Electric Machine Pulsed Control With Soft Torque Ramping
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Solution Overview
Problem
Conventional electric machines operate inefficiently under varying load conditions, as they are typically driven continuously, failing to maintain optimal energy conversion efficiency across a wide range of torque and speed variations.
Innovation Solution
Implementing pulsed control of electric machines, where the operation is intermittently modulated between different torque levels to meet operational demands while improving overall efficiency, with ramping transitions to minimize noise, vibration, and harshness (NVH).
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If continuous operation is used to meet torque demands, then the electric machine can deliver required output, but energy conversion efficiency deteriorates under varying load conditions
Solution Approach 1:
The patent applies periodic action by implementing pulsed operation modes where the electric machine operates in intermittent cycles rather than continuously. The controller switches between active torque-producing periods and idle periods, creating a periodic operation pattern that maintains average torque output while reducing overall energy consumption and improving efficiency under varying load conditions
2Use of energy by moving object
If pulsed operation is implemented to improve efficiency, then energy conversion efficiency improves, but noise, vibration, and harshness increase
Solution Approach 1:
The patent applies dynamics by implementing ramping transitions that dynamically adjust the torque output during switching between continuous and pulsed operation modes. The ramp generator creates smooth torque transitions rather than abrupt changes, dynamically adapting the torque profile to minimize NVH while maintaining the efficiency benefits of pulsed operation
Solution Approach 2:
The patent applies parameter changes by modifying the torque level parameter during transitions. The ramp generator adjusts the torque parameter smoothly from one level to another during switching events, changing the operational parameters to reduce the harmful effects of abrupt transitions while preserving the pulsed operation efficiency gains
3Speed
If abrupt switching between pulsed and continuous operation is used, then responsiveness to load changes improves, but noise, vibration, and harshness increase
Solution Approach 1:
The patent applies dynamics by implementing ramping transitions that dynamically adjust the torque output during switching between continuous and pulsed operation modes. The ramp generator creates smooth torque transitions rather than abrupt changes, dynamically adapting the torque profile to minimize NVH while maintaining the efficiency benefits of pulsed operation
Data Source
AI summary
An electric machine controller arranged to direct a power converter to cause a pulsed operation of an electric machine in selected operational ranges to deliver a desired output and to cause a continuous operation of the electric machine in selected operational ranges is provided. A ramp generator is adapted to provide a ramping between the pulsed operation and the continuous operation. In some embodiments, the ramp generator utilizes a quadratic, cubic or higher order ramping function. In some embodiments, during a first portion of the transitional period, the ramp generator causes pulsing between a first ramped transitional torque level and a second ramped transitional torque level that is lower than the first transitional torque level, and during a second portion of the transitional period, the ramp generator causes the electric machine to generate substantially zero torque in intervals between transitional pulses while ramping the first ramped transitional torque level.