Motor Loss Controller for High Frequency Rotor Loss Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional motor current controllers are ineffective in reducing high frequency rotor losses in high speed permanent magnet motors due to periodic disturbances and harmonic currents, which lead to increased motor heating and thermal issues.
Innovation Solution
A motor loss reducing controller system utilizing input band-shifting by disturbance frequency, integral control architecture, and output inverse band-shifting with phase delay compensation, which parses feedback signals into sine and cosine components, converts harmonic currents into DC values, and applies integral control to eliminate errors, and then inversely shifts the output back to the original frequency frame.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional motor current controllers are used, then the control system is simple, but high frequency rotor losses increase due to periodic disturbances and harmonic currents
Solution Approach 1:
The patent introduces an intermediary frequency shifting mechanism that transforms high frequency harmonic disturbances into DC components. This intermediary transformation allows the standard integral controller to effectively eliminate harmonic currents by treating them as DC errors, thereby reducing rotor losses without requiring a completely new control architecture
Solution Approach 2:
The patent changes the frequency parameter of the feedback signal through band-shifting operations. By multiplying the feedback signal by sine and cosine functions at the disturbance frequency, the harmonic components are shifted to DC (zero frequency), where they can be eliminated by integral control. This parameter transformation enables the controller to address high frequency losses using standard control techniques
2Reliability
If integral control is applied directly to harmonic currents, then the control action is effective, but the controller cannot eliminate periodic disturbances at specific frequencies
Solution Approach 1:
The patent applies preliminary frequency shifting action before the integral control operates. By pre-processing the feedback signal through band-shifting that converts harmonic frequencies to DC, the integral controller can then effectively eliminate these disturbances. This preliminary transformation prepares the signal in a form that maximizes the effectiveness of integral control for periodic disturbance rejection
3Productivity
If feedback signals are processed without band-shifting, then the control loop is simple, but harmonic currents cannot be converted into DC values for effective integral control
Solution Approach 1:
The patent substitutes a mathematical transformation mechanism (frequency band-shifting through multiplication with sine and cosine carriers) to replace what would otherwise require complex mechanical or physical filtering systems. This substitution efficiently converts harmonic currents to DC values in the signal domain, enabling effective integral control without physical modification of the motor system
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A motor loss controller (101) configured to band-shift a motor frequency signal by a multiple of a fundamental frequency into a parsed sine component and a cosine component and multiply a feedback signal (75) by each of the parsed sine component and the cosine component; perform integral control of a control value band-shifted sine component and a control value band-shifted cosine component, wherein the performing integral control is configured to at least one of eliminate or reduce a disturbance on an output of the motor loss controller by rejecting a DC disturbance in a band-shifted control value; inverse band-shift the sine component back to its original band; inverse band-shift the cosine component back to its original band; and sum the inverse band-shifted sine component and the inverse band-shifted cosine component together to result in a controller output (95).