EV Powertrain Harmonic Phase Matching for Noise Suppression
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Solution Overview
Problem
The noise generated by the powertrain in electric vehicles, particularly due to the drive motor and retarder, significantly affects the vehicle's NVH performance, and existing solutions have not effectively addressed this issue.
Innovation Solution
The powertrain design involves matching the harmonic order of the drive motor with the gear teeth of the retarder and adjusting the phase difference between the electromagnetic and noise harmonics to 180 degrees, with a tolerance of ±30 degrees, and using a control unit to generate a compensation harmonic to further offset any residual noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the drive motor and retarder are connected with specific phase relationship to offset noise harmonics, then noise reduction is achieved, but the device complexity increases due to precise alignment requirements
Solution Approach 1:
The connection structure is pre-designed with built-in phase offset features that automatically establish the required 180-degree phase difference between drive motor and retarder. This preliminary configuration eliminates the need for complex post-assembly alignment procedures while ensuring noise cancellation effectiveness.
Solution Approach 2:
A specialized connection structure acts as an intermediary component between the drive motor and retarder, incorporating built-in phase-shifting mechanisms. This mediator component simplifies the overall system by centralizing the phase adjustment function in a single dedicated component rather than requiring complex alignment of multiple components.
2Object-affected harmful factors
If the harmonic order of drive motor is matched with gear teeth quantity of retarder, then noise offsetting is achieved, but the adaptability decreases due to fixed parameter relationships
Solution Approach 1:
The system enables dynamic adjustment of harmonic order parameters and gear teeth quantities through modular component selection. Different drive motor configurations with varying pole counts can be paired with correspondingly adjusted retarder gear configurations, allowing the phase relationship and harmonic matching to be optimized for different application requirements while maintaining the noise cancellation principle.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively reduces the noise generated by the powertrain by reversing the harmonics, resulting in improved NVH performance.
Implementation Method 1
An electromagnetic noise harmonic generated by a drive motor reversely offsets a noise harmonic generated by a retarder
Data Source
AI summary
A drive motor and a retarder in a powertrain meet a condition that a harmonic order of the drive motor is the same as a quantity of gear teeth of an input shaft gear in the retarder such that a frequency of an electromagnetic noise harmonic generated by the drive motor is the same as a frequency of a noise harmonic generated by the retarder. When the drive motor and the retarder are coupled using a connection structure, a phase of the electromagnetic noise harmonic generated by the drive motor differs from a phase of the noise harmonic generated by the retarder by a set angle.