CN-121983016-A - Charging pile active noise reduction equipment and channel identification method thereof

CN121983016ACN 121983016 ACN121983016 ACN 121983016ACN-121983016-A

Abstract

The invention discloses active noise reduction equipment of a charging pile and a channel identification method thereof, and particularly relates to the technical field of noise reduction of the charging pile, wherein the active noise reduction equipment comprises a loudspeaker for playing white noise, and an error microphone for collecting sound and transmitting the sound to a controller; the controller models the secondary channel by using an LMS algorithm, starts noise reduction if sound pressure or power exceeds standard, provides sub-reference signals by the sensor and the reference microphone, inputs sound signals by the error microphone, calculates and outputs by using the FXLMS algorithm, and the loudspeaker emits reverse noise to offset the noise of the charging pile. According to the method, the controller calculates the secondary channel model, the FXLMS algorithm is used for further optimizing noise control, when the noise sound pressure level or the charging power exceeds a preset value, the system automatically starts a noise reduction process, reverse noise output is adjusted in real time, the method can dynamically adapt to the change of the charging pile noise in different environments, the influence caused by amplitude and phase change in the propagation process is effectively reduced, and the stability and the efficient noise reduction effect of the active noise reduction system are ensured.

Inventors

LU JIANWEI
SUN JINGQI
ZHAI SHENG
YANG SHUAI
SUI XINYAO
GUO QUAN
WANG HAN
WANG YINBO
Zhang Diehan

Assignees

合肥工业大学

Dates

Publication Date: 20260505
Application Date: 20260209

Claims (10)

1. The active noise reduction device for the charging pile is characterized by comprising a rotation speed sensor (105), a reference microphone (102), an error microphone (103), a loudspeaker (104) and a controller (101); The rotating speed sensor (105) is arranged inside the charging pile and integrated in the controller (101) for collecting a rotating speed signal of the cooling fan as a sub-reference signal; the reference microphone (102) is arranged at the air outlet of the charging pile and used for collecting noise discharged by the charging pile as a sub-reference signal; the error microphone (103) is arranged in the noise reduction area and used for collecting residual noise as an error signal; The loudspeaker (104) is arranged around the charging pile and used for emitting reverse noise to offset the noise of the charging pile; The controller (101) is arranged inside the charging pile and generates a secondary channel model by using an input signal, and simultaneously generates reverse noise with the same amplitude and opposite phase to the noise sound wave in a noise control stage.
2. The active noise reduction device for the charging pile according to claim 1, wherein the frequency of the reverse noise in the controller (101) is the same as the frequency of the charging pile noise, the sound wave amplitude of the reverse noise is equal to the sound wave amplitude of the charging pile noise, and the phase of the reverse noise is opposite to the phase of the charging pile noise.
3. The active noise reduction device for the charging pile according to claim 1, wherein the rotation speed sensor (105) and the reference microphone (102) input collected sub-reference signals to the controller (101), the sub-reference signals comprise fan rotation speed signals collected by the rotation speed sensor (105) and noise discharged by the charging pile collected by the reference microphone (102), and the controller (101) fuses the sub-reference signals into reference signals by using a fusion method.
4. The active noise reduction device for the charging pile according to claim 1, wherein the controller (101) fuses the sub-reference signals into the reference signals by using a fusion method, and the fusion method better reflects the noise characteristics of the charging pile by using the reference signals in consideration of the narrowband characteristics of the rotation speed sensor (105) and the broadband characteristics of the acoustic signals.
5. The method for identifying the active noise reduction channel of the charging pile is characterized by comprising the following steps of: S1, a loudspeaker (104) plays white noise before noise reduction starts, and the white noise propagates through a secondary channel to reach an error microphone (103); S2, the error microphone (103) collects white noise after passing through the secondary channel and inputs the white noise to the controller (101); s3, the controller (101) calculates a secondary channel model by using an LMS algorithm; S4, the sound pressure level or the charging power exceeds a preset value, and noise reduction begins; s5, the rotation speed sensor (105) and the reference microphone (102) input the acquired sub-reference signals to the controller (101); s6, the error microphone (103) inputs the collected sound signals to the controller (101); s7, the controller (101) calculates output by using FXLMS algorithm; s8, the loudspeaker (104) emits reverse noise to offset the noise of the charging pile.
6. The method of claim 5, wherein the step S1 is characterized in that white noise is played by a speaker (104) before noise reduction begins, and propagates through a secondary channel to reach an error microphone (103), the secondary channel comprises a peripheral circuit, electroacoustic equipment and a physical acoustic path, and the amplitude and phase of the signal are changed when the signal propagates through the secondary channel.
7. The method of claim 6, wherein the secondary channel model is a finite impulse response filter for estimating the secondary channel and compensating for errors due to signal propagation in the secondary channel.
8. The method for identifying the active noise reduction channel of the charging pile according to claim 5, wherein in the step S4, the sound pressure level or the charging power exceeds a preset value, the noise reduction is started: S4.1, the controller (101) collects the residual noise sound pressure level and the charging power in real time; S4.2, judging whether the sound pressure level of the residual noise is larger than a preset sound pressure level value; s4.3, if yes, executing a step S4.8; S4.4, if not, executing the step S4.5; s4.5, judging whether the charging power is larger than a power preset value or not; S4.6, if not, executing the step S4.1; S4.7, if yes, executing a step S4.8; s4.8, starting active noise reduction.
9. The method of claim 8, wherein the sound pressure level is set to 60dB at 6:00-22:00 and 50dB at 22:00-6:00, and the sound pressure level is set to a preset value that considers that daytime environmental noise is greater than nighttime environmental noise.
10. The method for identifying the active noise reduction channel of the charging pile according to claim 8, wherein the setting of the power preset value is to take the complete flow of the direct current fast charging pile charging into consideration, a high power charging stage with constant current and gradually increased voltage is selected, and the power preset value is generally set to 50kW-100kW.

Description

Charging pile active noise reduction equipment and channel identification method thereof Technical Field The invention relates to the technical field of noise reduction of charging piles, in particular to active noise reduction equipment of charging piles and a channel identification method thereof. Background With the popularization of electric vehicles, charging piles have been widely used in various metropolitan and public places as a main energy supply facility for electric vehicles. However, noise generated by the charging pile during the working process, especially under the condition of high charging power or frequent start-stop of equipment, tends to cause great noise pollution to the surrounding environment. Such noise not only affects the quality of life of surrounding residents, but may also cause discomfort to the user. Therefore, how to effectively control and reduce the noise of the charging pile in the working process becomes a current problem to be solved urgently. Conventional noise suppression methods rely on sound insulation or structural improvement, but these methods generally have limitations in terms of noise reduction effect and adaptability, and cannot provide continuous and effective noise suppression under different working environments and charging pile operation states. With the continuous progress of technology, active noise reduction technology is becoming an important direction in the noise control field due to its advantages in dynamic noise environments. The existing charging pile noise control technology mainly depends on physical sound insulation measures or simple noise shielding devices, although the methods can reduce noise to a certain extent, the problem that the effect is limited generally exists, particularly when the working state of a charging pile is changed, the sound insulation effect cannot be dynamically adjusted, the traditional noise suppression means cannot be adjusted in real time according to the dynamic characteristics of a noise source, fluctuation of noise frequency, amplitude and phase in the operation process of the charging pile cannot be dealt with, the prior art has great challenges in efficiently and stably reducing the noise of the charging pile, particularly under changeable environmental noise conditions, the traditional method cannot always optimize the noise reduction effect continuously, and meanwhile, the existing noise suppression technology generally lacks accurate noise source identification function, so that a noise propagation path cannot be accurately modeled, and the accuracy and the adaptability of the noise reduction effect are affected. Disclosure of Invention The invention aims to solve the defects in the prior art, and provides active noise reduction equipment for a charging pile and a channel identification method thereof. In order to achieve the above purpose, the present invention adopts the following technical scheme: A charging pile active noise reduction device and a channel identification method thereof comprise a rotation speed sensor, a reference microphone, an error microphone, a loudspeaker and a controller; The rotating speed sensor is arranged inside the charging pile and integrated in the controller for collecting a rotating speed signal of the cooling fan as a sub-reference signal; the reference microphone is arranged at the air outlet of the charging pile and used for collecting noise discharged by the charging pile as a sub-reference signal; The error microphone is arranged in the noise reduction area and used for collecting residual noise as an error signal; the loudspeaker is arranged around the charging pile and used for emitting reverse noise to offset the noise of the charging pile; the controller is arranged in the charging pile and generates a secondary channel model by using an input signal, and generates reverse noise with the same amplitude and opposite phase to the noise sound wave. The invention further provides that the frequency of the reverse noise in the controller is the same as that of the charging pile noise, the sound wave amplitude of the reverse noise is equal to that of the charging pile noise, and the phase of the reverse noise is opposite to that of the charging pile noise. The invention further provides that the rotating speed sensor and the reference microphone input the collected sub-reference signals to the controller, the sub-reference signals comprise fan rotating speed signals collected by the rotating speed sensor and noise discharged by the charging pile collected by the reference microphone, and the controller fuses the sub-reference signals into reference signals by using a fusion method. The controller is further configured to fuse the sub-reference signals into the reference signals by using a fusion method, wherein the fusion method considers the narrowband characteristics of the rotation speed sensor and the broadband characteristics of the acoustic signals, and better