Three-Phase Motor Noise Control Using Rotor-Angle Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional noise reduction methods for three-phase-driven electrical machines, such as active noise reduction, are ineffective in addressing environmental noise nuisance and are costly, while also failing to address secondary sound excitation due to vibrational excitation of component parts.
Innovation Solution
A method that records the angular state of the rotor, calculates a reference frequency, forms sine and cosine values, filters them using a secondary section modeled by a transfer function, and applies a superposition signal weighted by a feedback variable to the electrical machine's manipulated variables to reduce noise directly in the stator and rotor excitation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional active noise reduction systems are used in the passenger compartment, then noise perception is reduced, but the cost increases significantly and environmental noise nuisance is not prevented
Solution Approach 1:
The invention applies preliminary action by generating noise counteracting signals before the noise propagates to the passenger compartment. The control device calculates reference frequencies from the angular state of the rotor, generates corresponding sine and cosine values, and applies these as counter signals to the electrical machine's manipulated variables, preventing noise generation at the source rather than treating it after propagation.
Solution Approach 2:
The invention uses an intermediary approach by introducing a control device that acts as a mediator between the electrical machine and the noise environment. This control device processes the angular state information, calculates reference frequencies, generates weighted superposition signals, and applies them to reduce noise, serving as an intermediate system that connects the machine operation to noise reduction without requiring complex passive insulation or post-treatment systems.
2Object-affected harmful factors
If conventional sound insulation is applied, then some noise is reduced, but it is mostly unsuitable for electrical machine noise and does not address secondary sound excitation
Solution Approach 1:
The invention applies parameter changes by dynamically adjusting the noise reduction signals based on operating conditions. The control device calculates reference frequencies from the angular state, which varies with rotor position and speed. The sine and cosine values are weighted according to the feedback variable and reference signal vector, allowing the system to adapt to different operational states and frequency characteristics of the electrical machine, making it suitable for various noise conditions.
Solution Approach 2:
The invention uses feedback by continuously monitoring the angular state of the rotor and using this information to generate appropriate counter signals. The control device records the angular state, calculates reference frequencies based on this state, and uses the feedback from the machine's operation to adjust the weighting vector and superposition signals, creating a closed-loop system that adapts to the actual noise generation mechanisms of the electrical machine.
3Object-affected harmful factors
If noise reduction is applied, then primary noise is reduced, but secondary sound excitation from vibrational excitation of component parts is not addressed
Solution Approach 1:
The invention applies preliminary anti-action by generating counter signals that oppose both primary noise and secondary sound excitation before they occur. The control device calculates reference frequencies from the angular state and generates weighted superposition signals that are applied to the manipulated variables, creating anti-phase vibrations that cancel out both direct noise from the electrical machine and secondary excitations from component vibrations, effectively preventing both types of harmful factors.
Data Source
AI summary
A method for noise reduction of a three-phase-driven electrical machine includes recording an angular state of a rotor of the electrical machine, calculating a reference frequency on the basis of the recorded angular state, forming a sine and cosine value of the calculated reference frequency, and filtering the sine and cosine value. The method may also include recording a sound-related feedback variable, forming a weighting vector, forming a superposition signal, and applying the superposition signal to a manipulated variable of the electrical machine.