AC Electric Machine Noise Suppression via Current-Voltage Injection

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Solution Overview

Problem

Alternating current electric machines experience tonal noises over a wide speed range, which existing technologies struggle to effectively suppress.

Innovation Solution

A method and system that utilize current injection and voltage injection to suppress tonal noises, where the mode of injection (current or voltage) is determined based on the electric machine's frequency and torque, using a calibrated factor to transition between injection modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a single injection mode (current or voltage) is used to suppress tonal noises, then the suppression effectiveness is limited to a narrow speed range, but the system complexity remains low

Engineering Contradiction:

Improvespeed range coverageVSAvoidinjection mode switching mechanism

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system dynamically switches between current injection mode and voltage injection mode based on the operating speed range. A switching mechanism compares the current speed with threshold values and automatically selects the appropriate injection mode, enabling the system to adapt to different speed conditions while maintaining effective tonal noise suppression across the entire operating range

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the injection parameter type (current vs voltage) based on the operating speed range. By monitoring the electric machine frequency and comparing it with threshold frequencies, the system switches between different injection parameters to optimize tonal noise suppression effectiveness across low, medium, and high speed ranges

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If current injection is used at high frequencies, then the tonal noise suppression becomes ineffective, but the control simplicity is maintained

Engineering Contradiction:

Improvetonal noise suppression effectivenessVSAvoidoperating frequency range

Core Design Contradiction:

Object-affected harmful factorsVSSpeed

Solution Approach 1:

The system dynamically adjusts the injection mode based on operating frequency. When the electric machine frequency exceeds a predetermined threshold, the system automatically switches from current injection mode to voltage injection mode, ensuring effective tonal noise suppression across the entire frequency spectrum including high-frequency operating conditions

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS12212190B2Method and system to suppress tonal noises over a wide speed range in alternating current electric machines

Publication Date: 2025.01.28 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A method to suppress tonal noises over a wide speed range in an alternating current electric machine by current injection and voltage injection is provided. The method includes, within a computerized processor, monitoring a position sensor measuring a current electric machine frequency of the electric machine, comparing the current electric machine frequency to a sampling frequency of the position sensor, and operating one of a current injection mode and a voltage injection mode to suppress the tonal noises in the electric machine based upon the comparing.