Electric Machine Harmonic Control Using Precomputed Frequency Matrices
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Solution Overview
Problem
Existing electric drive systems face challenges in efficiently minimizing torque ripples and harmonics due to their design, leading to uneven torques and harmonic oscillations, which require complex control systems to compensate.
Innovation Solution
A method and control device that extract predetermined frequency components from manipulated or measured variables using a control matrix to calculate a control variable, allowing for efficient and robust control of electric machines, particularly focusing on minimizing harmonic harmonics with low computing load and adaptable control matrices for different applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If complex control systems are used to compensate for torque ripples and harmonics, then torque uniformity is improved, but device complexity increases
Solution Approach 1:
The patent extracts only the relevant frequency components (harmonic components) from the measured torque signal using spectral analysis, rather than processing the entire signal. This selective extraction allows the control system to focus computational resources on the specific frequency components that cause torque ripples, thereby improving torque uniformity while avoiding the need for complex full-spectrum control systems.
Solution Approach 2:
The patent transforms the torque control problem from the time domain to the frequency domain by analyzing torque at specific harmonic frequencies. By changing the parameter representation from time-based torque signals to frequency-based spectral components, the system can efficiently identify and compensate for torque ripples using simple amplitude and phase adjustments at each harmonic frequency, reducing overall control complexity.
2Manufacturing precision
If advanced control methods are implemented to minimize harmonics, then torque quality is improved, but computing load increases
Solution Approach 1:
The patent extracts only the specific harmonic frequency components that contribute to torque ripples, rather than performing comprehensive spectral analysis across all frequencies. By selectively extracting only the relevant harmonic components (e.g., 6th, 12th harmonics for PMSM), the system achieves effective torque quality improvement while significantly reducing the computational load compared to full-spectrum control methods.
Solution Approach 2:
The patent applies partial action by compensating for only the most significant harmonic components rather than attempting to eliminate all frequency components. This selective approach targets the dominant torque-ripple-causing harmonics with sufficient compensation amplitude and phase adjustment, achieving acceptable torque quality without the excessive computing requirements of complete harmonic elimination.
3Reliability
If comprehensive disturbance compensation is applied, then system robustness is improved, but control complexity increases
Solution Approach 1:
The patent implements feedback control by continuously measuring the actual torque output, analyzing its spectral components, and using this information to adjust the control signals. The measured torque signal is transformed into the frequency domain, and the compensating control signals are generated based on the detected harmonic components, creating a closed-loop system that automatically adapts to disturbances while maintaining simple control structure.
Solution Approach 2:
The patent introduces frequency domain transformation as an intermediary step between torque measurement and control signal generation. This intermediary transformation allows the system to identify harmonic components without requiring complex direct-time-domain control algorithms, simplifying the overall control structure while maintaining robust disturbance compensation capability through spectral analysis.
Data Source
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AI summary
The present invention discloses a control system for an electric machine. In order to control the electric machine, predetermined frequency components are extracted from manipulated variables or measurement variables of the electric machine and are multiplied by a previously calculated control matrix. The control matrix can be calculated in advance here. Different control matrices can be formed in advance for different applications. As a result, simple efficient and robust control of the electric machine is possible, in particular for optimising and minimising harmonics.