torque measurement accuracy deteriorates due to inconsistent results from conventional averaging methods
Solution Approach 1:
The system uses feedback from measured or estimated torque values to continuously adjust and refine torque calculations during pulsed operation. The controller uses recent torque measurements to determine appropriate averaging periods and filter settings, improving measurement accuracy through adaptive feedback control.
Solution Approach 2:
The system dynamically adjusts the torque calculation method based on operating conditions, switching between different averaging periods and filter settings depending on the pulse frequency and load conditions, making the measurement system adaptive rather than static.
3Reliability
If extensive manual calibration is performed for all operating scenarios, then system performance is improved, but device complexity and calibration requirements increase
Solution Approach 1:
The system performs preliminary calibration actions by automatically identifying resonant frequencies and optimal operating parameters during initial operation, preparing the system for efficient operation without requiring extensive pre-calibration for all possible scenarios.
Solution Approach 2:
The calibration system uses the vehicle's own operational data and sensors to automatically calibrate itself, eliminating the need for external calibration equipment and extensive manual testing across all operating conditions.
4Use of energy by moving object
If DMD pulsing frequency is increased to improve efficiency, then energy efficiency is improved, but power losses at the battery increase due to higher resistive losses
Solution Approach 1:
The system optimizes the dynamic motor drive pulsing frequency by adjusting operational parameters to avoid resonant frequencies and minimize power losses, transforming fixed-frequency operation into adaptive frequency modulation that balances efficiency gains against battery losses.
Data Source
AI summary
Methods, systems, and devices for electric machine drive calibration, verification, and efficiency improvement are disclosed herein. One electric machine controller for calibration includes a processor and memory and instructions that are stored in the memory and executable by the processor to identify a vehicle and/or electric machine frequency response during operation of the vehicle and use the electronic machine and a dynamic motor drive converter to provide source excitations based on the identified frequency response.