Research On Noise Characteristics Of Vehicle Alternator

In daily life,as one of the travel tools,the car plays an increasingly important role.Nowadays,the noise level of cars has become one of the main indicators that affect people’s ride comfort.With the gradual improvement of automobile road noise,wind noise and other noise problems,the noise of automobile generators has gradually emerged,which has become the focus of attention of major automobile manufacturers.As the main source of power for automotive power system equipment,automotive AC generators are required to have a better noise level.Under the background of people’s pursuit of better automobile noise level,this article will take automobile-powered generators as the analysis object,referenced basic engineering noise theory,and adopt the commonly used analysis methods for studying generator noise:order analysis method,focus on solving various noise problems.The methods adopted in this subject can provide a certain reference for reducing generator noise and have a certain reference value.The followings are the research I had did.(1)Mainly study the structure and working principle of vehicle alternator,and further study the noise types and generation mechanism of vehicle alternator.Analyzed the objective parameters of acoustics and the power of sound metering,which laid the foundation for accurately quantifying the noise level of generators.(2)Carry out the A sound level noise test under the no-load and load conditions of the generator,use the order analysis theory to determine the noise generation location and its cause,and obtain the main order of the generator noise.(3)The main factor affecting the noise of the generator in the low speed stage is the36 th order electromagnetic noise.Aiming at this noise problem,this paper will reasonably optimize the claw pole structure of the generator’s rotor,so as to reduce the electromagnetic noise of the generator at low speed.Use Ansys workbench software to analyze the parameters of the claw pole rotor using the data correlation analysis module,and parameters with high correlation were selected as optimization variables according to the results of the parameter analysis;then use multi-objective optimization algorithm in ANSYS RMxprt to optimize the claw pole structure to obtain the optimized Claw pole structure parameters.Carry out the optimized vehicle generator noise test,compare and analyze the noise data before and after optimization,and verify the correctness of the optimization method.(4)Ventilation noise is the main source of noise in the high-speed section of the generator.The sound pressure level-rotation speed curve of the noise is obtained through experiments,and the order analysis method is adopted to find the outstanding ventilation noise order;based on the vector synthesis theory of noise,the vector noise of each fan blade is calculated,and the change of the fan blade noise is found.And by improving the distribution angle of the fan blades,the more prominent order noise is reduced,thereby reducing the ventilation noise of the generator.Finally,the generator noise test is used to verify the correctness of the optimization method.This paper uses the method of experimental testing and simulation calculation to study and analyze the noise of generators,obtain the influencing factors and laws of generator noise,and propose corresponding solutions,which have reference value for engineering design.It has guiding significance for controlling the noise level of generators.