CN218158295U

CN218158295U - Acoustic acquisition circuit for detecting abnormal sound of transformer

Info

Publication number: CN218158295U
Application number: CN202221899983.3U
Authority: CN
Inventors: 叶华胜; 冯跃; 缪祥琎; 宋鑫源; 汤卫荣
Original assignee: Wenshan Power Supply Bureau of Yunnan Power Grid Co Ltd
Current assignee: Wenshan Power Supply Bureau of Yunnan Power Grid Co Ltd
Priority date: 2022-07-22
Filing date: 2022-07-22
Publication date: 2022-12-27
Anticipated expiration: 2032-07-22

Abstract

The utility model discloses a transformer abnormal sound detects acoustics collection circuit, it includes the sound sensor array, the signal output part of sound sensor is through signal conditioning module enlargies the back of filtering, according to the data acquisition chip of montage access multichannel, the data interaction interface of data acquisition chip is connected with the SDRAM chip in the FPGA module. The utility model discloses make pronunciation real-time processing ability stronger, circuit structure is more retrencied, the integrated level is high, multichannel is gathered in real time, is handled and output, and can prepositive background noise of getting rid of, suppresses background noise's function, improves the useful sound pickup capacity under sound collection quality and the noisy environment, has promoted the sound accuracy degree of transformer trouble abnormal sound.

Description

Acoustic acquisition circuit for detecting abnormal sound of transformer

Technical Field

The utility model relates to a transformer fault detection technical field specifically is a transformer trouble.

Background

The transformer is one of important power equipment in a power system, bears key tasks such as voltage change in the system, distribution and transmission of electric energy of a transformer substation and the like, and plays an important role in providing high-quality electric energy service and ensuring safe, reliable, high-quality and economic operation of the power system. The transformer in the power system has large usage amount, various capacity grades and specifications and long operation time, so that the accident rate of the transformer is correspondingly increased.

Under the environment of high voltage and strong electromagnetism, the transformer has important functions of electromagnetic exchange because of the inner winding and the iron core, if the transformer breaks down, the sound produced by the operation will change, and the research direction for judging the existence of equipment failure according to the sound is a research direction at home and abroad in recent years.

A single isolated microphone has drawbacks in terms of noise processing, sound source localization and tracking, speech extraction and separation, etc. Therefore, it is necessary to use a plurality of microphones to form an array, and add a spatial domain on the basis of the time-frequency domain, so as to perform real-time processing on signals from different spatial directions, so as to compensate for the defects of a single microphone.

To this end, CN 203301719U, "a multi-microphone voice communication", discloses an electronic product for multi-microphone voice communication under background noise and multi-voice environments, which includes an RF transceiver circuit, a DSP processing circuit, and a voice input circuit, where the voice input circuit includes 3 microphones, and at least one of the microphones is far from a sound source and is used for measuring background noise. The communication implementation process is that the noise reduction processing is carried out on the voice signals acquired by each microphone, then the Independent Component Analysis (ICA) and separation are carried out on the voice of each microphone channel through the DSP processing, and finally the voice signals are output by the switching circuit.

The scheme obtains independent components of the voice signal and the noise signal, and performs signal separation, so that the reaction speed is low, the complexity is too high, and the real-time processing is difficult. With the continuous expansion of the requirement on the scale of the microphone array, the above scheme obviously cannot meet the technical development requirement under the environment with high requirement on real-time data communication processing capacity, and a sound acquisition scheme with multiple channels, high-speed data throughput and synchronous data processing is necessary to be designed.

SUMMERY OF THE UTILITY MODEL

The utility model provides a transformer abnormal sound detects acoustics collection circuit for solve among the prior art multichannel sound signal separation, cause reaction rate slow, the complexity is too high, the difficult problem of real-time processing.

In order to solve the technical problem, the technical scheme of the utility model is that:

the acoustic acquisition circuit for detecting the abnormal sound of the transformer comprises a sound sensor array, wherein a signal output end of a sound sensor is amplified and filtered by a signal conditioning module and then is connected into a multi-channel data acquisition chip in a group mode, and a data interaction interface of the data acquisition chip is connected with an SDRAM (synchronous dynamic random access memory) chip in an FPGA (field programmable gate array) module.

Furthermore, the signal conditioning module comprises a signal amplifying circuit and a filter circuit, and each sound sensor is respectively connected with the signal amplifying circuit and the filter circuit in sequence.

The signal amplification circuit comprises a first operational amplifier, wherein a positive input terminal of the first operational amplifier is connected with a signal output end of a sound sensor through a sixth resistor, a first capacitor is connected between a negative input terminal and an output terminal of the first operational amplifier, two ends of the first capacitor are connected with a fourth resistor in parallel, the negative input terminal is further grounded through a third resistor, and the output terminal of the first operational amplifier is connected with an eleventh resistor and then serves as a signal amplification output end.

The filter circuit comprises a first differential operational amplifier, a positive input end of the first differential operational amplifier is connected with the signal amplification output end through a thirteenth resistor, a working voltage terminal of the first differential operational amplifier is connected with the signal amplification output end through a twelfth resistor and is connected with the positive input end through an eleventh capacitor, the positive input end of the first differential operational amplifier is further connected with a reference voltage through a twelfth capacitor grounding end, a negative input end of the first differential operational amplifier is connected with the reference voltage, and the output end of the first differential operational amplifier is used as a signal amplification noise filtering output end and is connected with one channel of the data acquisition chip.

Further, the signal amplifying circuit is a two-stage preamplifier circuit structure formed by the NJM2100, and the first differential operational amplifier is LTC6276.

Furthermore, the model of the data acquisition chip is AD7606, 8 sound sensors form a group and are correspondingly connected with 8 data acquisition channels of one data acquisition chip in a one-to-one correspondence mode, the FPGA module adopts a xilinxA7 series development board, and a 16-bit data parallel output end of the data acquisition chip is connected with a data reading end of the FPGA module.

Further, the acoustic sensor array is constituted by a microphone of model MPA 416.

Compared with the prior art, the beneficial effects of the utility model are that:

according to the scheme, the independent distributed signal conditioning modules are adopted to amplify and filter noise of the sound signals, so that sound sensor arrays with different quantities and specifications can be matched conveniently and flexibly; after the signals are conditioned, a plurality of sound signals are connected into a multi-channel data acquisition chip in a grouped mode, so that the synchronism of digital acquisition and processing is ensured, and the synchronous acquisition speed is increased; and the reading and caching of large data volume and the communication interaction with an upper computer are realized through the FPGA module, so that the aims of multi-channel, high-speed data throughput and sound acquisition of synchronous data processing are fulfilled.

Through this scheme, make pronunciation real-time processing ability stronger, circuit structure is more retrencied, the integrated level is high, multichannel is gathered in real time, is handled and output, and can prepositively get rid of background noise, suppresses background noise's function, improves the useful sound pickup capacity under sound collection quality and the noisy environment, has promoted the sound accuracy degree of transformer trouble abnormal sound.

Drawings

Fig. 1 is a schematic diagram of a circuit principle of the signal conditioning module of the present invention.

Fig. 2 is a schematic diagram of a circuit principle of the data acquisition part of the present invention.

Detailed Description

The following describes the present invention with reference to the accompanying drawings. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto. In addition, the technical features related to the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

The patent discloses a transformer abnormal sound detects acoustics collection circuit, it includes the sound sensor array, the signal output part of sound sensor is through signal conditioning module enlargies the back of filtering, according to the data acquisition chip of group access multichannel, the data interaction interface of data acquisition chip is connected with the SDRAM chip in the FPGA module. According to the scheme, the independent distributed signal conditioning modules are adopted to amplify and filter noise of the sound signals, so that sound sensor arrays with different quantities and specifications can be matched conveniently and flexibly; after the signals are conditioned, a plurality of sound signals are connected into a multi-channel data acquisition chip in a grouped mode, so that the synchronism of digital acquisition and processing is ensured, and the synchronous acquisition speed is increased; and the reading and caching of large data volume and the communication interaction with an upper computer are realized through the FPGA module, so that the aims of multi-channel, high-speed data throughput and sound acquisition of synchronous data processing are fulfilled.

Specifically, when detecting a transformer fault abnormal sound, because a relatively long safety distance needs to be maintained and interference such as ambient noise is caused, a situation that a fault abnormal sound signal of the transformer is not obvious often occurs, so that noise needs to be eliminated and an effective transformer sound signal needs to be extracted before sound data operation diagnosis, and a signal conditioning module is adopted for preprocessing. The signal conditioning module comprises a signal amplifying circuit and a filter circuit, each sound sensor is respectively connected with one signal amplifying circuit and one filter circuit in sequence, as 8 sound sensors Mic 1-Mic 8 shown in fig. 1 are a group of corresponding signal conditioning module combinations, because the signal amplifying circuit and the filter circuit corresponding to each sound sensor have the same structural parameters, only the circuits corresponding to the first sound sensor Mic1 and the eighth sound sensor Mic8 are shown in fig. 1, and the middle 6 sound sensors Mic 2-Mic 7d circuits are omitted.

As shown in fig. 1, the signal amplifying circuit includes a first operational amplifier, a positive input terminal of the first operational amplifier is connected to a signal output terminal of a sound sensor through a sixth resistor R6, a first capacitor C1 is connected between a negative input terminal and an output terminal of the first operational amplifier, two ends of the first capacitor C1 are further connected in parallel to a fourth resistor R4, the negative input terminal is further grounded through a third resistor R3, and the output terminal of the first operational amplifier is connected to an eleventh resistor R11 and then serves as a signal amplifying output terminal.

The filter circuit comprises a first differential operational amplifier 1C, a positive input end of the first differential operational amplifier 1C is connected with the signal amplification output end through a thirteenth resistor R13, a working voltage terminal of the first differential operational amplifier 1C is connected with the signal amplification output end through a twelfth resistor R12 and is connected with a positive input end through an eleventh capacitor C11, the positive input end of the first differential operational amplifier 1C is further connected with a ground end GND of a twelfth capacitor C12, a negative input end of the first differential operational amplifier 1C is connected with a reference voltage VREF, and an output end of the first differential operational amplifier 1C is connected with one channel ADD1 of the data acquisition chip as a signal amplification noise filtering output end.

Preferably, the signal amplifying circuit is a two-stage pre-amplifying circuit structure with a model number of NJM2100, and the first differential operational amplifier 1C has a model number of LTC6276. The NJM2100 is an operational amplifier featuring low operating voltage and low saturation output voltage, and has two transistors 1A and 1B for amplification therein, which are a two-stage preamplifier circuit formed by the circuit shown in FIG. 1. The LTC6276 has the characteristics of low power and low noise, and has high working efficiency.

As a specific scheme, as shown in fig. 2, the model of the data acquisition chip is AD7606, the 8 sound sensors form a group and are correspondingly connected with the 8 data acquisition channels of one data acquisition chip in a one-to-one correspondence manner, and the rest peripheral circuits of the AD7606 are not shown in the figure and are designed by referring to the description of the chip. The FPGA module adopts a xilinxA7 series development board (not shown), and a 16-bit data parallel output end of the data acquisition chip is connected with a data reading end of the FPGA module.

According to the technical scheme, an AD7606 chip is used as a core to carry out a data acquisition and conversion module, and ADIN 1-ADIN 8 of the data acquisition and conversion module receive analog signals which are output by a microphone in a sensing manner and are amplified and denoised; DB 0-DB 15 are used as parallel output ends of data, and the 16-bit data which are acquired and subjected to AD conversion are sent to a core board of the FPGA module in a parallel mode. The sampling precision of the AD7606 chip is controllable, and 8 channels synchronously sample in parallel. When the array specification quantity is more, a plurality of groups of sound sensors can be adopted to correspond to a plurality of AD7606 chips, in the abnormal sound diagnosis test of the transformer, the accuracy can be ensured by obtaining an 8X 8 microphone array, 8 chips can be correspondingly adopted, and an upper computer can be used for synchronous communication of the chips.

The sound sensor array is composed of microphones of MPA416 type, the sensitivity of the sound sensor array can reach 50Mv/Pa, the background noise is low, the frequency response range is 20 Hz-20 kHz, the main frequency of sound signals emitted by the transformer is 100Hz or signals with frequency higher than 1000Hz such as frequency multiplication of 200Hz and 300Hz are almost nonexistent, and the response range of 20 Hz-20 kHz can completely cover the sound emitted by the transformer. When the MPA416 forms an array, the phase difference can be controlled to be 3-5 degrees, the stability is good, the volume is small, the structure is simple, the electroacoustic performance is good, the frequency response consistency and the phase consistency are good, and the accuracy of the microphone array for receiving sound signals is ensured.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. It will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made in the embodiments without departing from the principles and spirit of the invention, and the scope of the invention is to be accorded the full scope of the claims.

Claims

1. The utility model provides a transformer abnormal sound detects acoustics collection circuit, includes sound sensor array, its characterized in that: and the signal output end of the sound sensor is amplified and filtered by the signal conditioning module and then is connected into a multi-channel data acquisition chip in a group mode, and a data interaction interface of the data acquisition chip is connected with an SDRAM (synchronous dynamic random access memory) chip in the FPGA module.

2. The acoustic transformer abnormal sound detection acquisition circuit according to claim 1, wherein: the signal conditioning module comprises a signal amplifying circuit and a filter circuit, and each sound sensor is respectively connected with the signal amplifying circuit and the filter circuit in sequence;

the signal amplification circuit comprises a first operational amplifier, a positive input terminal of the first operational amplifier is connected with a signal output end of a sound sensor through a sixth resistor, a first capacitor is connected between a negative input terminal and an output terminal of the first operational amplifier, both ends of the first capacitor are also connected with a fourth resistor in parallel, the negative input terminal is also grounded through a third resistor, and the output terminal of the first operational amplifier is connected with an eleventh resistor and then serves as a signal amplification output end;

3. The acoustic transformer abnormal sound detection acquisition circuit according to claim 2, wherein: the signal amplifying circuit is of a double-stage pre-amplifying circuit structure formed by adopting a model NJM2100, and the first differential operational amplifier is of a model LTC6276.

4. The transformer abnormal sound detection acoustic collection circuit according to claim 3, wherein: the model of the data acquisition chip is AD7606, 8 sound sensors form a group and are correspondingly connected with 8 data acquisition channels of one data acquisition chip in a one-to-one correspondence mode, the FPGA module adopts a xilinxA7 series development board, and a 16-bit data parallel output end of the data acquisition chip is connected with a data reading end of the FPGA module.

5. The acoustic collecting circuit for detecting abnormal noise of a transformer according to any one of claims 1 to 4, wherein: the acoustic sensor array is made up of a microphone model MPA 416.