Electric Machine Pulsed Control for Sweet-Spot Efficiency
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Solution Overview
Problem
Existing electric machines often operate inefficiently due to varying operating conditions, with energy conversion efficiency dropping when operating outside the 'sweet spot' of speed and torque.
Innovation Solution
Implementing pulsed control of electric machines by intermittently driving them between a high output level and a zero output level, optimizing energy conversion efficiency by aligning operation with the machine's most efficient operating conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the electric machine operates continuously to meet varying load conditions, then the machine can handle different torque and speed requirements, but the energy conversion efficiency drops when operating outside the sweet spot
Solution Approach 1:
The patent applies periodic action by pulsing the electric machine on and off in a cyclic manner. Instead of continuous operation, the machine is activated in periodic intervals to deliver required torque only when necessary, thereby maintaining adaptability to varying load conditions while minimizing energy consumption and avoiding operation in inefficient regions.
Solution Approach 2:
The control system dynamically adjusts the pulsing frequency and duty cycle based on real-time load conditions, torque requirements, and motor speed. This dynamic adaptation allows the system to maintain versatility across different operating conditions while optimizing energy efficiency by keeping the motor in or near its sweet spot during active periods.
2Loss of energy
If the electric machine is pulsed between high and zero output levels to improve energy efficiency, then energy conversion efficiency increases, but the machine cannot continuously meet torque requirements
Solution Approach 1:
The control system continuously monitors load conditions, torque requirements, and motor speed, using this feedback to dynamically adjust the pulsing frequency and duty cycle. This ensures that the pulsed operation reliably meets torque requirements while maintaining energy efficiency, as the system adapts in real-time to changing demands.
Solution Approach 2:
The system changes operational parameters by pulsing the motor between distinct output levels (high and zero) rather than operating continuously at intermediate levels. This parameter change strategy allows the motor to operate only in efficient regions while still meeting torque requirements through appropriate pulsing frequency and duty cycle selection.
3Loss of energy
If the motor operates at high efficiency points with pulsed control, then energy efficiency improves, but the complexity of the control system increases
Solution Approach 1:
The control system manages complexity by focusing on changing key operational parameters (pulsing frequency and duty cycle) rather than controlling all motor variables continuously. This parameter-based approach simplifies the control architecture while still achieving high energy efficiency through pulsed operation in the motor's sweet spot.
4Loss of energy
If the electric machine operates in the sweet spot region, then energy conversion efficiency is maximized, but the machine cannot respond to widely varying torque and speed demands
Solution Approach 1:
The system uses periodic pulsing to keep the motor in or near its sweet spot while meeting varying torque demands. By activating the motor in periodic intervals rather than continuously, the system maintains high energy efficiency during operation while adapting to different load conditions through frequency and duty cycle modulation.
Solution Approach 2:
The control system dynamically adjusts pulsing parameters based on real-time operating conditions, enabling the motor to maintain high efficiency in the sweet spot region while responding adaptively to widely varying torque and speed demands through continuous parameter optimization.
Data Source
AI summary
Methods, controllers and electric machine systems are described that facilitate pulsed control of electric machines (e.g., electric motors and generators) to improve the machine's energy conversion efficiency. Under selected operating conditions, the electric machine is intermittently driven (pulsed). The pulsed operation causes the output of the electric machine to alternate between a first output level and an off state. The output levels are selected such that the electric machine has a higher energy conversion efficiency during the pulsed operation than the electric machine would have when operated at a third output level that would be required to drive the electric machine in a continuous manner to deliver the desired output. In some embodiments, the power converter it turned off during at least portions of the time that the electric machine is pulsed off.